ALBERT

Description: Declines in Ogallala aquifer levels used for irrigation has prompted research to identify methods for optimizing water use efficiency (WUE) of cotton (Gossypium hirsutum L). In this experiment, conducted at Lubbock, TX, USA in 2014, our objective was to test two canopy temperature based stress indices, each at two different irrigation trigger set points: the Stress Time (ST) method with irrigation triggers set at 5.5 (ST_5.5) and 8.5 h (ST_8.5) and the Crop Water Stress Index (CWSI) method with irrigation triggers set at 0.3 (CWSI_0.3) and 0.6 (CWSI_0.6). When these irrigation triggers were exceeded on a given day, the crop was deficit irrigated with 5 mm of water via subsurface drip tape. Also included in the experimental design were a well-watered (WW) control irrigated at 110% of potential evapotranspiration and a dry land (DL) treatment that relied on rainfall only. Seasonal crop water use ranged from 353 to 625 mm across these six treatments. As expected, cotton lint yield increased with increasing crop water use but lint yield WUE displayed asignificant (p ≤ 0.05) peak near 3.6 to 3.7 kg ha−1 mm−1 for the ST_5.5 and CWSI_0.3 treatments, respectively. Our results suggest that WUE may be optimized in cotton with less water than that needed for maximum lint yield.

Description: The irrigation water available for agriculture will be scarce in the future due to increased competition for water with other sectors, and the issue may become more serious due to climate change. In Chile, the table grape is only cultivated under irrigation. A five-year research program (2007–2012) was carried out in the Aconcagua Valley, the central area of grapes in Chile, to evaluate the response of table grape vines (Vitis vinifera L., cv Thompson Seedless) to different volumes of irrigation water. Four irrigation treatments were applied: 60, 88, 120 and 157% of crop evapotranspiration (ETc) during the first four years, and 40, 54, 92 and 108% of ETc in the last year. Irrigation over 90%–100% of ETc did not increase fruit yield, whereas the application of water below 90% ETc decreased exportable yield, berry size and pruning weight. For example, 60% ETc applied water reduced exportable yield by 20%, and only 40% of the berries were in the extra and large category size, while pruning weight was 30% lower in comparison to the treatment receiving more water.

Description: New risk-based solvency requirements for insurance companies across European markets have been introduced by Solvency II and will come in force from 1 January 2016. These requirements, derived by a Standard Formula or an Internal Model, will be by far more risk-sensitive than the required solvency margin provided by the current legislation. In this regard, a Partial Internal Model for Premium Risk is developed here for a multi-line Non-Life insurer. We follow a classical approach based on a Collective Risk Model properly extended in order to consider not only the volatility of aggregate claim amounts but also expense volatility. To measure the effect of risk mitigation, suitable reinsurance strategies are pursued. We analyze how naïve coverage as conventional Quota Share and Excess of Loss reinsurance may modify the exact moments of the distribution of technical results. Furthermore, we investigate how alternative choices of commission rates in proportional treaties may affect the variability of distribution. Numerical results are also figured out in the last part of the paper with evidence of different effects for small and large companies. The main reasons for these differences are pointed out.

Description: In this paper, we study the valuation of stochastic cash flows that exhibit dependence on interest rates. We focus on insurance liability cash flows linked to an index, such as a consumer price index or wage index, where changes in the index value can be partially understood in terms of changes in the term structure of interest rates. Insurance liability cash flows that are not explicitly linked to an index may still be valued in our framework by interpreting index returns as so-called claims inflation, i.e., an increase in claims cost per sold insurance contract. We focus primarily on the case when a deep and liquid market for index-linked contracts is absent or when the market price data are unreliable. Firstly, we present an approach for assigning a monetary value to a stochastic cash flow that does not require full knowledge of the joint dynamics of the cash flow and the term structure of interest rates. Secondly, we investigate in detail model selection, estimation and validation in a Heath–Jarrow–Morton framework. Finally, we analyze the effects of model uncertainty on the valuation of the cash flows and how forecasts of cash flows and interest rates translate into model parameters and affect the valuation.

Description: This paper develops an extended financial stress measure that considers the supervisory objective of identifying risks to the stability of the financial system. The measure provides a continuous and bounded signal of financial stress using daily public market data. Broad coverage of material financial system markets over time is achieved by leveraging dynamic credit weights. We consider how this measure can be used to monitor, analyze, and alert financial system stress.

Description: This paper develops a financial stress measure for the United States, the Cleveland Financial Stress Index (CFSI). The index is based on publicly available data describing a six-market partition of the financial system comprising credit, funding, real estate, securitization, foreign exchange, and equity markets. This paper improves upon existing stress measures by objectively selecting between several index weighting methodologies across a variety of monitoring frequencies through comparison against a volatility-based benchmark series. The resulting measure facilitates the decomposition of stress to identify disruptions in specific markets and provides insight into historical stress regimes.

Description: Guarantees are often seen as the key characteristics of pension saving products, but securing them can become costly and is of central relevance especially in the course of the current low interest rate environment. In this article, we deal with the question of how costly the typical types of guarantees are, in the sense that they reduce a pension saving scheme’s financial performance over time. In this context, we aim to provide a presentation of insights from selected literature studying the impact of point-to-point guarantees and cliquet-style interest rate guarantees on the performance of pension contracts. The comparative analysis emphasizes that, in most cases, guarantee costs are not negligible with regard to a contract’s financial performance, especially compared to benchmarks, and that customers knowingly opt for such guarantees (or not) is, thus, indispensable. To further investigate the willingness-to-pay for guarantees in life insurance is an area for future research, in particular for innovative contract design.

Description: Arsenic (As) in soils causes several detrimental effects, including death. Arsenic toxicity in soybean plants (Glycine max L.) has been little studied. Arbuscular mycorrhiza (AM) increase the tolerance of host plants to abiotic stress, like As. We investigated the effects of AM fungi on soybean grown in As-contaminated soils. A pot experiment was carried out in a glasshouse, at random with five replications. We applied three levels of As (0, 25, and 50 mg As kg−1), inoculated and non-inoculated with the AM fungus Rhizophagus intraradices (N.C. Schenck & G.S. Sm.) C. Walker & A. Schüßler. Plant parameters and mycorrhizal colonization were measured. Arsenic in the substrate, roots, and leaves was quantified. Arsenic negatively affected the AM percentage of spore germination and hyphal length. As also affected soybean plants negatively: an extreme treatment caused a reduction of more than 77.47% in aerial biomass, 68.19% in plant height, 78.35% in number of leaves, and 44.96% reduction in root length, and delayed the phenological evolution. Mycorrhizal inoculation improved all of these parameters, and decreased plant As accumulation (from 7.8 mg As kg−1 to 6.0 mg As kg−1). AM inoculation showed potential to reduce As toxicity in contaminated areas. The AM fungi decreased As concentration in plants following different ways: dilution effect, less As intake by roots, and improving soybean tolerance to As.

Description: Maize (Zea mays L) is the most important food grain in sub-Saharan Africa and is mostly grown by small-scale farmers under rainfed conditions. Aluminum toxicity caused by low pH is one of the abiotic factors limiting maize production among smallholder farmers. Therefore, breeding maize hybrids that are tolerant to aluminum toxicity will sustain and increase maize production in these areas. Hence this study was undertaken to assess the genotypic variation for aluminum toxicity in maize inbred lines. Fourteen maize inbred lines of historical importance that are used in maize hybrid breeding in Zambia were studied for seedling root variation under different aluminum concentrations using hydroponic conditions. The aluminum tolerance membership index based on three traits (actual root length, relative root length and root length response) classified genotypes L3233 and L1214 as highly tolerant, L5527 and ZM421 as tolerant, and L12, L3234, and ZM521 as intermediate. The high PCV, GCV, and heritability observed for the root traits indicate that opportunities for selection and breeding for aluminum tolerance among Zambian inbred lines exist. Furthermore, the study indicated that a higher genetic gain would be expected from net root growth followed by shoot length response as selection traits, thus supporting the use of root traits for aluminum tolerance screening.

Description: The objective of this study is to understand which requirements for cereal cultivars—with regard to climate change adaptation—are in demand by farmers and advisors, and to clarify whether there are any differences in their assessments. A comparative survey was used to collect data from 410 farmers and 114 advisors in Germany. The majority of both farmers and advisors reported perceivable effects of climatic change on plant production. The increase in droughts and hot spells, the increased incidence of torrential rain, and mild winters were mentioned as the main effects of climate change. For climate change adaptation, the farmers and advisors mostly relied on a locally-adapted cultivar selection. It is estimated that eco-stability, grain yield, resistance to lodging and drought tolerance are important cultivar properties. In the study, farmers and advisors equally pointed out the need for additional cultivar evaluation according to eco-stability. Finally, only minor differences regarding farmers’ and advisors’ assessments were found within the study. The outcome of this research points to the need of implementing farmers’ demands in cultivar recommendations. For example, an impartial assessment of cultivars’ eco-stability could help support the choice of cultivars and reduce the growing risks in cereal production with regard to climate change.

Description: Extreme weather and climate change can have a significant impact on all types of infrastructure and assets, regardless of location, with the potential for human casualties, physical damage to assets, disruption of operations, economic and community distress, and environmental degradation. This paper describes a methodology for using extreme weather and climate data to identify climate-related risks and to quantify the potential impact of extreme weather events on certain types of transportation infrastructure as part of a vulnerability screening assessment. This screening assessment can be especially useful when a large number of assets or large geographical areas are being studied, with the results enabling planners and asset managers to undertake a more detailed assessment of vulnerability on a more targeted number of assets or locations. The methodology combines climate, weather, and impact data to identify vulnerabilities to a range of weather and climate related risks over a multi-decadal planning period. The paper applies the methodology to perform an extreme weather and climate change vulnerability screening assessment on transportation infrastructure assets for the State of Tennessee. This paper represents the results of one of the first efforts at spatial vulnerability assessments of transportation infrastructure and provides important insights for any organization considering the impact of climate and weather events on transportation or other critical infrastructure systems.

Description: This paper studies the problem of optimal reinsurance contract design. We let the insurer use dual utility, and the premium is an extended Wang’s premium principle. The novel contribution is that we allow for heterogeneity in the beliefs regarding the underlying probability distribution. We characterize layer-reinsurance as an optimal reinsurance contract. Moreover, we characterize layer-reinsurance as optimal contracts when the insurer faces costs of holding regulatory capital. We illustrate this in cases where both firms use the Value-at-Risk or the conditional Value-at-Risk.

Description: We study risk-minimization for a large class of insurance contracts. Given that the individual progress in time of visiting an insurance policy’s states follows an F -doubly stochastic Markov chain, we describe different state-dependent types of insurance benefits. These cover single payments at maturity, annuity-type payments and payments at the time of a transition. Based on the intensity of the F -doubly stochastic Markov chain, we provide the Galtchouk-Kunita-Watanabe decomposition for a general insurance contract and specify risk-minimizing strategies in a Brownian financial market setting. The results are further illustrated explicitly within an affine structure for the intensity.

Description: The intermarket analysis, in particular the lead–lag relationship, plays an important role within financial markets. Therefore, a mathematical approach to be able to find interrelations between the price development of two different financial instruments is developed in this paper. Computing the differences of the relative positions of relevant local extrema of two charts, i.e., the local phase shifts of these price developments, gives us an empirical distribution on the unit circle. With the aid of directional statistics, such angular distributions are studied for many pairs of markets. It is shown that there are several very strongly correlated financial instruments in the field of foreign exchange, commodities and indexes. In some cases, one of the two markets is significantly ahead with respect to the relevant local extrema, i.e., there is a phase shift unequal to zero between them.

Description: The mobilization of nutrients from fish sludge (i.e., feces and uneaten feed) plays a key role in optimizing the resource utilization and thus in improving the sustainability of aquaponic systems. While several studies have documented the aerobic and anaerobic digestion performance of aquaculture sludge, the impact of the digestate on plant growth has yet to be understood. The present study examines the impact of either an aerobic or an anaerobic digestion effluent on lettuce plant growth, by enriching a mixture of aquaculture and tap water with supernatants from both aerobic and anaerobic batch reactors. The lettuce plants grown in the hydroponic system supplied with supernatant from an anaerobic reactor had significantly better performance with respect to weight gain than both, those in the system where supernatant from the aerobic reactor was added, as well as the control system. It can be hypothesized that this effect was caused by the presence of NH4+ as well as dissolved organic matter, plant growth promoting rhizobacteria and fungi, and humic acid, which are predominantly present in anaerobic effluents. This study should therefore be of value to researchers and practitioners wishing to further develop sludge remineralization in aquaponic systems.

Description: Arbuscular mycorrhizal fungi (AMF) play a major role in the uptake of nutrients by agricultural plants. Nevertheless, some agricultural practices can interrupt fungal-plant signaling and thus impede the establishment of the mycorrhizal symbiosis. A field experiment performed over a 5-year period demonstrated that both the absence of tillage and of nitrogen (N) fertilization improved AMF colonization of wheat roots. Moreover, under no-till conditions, N uptake and aboveground biomass production did not vary significantly between N-fertilized and N-unfertilized plots. In contrast, both N uptake and above ground biomass were much lower when N fertilizer was not added during conventional tillage. This finding strongly suggests that for wheat, no-till farming is a sustainable agricultural system that allows a gradual reduction in N fertilizer use by promoting AMF functionality and at the same time increasing N uptake.

