Multivariate analysis as a tool in the assesment of thinning of segae date palm cultivar (phoenix dactylifera L.)

Different hand thinning treatments were conducted on Segae date palm cultivar to study their effect on bunch yield and fruit quality. Five thinning treatments; control (no thinning (A)), removing 10 cm of strands length per bunch (B), removing 20 cm of strands length per bunch (C), removing the middle of the bunch (D), removing the middle of the bunch and removing 10 cm of strands length per bunch (E) were investigated at Deirab, Riyadh, Saudi Arabia. Fruit thinning substantially decreased bunch yield and increased fruit weight, flesh weight, flesh weight, fruit size, fruit dimensions in both seasons as compared with the control (no thinning) treatment. Fruit thinning had significant effect on the fruit acidity, total soluble solids and total sugars in both seasons. Thinning treatments had no effect on seed weight, reducing sugars, non-reducing sugars and moisture content in two seasons. It could be recommended that removing the middle of the bunch and removing 10 cm of strands length per bunch (treatment E) is the most appropriate practice for thinning as it gave the highest bunch yield with best fruit quality as compared with other applied treatments. Principle component analysis determined into three components which explained 82.92 percentage and 82.11 percentage of the total variance in the first and second seasons, respectively. First component (50.98 percentage and 43.20 percentage) strongly influenced by fruit length, fruit diameter, fruit weight, fruit volume, seed weight and flesh weight at first and second seasons, respectively. second component (19.69 percentage and 24.95) was affected strongly by total sugars, non-reducing sugars and bunch weight and total sugars, non-reducing sugars at first and second seasons, respectively. Third component (12.24 percentage and 13.97) was affected strongly by total soluble solids and moisture content at first and second seasons, respectively. This information can be used for future studies and can be used in identifying the best method to hand thinning in Segae date palm cultivar, which can be applied to get the higher the productivity with the high quality of the physical and chemical characteristics of the fruits. (author)