Abstract
Tow isolated experiments were conducted in the field of the College of Agriculture & Forestry / University of Mosul , during the 2006 growing season . The first was on Anna cv. young apple trees and the second was on Vistabella cv. young apple trees which were grafted on MM.106 rootstock, and planted in sandy clay lomy soil at 4×4 meters apart under drip irrigation system , to investigate the effect of sulphur , nitrogen , ascorbic acid and their interactions on leaves S , N , P and K concentrations.Three levels of each sulphur ( 0 , 100 and 200 gm. tree-1, S0 , S1 and S2 respectively ) , and nitrogen ( 0 , 30 and 60 gm. tree -1 , N0 , N1 and N2 respectively ) and two levels of ascorbic acid ( 0 and 125 mg.L.-1, A0 and A1 respectively) were used . The results of both experiments indicated that Sulphur application significantly increase leaves S , N , P and K concentration at both CVS.While nitrogen application leds to significant increase in leaves S and N concentration of both cultivars and K in leaves of Vistabella CV.and significant decrease of leaves P in both cultivars.Whereas ascorbic acid spray led to significant increase in leaves N in both cultivars and leaves S , P and K in Anna cultivar.All interactions among sulphur , Nitrogen and ascorbic acid significantly effected leaves S , N , P and K concentrations on both cultivars , except the effect of S X N and N X Ascorbic acid interactions on K concentration in leaves of Anna CV. , and the effect of S X Ascorbic acid interaction on S concentration in leaves of Vistabella CV.The treatment 200gm S.tree-1 + 60gm.N .tree-1 + foliar spray of ascorbic acid at 125mg.L-1 was the best , the percentage of S , N , P and K on it was 0.34 , 2.94 , 0.295 and 1.99 % respectively in leaves of Anna CV.and 0.49 , 1.81 , 0.223 and 2.11% respectively in the leaves of Vistabella CV.
