EFFECT OF POTASSIUM FERTILIZATION ON ANNA APPLE TREES GROWN IN SANDY SOILS OF EGYPT

The effect of applying different doses from 0 to 2 kg of potas­sium sulphate/tree, divided in four applications, was investigated on Anna apple trees on M.M. 106 stock grown at newly reclaimed sandy soils under a drip irrigation system. No significant effect in leaf N and P content occurred in response to fertilizer addition, yet, K, Fe. Zn and Mg contents increased by application of 1.5 or 2.0 K of K2 SO4 .Likewise, obvious increases in leaf total soluble and non soluble carbohydrates were evident. Significant increase in fruit set and decrease in fruit drop were also noticed. Fruit weight, volume, flesh firmness and T.S.S. values increased by 1.5 and 2.0 Kg rate of fertilizer resulting into higher values of T.S.S. /acidity that caused earlier fruit ripening. However, acid con­tent was not affected. Yield was highly increased by the high rates of potassium sulphate additions.