Effect of Some Thinning Practices on Yield and Fruit Quality of Sewi Date Palm Grown in Farafra Region

The present study was carried out during two successive seasons (2016 and 2017) at El-Frafra Oasis District, Egypt. Female ‘Sewi’ date palms of healthy, nearly homogenous in growth, as well as fruiting ability, were selected. The selected palms were pruned after harvesting and leaf bunch ratio was adjusted to 8 leaves per bunch during both seasons of study. The effect number of bunch per palm (8, 10 or 12) and thinning % by cutting out a number of strands from the centre of the bunch enough to remove about (0, 10, 20 and 30%) and their combinations were investigated. Anyhow, the influence was evaluated through the response of the different (productivity, fruit physical and chemical properties) to the specific and interaction effects of both investigated factors. The obtained results revealed the greatest fruit weight per bunch was always in significant concomitant to 8 bunches per palm +zero thinning % during both seasons. Moreover, the highest fruit weight per palm was significantly coupled to 12 bunches/palm + zero thinning level. However, the highest values of fruit weight (g) and fruit dimensions were significantly induced by 8bunches/palm + 30 thinning %. Anyhow, the heaviest fruit pulp weight was significantly coupled with (8 bunches /palm +30% thinning) the highest fruit seed weight was exhibited significantly by (8bunches/palm +30% thinning level) and (10 bunches/palm +30% thinning level). Meanwhile, the lowest fruit moisture content was significantly coupled with the 8bunches/palm +30% thinning level. However, the highest value of TSS % and total sugars % was significantly coupled with 8 bunches/palm + 30% thinning. Overall, the use of 8 bunches/palm with 30% thinning level of strands from the center of the bunch was the best in most of the measurements studied.