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.
This study was conducted in a green house at the Faculty of Agriculture
Sana'a University, during 2000-2001 and 2002 growing season. The objective
of the study was to obtain a genetic information on total soluble solids in the
tomato fruits in ord
er to estimate the gene action effects, which control
inheritance, heterosis, degree of dominance and heritability in term of broad
sense and narrow sense, as will as, reduction inbreeding depression in F2, for
understanding the suitable method for genetic improvement of quality.
Two tomato cultivars were used for genetic screening and cross breeding for
F1 hybrid production. F1 was cross bred with the parents for getting back cross
P1 and P2. Also, F2 was obtained. The results revealed, the heterosis in F1 based
on average of mid parents was 7.94% as compared with average of higher
parents (-2.21%). The degree of dominance was less than 1.0, which indicate
partial dominance, additive gene action variance was higher than the non
additive gene action variance which reflected on the narrow sense heritability
(h2 n.s), that reached 81.37%. The reduction in inbreeding depression in F2
reached 15.82%. The overall results indicated that, selection and hybridization
methods seem to be a good method for improving quality of total soluble solids
in tomato.
The experiment was conducted during the two seasons (2015 , 2016 ) on the Lemon trees
cv (Meyer ) aiming at studying the effect of the foliar spraying with the nutrients ( boron ,
zinc and iron ) on physical and chemical properties of the fruits Th
ese nutrients were
sprayed separately or as a mixture .
The average of each of the physical properties of the fruit (length , width , firmness,
volume and weight of the fruit ) , in addition to rind thickness and the fruits ` juice volume,
,the chemical properties of the fruit juice (total soluble solids, total sugars, total acidity,
vitamin C) were studied. An increase was observed in all the studied parameters in the
sprayed treatments compared to the control from( 6.37%- 3.33% -0.37% -
34.57mg%)to(9.33% -4.88% -1.89% -43.5%) in the first season and( 9.75% 5.87- 3.32% -
45%) in the second season, respectively. As a result of the statistical analysis, there were
significant differences between all the studied treatments and the control with overpass of
the treatment of the three elements (iron chelate + boron oxide + zinc chelate ) of all
treatments in the most of the studied figures in both seasons. Statistical analysis of the fruit
rind thickness showed the absence of the significant differences among the studied
treatments.
