Effect of pollen source on fruit set, yield, and physical properties of tissue culture-derived and offshoot-derived date palm, cv. ‘Barhi’ and ̒ Piarom’

The present study was carried out to evaluate the effects of different pollen sources, i.e. genotypes 7001 (control), 7005, 7013, 7030, and tissue culture-derived ‘Boyer 11’, on two maternal plant cultivars, i.e. ‘Barhi’ and ‘Piarom’ (tissue culture-derived and offshoot-derived). The quantitative properties of fruits were evaluated for a period of two years (2018-2019). A population of 30 ten-year-old trees was selected from each cultivar. Fruit physical properties were measured, including fruit length and diameter, the fruit length-to-diameter ratio, fruit volume, seed length and diameter, seed weight, and yield. The results showed that the highest percentage of natural fruit set was related to offshoot-derived trees of cv. ‘Barhiʼ, with pollen from genotypes 7030 and 7013. The lowest was found in tissue culture-derived trees of cv. ‘Piaromʼ, with pollen from the genotype 7001 (control). In general, offshoot-derived ‘Barhi’ and ‘Piarom’ cultivars were preferable to their tissue culture-derived trees, since they caused better quantitative and qualitative traits. Furthermore, genotypes 7013 and 7030 were selected as the most suitable pollinizers because of increasing the percentage of fruit set, reducing the number of parthenocarpic fruits, and improving the quantitative and qualitative properties of fruits in tissue culturederived and offshoot-derived date palm cultivars (‘Barhi’ and ‘Piarom’).