FREE AMINO-ACIDS AS INDICATORS OF LITTLE LEAF IN ZINC-DEFICIENCY IN THE PISTACHIO (PISTACIA-VERA L CULTIVAR KERMAN)

Zinc deficiency of commercial pistachio trees is characterized visuall y as 'little leaf', analytically by low levels of zinc, and internally by increases in N, P and total soluble N. Under a range of zinc defic iencies, blocks in metabolism arise which lead to the accumulation of free arginine N. Over the growing season, arginine N in healthy leaves is normally used for amino acid and protein synthesis. The physiologi cal states induced by zinc deficiencies reversibly alter the internal correlations among free amino acid components of the soluble N pool. S everal correlations are rigidly maintained over the growth and develop mental age of leaves, so as to support the visual indices for zinc def iciency.