Description: The Turkish Private Pension System is an investment system which aims to generate income for future consumption. This is a volunteer system, and the contributions are held in individual portfolios. Therefore, management of the funds is an important issue for both the participants and the insurance company. In this study, we propose an optimal private pension plan with a guarantee feature that is based on Constant Proportion Portfolio Insurance (CPPI). We derive a closed form formula for the optimal strategy with the help of dynamic programming. Moreover, our model is evaluated with numerical examples, and we compare its performance by implementing a sensitivity analysis.

Description: Foliar fertilization, or the application of nutrient solutions to the foliage of plants, has become a very important tool as a supplement to traditional soil fertilization. So far, knowledge about the real mechanisms of foliar nutrient uptake is still limited. In this study different manganese (Mn) and zinc (Zn) carriers differing in their solubility and chemical characteristics (chelated or non-chelated, with or without the presence of a surfactant-penetrant) were compared with regard to their penetration characteristics through enzymatically-isolated cuticles. The experiments were explicitly conducted under high humidity conditions in order not to penalize compounds with a higher deliquescent point. The results show that Mn penetrates more rapidly through the cuticle than Zn ions for unknown reasons. The addition of a surfactant-penetrant enhances the penetration rate in the case of Mn ions. This trend is much less pronounced for zinc ions. Formulations based on insoluble carriers, such as carbonate or oxide, only poorly penetrate through the cuticle. In order to rapidly control micronutrient deficiency problems, only fully water soluble micronutrient carriers should be used.

Description: Nitrogen (N) losses negatively impact groundwater quality. Spring wheat genotypes varying in N-fertilizer recovery were studied (by using lysimeters) for their potential to minimize NO3-N leaching during spring and summer, over a three-year period. Additionally, we examined to what extent root growth and NO3-N leaching explain the well-known difference found between apparent and isotopic N recovery. The genotypes were grown under low (2 g m−2) and high (27 g m−2) N fertilizer supply. On average, the apparent and isotopic recoveries of N fertilizer by wheat were 43% and 51%, respectively. The three genotypes varied in fertilizer N recovery but not in NO3-N leaching, which only accounted for 15% of the applied N fertilizer. The differences in N uptake, fertilizer N recovery and root growth among the genotypes were not associated with the leached NO3-N because root growth and N uptake were not well synchronized with NO3-N leaching. Already at stem elongation 70% to 98% of the season-long NO3-N leaching had already taken place. Thus, the ability to minimize in-season NO3-N leaching by using spring wheat genotypes with higher fertilizer N recovery was limited because maximum N leaching occurred in the early crop season.

Description: Agronomic N-use efficiency is the basis for economic and environmental efficiency, and an effective agro-ecosystem management practice, improving nutrient use efficiency, is a crucial challenge for a more sustainable production of horticultural, industrial and cereal crops. However, discrepancy between theory and practice still exists, coming from large gaps in knowledge on net-N immobilization/mineralization rates in agro-ecosystems, as well as on the effects of indigenous and applied N to crop response. A more thorough understanding of these topics is essential to improve N management in agricultural systems. To this end, the present Special Issue collects research findings dealing with different aspects of agronomic efficiency of N in different agro-ecosystems, and environmental impact derived from fertilization management practices. In particular, the Special Issue contains selected papers, which concern a wide range of topics, including analyzing tools, options of management, calculation equation and modeling approaches.

Description: A two-year field study was conducted to investigate the performance of a lightweight trash-board moldboard plow (with and without a trash-board), as influenced by stubble height and water content. Both fields were measured for the performance of a trash-board moldboard plow when used during the optimization of the plowing depth, the water content, and the reaction forces. The results showed that in the first year, when a trash-board was required, the results were significantly different. The fields had lower draft and reaction force in the soil with only stubble height, which was greater than that in the soil with dense straw for all water content levels. This was also observed in the second year for the whole depth. This study shows that the moldboard plow with a trash-board provided minimum draft and reaction forces with only straw and heavy straw. The results indicate that straw nearby shear significantly increased displacement for all treatments, with variance of straw nearby moldboard. Hence, the results verify that a trash-board continuously created large soil fragmentation with different water content. Straw labels create a position of straw which also allows for better results. It is important to install trash-boards with the moldboard plow for heavy straw incorporation.

Description: This paper studies the dependence between coupled lives, i.e., the spouses’ dependence, across different generations, and its effects on prices of reversionary annuities in the presence of longevity risk. Longevity risk is represented via a stochastic mortality intensity. We find that a generation-based model is important, since spouses’ dependence decreases when passing from older generations to younger generations. The independence assumption produces quantifiable mispricing of reversionary annuities, with different effects on different generations. The research is conducted using a well-known dataset of double life contracts.

Description: Greater early vigour has potential for increasing biomass and grain yields of wheat crops in Mediterranean-type environments. Embryo size is an important determinant of early vigour in barley and likely to contribute to greater vigour in wheat. Little is known of the underlying genetic control for embryo size, or its genetic association with early vigour in wheat. Over 150 doubled-haploid lines in each of three unrelated wheat populations varying for embryo size and early vigour were phenotyped across multiple controlled environments. The Quantitative Trait Locus (QTL) mapping was then undertaken to understand genetic control and chromosomal location of these characteristics. Genotypic variance was large and repeatable for embryo and leaf size (width and length) but not specific leaf area or coleoptile tiller size. Genetic correlations for embryo size with leaf width and area were moderate to strong in size while repeatabilities for embryo size and early vigour were high on a line-mean basis. Multiple genomic regions were identified of commonly small genetic effect for each trait with many of these regions being common across populations. Further, collocation of regions for many traits inferred a common genetic basis for many of these traits. Chromosomes 1B, 5B, 7A and 7D, and the Rht-B1b and Rht-D1b-containing chromosomes 4B and 4D contained QTL for embryo size and leaf width. These studies indicate that while early vigour is a genetically complex trait, the selection of larger embryo progeny can be readily achieved in a wheat breeding program targeting development of high vigour lines.

Description: In this paper, a dynamic inflation-protected investment strategy is presented, which is based on traditional asset classes and Markov-switching models. Different stock market, as well as inflation regimes are identified, and within those regimes, the inflation hedging potential of stocks, bonds, real estate, commodities and gold are investigated. Within each regime, we determine optimal investment portfolios driven by the investment idea of protection from losses due to changing inflation if inflation is rising or high, but decoupling the performance from inflation if inflation is low. The results clearly indicate that these asset classes behave differently in different stock market and inflation regimes. Whereas in the long-run, we agree with the general opinion in the literature that stocks and bonds are a suitable hedge against inflation, we observe for short time horizons that the hedging potential of each asset class, especially of real estate and commodities, depend strongly on the state of the current market environment. Thus, our approach provides a possible explanation for different statements in the literature regarding the inflation hedging properties of these asset classes. A dynamic inflation-protected investment strategy is developed, which combines inflation protection and upside potential. This strategy outperforms standard buy-and-hold strategies, as well as the well-known 1 N -portfolio.

Description: In order to standardize the quality of agricultural products, it is necessary to control the factors affecting plant development, such as plant nutrition. The best results in terms of homogeneity of the quality of vegetable crops were achieved using inert substrates and application of nutrients; however, production costs are high due to the cost of irrigation systems and substrate management and importation. This work aims to evaluate the effect of the local substrate mix and the amount of organic fertilizer on different quality parameters of coriander. To evaluate the quality of coriander, we considered different parameters such as size, biomass, antioxidant capacity and aroma (evaluated by volatile compounds detection with gas chromatography). The results show that the culture system differentially affects each parameter, and the compounds associated with the aroma of coriander and the diameter of plants are sensitive to the culture system, while the length of plants, number of leaves and antioxidant activity are not affected by the concentration of fertilizer. Moreover, organic farming conditions do not reduce quality parameters of the crops when using adequate fertilization. Additionally, local substrates would be practical substitutes for expensive importations.

Description: In intensive agriculture, N supply often exceeds crop requirements, even in nitrate vulnerable zones (NVZ). In farmland, the N surplus gives rise to NO3− leaching and consequent groundwater pollution. The present study aimed at proposing measures to reduce N leaching and hence improve N efficiency in a buffalo livestock farm located in the NVZ of Latina plain (Central Italy). The farm was cultivated with forage crops in a double annual crop rotation: Italian ryegrass (Lolium multiflorum Lam.) in winter and silage corn (Zea mays L.) in summer. Mineral and organic fertilizers were supplied to both crops. The annual N budget and soil solution NO3-N concentrations were evaluated using a modeling approach. The performance of the WinEPIC model in simulating the response of the NO3-N concentration in percolation to the N application rate was assessed and validated by field measurements of the NO3-N concentration in the soil solution. Three scenarios were proposed to identify the best practice to minimize the environmental impact of N application without significant yield loss. Also, recommendations of best practices in N fertilization and animal manure spreading were given. This study thus provides useful preliminary information for decision-making in agriculture/environmental policies.

Description: Genotypic variation in N efficiency defined as high grain yield under limited nitrogen (N) supply of winter oilseed-rape line-cultivars has been predominantly attributed to N uptake efficiency (NUPT) through maintained N uptake during reproductive growth related to functional stay-green. For investigating the role of stay-green, N retranslocation and N uptake during the reproductive phase for grain yield formation, two line cultivars differing in N starvation-induced leaf senescence were grown in a field experiment without mineral N (N0) and with 160 kg N·ha−1 (N160). Through frequent harvests from full flowering until maturity N uptake, N utilization and apparent N remobilization from vegetative plant parts to the pods could be calculated. NUPT proved being more important than N utilization efficiency (NUE) for grain yield formation under N-limiting (N0) conditions. For cultivar differences in N efficiency, particularly N uptake during flowering (NUPT) and biomass allocation efficiency (HI) to the grains, were decisive. Both crop traits were related to delayed senescence of the older leaves. Remobilization of N particularly from stems and leaves was more important for pod N accumulation than N uptake after full flowering. Pod walls (high N concentrations) and stems (high biomass) mainly contributed to the crop-residue N at maturity. Decreasing the crop-inherent high N budget surplus of winter oilseed-rape requires increasing the low N remobilization efficiency particularly of pod-wall N to the grains. Addressing this conclusion, multi-year and -location field experiments with an extended range of cultivars including hybrids are desirable.

Description: Stripe rust (caused by Puccinia striiformis f. sp. tritici) of wheat (Triticum aestivum) is a devastating disease in temperate regions when susceptible varieties are grown and environmental conditions sustain high disease pressures. With frequent and severe outbreaks, disease resistance is a key tool for controlling stripe rust on wheat. The goal of this research was to identify quantitative trait loci (QTL) involved in stripe rust resistance from the important US Pacific Northwest soft white winter wheat varieties “Eltan” and “Finch”. An F2:5 recombinant inbred line (RIL) mapping population of 151 individuals derived from the Finch × Eltan cross was developed through single seed descent. A linkage map comprising 683 unique single nucleotide polymorphism (SNP) loci and 70 SSR markers were used to develop 22 linkage groups consisting of 16 of the 21 chromosomes. Stripe rust data were collected on the RILs during the summers of 2012 to 2014. QTL analysis identified two genomic regions on chromosomes 4A (QYrel.wak-4A) and 6B (QYrfi.wak-6B) associated with resistance from Eltan and Finch, respectively. The results of the QTL analysis showed that QYrel.wak-4A and QYrfi.wak-6B reduced infection type and disease severity. Based upon both molecular and phenotypic differences, QYrel.wak-4A is a novel QTL for adult plant resistance (APR) to stripe rust.

Description: Ascochyta blight (AB) caused by Ascochyta rabiei (Pass.) Labr. is an important and widespread disease of chickpea (Cicer arietinum L.) worldwide. The disease is particularly severe under cool and humid weather conditions. Breeding for host resistance is an efficient means to combat this disease. In this paper, attempts have been made to summarize the progress made in identifying resistance sources, genetics and breeding for resistance, and genetic variation among the pathogen population. The search for resistance to AB in chickpea germplasm, breeding lines and land races using various screening methods has been updated. Importance of the genotype × environment (GE) interaction in elucidating the aggressiveness among isolates from different locations and the identification of pathotypes and stable sources of resistance have also been discussed. Current and modern breeding programs for AB resistance based on crossing resistant/multiple resistant and high-yielding cultivars, stability of the breeding lines through multi-location testing and molecular marker-assisted selection method have been discussed. Gene pyramiding and the use of resistant genes present in wild relatives can be useful methods in the future. Identification of additional sources of resistance genes, good characterization of the host–pathogen system, and identification of molecular markers linked to resistance genes are suggested as the key areas for future study.

Description: Field experiments at Oakes, ND, USA in 2010 and Carrington, ND, USA in 2011 were conducted to evaluate the potential for cover crops grown in the Northern Great Plains, USA in order to reduce weed emergence and density in irrigated potatoes. Treatments included five cover crop treatments and three cover crop termination treatments. Termination of cover crops was done with glyphosate, disk-till, and roto-till. Cover crop biomass accumulation was greatest for rye/canola and triticale at Oakes, and hairy vetch and hairy vetch/rye at Carrington. Cover crop and termination affected weed control 14, 29, and 51 days after planting (DAP) at Oakes. Weed control at Carrington was at least 90% for all cover crop and termination treatments at all three evaluation timings. Marketable yield at Oakes was greater when roto-till was used to terminate the cover crops compared with disk-till or herbicide, which is beneficial for organic systems where herbicides are not used. Marketable yield at Carrington was not affected by cover crop or termination treatments. Results suggest that cover crops can successfully be integrated into irrigated potato production for weed control with yields equal to no cover crop, and with attention to potential mechanical difficulties.

