The present work was carried out during 1999 and 2000 seasons to
investigate the influence of potassium application on fresh and subsequent raisins
yield and their qualities, Potassium applications; especially at 350 g K2S04 Ivine
significantly increased clusters and berries weight, juice volume and total soluble
solids (TSS%). The increase in TSS reached 23.4 % over the control of the two
seasons of the study. Total acidity took almost an opposite trend to that of both
TSS% and TSS/acid ratio. Potassium applications prolonged the sun-drying period by 5-6 days over the
control, whereas the longest period of sun-drying adequate to reach to raisins; 16-18
% moisture content was obtained with the highest rate of potassium (350 g/vine).
Thus, the sun-drying ratio was lowered as a result of potassium applications. Also, the weight and size of raisin berries significantly increased over control
level due to potassium application. An obvious effect of potassium on rehydration
ratio of raisins was noticed. the highest rate of potassium applied, increased the ratio
by 29 % over control. Potassium application also improved both sugar content and yield of raisins
per ton fresh grape as well as quality of produced raisins,