ISSN:
1573-5036
Keywords:
B deficiency diagnosis
;
boron (B)
;
Brassica napus
;
critical B concentration
;
functional B requirement
;
leaf elongation
;
oilseed rape
;
shoot growth
Source:
Springer Online Journal Archives 1860-2000
Topics:
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Abstract Plant analysis can diagnose boron (B) deficiency when the standards used have been properly developed by establishing that a close relationship exists between B concentration in a plant part and its physiological function. The purpose of the present study was to demonstrate the importance of choosing the growing immature leaves for B deficiency diagnosis and for establishing critical B concentrations for the diagnosis of B deficiency in oilseed rape (Brassica napus). In Experiment 1, the plants were subject to seven levels of B supply using programmed nutrient addition, for the estimation of critical B concentrations in plant parts for shoot growth. In Experiment 2, the plants were treated with two levels of B supply in solution: 10 (+B) and 0 (-B) μM B, for the estimation of functional B requirements for leaf elongation. The results showed that critical B concentrations varied amongst the plant parts sampled and decreased with leaf age. As B taken up by roots is largely phloem-immobile, B concentrations in mature leaves are physiologically irrelevant to plant B status at the time of sampling, giving rise to a significant over- or underestimation of the B requirement for plant growth. By contrast, a growing, immature leaf, in this case the youngest open leaf (YOL), was the most reliable plant part for B deficiency diagnosis. Critical B concentrations developed from both methods were comparable-i.e. 10–14 mg B kg−1 dry matter in the YOL at vegetative growth stages up to stem elongation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00011434
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