This study was carried out at the Agricultural Scientific Research center In Sweida -
GCSAR to study the effect of potassium sulfate and organic manure on some of soil
characteristic in addition to tree growth vigor and fruit traits of Starking del
icious apple
cultivar. The results revealed significant effect in reducing the (pH) of the soil in the three
treatments; potassium sulfate fertilization, organic manure fertilization and application of
potassium sulfate and organic manure together which were (6.608), (6.708) and (6.558),
respectively, in the comparison with the control (6.768). In addition, significant differences
were shown in the (EC) between the former treatments (0.1532 ds / m), (0.1692 ds / m) and
(0.0937 ds / m) compared to the control (0.2217 ds / m). Concerning growth vigor and fuit
traits, the results showed a significant increase in the average of shoot length in the
previous treatments (66.43, 77.33 and 71.37 cm, respectively), compared to the control
(59.37 cm), while showed a significant increase in leaf area in organic manure treatment
and potassium sulfate with organic manure together (35.54 and 37.21 cm 2, respectively),
compared to the control (30.54 cm 2). The results of analysis of variance in fruit firmness
showed higher significant variation of potassium treatment (8.477 kg / cm 2) than the
other treatments which, also revealed significant increase of total soluble solids
(16.82%,15.2% and15.37%,respectively) compared to the control (14.23%), and a
significant increase in total sugars and in percentage of treatable acidity. Consequently, the
result showed that the addition of soil fertilizers treatment contributed to improve some of
soil characters, tree growth vigor and some of the quantitative and qualitative traits of
apple fruits.
