Impact of pollination time of the day on the fruit, yield, and quality traits of date palm cultivar Khalas

Abstract: The present study was conducted during the 2017 and 2018 seasons on date palm cv. Khalas to determine the most effective daytime to pollinate female palms to obtain optimum fruit set, yield, and best fruit characteristics. Nine, twelve-year-old date palm trees were selected for the experiment, and five spathes from each palm were chosen for pollination. These palms were pollinated at three different daytimes, i.e., at 8am (morning), 11am (late morning), and 2pm (afternoon). The experiment was laid out on Randomized Complete Block Design with three replicates for each treatment. The outcome of the study indicated significant differences among three pollination times. Date palm cv. Khalas pollinated at 11am exhibited significantly promising results regarding fruit set percentage, parthenocarpic fruit percentage, biser fruit percentage, tamar fruit percentage, bunch weight, yield per palm, fruit fresh weight, fruit length, fruit width, fruit volume, pulp weight, pulp ratio, seed ratio, pulp:seed ratio, seed weight, seed length, and fruit moisture content; however, fruit drop percentage, seed width, total soluble solids, total sugar, reducing sugar, and non-reducing sugar were not significantly affected by any pollination times. Pollination carried out at 2pm closely following to 11am pollens application time, and a number of attributes were non-significant between the two times such as fruit set percentage, parthenocarpic fruit percentage, biser fruit percentage, tamar fruit percentage, bunch weight, yield per palm, fruit volume and seed length. Early pollination time (8am) showed poor results regarding most of the attributes studied. Therefore, it is concluded that pollination should be carried out around the middle of the day when the ambient temperature is optimum, which favours pollen germination and positively influence fruit yield and quality attributes.