Design, development, and performance evaluation of a ducted fan date palm (Phoenix dactylifera L.) pollinator

Abstract

Date palm is a dioecious tree that bearing male and female inflorescence on separate trees. Although pollination of date palm occurs naturally, in order to guarantee productivity, the artificial pollination can be carried out in commercial date farms. Up to now, an efficient mechanical pollinator has not been developed, and pollination is still carried out manually in most date farms. In this regard, an ultra-light, efficient electrical date palm pollinator was designed and developed consists of a ducted fan, a body and container composed of light polyethylene terephthalate (PET), and a 6.5 m long boom, which was made from carbon fiber. The apparatus overall weight was less than 2 kg, which makes the apparatus as a portable machine to sprinkle pollen/pollen-flour blend. The container had the capacity of approximately 70 g pollen, which could pollinate up to 140 trees in each charge. The pollinator performance was evaluated on the Mazafati cultivar by the aid of a complete randomized designed experiment with five pollinated treatments (traditional, 0.5 g pollen, 2.5 g pollen, 5.5 g pollen-flour blend, and 2.5 g pollen with no repetition) and a non-pollinated treatment. Furthermore, the pollination and fruit setting efficiencies, pollen consumption index (fruits/g pollen), and the airflow characteristics of the pollinator were determined. Therefore, a model was introduced to determine the required pollen or blend (pollen-flour) mass flow rate as a function of discharged air velocity. According to findings, no significant difference was noted regarding the pollination and fruit setting efficiencies among five pollination treatments (p-value<0.05). Furthermore, the treatments with higher fruit settings had lower fruit weight, while no significant difference was noted in seed weight among all treatments (p-value<0.05). However, the mean fruit weight associated with 0.5 g pollen treatment was significantly greater than other pollinated treatments. Generally speaking, the introduced pollinator could properly work as a replacement for the traditional method.