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 chara
cters.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.
The experiment was conducted at the vegetable research farm, Depart.of
Hort. and Forst. Resea., Nenivah during the growing season of ١٩٩٤ and ١٩٩٥.
The objective of the research was to investigate the effect of plant spacing
(١٠, ٢٠, ٣٠ cm) and phosphorus fertilizer (٠, ٢٥, ٥٠, ٧٥ kg.P٢O٥/donum),on
yield and other related traits of Cowpeas.
