Sulfur Deficiency Influences Vegetative Growth, Chlorophyll and Element Concentrations, and Amino Acids of Pecan

in Journal of the American Society for Horticultural Science

Greenhouse-grown pecan [Carya illinoensis (Wangenh.) C. Koch] seedlings were treated with S as SO4-2 (0 to 4 mm) to determine the effect of S on its vegetative growth, chlorophyll concentration, nutrition, and free and protein amino acid content. Sulfur deficiency symptoms occurred when leaf S was ≈1.5 mg·g-1 dry weight or less. Chlorophyll concentration and growth increased curvilinearly with leaf S and had not peaked when leaf S was 2.7 mg·g-1 dry weight. The N : S ratio in the leaf and leaf S were equally reliable indicators of the S status of the plant, but the optimum ratio was less than the value of 15 found in other plant species. Calcium and Mg decreased with S application, suggesting a direct SO4-2 or NH4+ effect. The concentration of all other elements determined was elevated, in one or more plant parts, when S deficiency symptoms were visible. The most conspicuous effect of S deficiency on N metabolism was a greatly expanded free amino acid pool, mainly arginine. The concentration of free amino acids decreased exponentially with leaf S. Conversely, protein amino acid was inhibited by S deficiency and increased with leaf S concentration or, perhaps more specifically, with methiouine.

If the inline PDF is not rendering correctly, you can download the PDF file here.

All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 55 15 1
PDF Downloads 86 40 0