Effect of Mineral Fertilization Rates and Method of Triple Superphosphate Application on Some Chemical Properties of Berry of the Grapevine Cultivar, Al-Helwani

The research experiment was carried out during the 2007, 2008 and 2009 seasons on grape variety Al- Helwani (10 years old) to study the effect of NPK fertilization rates and the triple superphosphate (T.S.P) application method on some fruits characters.Three fertilization NPK rates were used, rate 1 (75:25:50) kg/ ha, twofold and fourfold of rate 1, in three replicates in addition to control. The application of (T.S.P) was on soil surface and at 30 cm depth. The results showed significant increase of the total soluble solids (TSS), pH and vitamin C compared to control. while the content of TSS in juice increased by 40.9%, 44.6%, 50.3% in the three rates, respectively, compared to control, pH increased from 5.45 in control to 5.92; 5.89; 5.73 in the three rates, respectively, in turn, significant decrease in total acidity (TA) was noted by 15.3, 11.1 and 42.8%, in the three rates, respectively, compared to control. ASignificant increase of (TSS) by 2.5% and vitamin C by 10 % in deep T.S.P application compared to the surface application, on the other hand, (TA) decreased significantly by 4.2%, while, there was no significant differences in pH, in both treatments.