Description: Soil and water pollution by metals and other toxic chemicals is difficult to measure and control, and, as such, presents an ongoing global threat to sustainable agriculture and human health. Efforts to remove contaminants by plant-mediated pathways, or “phytoremediation”, though widely studied, have failed to yield consistent, predictable removal of biological and chemical contaminants. Emerging research has revealed that one major limitation to using plants to clean up the environment is that plants are programmed to protect themselves: Like white blood cells in animals, border cells released from plant root tips carry out an extracellular trapping process to neutralize threats and prevent injury to the host. Variability in border cell trapping has been found to be correlated with variation in sensitivity of roots to aluminum, and removal of border cell results in increased Al uptake into the root tip. Studies now have implicated border cells in responses of diverse plant roots to a range of heavy metals, including arsenic, copper, cadmium, lead, mercury, iron, and zinc. A better understanding of border cell extracellular traps and their role in preventing toxin uptake may facilitate efforts to use plants as a nondestructive approach to neutralize environmental threats.

Description: A decrease in water resources around the globe in irrigated agriculture has resulted in a steep decline in irrigation water availability. Therefore, management options for efficient use of available irrigation water are inevitable. Deciding the critical time, frequency and amount of irrigation are compulsory to achieve higher crop outputs. Hence, this two-year field study was conducted to assess the role of different row spacings, i.e., 20, 25 and 30 cm, on growth, productivity, and water use efficiency (WUE) of wheat under deficit supplemental irrigation (DSI) at the vegetative and reproductive phase by using surplus supplemental irrigation (SSI) throughout the growing season as the control. DSI at both growth stages, and the reproductive stage in particular, changed the crop allometry, yield and net income of wheat. However, narrow spacing (20 cm) resulted in efficient use of available irrigation water (DSI and SSI) with higher yield, WUE and economic returns. Interestingly, wider spacing resulted in a higher number of grains per spike with higher 1000-grain weight under SSI and DSI, but final yield output remained poor due to a lower number of productive tillers. It was concluded that reducing irrigation during the vegetative stage is less damaging compared with the reproductive phase; therefore, sufficient supplemental irrigation must be added at the reproductive stage, particularly during grain-filling. Further, narrow spacing (20 cm) resulted in efficient utilization of available irrigation water; therefore, wheat must be grown at a narrow spacing to ensure the efficient utilization of available irrigation water.

Description: A mixture of red and blue light-emitting diodes (LEDs; at a ratio of 7:3, respectively) were used to analyze the effects of different photosynthetic photon flux densities (PPFDs) (40, 80, and 120 µmol m−2 s−1 hereafter known as LED 40, 80, and 120, respectively) on the micropropagation of Gerbera jamesonii Bolus shoots. The experiment also examined the effect of 6-benzyladenine (BA) in 1, 2.5, and 5 µM concentrations in the media. Biometrical observations and analyses of leaf morphometry and photosynthetic pigment content were conducted. Shoot multiplication increased with an increasing BA concentration. A PPFD of 80 µmol m−2 s−1 and 5 µM BA is suggested as efficient for shoot propagation and economically viable. LED 120 increased the leaf blade area and its width, and circularity and elongation ratios. The intensity of light did not affect the fresh weight, which increased at higher BA concentrations (2.5 and 5 μM). The dry weight content decreased with increasing cytokinin concentration; the greatest content was observed on media with 1 µM BA under PPFD 120 µmol m−2 s−1. LED 80 increased the photosynthetic pigments content in the leaves in comparison to the standard intensity of LED 40. Increased BA concentration raises the content of chlorophyll a.

Description: In this paper, we measure the systemic risk with a novel methodology, based on a “spatial-temporal” approach. We propose a new bank systemic risk measure to consider the two components of systemic risk: cross-sectional and time dimension. The aim is to highlight the “time-space dynamics” of contagion, i.e., if the CDS spread of bank i depends on the CDS spread of other banks. To do this, we use an advanced spatial econometrics design with a time-varying spatial dependence that can be interpreted as an index of the degree of cross-sectional spillovers. The findings highlight that the Eurozone banks have strong spatial dependence in the evolution of CDS spread, namely the contagion effect is present and persistent. Moreover, we analyse the role of the European Central Bank in managing contagion risk. We find that monetary policy has been effective in reducing systemic risk. However, the results show that systemic risk does not imply a policy intervention, highlighting how financial stability policy is not yet an objective.

Description: Soil pH is a key factor affecting the growth of blueberries. Understanding the response mechanism of blueberries to different pH values and selecting suitable evaluation indexes are the basis of breeding new blueberry cultivars with high pH tolerances. The effects of different soil pH treatments for 17 months on the plant growth, fruit yield, photosynthetic characteristics, and leaf microelement concentration of Vaccinium ashei Reade ‘Climax’ and V. corymbosum hybrid ‘Chaoyue No. 1′ were studied. Plant height, main stem diameter, branch number per plant, leaf dry weight, stem dry weight, root dry weight, and total dry weight decreased with increasing soil pH. With an increase in soil pH, the first flowering date, 50% flowering date, first ripening date, and 50% ripening date of the two cultivars were postponed, and the flower bud numbers per plant, the floret numbers per bud, and yield per plant showed a downward trend. Moreover, the fruit quality decreased, which was reflected in the increase in the titratable acid content (TA) and the decrease in the total soluble solids content (TSS) and the TSS:TA ratio in the high pH treatment. With increasing soil pH, the chlorophyll content index (CCI), maximal photochemical efficiency of the PSII (Fv/Fm), quantum photosynthetic yield of the PSII (Y(II)) and net photosynthetic rate (Pn) of the two cultivars showed a downward trend, and some microelement concentrations in the leaves were imbalanced. Under high pH treatment, ‘Chaoyue No. 1′ had a relatively higher plant biomass and fruit yield, so it had a stronger tolerance to high pH than ‘Climax’ did. More strongly acidified rhizosphere soil capacity, as well as higher CCI, Fv/Fm, Y(II), and Pn values were the main reasons for the high pH tolerance of ‘Chaoyue No. 1′. Compared with destructive biomass indicators such as plant weight, nondestructive indicators such as CCI, Fv/Fm, and Y(II) can be more valuable indicators for fast and accurate evaluation of blueberry tolerance to high pH at early stages of treatment.

Description: Due to its possible utilization in cosmetics, medicine and crop protection, as a valuable alternative to petrochemical-derived products, hemp essential oil is now considered a product with high value added and a promising marketing potential. This experiment was conducted with the aim of evaluating the effect of four different locations of Northern Italy during two years (four environments) and three hemp monoecious varieties on the production and quality of essential oils (EOs) obtained by inflorescences harvested at full flowering of female flowers. The highest inflorescence yield was obtained at Maiano 2017, where a superficial groundwater layer (1.5 m) was present, with values that ranged from 1.69 of Fedora to 2.06 t ha−1 of Futura. EOs production ranged between 3.4 and 4.9 L ha−1, affected mainly by the variety effect. The terpene in EOs, very similar between varieties and environments, was mainly composed of sesquiterpenes (caryophillene and humulene, as the most abundant) rather than monoterpenes (α-pinene, β-myrcene and trans-β-ocimene, in particular). Phytocannabinoids, and in particular cannabidiol (CBD), were not removed from tissues by the steam during hydrodistillation, and if this is confirmed by further experiments, the residual biomass, now considered as waste, could assume significant importance as a source for further utilization.

Description: The role of small bioactive molecules (〈500 Da) in mechanisms improving resource use efficiency in plants under stress conditions draws increasing interest. One such molecule is omeprazole (OMP), a benzimidazole derivative and inhibitor of animal proton pumps shown to improve nitrate uptake and exclusion of toxic ions, especially of chloride from the cytosol of salt-stressed leaves. Currently, OMP was applied as substrate drench at two rates (0 or 10 μM) on hydroponic basil (Ocimum basilicum L. cv. Genovese) grown under decreasing NO3−:Cl− ratio (80:20, 60:40, 40:60, or 20:80). Chloride concentration and stomatal resistance increased while transpiration, net CO2 assimilation rate and beneficial ions (NO3−, PO43−, and SO42−) decreased with reduced NO3−:Cl− ratio under the 0 μM OMP treatment. The negative effects of chloride were not only mitigated by the 10 μM OMP application in all treatments, with the exception of 20:80 NO3−:Cl−, but plant growth at 80:20, 60:40, and 40:60 NO3−:Cl− ratios receiving OMP application showed maximum fresh yield (+13%, 24%, and 22%, respectively), shoot (+10%, 25%, and 21%, respectively) and root (+32%, 76%, and 75%, respectively) biomass compared to the corresponding untreated treatments. OMP was not directly involved in ion homeostasis and compartmentalization of vacuolar or apoplastic chloride. However, it was active in limiting chloride loading into the shoot, as manifested by the lower chloride concentration in the 80:20, 60:40, and 40:60 NO3−:Cl− treatments compared to the respective controls (−41%, −37%, and −24%), favoring instead that of nitrate and potassium while also boosting photosynthetic activity. Despite its unequivocally beneficial effect on plants, the large-scale application of OMP is currently limited by the molecule’s high cost. However, further studies are warranted to unravel the molecular mechanisms of OMP-induced reduction of chloride loading to shoot and improved salt tolerance.

Description: There is a growing body of research that recognizes the potentials of biochar application in agricultural production systems. However, little is known about the effects of biochar, especially hydrochar, on production of containerized seedlings under nursery conditions. This study aimed to test the effects of hydrochar application on growth, quality, nutrient and heavy metal contents, and mycorrhizal association of containerized pine seedlings. The hydrochar used in this study was produced through hydrothermal carbonization of paper mill biosludge at 200 °C. Two forms of hydrochar (powder and pellet) were mixed with peat at ratios of 10% and 20% (v/v) under three levels of applied commercial fertilizer (nil, half and full rates). Application of hydrochar had positive or neutral effects on shoot biomass and stem diameter compared with control seedlings (without hydrochar) under tested fertilizer levels. Analysis of the natural logarithmic response ratios (LnRR) of quality index and nutrient and heavy metal uptake revealed that application of 20% (v/v) hydrochar powder or pellet with 50% fertilizer resulted in same quality pine seedlings with similar heavy metal (Cu, Ni, Pb, Zn and Cr) and nutrient (P, K, Ca and Mg) contents as untreated seedlings supplied with 100% fertilizer. Colonization percentage by ectomycorrhizae significantly increased when either forms of hydrochar were applied at a rate of 20% under unfertilized condition. The results of this study implied that application of proper rates of hydrochar from biosludge with adjusted levels of liquid fertilizer may reduce fertilizer requirements in pine nurseries.

Description: The tank cascade system (TCS) has been used for over 2000 years for water management in Sri Lanka. Since surface water is limited in the dry zone of Sri Lanka, agricultural production, especially of upland crops, relies on groundwater for irrigation. We sampled 29 wells in the Ulagalla cascade, a prominent TCS near Anuradhapura city in the dry zone of Sri Lanka, in Yala (dry) and Maha (wet) seasons, the two main cropping seasons in Sri Lanka. We evaluated the suitability of groundwater for irrigation using the analytic hierarchy process and geographical information system. Water quality did not vary notably between seasons. However, it deteriorated with the onset of high intensity heavy rain, especially during the Maha season. A water quality zoning map indicated that groundwater in 4% and 96% of the study area is suitable and moderately suitable for irrigation, respectively. Irrigation water quality in tank cascade landscapes and similar environments can be assessed using this methodology and our results.

Description: Soils in tropical croplands are becoming degraded because of soil carbon (C) depletion. Local farmers in South India use a specific management of traditional cultivation, i.e., broadcast seeding. However, for sustainable C management, there is no quantitative data on the CO2 flux under this management. Our objectives were to (1) estimate the annual CO2 flux, and (2) evaluate the effect of traditional cultivation management (seeding rate) on the CO2 flux. Our field experiment was conducted in South India, from 2015 to 2017, including two cultivation periods with four cultivation management treatments (traditional cultivation management plot (T), fixed density plot (FD), no thinning plot (NT), and bare plot (B)). The seeding rate in the FD plot was ca. 50% of the T plot. We applied 1.1 Mg C ha−1 farmyard manure just before the experiment as a C input. We found that broadcasting, thinning, and cultivation increased soil moisture, while the CO2 efflux rate showed no significant difference between treatments throughout the experimental period. This indicates that cultivation management did not affect the CO2 flux. The total CO2 fluxes for two years were estimated at 2.2–2.7 Mg C ha−1. Our results indicate that it is necessary to apply larger or more frequent C inputs to prevent C depletion.

Description: The rye (Secale cereale L.) 5R chromosome contains some elite genes that can be used to improve wheat cultivars. In this study, a set of 5RKu dissection lines was obtained, and 111 new PCR-based and 5RKu-specific markers were developed using the specific length amplified fragment sequencing (SLAF-seq) method. The 111 markers were combined with the 52 5RKu-specific markers previously reported, and 65 S. cereale Lo7 scaffolds were physically mapped to six regions of the 5RKu chromosome using the 5RKu dissection lines. Additionally, the 5RLKu arm carried stripe rust resistance gene(s) and it was located to the region L2, the same region where 22 5RKu-specific markers and 11 S. cereale Lo7 scaffolds were mapped. The stripe rust resistance gene(s) located in the 5RLKu arm might be new one(s) because its source and location are different from the previously reported ones, and it enriches the resistance source of stripe rust for wheat breeding programs. The markers and the S. cereale Lo7 scaffolds that were mapped to the six regions of the 5RKu chromosome can facilitate the utilization of elite genes on the 5R chromosome in the improvement of wheat cultivars.

