ALBERT

Description: Trees are essential natural resources for ecosystem balance, regional development, and urban greening. Preserving trees has become a crucial challenge for society. It is common for the use of invasive or even destructive techniques for health diagnosis of these living structures, and interventions after visual inspection. Therefore, the dissemination and implementation of increasingly less aggressive techniques for inspection, analysis and monitoring techniques are essential. The latest high-definition thermal cameras record thermal images of high resolution and sensitivity. Infrared thermography (IRT) is a promising technique for the inspection of trees because the tissue of the sap is practically on the surface of the living structure. The thermograms allow the identification of deteriorated tissues and to differentiate them from healthy tissues, and make an observation of the tree as a functional whole body. The aim of this study is to present, based on differences in the temperatures field given by the thermal images, a qualitative analysis of the status of two different arboreal species, Quercus pyrenaica Willd and Olea europaea L. The results show the IRT as an expeditious, non-invasive and promising technique for tree inspection, providing results that are not possible to reach by other methods and much less by a visual inspection. The work represents a contribution to make IRT a tree decision-making tool on the health status of trees.

Description: Scarcity of good-quality irrigation water is a major impediment to meet food demand for a growing world population. Recycled waters may be available locally more affordably, but their higher salinity is a concern. Salinity effects on spinach mineral composition, antioxidant capacity, photosynthesis, and gene expression have not been established. Spinach cv. Raccoon was greenhouse-grown and irrigated with four levels of water salinity of electrical conductivities (ECiw) of 1.4 (control) or ranging from 3.6 to 9.4 dS m−1, combined with three levels of K (3, 5, and 7 meq L−1). Irrigation waters had 2, 20, 40, and 80 meq L−1 of NaCl. After 23 treatment days, plants significantly accumulated Na and Cl in shoots and roots with increasing salinity, regardless of the K concentration in the irrigation water. Plants exhibited no visual symptoms of salt toxicity and there were no differences in shoot growth. Plants maintained their overall concentrations of mineral nutrients, physiological parameters, and oxalic acid across salinity treatments. Leaves retained all their antioxidant capacity at 20 meq L−1 NaCl, and 74% to 66% at 40 and 80 meq L−1 NaCl, respectively. Expression analyses of ten genes, that play important role in salt tolerance, indicated that although some genes were upregulated in plants under salinity, compared to the control, there was no association between Na or K tissue concentrations and gene expression. Results clearly show that spinach maintains its growth, mineral composition, and antioxidant capacity up to ECiw = 9.4 dS m−1. As this salinity is equivalent to a soil salinity of 4.5 dS m−1, spinach can tolerate over two-fold its previously-considered salinity threshold. Thus, growers can cultivate spinach using recycled, saline, waters without detriment to shoot biomass accumulation, and nutritional value.

Description: Although alfalfa is moderately tolerant of salinity, the effects of salinity on nutrient composition and forage parameters are poorly understood. In addition, there are no data on the effect of salinity on the antioxidant capacity of alfalfa. We evaluated four non-dormant, salinity-tolerant commercial cultivars, irrigated with saline water with electrical conductivities of 3.1, 7.2, 12.7, 18.4, 24.0, and 30.0 dS·m−1, designed to simulate drainage waters from the California Central Valley. Alfalfa shoots were evaluated for nutrient composition, forage parameters, and antioxidant capacity. Salinity significantly increased shoot N, P, Mg, and S, but decreased Ca and K. Alfalfa micronutrients were also affected by salinity, but to a lesser extent. Na and Cl increased significantly with increasing salinity. Salinity slightly improved forage parameters by significantly increasing crude protein, the net energy of lactation, and the relative feed value. All cultivars maintained their antioxidant capacity regardless of salinity level. The results indicate that alfalfa can tolerate moderate to high salinity while maintaining nutrient composition, antioxidant capacity, and slightly improved forage parameters, thus meeting the standards required for dairy cattle feed.