الكلمات المفتاحية
Boron, potassium, zinc, date palm, Kimri stage, Phoenix dactylifera L., Deglet Nour, fruit retention
ملخص البحث
The present study was carried out on Phoenix dactylifera L. cv. Deglet Nour to investigate the effect of boron, zinc and potassium on percentage of fruit retention and fruit physical characteristics. Bunches were
sprayed with boric acid (1000,1500 and 2000 ppm), zinc sulfate (250, 500 and 750 ppm), potassium nitrate (1 and 2%) and potassium sulfate (1 and 2%). Results proved that all the studied treatments resulted in a significant increase in the percentage of retained fruits compared with the control in both studied seasons. Higher percentage of retained fruits was resulted from KNO3 and K2SO4 at (1&2%) and H3BO3 at 2000 ppm in both studied seasons. All the studied parameters were increased significantly from the first date 75 days after pollination (DAP) to the last one (115 DAP) which has the highest values in both seasons. Boron spraying at
1000 and 1500 ppm and zinc sulfate at 250 and 500 ppm significantly increased fruit weight, fruit size, fruit Length, and fruit Diameter, flesh weight and seed weight at different sampling dates compared to other the
treatments including the control . In general, the highest values of fruit weight, fruit size, fruit Length, and fruit Diameter, flesh weight were resulted from zinc sulfate at 250 ppm in both seasons. There were no significant
differences among treatments in total soluble solids. The results of this study showed that mineral nutrients increased fruit retention percentage and fruit physical properties of date palm. Therefore, it is concluded that the
foliar application of zinc, boron and potassium may be applied in order to increase the production and to control
the fruit drop of date palm.