Description: Assessing and prescribing fertilizer use is critical to profitable and sustainable coffee production, and this is becoming a priority concern for the Robusta coffee industry. In this study, annual survey data of 798 farms across selected Robusta coffee-producing provinces in Vietnam and Indonesia between 2008 and 2017 were used to comparatively assess the fertilizer management strategies in these countries. Specifically, we aimed to characterize fertilizer use patterns in the key coffee-growing provinces and discuss the potential for improving nutrient management practices. Four types of chemical (NPK, super phosphate, potassium chloride and urea) and two of natural (compost and lime) fertilizers were routinely used in Vietnam. In Indonesia, NPK and urea were supplemented only with compost. Farmers in Vietnam applied unbalanced quantities of chemical fertilizers (i.e., higher rates than recommended) and at a constant rate between years whereas Indonesian farmers applied well below the recommended rates because of poor accessibility and financial support. The overuse of chemical fertilizers in Vietnam threatens the sustainability of Robusta coffee farming. Nevertheless, there is a potential for improvement in both countries in terms of nutrient management and sustainability of Robusta coffee production by adopting the best local fertilizer management practices.

Description: Perennial ryegrass (Lolium perenne L.) is one of the most important forage grass species in temperate regions of the world, but it is prone to having poor persistence due to the incidence of abiotic and biotic stresses. This creates a challenge for livestock producers to use their agricultural lands more productively and intensively within sustainable limits. Breeding perennial ryegrass cultivars that are both productive and persistent is a target of forage breeding programs and will allow farmers to select appropriate cultivars to deliver the highest profitability over the lifetime of a sward. Conventional methods for the estimation of pasture persistence depend on manual ground cover estimation or counting the number of surviving plants or tillers in a given area. Those methods are subjective, time-consuming and/or labour intensive. This study aimed to develop a phenomic method to evaluate the persistence of perennial ryegrass cultivars in field plots. Data acquisition was conducted three years after sowing to estimate the persistence of perennial ryegrass using high-resolution aerial-based multispectral and ground-based red, green and blue(RGB) sensors, and subsequent image analysis. There was a strong positive relationship between manual ground cover and sensor-based ground cover estimates (p 〈 0.001). Although the manual plant count was positively correlated with sensor-based ground cover (p 〈 0.001) intra-plot plant size variation influenced the strength of this relationship. We conclude that object-based ground cover estimation is most suitable for use in large-scale breeding programs due to its higher accuracy, efficiency and repeatability. With further development, this technique could be used to assess temporal changes of perennial ryegrass persistence in experimental studies and on a farm scale.

Description: High input costs combined with multiple management and material inputs have threatened cotton productivity. We hypothesize that this problem can be addressed by a single fertilization at flowering with late sowing in a moderately populated plant stand. Field experiments were conducted to evaluate the cotton biomass accumulation, phosphorus dynamics, and fiber quality under three planting densities (low, 3 × 104; moderate, 6 × 104; and dense, 9 × 104 ha−1) and two cultivars (Zhongmian-16 and J-4B). High planting density had 6.2 and 12.6% larger stems and fruiting nodes m−2, while low density produced a 37.5 and 59.4% maximum height node ratio. Moderate density produced 26.4–15.5%, 24.7–12.6%, and 10.5–13.6% higher biomass accumulation rate at the peak bloom, boll set, and plant removal stages over low and high density in both years, respectively. J-4B produced a higher reproductive organs biomass yield when compared with Zhongmian-16 in both years. This higher biomass formation was due to both the higher average (0.8 VT kg·ha−1·d−1) and maximum (1.0 VM kg·ha−1·d−1) reproductive organ phosphorus uptake, respectively. Plants with low density had 5.3–18.5%, 9.5–15%, and 7.8–12.8% greater length, strength, and micronaire values over moderate and dense plants, respectively. Conclusively, moderate density with J-4B is a promising option for improved biomass, phosphorus acquisition, and fiber quality under a short season.

Description: Three rust diseases namely; stem rust caused by Puccinia graminis f. sp. tritici (Pgt), leaf rust caused by Puccinia triticina (Pt), and stripe rust caused by Puccinia striiformis f. sp. tritici (Pst), are the most common fungal diseases of wheat (Triticum aestivum L.) and cause significant yield losses worldwide including Australia. Recently characterized stripe rust resistance genes Yr51 and Yr57 are effective against pre- and post-2002 Pst pathotypes in Australia. Similarly, stem rust resistance genes Sr22, Sr26, and Sr50 are effective against the Pgt pathotype TTKSK (Ug99) and its derivatives in addition to commercially important Australian pathotypes. Effectiveness of these genes make them good candidates for combining with known pleiotropic adult plant resistance (PAPR) genes to achieve durable resistance against three rust pathogens. This study was planned to transfer rust resistance genes Yr51, Yr57, Sr22, Sr26, and Sr50 into two Australian (Gladius and Livingston) and two Indian (PBW550 and DBW17) wheat cultivars through marker assisted selection (MAS). These cultivars also carry other rust resistance genes: Gladius carries Lr37/Yr17/Sr38 and Sr24/Lr24; Livingston carries Lr34/Yr18/Sr57, Lr37/Yr17/Sr38, and Sr2; PBW550 and DBW17 carry Lr34/Yr18/Sr57 and Lr26/Yr9/Sr31. Donor sources of Yr51 (AUS91456), Yr57 (AUS91463), Sr22 (Sr22/3*K441), Sr26 (Sr26 WA1), and Sr50 (Dra-1/Chinese Spring ph1b/2/3* Gabo) were crossed with each of the recurrent parents to produce backcross progenies. Markers linked to Yr51 (sun104), Yr57 (gwm389 and BS00062676), Sr22 (cssu22), Sr26 (Sr26#43), and Sr50 (Sr50-5p-F3, R2) were used for their MAS and markers csLV34 (Lr34/Yr18/Sr57), VENTRIUP-LN2 (Lr37/Yr17/Sr38), Sr24#12 (Sr24/Lr24), and csSr2 (Sr2) were used to select genes present in recurrent parents. Progenies of selected individuals were grown and selected under field conditions for plant type and adult plant rust responses. Final selections were genotyped with the relevant markers. Backcross derivatives of these genes were distributed to breeding companies for use as resistance donors.

Description: Reducing soil tillage can lead to many benefits, but this practice often increases weed abundance and thus the need for herbicides, especially during the transition phase from inversion tillage to non-inversion tillage. We evaluated if subsidiary crops (SCs, e.g., cover crops) can mitigate the effects of non-inversion tillage on weed abundance. Two-year experiments studying SC use, tillage intensity, and nitrogen (N) fertilization level were carried out twice at six sites throughout northern and central Europe. SCs significantly reduced weed cover throughout the intercrop period (−55% to −1% depending on site), but only slightly during the main crops. Overall weed abundance and weed biomass were higher when using non-inversion tillage with SCs compared to inversion tillage without SCs. The effects differed due to site-specific weed pressure and management. With increasing weed pressure, the effect of SCs decreased, and the advantage of inversion over non-inversion tillage increased. N fertilization level did not affect weed abundance. The results suggest that SCs can contribute by controlling weeds but cannot fully compensate for reduced weed control of non-inversion tillage in the transition phase. Using non-inversion tillage together with SCs is primarily recommended in low weed pressure environments.

Description: Chamomile (Matricaria chamomilla L.) is a well-known medicinal plant species in which the products requested from the market are those that are derived from the organic system. The study was conducted to assess the allelopathic effects, as natural herbicides, of two essential oils extracted from oregano (Origanum vulgare L.) and rosemary (Rosmarimum officinalis L.), with the objective of exploring the possibility of their utilization for future weed management. A field experiment was conducted over two seasons, when the infestation of 15 different weed species was detected. Each essential oil was applied at two different concentrations (50% diluted and undiluted), three times during the chamomile crop under an organic farm system. The results demonstrated that the germination of different weed species was affected differently by the type of essential oils and especially by their concentrations. The undiluted oils inhibited most of the germination of several weed species, highlighting a significantly higher percentage of Weed Control Efficiency (WCE) and suggesting the potential to be used as bio-herbicides. Bioherbicidal weed control methods could offer an advantage with respect to hand weeding, particularly from an economic point of view.

Description: The establishment and application of a spectral library is a critical step in the standardization and automation of remote sensing interpretation and mapping. Currently, most spectral libraries are designed to support the classification of land cover types, whereas few are dedicated to agricultural remote sensing monitoring. Here, we gathered spectral observation data on plants in multiple experimental scenarios into a spectral database to investigate methods for crop classification (16 crop species) and status monitoring (tea plant and rice growth). We proposed a set of screening methods for spectral features related to plant classification and status monitoring (band reflectance, vegetation index, spectral differentiation, spectral continuum characteristics) that are based on ISODATA and JM distance. Next, we investigated the performance of different machine learning classifiers in the spectral library application, including K-nearest neighbor (KNN), Random Forest (RF), and a genetic algorithm coupled with a support vector machine (GA-SVM). The optimal combination of spectral features and the classifier with the highest classification accuracy were selected for crop classification and status monitoring scenarios. The GA-SVM classifier performed the best, which produced an accuracy of OAA = 0.94, Kappa = 0.93 for crop classification in a complex scenario (crops mixed with 71 non-crop plant species), and promising accuracies for tea plant growth monitoring (OAA = 0.98, Kappa = 0.97) and rice growth stage monitoring (OAA = 0.92, Kappa = 0.90). Therefore, the establishment of a plant spectral library combined with relevant feature extraction and a classification algorithm effectively supports agricultural monitoring by remote sensing.

Description: Crop models are useful tools to evaluate the effects of agricultural management on ecosystem services. However, before they can be applied with confidence, it is important to calibrate and validate crop models in the region of interest. In this study, the Environmental Policy Integrated Climate (EPIC) model was evaluated for its potential to simulate maize yield using limited data from field trials on two maize cultivars. Two independent fields at the Cradock Research Farm were used, one for calibration and one for validation. Before calibration, mean simulated yield was 8 t ha−1 while mean observed yield was 11.26 t ha−1. Model calibration improved mean simulated yield to 11.23 t ha−1 with a coefficient of determination, (r2) = 0.76 and a model efficiency (NSE) = 0.56. Validation with grain yield was satisfactory with r2 = 0.85 and NSE = 0.61. Calibration of potential heat units (PHUs) and soil-carbon related parameters improved model simulations. Although the study only used grain yield to calibrate and evaluate the model, results show that the calibrated model can provide reasonably accurate simulations. It can be concluded that limited data sets from field trials on maize can be used to calibrate the EPIC model when comprehensive experimental data are not available.

Description: Lemon processing generates thousands of tons of residues that can be preserved as flours by thermal treatment to obtain phenolic compounds with beneficial bioactivities. In this study, the effect of different drying temperatures (40, 50, 60, 70, 80, 90, 100 and 110 °C) on the Total Phenolic Content (TPC), antioxidant and antimicrobial activities of phenolic compounds present in Citrus. lemon (L.) Burn f waste was determined. Identification and quantification of phenolic compounds were also performed by UPLC-PDA and UPLC-ESI-MS analysis. Eriocitrin (19.79–27.29 mg g−1 DW) and hesperidin (7.63–9.10 mg g−1 DW) were detected as the major phenolic compounds in the flours by UPLC-PDA and confirmed by UPLC-ESI-MS. Antimicrobial activity determined by Minimum Inhibitory Concentration (MIC) against Salmonella typhimurium, Escherichia coli and Staphylococcus aureus was observed. Accordingly, a stable functional flour as a source of bioactive phenolic compounds obtained from lemon residues at 50 °C may be produced as a value-added product useful in various industrial sectors.

Description: Fusarium Head Blight (FHB, scab) is a destructive fungal disease that causes extensive yield and quality losses in wheat and other small cereals. Biological control of FHB is considered to be an alternative disease management strategy that is environmentally benign, durable, and compatible with other control measures. In this study, to screen antagonistic bacteria with the potential to manage FHB, 113 endophytes were isolated from the stems, leaves, panicles, and roots of wheat. Among them, six strains appeared to effectively inhibit Fusarium graminearum growth and one isolate, XS-2, showed a highly antagonistic effect against FHB. An in vitro antagonistic test of XS-2 on wheat heads confirmed that XS-2 could suppress the disease severity of FHB. The 16S rDNA sequence analysis revealed that XS-2 is a strain of Bacillus amyloliquefaciens. Antagonistic spectrum analyses showed that XS-2 had antagonistic effects against two and four types of cotton and fruit tree pathogens, respectively. The fermentation condition assays showed that glucose and peptone are the most suitable nutrient sources for XS-2, and that the optimal pH value and temperature for fermentation were 7.4 and 28 °C, respectively. Our study indicates that XS-2 has a good antagonistic effect on FHB and lays a theoretical foundation for the application of the strain as a biological agent in the field to control FHB.

