This experiment was carried out during two successive seasons of 2002 and 2003 at the Experimental Orchard of Fruit Section, Faculty of Agriculture, Assiut University. This investigation was executed on Manfalouty pomegranate trees planted in heavy loam soil to explain the effect of flower thinning on the yield, fruit splitting and quality of this cultivar. The flower thinning was manually exercised according to the fruit set times. The first flower thinning level was applied beyond the third time of fruit set (7-13 May), the second level was applied after the forth fruit set time (25 May-1 June) while the third level was applied after the fifth fruit set time (15-21 June) in addition to the control. All the flowers that appear after the previous dates were weekly detached till the end of flowering season.
The obtained results indicated that the flower thinning led to a significant decrease of total number of fruits produced by the tree comparing to the control. The first level of flower thinning gave the lowest number of fruits. On the other hand, the yield (kg/tree) gave an opposite trend where all the treatments caused an increase in yield weight comparing to the control. The increment percentages of yield (kg/tree) were 7.5, 7.1 and 1.6 % for the first, second and third level of flower thinning, respectively compared to the control. However, the reduction percentages of fruit number/tree were 20.7, 13.0 and 8.5 % for such treatments, respectively comparing to the control. All treatments significantly decreased the percentage of fruit splitting comparing to the control. Since, the first level of flower thinning was the best treatment in this respect. The fruit splitting percentage was 11.2, 14.4, 15.4 and 18.7% for the first, second, third level of flower thinning and control, respectively. The flower thinning treatments caused a significant increase in fruit weight comparing to the control trees. So, the average fruit weight reached 415.3, 384.6 and 331.7 g for the three levels of thinning, respectively, while it was 293.8 g in the control. Such increase in fruit weight was reflected to an increase in yield weight (kg/tree) of thinning treatments. Moreover, the flower thinning levels especially the first level led to a significant increase of TSS % and TSS/acid ratio comparing to the control. On the other hand, all the thinning treatments decreased the total acidity percentage.