Use of the New Cytokinin Derivative, Cppu and Fine Water Mist Prior Pollination as Thinning Agents for “barhi” and “lulu” Date Palm Bunches

Bunch thinning is one of the main cultural practices that enhance fruit quality. Hand thinning of date palm bunches is tedious and can not be implemented on a large scale. In this study, the cytokinin derivative CPPU [Nchloro4 pyridyl) N-phenyl urea] and fine mist of water were used 2 days prior pollination as thinning agent via reducing fruit set of Barhi and Lulu cultivars in two separate studies. In Barhi experiment, fine mist of water for 3 mins, CPPU at 20 or 30 ppm, in addition to the control (no treatment) were used while in Lulu experiment, the fine mist of water was used for either 1 min, 3 mins or 5 mins plus the control (no treatment). Four strands were collected from each bunch at the Kimri stage in both experiments for the determination of some physical and chemical fruit characteristics, while in Barhi, harvest time parameters were also taken. Both treatments of fine mist and CPPU prior pollination resulted in a significant reduction of fruit set in Barhi strand while CPPU was more effective than water mist at the kimri stage. At ripening, fruit weight and size of Barhi were significantly increased by CPPU especially at 20 ppm as compared with the control. Furthermore, in Lulu study, using fine mist of water prior pollination for 3 or 5 mins resulted in a significant reduction in fruit set as compared with the control while other fruit parameters were not significantly affected at the kimri stage. J.Agric.&Env.Sci.Alex.Univ.,Egypt Vol.4 (2)2005 127 The two studies provided a new and safe approach that could be adopted by date palm growers to thin out their bunches whether by CPPU or fine mist of water depending on the desired degree of thinning.