Description: China has attained rice sufficiency with the increased use of nitrogen (N) fertilizer, but this has led to serious N pollution. China has the world’s highest use of N with the lowest N use efficiency (NUE). Including livestock production, China’s agriculture sector has surpassed industry as the greatest polluter of water. Using plastic film on raised-beds, combined with improved agronomic practices, can boost rice yield by 50% with 36% less N fertilizer use, 30% higher NUE, and stabilized the yield of 9.75 t ha−1. It also counters the effects of drought and low ambient temperature. A six-year study was conducted combining no-tillage, crop-residue mulch, and plastic cover, alternating organic rice and rapeseed production. All the treatments, fertilized with biogas slurry and rapeseed meal, gave rice yields of 7.0 to 10.7 t ha−1, well above China’s average of 6.5 t ha−1. In this time, soil organic matter increased from 1.6% to 4.2%. In the first four years, the combination of crop-residue mulch with plastic cover had a slightly higher yield than mulch alone. In the fifth and sixth years, the latter treatment surpassed the use of plastic cover with crop-residue mulch. Trials with a biodegradable film show that plastic pollution can be dealt with.

Description: The aim of the study was to determine the Actinobacteria structure in cultivated (C) versus non-cultivated (NC) soils divided into three groups (autogenic, hydrogenic, lithogenic) with consideration its formation process in order to assess the Actinobacteria sensitivity to agricultural soil use and soil genesis and to identify factors affecting their abundance. Sixteen C soil samples and sixteen NC samples serving as controls were taken for the study. Next generation sequencing (NGS) of the 16S rRNA metagenomic amplicons (Ion Torrent™ technology) and Denaturing Gradient Gel Electrophoresis (DGGE) were applied for precise determination of biodiversity. Generally, greater abundance of Actinobacteria in the NC soils relative to the C soils was found. Moreover, it was indicated that the actinobacterial diversity depended on both the soil genesis and the land use; however, this effect directly depended on the particular family and genera. Two factors: redox potential (Eh) and total carbon (TC) seemed to had a significant effect on the diversity of Actinobacteria. More precisely, Actinobacteria from the NC soils displayed a greater affinity for each other and were clearly influenced by Eh, whilst those from the C soils were mostly influenced by TC.

Description: Adoption of no-till systems in Eastern Washington has been slow due to the difficulty of managing wheat (Triticum aestivum L.) straw residue and the unknown decomposition potential of cultivars. We hypothesize that by analyzing wheat straw with near-infrared spectroscopy (NIRS), calibration models can be developed to accurately predict fiber and chemical constituents of wheat, determining straw decomposition potential. Straw from a panel of 480 soft winter wheat cultivars adapted to the Pacific Northwest are analyzed for neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), cellulose, hemicellulose, carbon (C), and nitrogen (N). Using modified partial least squares regression and cross validation techniques, specific environment and broad-based NIRS models are calibrated and predictive ability is validated. R2cal values from broad models are better than the specific models, and are 0.85 (NDF), 0.86 (ADF), 0.65 (ADL), 0.88 (cellulose), 0.42 (hemicellulose), 0.67 (C), and 0.73 (N). The corresponding SEP values are 1.68% (NDF), 1.54% (ADF), 0.62% (ADL), 1.14% (cellulose), 1.11% (hemicellulose), 1.23% (C), and 0.06% (N). A Finch × Eltan breeding population is used to further validate models and prediction accuracies for variety selection within a breeding program scenario. The broad NIRS models prove useful for estimating high and low ranges of NDF, ADF, and cellulose in wheat cultivars which translate into characteristics of slow and fast decomposition potential.

Description: The inclusion of species with allelopathic activity in crop rotation systems may have benefits for crop management such as weed control, but less is understood about their wider impacts on succeeding crops. The main objective of this study was to investigate the effects of two allelopathic species (spearmint and peppermint) on growth, physiological characteristics, and yield of a following maize crop. Thus, field experiments were carried out at two sites, according to a randomized complete block design, while the examined treatments were: (a) fallow–fallow–maize crop rotation system (FFM), (b) spearmint–spearmint–maize crop rotation system (SSM), and (c) peppermint–peppermint–maize crop rotation system (PPM). Our results indicated that the inclusion of spearmint or peppermint in crop rotation systems negatively affect the growth of maize plants. The highest plant height was recorded for FFM rotation system where no allelopathic species were used. At both sites and for four sampling dates, the aboveground dry biomass was also affected by the implemented crop rotation system. In particular, dry biomass was significantly lower in the PPM and SSM crop rotation systems comparing to the FFM system, whereas there were no significant differences between these two crop rotation systems. Similar to the maize biomass, the highest values of photosynthetic rate, stomatal conductance, and relative chlorophyll content were observed for the FFM rotation system. Additionally, differences in grain yield were observed among the tested crop rotation systems. Grain yield ranged from 10,200 to 13,346 kg ha−1 and from 11,773 to 14,106 kg ha−1 at site A and B, respectively, while it was reduced by 16.54–23.58% and 12.16–17.83% in the SSP and PPM rotation systems comparing to the FFM system. In conclusion, our results indicate that the inclusion of peppermint or spearmint in crop rotation may inhibit plant growth and reduce grain yield of maize as successive crop, an effect that could be attributed to the allelopathic activity of spearmint and peppermint.

Description: The Midwestern U.S. landscape is one of the most highly altered and intensively managed ecosystems in the country. The predominant crops grown are maize (Zea mays L.) and soybean [Glycine max (L.) Merr]. They are typically grown as monocrops in a simple yearly rotation or with multiple years of maize (2 to 3) followed by a single year of soybean. This system is highly productive because the crops and management systems have been well adapted to the regional growing conditions through substantial public and private investment. Furthermore, markets and supporting infrastructure are highly developed for both crops. As maize and soybean production have intensified, a number of concerns have arisen due to the unintended environmental impacts on the ecosystem. Many areas across the Midwest are experiencing negative impacts on water quality, soil degradation, and increased flood risk due to changes in regional hydrology. The water quality impacts extend even further downstream. We propose the development of an innovative system for growing maize and soybean with perennial groundcover to recover ecosystem services historically provided naturally by predominantly perennial native plant communities. Reincorporating perennial plants into annual cropping systems has the potential of restoring ecosystem services without negatively impacting grain crop production and offers the prospect of increasing grain crop productivity through improving the biological functioning of the system.

Description: Rice blast is a serious fungal disease of rice (Oryza sativa L.) that is threatening global food security. It has been extensively studied due to the importance of rice production and consumption, and because of its vast distribution and destructiveness across the world. Rice blast, caused by Pyricularia oryzae Cavara 1892 (A), can infect aboveground tissues of rice plants at any growth stage and cause total crop failure. The pathogen produces lesions on leaves (leaf blast), leaf collars (collar blast), culms, culm nodes, panicle neck nodes (neck rot), and panicles (panicle blast), which vary in color and shape depending on varietal resistance, environmental conditions, and age. Understanding how rice blast is affected by environmental conditions at the cellular and genetic level will provide critical insight into incidence of the disease in future climates for effective decision-making and management. Integrative strategies are required for successful control of rice blast, including chemical use, biocontrol, selection of advanced breeding lines and cultivars with resistance genes, investigating genetic diversity and virulence of the pathogen, forecasting and mapping distribution of the disease and pathogen races, and examining the role of wild rice and weeds in rice blast epidemics. These tactics should be integrated with agronomic practices including the removal of crop residues to decrease pathogen survival, crop and land rotations, avoiding broadcast planting and double cropping, water management, and removal of yield-limiting factors for rice production. Such an approach, where chemical use is based on crop injury and estimated yield and economic losses, is fundamental for the sustainable control of rice blast to improve rice production for global food security.

Description: A study was conducted in an irrigated arid agroecosystem in southwestern USA, to compare two conservation tillage systems (strip tillage (ST) and no-tillage (NT)) to conventional, plow-based tillage (PT) system. Corn silage (Zea mays L.) was planted in this trial. Growth parameters (plant population and height) of corn silage were measured during the season and yield was evaluated at harvest. Soil physical measurements assessed included mean weight diameter of dry aggregates, wet aggregate stability, and penetrometer resistance. While soil biological measurements included total microbial biomass, diversity index (DI), total bacteria biomass, total fungi biomass (TFB), arbuscular mycorrhizae fungi (AMF), and total saprophytes. Results showed that plant population and silage yield at 65% moisture content were not significant with tillage during both trial years. Soil physical parameters were mostly not significant with tillage, while three out of the six biological measurements (DI, TF, and AM) were significant with tillage at p ≤ 0.05. No-tillage had higher DI and TFB than the ST, but not different from PT, while AMF was significantly higher in PT than ST, but not different from NT. The study demonstrates that farmers in the study region can adopt conservation tillage without yield losses during the early years of transition.

Description: The frequency of drought periods influences the yield potential of crops under field conditions. The change in morphology and anatomy of plants has been tested during drought stress under controlled conditions but the change in physiological processes has not been adequately studied in separate studies but needs to be reviewed collectively. This review presents the responses of green peas, snap beans, tomatoes and sweet corn to water stress based on their stomatal behaviour, canopy temperature, chlorophyll fluorescence and the chlorophyll content of leaves. These stress markers can be used for screening the drought tolerance of genotypes, the irrigation schedules or prediction of yield.

Description: A combination of organic and conservation approaches have not been widely tested, neither considering agronomic implications nor the impacts on the environment. Focussing on the effect of agricultural practices on greenhouse gas (GHG) emissions from soil, the hypothesis of this research is that the organic conservation system (ORG+) may reduce emissions of N2O, CH4 and CO2 from soil, compared to an integrated farming system (INT) and an organic (ORG) system in a two-year irrigated vegetable crop rotation set up in 2014, in a Mediterranean environment. The crop rotation included: Savoy cabbage (Brassica oleracea var. sabauda L. cv. Famosa), spring lettuce (Lactuca sativa L. cv. Justine), fennel (Foeniculum vulgare Mill. cv. Montebianco) and summer lettuce (L. sativa cv. Ballerina). Fluxes from soil of N2O, CH4 and CO2 were measured from October 2014 to July 2016 with the flow-through non-steady state chamber technique using a mobile instrument equipped with high precision analysers. Both cumulative and daily N2O emissions were mainly lower in ORG+ than in INT and ORG. All the cropping systems acted as a sink of CH4, with no significant differences among treatments. The ORG and ORG+ systems accounted for higher cumulative and daily CO2 emissions than INT, maybe due to the stimulating effect on soil respiration of organic material (fertilizers/plant biomass) supplied in ORG and ORG+. Overall, the integration of conservation and organic agriculture showed a tendency for higher CO2 emissions and lower N2O emissions than the other treatments, without any clear results on its potential for mitigating GHG emissions from soil.

Description: Climate change is viewed as a cause in accelerating the rate of invasion by alien species in addition to the globalization of anthropogenic activities. Ecological niche modeling has become an instrument in predicting invasion from natural or invaded ranges to uninvaded ranges based on the presence records of organisms and environmental parameters. This study explored the changes in the distributions of globally noxious alien species (Aegratina adenophora, Ageratum conyzoides, Chromolaena odorata, Lantana camara, Mikania micrantha, and Parthenium hysterophorus) in Bhutan, to provide evidence that even a mountain environment is under the threat of invasion given the change in climatic conditions. With fairly high accuracy, the model results suggest that there will be a potential increase in the areas of invasion among most of the species, except Parthenium hysterophorus, which will experience a northerly shift and decline in distribution. The results also indicate changes in patterns of invasion, some becoming more concentrated toward a given direction, while others become more dispersed over time. This study provides a framework that can be used in the strategic control of the species, future detection surveys, and further research.

Description: Phenolic compounds in basil (Ocimum basilicum) plants grown under a controlled environment are reduced due to the absence of ultraviolet (UV) radiation and low photosynthetic photon flux density (PPFD). To characterize the optimal UV-B radiation dose and PPFD for enhancing the synthesis of phenolic compounds in basil plants without yield reduction, green and purple basil plants grown at two PPFDs, 160 and 224 μmol·m−2·s−1, were treated with five UV-B radiation doses including control, 1 h·d−1 for 2 days, 2 h·d−1 for 2 days, 1 h·d−1 for 5 days, and 2 h·d−1 for 5 days. Supplemental UV-B radiation suppressed plant growth and resulted in reduced plant yield, while high PPFD increased plant yield. Shoot fresh weight in green and purple basil plants was 12%–51% and 6%–44% lower, respectively, after UV-B treatments compared to control. Concentrations of anthocyanin, phenolics, and flavonoids in green basil leaves increased under all UV-B treatments by 9%–18%, 28%–126%, and 80%–169%, respectively, and the increase was greater under low PPFD compared to high PPFD. In purple basil plants, concentrations of phenolics and flavonoids increased after 2 h·d−1 UV-B treatments. Among all treatments, 1 h·d−1 for 2 days UV-B radiation under PPFD of 224 μmol·m−2·s−1 was the optimal condition for green basil production under a controlled environment.

Description: Auxin regulates diverse aspects of growth and development. Furthermore, polar auxin transport, which is mediated by the PIN-FORMED (PIN) and AUXIN1/LIKE-AUX (AUX/LAX) proteins, plays a crucial role in auxin distribution. In this study, six PIN and four AUX/LAX genes were identified in ramie (Boehmeria nivea L.). We used qRT-PCR to characterize and analyze the two gene families, including phylogenetic relationships, intron/exon structures, cis-elements, subcellular localization, and the expression patterns in different tissues. The expression of these genes in response to indole-3-acetic acid (IAA) treatment and drought stress was also assessed; the results indicate that most of the BnAUX/LAX and BnPIN genes were regulated as a result of IAA treatment and drought stress. Our study provides insights into ramie auxin transporters and lays the foundation for further analysis of their biological functions in ramie fiber development and adaptation to environmental stresses.

