Effect of Pollen Quantity on Fruit Set, Seed Germination and Plantlet Vigor of Date Palm cv. Deglet Nour

Abstract

Deglet Nour, the most frequent in Algeria and Tunisia date palm cultivar is commonly referred to as “queen of all dates” due to its superior quality in terms of texture and taste. Date palms are dioecious plants and require artificial pollination to reach an economic yield. Despite the development in artificial pollination methods, hand pollination is still the most used technique in North African countries. However, the practices remain not well controlled particularly in terms of pollen quality. Therefore, enormous pollen quantity was used for pollination. In this study, the effect of four pollen densities was recorded, which represent 67, 87 and 97% lower than the control pollen quantity. The effect was observed on fruit set, retention and quality; seed germination; and plantlets vigor. The fruit size and weight (fresh and dry matter), moisture content, and yield were significantly reduced with the decreasing pollen density. The fruit set was not influenced by pollen density in maturation stages; kemari, khalal and rutab. However, fruit retention decreased significantly by pollen density. The seed germination was reduced significantly; while, there was no effect on seedling growth between all pollen treatments. It was found that the density of one (67% lower than control) and three strands (control) had the same effect on the investigated properties. The study provides significant insights regarding how different pollen densities will affect the fruit quality and yield of date palms.