Effect of some thinning methods to enhance the quality and productivity of Sewy date palm cultivar

Abstract

This research was conducted in two consecutive seasons (2020 and 2021) in a private orchard in the EL Badrashin region, Giza Governorate. To investigate the effect of two chemical compounds, ethephon (Ethrel) and naphthalene acetic acid (NAA), on date fruit thinning to improve the fruit quality of Sewy date palm by spraying this chemical twice after 15 and 25 days of pollination. Twenty-eight female trees were randomly selected from the Sewy cultivar, aged 20 years, to conduct the experiment. These trees were pollinated with pollen grain from one male in both seasons on the first day of the opening of the spath. All palm trees were treated with the same standard agricultural practices. Ten bunches per palm were kept for the thinning experiment, and all other bunchs that appeared were removed. Individual bunches were covered with plastic bags before and after spraying. 14 palm trees were sprayed with ethephon at a concentration of 0, 100, 150 and 200 ppm, and another 14 trees were sprayed with NAA at a concentration of 0, 50, 100 and 150 ppm. One concentration of the studied chemicals was sprayed on three bunches on each tree (repeated), except for a control one bunch was sprayed with water on each tree. Spraying bunches with NAA at 150 ppm or ethephon at 200 ppm gave a significant increment than the other treatments in both seasons. NAA at 150 ppm or ethephon at 200 ppm after 25 days of pollination gave the highest fruit weight (18.75 and 18.30 g, respectively) and the highest fruit length (4.54 and 4.50 cm, respectively) followed by NAA at 100 ppm or ethephon at 150 ppm compared to the second time after 15 days of pollination. While the control recorded the lowest fruit weight and
fruit length in Sewy date palm cultivar. In this regard NAA at 150 ppm treatments are good to enhance fruit quality, fruit weight, fruit length and the development of fruits.