Description: The genetic architecture and the genetic loci controlling commodity traits in this Hami melon have not been characterized. Multiplexed shotgun genotyping (MSG) was used to genotype an F2 population of 370 Chinese Hami melon progeny. A total of 47,609 single nucleotide polymorphism (SNP) markers were obtained after strict filtering. Thebins were used to construct a genetic linkage map with a total length of 1572.954 cM. Quantitative trait locus (QTL) analysis revealed that fruit color was controlled by one major gene about 2 Mb region on chr09, while exocarp color (EC) was controlled by one major gene about 1.9 Mb on chr04, and skin spotting was controlled by two dominant genes, one in the same region of chr04as the EC QTL and the other in the 1031.05 kb region on chr02. Two major QTLs on chr03 and chr05 were related pleiotropically to several quantitative fruit traits, namely, edge sugar content (ES), center sugar content (CS), fruit weight (FW), and fruit length (FL). A further QTL on chr09 also influenced ES, while five other QTLs affected FL. This study was the first to conduct genetic architecture analysis and QTL mapping in Chinese Hami melon with high-density markers and a large target population.

Description: The sector of SME is the major force for the national economic and social development. Financial risk is one of the key threats to the activity of small and medium enterprises. The most common manifestation of the financial risk of SMEs is difficulty in financing the business and lack of funds for development. Banks are unwilling to grant loans to such companies. Moreover, it is the rising operating costs that cause shrinking profits, which may result in corporate debt, difficulty in debt repayment, and consequently, high financial risk of these entities. Numerous differences in conducting the activity of small and large enterprises intensify this risk and mean that the model of credit financing for companies is not adjusted to the capabilities and principles of the operation of small enterprises. Therefore, risk management is one of the most important internal processes in small and medium enterprises. The identification of factors that affect the level of financial risk in these entities is therefore crucial. The main objective of this research was to analyze the impact of selected parametric characteristics of the SME sector on the intensity of financial risk they take. This objective was accomplished on the basis of the survey with the participation of Polish SMEs. In order to test the adopted research assumptions, the linear regression model was used with four continuous variables for each type of the identified financial risk. Based on the final research results, the logit model was obtained for the risk of insufficient profits. It was indicated that both the internationalization of the company and the ability to manage risk are the only factors that affect a high level of risk of low income. The article ends with the discussion and the comparison with some previous research in this area.

Description: We consider a two-dimensional ruin problem where the surplus process of business lines is modelled by a two-dimensional correlated Brownian motion with drift. We study the ruin function P ( u ) for the component-wise ruin (that is both business lines are ruined in an infinite-time horizon), where u is the same initial capital for each line. We measure the goodness of the business by analysing the adjustment coefficient, that is the limit of − ln P ( u ) / u as u tends to infinity, which depends essentially on the correlation ρ of the two surplus processes. In order to work out the adjustment coefficient we solve a two-layer optimization problem.

Description: Warm-season turfgrass species prevail in tropical and subtropical areas, but can also be grown in the transition zone. In this case, cold tolerance is a key aspect for germination and successful turfgrass establishment. The germination response to sub-optimal temperatures was investigated for Cynodon dactylon (cvs Jackpot, La Paloma, Transcontinental, Yukon, Riviera), Buchloe dactyloides (cv SWI 2000) and Paspalum vaginatum (cv Pure Dynasty). Four temperature regimes were applied, i.e., 20/30 °C, 15/25 °C, 10/20 °C and 5/15 °C, with a 12:12 h (light:dark) photoperiod. Germination assays were performed twice, with six replicates (Petri dishes) per treatment in each experiment, fifty seeds per dish. The final germinated percentages at last inspection time (FGP) were obtained for each Petri dish and processed by using a generalized linear mixed model (binomial error and logit link). Germination curves were fitted to each Petri dish by using time-to-event methods and germination rates (GR) for the 10th, 20th and 30th percentiles were derived and used to fit a linear thermal-time model. For all cultivars, FGP decreased with decreasing mean daily temperatures. Base temperatures (Tb) ranged between 11.4 °C and 17.0 °C, while the thermal time to obtain 30% germination ranged from 51.3 °C day for SWI 2000 to 144.0 °C day for Pure Dynasty. The estimated parameters were used to predict germination time in the field, considering the observed soil temperatures in Legnaro. The estimated date for the beginning of germination in the field would range from early April for SWI 2000 and Transcontinental to mid-May for Riviera. These results might be used as a practical support for planning spring sowing, which is crucial for successful turfgrass establishment, especially without irrigation.

Description: Terminal drought greatly enhanced Aspergillus flavus Link infection (AI) and aflatoxin contamination (AC) in peanut. Identification of new surrogate traits which have an association with AC may be effective to improve peanut varieties with reduced AI and AC. The objective of this work was to examine the relationships of nutrient uptake and N2-fixation (NF) with AC in peanut in a terminal drought condition. Five peanut varieties were tested in well-watered (WW) and terminal drought (TD) conditions (1/3 available water (AW) from R7 (7th reproductive growth stage; beginning of pod maturity stage)). Data were collected for nutrient uptake (nitrogen, phosphorus, potassium, calcium, magnesium), nodule dry weight (NDW), and NF. AI and AC were also examined. Nutrient uptake, NDW, and NF had negative and significant correlations with AI and AC in the TD condition. Negative and significant correlations of the drought tolerance index of nutrient uptake, NDW, and NF with AI and AC were also observed in the TD condition. The results showed that the ability to maintain nutrient uptake and NF in TD might be a mechanism of tolerance to AI and AC. Moreover, due to their negative impacts on AI and AC, nutrient uptake and NF could be used as selection traits for resistance to AI and AC in peanut in TD.

Description: Red rice (O. sativa) is one the most prevalent and damaging weed problems in direct seeding rice systems worldwide and can cause significant losses in rice productivity and quality. Red rice has been a problem in the United States for decades, and it is a growing problem in Asia, where 90 percent of the global rice production occurs. Unlike for other crops, where genetically engineered (GE) herbicide tolerant varieties are available, to date, Clearfield (CL) and Provisia rice are the only technologies available to selectively control red rice using chemical herbicides in commercial rice fields. We develop a counterfactual scenario without CL rice and ascertain the yield and quality losses due to red rice infestation in the Mid-South of the United States. Our findings suggest that even with the higher costs of CL rice, relative to non-CL rice, that the returns are $0.15, $0.36, and $0.54 more for every dollar invested than non-CL rice with a light, moderate, and heavy initial red rice infestation rate, respectively. These results imply that the higher upfront costs for CL rice are offset by more than proportional higher profits relative to their non-CL rice counterparts.

Description: According to the assumptions of Organisation for Economic Co-operation and Development OECD, the share of biofuels in the global transport sector is estimated to reach 15–23% by 2050. The triticale can be used to produce bioethanol. The appropriate production process should generate as much renewable energy as possible per production unit. Plant production can be carried out in various tillage systems and using appropriate doses of nitrogen fertilization. The objective of this study is to compare the effect of traditional tillage system (TRD) and reduced (RED) tillage technology and nitrogen fertilizer (0, 40, 80, 120 kg N ha−1) on grain and bioethanol yield of spring triticale. The field experiment was performed in the south east of Poland (50°42′ N, 23°15′ E) on medium dystrophic typical brown soil. Based on research and calculations, the TRD system and between 40 and 80 kg ha−1 of N fertilizer are recommended for use in the cultivation of triticale for bioethanol production purposes. Such a variant will ensure a sufficient yield of grain (5.190 and 5.803 t ha−1), starch (3.462 and 3.871 t ha−1) and bioethanol (2487.3 and 2780.7 L ha−1) and good agronomic efficiency of N fertilizer (16.96 and 12.15 L of bioethanol per 1 kg of nitrogen (N) applied). The best ratio of energy efficiency of bioethanol production (EROI—Energy Return on (Energy) Investment or “net energy”) was recorded for the TRD system (1.138:1) and for the N fertilizer at 40 kg N ha−1 (1.144:1).

Description: Since the 2008–2009 financial crisis, banks have introduced a family of X-valuation adjustments (XVAs) to quantify the cost of counterparty risk and of its capital and funding implications. XVAs represent a switch of paradigm in derivative management, from hedging to balance sheet optimization. They reflect market inefficiencies that should be compressed as much as possible. In this work, we present a genetic algorithm applied to the compression of credit valuation adjustment (CVA), the expected cost of client defaults to a bank. The design of the algorithm is fine-tuned to the hybrid structure, both discrete and continuous parameter, of the corresponding high-dimensional and nonconvex optimization problem. To make intensive trade incremental XVA computations practical in real-time as required for XVA compression purposes, we propose an approach that circumvents portfolio revaluation at the cost of disk memory, storing the portfolio exposure of the night so that the exposure of the portfolio augmented by a new deal can be obtained at the cost of computing the exposure of the new deal only. This is illustrated by a CVA compression case study on real swap portfolios.

Description: Tamarix spp. are ecological threats in the Southwest U.S.A. because they displace native vegetation, increase soil salinity, and negatively affect soil microbial communities. After Tamarix L. removal, legacy effects often necessitate restoration to improve ecosystem services of Tamarix-impacted communities. Commercial mycorrhizae fungal inoculation has been recommended to improve restoration success, although inoculation treatments are rarely tested on lesser-known facultative riparian species. Our study asked two questions: (1) Can a commercial mycorrhizal fungal inoculant increase native Baccharis salicifolia (Ruiz & Pav.) Pers. (mule-fat) performance against Tamarix chinensis Lour. (i.e., tamarisk) and is this influenced by tamarisk leaf litter? (2) Is mycorrhizal colonization of mule-fat roots influenced by tamarisk stem density and leaf litter? A greenhouse experiment was performed with mule-fat cuttings in soil collected from a tamarisk monoculture. Treatments were factorial combinations of tamarisk stem densities (0, 1, 2, 3, 4 stems pot−1) with or without mycorrhizal inoculation and tamarisk litter. There were five replications and two greenhouse runs. The total biomass of both species was determined and mule-fat arbuscular mycorrhizal colonization rates were determined via the magnified intersection method. Increasing tamarisk biomass negatively affected mule-fat biomass, but there were interactions with tamarisk biomass, litter and mycorrhizal inoculation, with litter and inoculation increasing mule-fat growth at high tamarisk biomass. Arbuscular mycorrhizal colonization was high in all treatments, yet at higher tamarisk stem densities, inoculation and litter improved colonization. Interestingly, litter did not negatively impact mule-fat as predicted. Moreover, litter and mycorrhizal inoculum interacted with tamarisk to improve mule-fat growth at higher tamarisk biomass, suggesting an opportunity to improve restoration success when in competition with tamarisk.

Description: The productivity of maize in Ethiopia has remained lower than the world average because of several biotic and abiotic factors. Stemborers and poor soil fertility are among the main factors that contribute to this poor maize productivity. A novel cropping strategy, such as the use of push-pull technology, is one of the methods known to solve both challenges at once. A push-pull technology targeting the management of maize stemborers was implemented in the Hawassa district of Ethiopia with the ultimate goal of increased food security among smallholder farmers. This study evaluated farmers’ perception of push-pull technology based on their experiences and observations of the demonstration plots that were established on-farm in Dore Bafano, Jara Gelelcha and Lebu Koremo village of the Hawasa district in 2016 and 2017. This study examined farmers’ perception of the importance of push-pull technology in controlling stemborers and improving soil fertility and access to livestock feed. In both cropping seasons, except for Jara Gelelcha, the maize grain yields were significantly higher in the climate-adapted push-pull plots compared to the maize monocrop plots. The majority (89%) of push-pull technology-practising farmers rated the technology better than their maize production methods on attributes such as access to new livestock feed and the control of stemborer damage. As a result, approximately 96% of the interviewed farmers were interested in adopting the technology starting in the upcoming crop season. Awareness through training and effective dissemination strategies should be strengthened among stakeholders and policymakers for the sustainable use and scaling-up of push-pull technology.

Description: Use of saline water for irrigation is essential to mitigate increasing agricultural water demands in arid and semi-arid regions. The objective of this study is to address the potential of using straw biochar as a soil amendment to promote wheat production under saline water irrigation. A field experiment was conducted in a clay loam soil from eastern China during 2016/2017 and 2017/2018 winter wheat season. There were five treatments: freshwater irrigation (0.3 dS m−1), saline water irrigation (10 dS m−1), saline water irrigation (10 dS m−1) combined with biochar of 10, 20, 30 t ha−1. Saline water irrigation alone caused soil salinization and decreased wheat growth and yield. The incorporation of biochar decreased soil bulk density by 5.5%–11.6% and increased permeability by 35.4%–49.5%, and improved soil nutrient status. Biochar also reduced soil sodium adsorption ratio by 25.7%–32.6% under saline water irrigation. Furthermore, biochar alleviated salt stress by maintaining higher leaf relative water content and lower Na+/K+ ratio, and further enhanced photosynthesis and relieved leaf senescence during reproductive stages, leading to better grain formation. Compared to saline water irrigation alone, biochar application of 10 and 20 t ha−1 significantly increased wheat grain yield by 8.6 and 8.4%, respectively. High dose of biochar might increase soil salinity and limit N availability. In the study, biochar amendment at 10 t ha−1 would be a proper practice at least over two years to facilitate saline water irrigation for wheat production. Long-term studies are recommended to advance the understanding of the sustainable use of straw biochar.

Description: Chokeberry (Aronia melanocarpa L.) contains a large number of bioactive compounds, which make of it a highly nutritional and antioxidant food with anti-cancer and anti-inflammatory properties. It has been recently seen its consumption increased because of its interesting composition and properties as a functional food. The ultrasound-assisted extraction method has been optimized, since it is a simple and fast technique to extract phenolic compounds, as well as anthocyanins, not only separately but also simultaneously. Multiple response has been optimized and demonstrated an effectiveness level similar to the individual ones. This represents a considerable reduction in costs, time and work. The optimal conditions for simultaneous extractions were: 54% methanol as extraction solvent at pH 2.72 and 69.4 °C temperature, 70% amplitude, 0.7 s cycle, and 0.5:18.2 g:mL sample mass/solvent volume ratio. The developed methods showed a high precision level with coefficients of variation lower than 5%. The methods were successfully applied to commercial samples. Additionally, the extraction of other compounds of biological interest, such as organic acids and sugars, was also studied.

Description: In Chile, durum wheat is cultivated in high-yielding Mediterranean environments, therefore breeding programs have selected cultivars with high yield potential in addition to grain quality. The genetic progress in grain yield (GY) between 1964 and 2010 was 72.8 kg ha−1 per year. GY showed a positive and significant correlation with days to heading, kernels per unit ground area and thousand kernel weight. The gluten and protein content tended to decrease with the year of cultivar release. The correlation between the δ13C of kernels and GY was negative and significant (−0.62, p 〈 0.05, for all cultivars; and −0.97, p 〈 0.001, excluding the two oldest cultivars). The yield progress (genetic plus agronomic improvements) of a set of 40–46 advanced lines evaluated between 2006 and 2015 was 569 kg ha−1 per year. Unlike other Mediterranean agro-environments, a longer growing cycle together with taller plants seems to be related to the increase in the GY of Chilean durum wheat during recent decades.

Description: Optimal manure management can maximize agronomic benefits and minimize environmental impacts. Field experiments were conducted in the Pacific Northwest (Vancouver, Canada) to determine how chicken and horse manures that were fall-applied to meet nitrogen crop demand affect soil ammonium (NH4+) and nitrate (NO3−), apparent net mineralization (ANM) and nitrification (ANN), crop biomass and nutrient concentration, and fluxes of nitrous oxide (N2O), carbon dioxide (CO2), and methane (CH4). Relative to horse manure, chicken manure increased soil NH4+ by 60-fold, ANM by 2-fold, and ANN by 4-fold. Emissions of N2O (+600%) and CO2 (+45%) were greater and growing season CO2 emissions (−40%) were lower after application of chicken than horse manure. Productivity of cover crop (+30%), legume cover crop (−25%), and squash cash crop (+20%) were affected by chicken relative to horse manure. Overall, fall-applied chicken manure increased yields, N availability, and environmental impacts relative to horse manure.

Description: The burdens of malnutrition, protein and micronutrient deficiency, and obesity cause enormous costs to society. Crop nutritional quality has been compromised by the emphasis on edible yield and through the loss of biodiversity due to the introduction of high-yielding, uniform cultivars. Heirloom crop cultivars are traditional cultivars that have been grown for a long time (〉50 years), and that have a heritage that has been preserved by regional, ethnic, or family groups. Heirlooms are recognized for their unique appearance, names, uses, and historical significance. They are gaining in popularity because of their unique flavors and cultural significance to local cuisine, and their role in sustainable food production for small-scale farmers. As a contrast to modern cultivars, heirlooms may offer a welcome alternative in certain markets. Recently, market channels have emerged for heirloom cultivars in the form of farmer–breeder–chef collaborations and seed-saver organizations. There is therefore an urgent need to know more about the traits available in heirloom cultivars, particularly for productivity, stress tolerance, proximate composition, sensory quality, and flavor. This information is scattered, and the intention of this review is to document some of the unique characteristics of heirloom cultivars that may be channeled into breeding programs for developing locally adapted, high-value cultivars.

Description: Acid soils and associated Al3+ toxicity are prevalent in Ethiopia where normally Al3+-sensitive durum wheat (Triticum turgidum ssp durum Desf.) is an important crop. To identify a source of Al3+ tolerance, we screened diverse Ethiopian durum germplasm. As a center of diversity for durum wheat coupled with the strong selection pressure imposed by extensive acid soils, it was conceivable that Al3+ tolerance had evolved in Ethiopian germplasm. We used a rapid method on seedlings to rate Al3+ tolerance according to the length of seminal roots. From 595 accessions screened using the rapid method, we identified 21 tolerant, 180 intermediate, and 394 sensitive accessions. When assessed in the field the accessions had tolerance rankings consistent with the rapid screen. However, a molecular marker specific for the D-genome showed that all accessions rated as Al3+-tolerant or of intermediate tolerance were hexaploid wheat (Triticum aestivum L.) that had contaminated the durum grain stocks. The absence of Al3+ tolerance in durum has implications for how Al3+ tolerance evolved in bread wheat. There remains a need for a source of Al3+-tolerance genes for durum wheat and previous work that introgressed genes from bread wheat into durum wheat is discussed as a potential source for enhancing the Al3+ tolerance of durum germplasm.

Description: The availability of big data in agriculture, enhanced by free remote sensing data and on-board sensor-based data, provides an opportunity to understand within-field and year-to-year variability and promote precision farming practices for site-specific management. This paper explores the performance in durum wheat yield estimation using different technologies and data processing methods. A state-of-the-art data cleaning technique has been applied to data from a yield monitoring system, giving a good agreement between yield monitoring data and hand sampled data. The potential use of Sentinel-2 and Landsat-8 images in precision agriculture for within-field production variability is then assessed, and the optimal time for remote sensing to relate to durum wheat yield is also explored. Comparison of the Normalized Difference Vegetation Index(NDVI) with yield monitoring data reveals significant and highly positive linear relationships (r ranging from 0.54 to 0.74) explaining most within-field variability for all the images acquired between March and April. Remote sensing data analyzed with these methods could be used to assess durum wheat yield and above all to depict spatial variability in order to adopt site-specific management and improve productivity, save time and provide a potential alternative to traditional farming practices.

Description: Kura clover living mulch (KCLM) systems have been previously investigated for their incorporation into upper Midwestern row crop rotations to provide ecosystem services through continuous living cover. Reductions in soil erosion and nitrate loss to surface and groundwater have been reported, but factors affecting agronomic performance and nutrient management are not well defined. To achieve realized environmental benefits, research must develop agronomic management techniques, determine economic opportunities, and provide management recommendations for row crop production in KCLM systems. Two experiments were conducted in 2017 and 2018 to determine the response to N fertilizer application for maize production in KCLM. The first-year maize experiment followed forage management, and the second-year maize experiment followed maize after forage management. Eight fertilizer N treatments ranging from 0–250 kg N ha−1 were applied to each experiment and grain and stover yields were compared to conventionally managed maize hybrid trials that were conducted nearby. First-year maize did not need fertilizer N to maximize yield and profitability in either growing season, and second-year maize required a fertilizer N rate near local University guidelines for maize following soybean. The net economic return from maize grain and stover in the KCLM averaged over first and second-year maize experiments and 2017 and 2018 growing seasons were $138 ha−1 greater than the conventional comparison.

Description: The agricultural area in the Po Valley is prone to high nitrous oxide (N2O) emissions as it is characterized by irrigated maize-based cropping systems, high amounts of nitrogen supplied, and elevated air temperature in summer. Here, two monitoring campaigns were carried out in maize fertilized with raw digestate in a randomized block design in 2016 and 2017 to test the effectiveness of the 3, 4 DMPP inhibitor Vizura® on reducing N2O-N emissions. Digestate was injected into 0.15 m soil depth at side-dressing (2016) and before sowing (2017). Non-steady state chambers were used to collect N2O-N air samples under zero N fertilization (N0), digestate (D), and digestate + Vizura® (V). Overall, emissions were significantly higher in the D treatment than in the V treatment in both 2016 and 2017. The emission factor (EF, %) of V was two and four times lower than the EF in D in 2016 and 2017, respectively. Peaks of NO3-N generally resulted in N2O-N emissions peaks, especially during rainfall or irrigation events. The water-filled pore space (WFPS, %) did not differ between treatments and was generally below 60%, suggesting that N2O-N emissions were mainly due to nitrification rather than denitrification.

Description: This paper revisits the spectrally negative Lévy risk process embedded with the general tax structure introduced in Kyprianou and Zhou (2009). A joint Laplace transform is found concerning the first down-crossing time below level 0. The potential density is also obtained for the taxed Lévy risk process killed upon leaving [ 0 , b ] . The results are expressed using scale functions.

Description: Although compost and biochar received high attention as growing media, little information is available on the potential of vineyard by-products for the production and use of composted solid digestate (CSD) and biochar (BC). In the present study, two experiments are reported on CSD and BC mixed with commercial peat (CP) for grapevine planting material production. Four doses (0, 10%, 20%, 40% vol.) of CSD and BC were assessed in the first and second experiment, respectively. CSD mixed at a dose of 10% recorded the highest values of shoot dry weight (SDW) and a fraction of total dry biomass allocated to shoot (FTS), both cropping bench-graft and bare-rooted vine. On the other hand, CSD mixed at a dose of 40% displayed the highest values of SDW and FTS, cropping two-year-old vine. BC used at a dose of 10% improved SDW, root dry weight, total dry weight, FTS, shoot diameter, and height on bare-rooted vine. The present study shows that CSD and BC, coming from the valorization of vineyard by-products, can be used in the production of innovative growing media suitable for nursery grapevine production. Further studies are needed to assess the combined applications of CSD and BC in the same growing media.

Description: The application of nitrification inhibitors (NIs) shows promise in prolonging the ammonium presence in soil with beneficial effects for agriculture ecosystems and climate change mitigation. Although the inhibitory effect (IE) of NIs has been studied in the presence of various environmental and edaphic conditions, little is known about the effect of soil nitrification potential (NP) on the effectiveness of NIs. Here, laboratory-scale experiments were conducted to investigate the effect of the variation in soil NP rates, among land-use type and temperature, on the performance of two nitrification inhibitors, dicyandiamide (DCD) and 3,4-dimethypyrazole phosphate (DMPP), at four NI application rates imposed upon eight cropland and non-cropland soils. We found that the IE of DCD and DMPP were organized according to soil NP rates. Nevertheless, NP was lower in non-cropped soil than in cropped systems, and DMPP-based inhibition was higher than DCD. The IE of both NIs decreased with NP and the amount of NI required to achieve an IE ≈ 50%, was significantly reduced for soils that exhibited the lowest NP rates, especially for DMPP. However, the temperature did not appear to have a major influence on IE of both DCD and DMPP, demonstrating the potential of NIs to inhibit nitrification for a wider temperature range, dependent on the NI application rate. Our findings provide evidence that change in soil NP rate has important influences on the efficacy of NI which required great consideration for N-fertilizer optimization with the application of nitrification inhibitors.

Description: This study investigated the influence of biological control agents and plant growth promoters on the chemical composition of the cultivars Panda and Kora buckwheat sprouts. Before sowing, seeds were soaked in solutions containing Bacillus subtilis bacteria, Pythium oligandrum oospores, Ecklonia maxima algae extract, and/or nitrophenols. The sprouts of the Panda displayed higher levels of protein, fat, and dietary fiber fractions than the Kora. Measurable effects of biological control agents (BCAs) and plant growth promoters (PGPs) on the chemical composition of sprouts were also confirmed. Soaking the seeds in a solution containing P. oligandrum oospores resulted in a decrease in the level of crude ash in sprouts, while the addition of nitrophenols increased the level of both crude ash and protein. We also found statistically significant effects of interactions between the cultivar and BCA and/or PGP for each of the examined components.

Description: During biogas production anaerobic digestion of plant material produces a nutrient-rich residue called digestate. The application of the nutrients present in the digestate should improve soil fertility, particularly in nutrient poor soils, and thus crop yield, promoting the closure of the nutrient cycle. This study evaluated the effect of digestate application on the germination and early stages of plant development since these are the first steps to be considered when studying the benefits on plant growth in low fertility substrates. A greenhouse experiment was conducted to evaluate the effects of three substrates of different texture and fertility (field loam, field sand, sand), as well as type and amount of fertilizer (pure maize digestate vs. inorganic nitrogen/phosphorus/potassium (NPK) fertilizer) on both germination and early plant performance of maize (Zea mays L. subsp. mays). While digestate and NPK fertilizer applications had no significant effect on germination in the two field soils, digestate applications significantly decreased the germination rate in sand (36–82% reduction) due to an increase of surface water repellency. In contrast, for aboveground biomass yield, the most positive fertilization effects of digestate application were found on sand (up to 3.5 times the biomass of the unamended control) followed by field sand (1.5 times), compared to no effect for field loam. Our findings suggest that digestate application have positive fertilization effects in low-fertility substrates, similar to NPK, even though digestate application may have a negative impact on the permeability in sandy substrates that could interfere with germination.

Description: Citrus bacterial canker (CBC), caused by the plant pathogenic bacterium Xanthomonas citri subsp. citri (Xcc), is a devastating disease in many commercial citrus cultivars. Every year, CBC causes a substantial reduction in fruit quality and quantity that corresponds to significant economic losses worldwide. Endophytic microorganisms produce numerous bioactive secondary metabolites that can control plant pathogens. We investigated the antagonistic activities of 66 endophytic bacteria isolated from nine citrus cultivars to control streptomycin-resistant Xcc. The suspension of Endophytic Bacteria-39 (EB-39), identified as Bacillus velezensis, exhibited the highest antibacterial activity against three wild-type and six streptomycin-resistant Xcc strains, with the inhibition zones between 39.47 ± 1.6 and 45.31 ± 1.6 mm. The ethyl acetate extract of EB-39 also controlled both wild-type and streptomycin-resistant Xcc strains, with the inhibition zones between 29.28 ± 0.6 and 33.88 ± 1.3 mm. Scanning electron microscopy indicated the ethyl acetate extract of EB-39-induced membrane damage and lysis. The experiments using the detached leaves of a susceptible Citrus species showed that EB-39 significantly reduced the incidence of canker on the infected leaves by 38%. These results strongly suggest that our newly isolated EB-39 is a novel biocontrol agent against CBC caused by wild-type and streptomycin-resistant Xcc strains.

Description: Although arbuscular mycorrhizal (AM) fungi are known to promote growth and yield of agricultural crops, inoculation methods for effective scaling up from greenhouse to the field are still underexplored. The application of single or mixed beneficial AM fungal isolates is hindered by the lack of experimental reproducibility of findings at different scales and the cost-effectivity of inoculation methods. Seed coating has been considered a feasible delivery system of AM fungal inocula for agricultural crops. In this study, the impact of single and multiple AM fungal isolates applied via seed coating on chickpea productivity was evaluated under greenhouse and field conditions. Overall, plants inoculated with multiple AM fungal isolates had better performance than those inoculated with single AM isolate under greenhouse and field conditions. While plants in greenhouse displayed higher shoot dry weight (14%) and seed individual weight (21%), in field, inoculation with multiple AM isolates increased pod (160%), and seed (148%) numbers, and grain yield (140%). Under field conditions, mycorrhizal root colonization was significantly higher in chickpea plants inoculated with multiple AM fungal isolates compared to other treatments. These findings highlight the potential of field-inoculation with multiple AM fungal isolates via seed coating as a sustainable agricultural practice for chickpea production.

Description: The rice production system in Japan is changing due to the aging of rice farmers, shortage of labor, mechanization, and increase of large-scale rice fields and increased application of direct sowing, all of which contribute to the lack of sophisticated weed management practices. Because the changing production system has not improved and likely worsened weed management practices, weedy rice (Oryza sativa L.) has become a serious threat to rice production in Japan. We analyzed weedy rice accessions from Nagano, the central part of Japan, and other rice accessions to elucidate the origin of this weedy rice using a whole-genome single nucleotide polymorphism (SNP) array. For developing sustainable weedy rice management practices, the elucidation of the origin of re-emerging weedy rice is crucial. Population genetic analysis indicated that weedy rice in Nagano was phylogenetically independent from the local red rice cultivar with low genetic diversity. Past and recently re-emerging weedy rice ecotypes in Nagano shared a similar genetic background which implies the evolution of weedy rice by severe natural selection. Window-based FST and selection sweep analysis revealed the divergence of some of the known key domestication-related genes, such as shattering gene sh4 and qsh1, of weedy rice from domesticated rice cultivars.

Description: Crop residues are an important source of plant nutrients. However, information on the various methods of residue management on micronutrients in soil and wheat (Triticum aestivum L.) over time is limited. A long-term (84-year) agroecosystem experiment was assessed to determine the impact of fertilizer type and methods of crop residue management on micronutrients over time under dryland winter wheat-fallow rotation. The treatments were: no N application with residue burning in fall (FB), spring (SB), and no residue burn (NB); 45 kg N ha−1 with SB and NB; 90 kg N ha−1 with SB and NB; pea vines; and farmyard manure (FYM) and a nearby undisturbed grass pasture (GP). Wheat grain, straw, and soil samples from 1995, 2005, and 2015 were used to determine tissue total and soil Mehlich III extractable Mn, Cu, B, Fe, and Zn, and soil pH. After 84 years, extractable Mn and B in the top 10 cm of soil decreased in all plots, except for B in FYM and SB. The FYM plots had the highest extractable Mn (114 mg kg−1) in the top 10 cm soil; however, it declined by 33% compared to the GP (171 mg kg−1). Extractable Zn in the top 10 cm of soil increased with FYM while it decreased with inorganic N application in 2015; however, total Zn in grain increased by 7% with inorganic N (90 kg ha−1) application compared to FYM application. The results suggest that residue management had similar impact on soil micronutrients. Inorganic N and FYM application can be integrated to reduce micronutrient losses from cultivation.

Description: The tropical multiuse tree Jatropha curcas L. (jatropha) is highly promoted as oilseed crop for biodiesel production and for climate change mitigation, but cultivation practices require further research. The objectives of this study were to assess the effects of varying plant spacings (2.0 m × 4 m compared to 1.5 m × 4 m), crop establishment methods (raising plantlets in a nursery prior to planting to the field compared to direct sowing) and genotypes on seed yield, seed quality and plant height, recorded at a dry-subhumid location in Madagascar (Ihosy) and at a humid location in Cameroon (Batchenga). Averaged across treatment variants and genotypes, seed yield and seed oil content were higher at the dry-subhumid site and in particular the narrower spacing reached higher seed yields per unit area than the wider spacing. At the humid site, plant growth was characterized by strong accumulation of biomass. The establishment method tested at the dry-subhumid site showed no significant differences in the recorded parameters. Our results encourage to re-think common practices in jatropha cultivation and underpin the importance of the correct choice of location, genotype and agronomic practices considering the interactions between all factors.

Description: In New Zealand, pastoral farming for dairy and meat production is the major land use. As with any agricultural production system, weeds are a threat to efficient pasture production in New Zealand. In this review, we outline the problems caused by weeds in New Zealand pastures, and the management strategies being used to control them. There are currently 245 plant species from 40 plant families that are considered to be troublesome weeds in New Zealand pastures. The application of herbicides is an important approach to manage weeds in New Zealand pastures; however, a key to the success of these pastures is the use of clovers in combination with the grasses, so the challenge is to find herbicides that selectively control weeds without damaging these legumes. The use of spot spraying and weed wiping are often required to ensure selective control of some weed species in these pastures. Non-chemical agronomic approaches such as grazing management and using competitive pasture species often play a more important role than herbicides for weed management in many New Zealand pastures. Thus, integrated weed management using a combination of herbicides and good pasture management strategies leads to the most cost-effective and efficient control of pasture weeds in New Zealand.

Description: The main aim of this study is to identify and investigate specific humates (Hs) as potential biostimulants. Five specialty lignosulfonates (LS1-5), one commercial leonardite-humate (PH), and one commercial lignosulfonate (LH), were analyzed for their carbon, nitrogen, and sulfur contents, and the distribution of functional groups using Fourier transform infrared (FTIR) and Raman spectroscopies. Hs were further supplied for two days to Zea mays L. in hydroponics to test their capacity to trigger changes in physiological target-responses. LS1, LS2, LS3, and LS5 determined the most pronounced effects on plant growth and accumulation of proteins and phenolics, perhaps because of their chemical and spectroscopic features. Root growth was more increased (+51–140%) than leaf growth (+5–35%). This effect was ascribed to higher stimulation of N metabolism in roots according to the increased activity of N-assimilation enzymes (GS and GOGAT) and high consumption of sugars for energy-dependent processes. Increased values of RuBisCO, SPAD (Soil Plant Analysis Development values), and leaf sugar accumulation refer to enhanced photosynthesis attributed to Hs. We conclude that Hs tested in this study functioned as biostimulants, but the specialty lignosulfonates were more efficient in this role, possibly because of the type of starting material and process used for their production, which may have influenced their chemical properties.

Description: Dutch bucket hydroponic trials were conducted with the aim to evaluate the effects of different hydroponic fertilizers (5N-4.8P-21.6K, 5N-5.2P-21.6K, and 7N-3.9P-4.1K) on growth, fruit production, and the fruit quality (fruit shape index) parameters of two cultivars of sweet pepper (Capsicum annuum L.) and on two cultivars of eggplant (Solanum melongena L.). For sweet pepper yield, the 5N-4.8P-21.6K fertilizer was responsible for the greatest yield for both cultivars. For sweet pepper fresh and dry shoot weight interaction, the ‘Orangella’ cultivar had greater growth in 5N-4.8P-21.6K and 5N-5.2P-21.6K fertilizers, whereas there was no difference among cultivars in 7N-3.9P-4.1K. Shape index was not affected by fertilizers or cultivars. For the eggplant yield, there was no main effect nor interaction between fertilizers and cultivars for fruit yield, while the interaction between fertilizers and cultivars was significant for shoot fresh weight production. Shoot fresh weight was greater for ‘Angela’ than ‘Jaylo’ in 5N-4.8P-21.6K and 7N-3.9P-4.1K. Furthermore, both eggplant cultivars were affected with yellowing of fruits in all fertilizer treatments after 2 months, which was probably due to the accumulation of nutrients in the closed hydroponic system. Therefore, hydroponic producers could select 5N-4.8P-21.6K and 5N-5.2P-21.6K fertilizers for the cultivation of the ‘Orangella’ cultivar of sweet pepper based on yield. It is important to evaluate more fertilizers and cultivars for eggplant hydroponic cultivation.

Description: We obtain closed-form expressions for the value of the joint Laplace transform of the running maximum and minimum of a diffusion-type process stopped at the first time at which the associated drawdown or drawup process hits a constant level before an independent exponential random time. It is assumed that the coefficients of the diffusion-type process are regular functions of the current values of its running maximum and minimum. The proof is based on the solution to the equivalent inhomogeneous ordinary differential boundary-value problem and the application of the normal-reflection conditions for the value function at the edges of the state space of the resulting three-dimensional Markov process. The result is related to the computation of probability characteristics of the take-profit and stop-loss values of a market trader during a given time period.

Description: The Growth-Optimal Portfolio (GOP) theory determines the path of bet sizes that maximize long-term wealth. This multi-horizon goal makes it more appealing among practitioners than myopic approaches, like Markowitz’s mean-variance or risk parity. The GOP literature typically considers risk-neutral investors with an infinite investment horizon. In this paper, we compute the optimal bet sizes in the more realistic setting of risk-averse investors with finite investment horizons. We find that, under this more realistic setting, the optimal bet sizes are considerably smaller than previously suggested by the GOP literature. We also develop quantitative methods for determining the risk-adjusted growth allocations (or risk budgeting) for a given finite investment horizon.

Description: In soybean production, the shade avoidance response can affect yield negatively in both mono- and inter-cropping systems due to increased heterogeneity of the crop and lodging. This is mainly regulated by photoreceptors responding to the ratio between red and far-red light (R:FR) and photosynthetic photon flux density (PPFD). In this study, three soybean cultivars were grown under different R:FR and PPFD in a light emitting diode (LED) climate chamber to disentangle the effect of each on morphology and dry matter. Results showed that plant organs were influenced differently and indicated an interaction with the increase in assimilates at high PPFD. Internode elongation was mainly influenced by low PPFD with an additive effect from low R:FR, whereas petiole elongation responded strongly under low R:FR. Hence, petiole elongation can be seen as the main response to the threat of shade (high PPFD and low R:FR) and both petiole and internode elongation as a response to true shade (low PPFD and low R:FR). Interactions between cultivar and light treatment were found for internode length and diameter and leaf mass ratio, which may be unique properties for specific cropping systems.

Description: Future climatic conditions might have severe effects on grapevine architecture, which will be highly relevant for vineyard management decisions on shoot positioning, pruning or cutting. This study was designed to help gaining insight into how, in particular, increasing temperatures might affect grapevine canopies. We developed a functional-structural model for Riesling, Virtual Riesling, based on digitised data of real plants and a comprehensive state-of-the-art data analysis. The model accounts for the variability in temperature-sensitive morphological processes, such as bud break and appearance rates. Our simulation study using historical weather data revealed significant effects of the thermal time course over the year on bud burst of the cane and on primary shoots. High variabilities in these events affect canopy growth and leaf area distribution. This report shows that Virtual Riesling can be useful in assessing the significance of changing temperatures for grapevine architecture and thereby considering management techniques such as vertical shoot positioning. Further developments of Virtual Riesling might support the knowledge gain for developing necessary adaptations in future vineyard management and, thus, facilitate future work on climate change research using functional-structural model approaches.

Description: Intermediate wheatgrass (IWG, Thinopyrum intermedium, (Host) Barkworth & D.R. Dewey subsp. intermedium, 2n = 6x = 42) is a novel perennial crop currently undergoing domestication efforts. It offers remarkable ecosystem services and yields higher relative to other perennial grain crops. While IWG is mostly resistant to Fusarium head blight (FHB), identifying genomic regions associated with resistance will help protect the crop from potential disease epidemics. An IWG biparental population of 108 individuals was developed by crossing parents differing in their response to FHB and bacterial leaf streak (BLS). The population was screened for disease reaction over three years using isolates collected from IWG plants in St. Paul, Minnesota, USA. Linkage maps representing the 21 IWG chromosomes were constructed from 4622 Single Nucleotide Polymorphism (SNP) markers, with one SNP at every 0.74 cM. Interval mapping identified 15 quantitative trait loci (QTL) associated with FHB resistance and 11 with BLS resistance. Models with two or three QTL combinations reduced FHB disease severity by up to 15%, and BLS by up to 17%. When markers associated with FHB resistance were used as cofactors in genomic selection models, trait predictive ability improved by 24–125%. These genomic regions and genetic markers associated with FHB and BLS resistance can also be used to safeguard annual cereal grains through gene introgression and selective breeding.