Feasibility of Mechanical Pollination in Tree Fruit and Nut Crops: A Review

Abstract

Pollination is essential for the production of most fruit and nut crops, yet it is often a limiting factor for both yield and product quality. Mechanical pollination (MP) systems offer the potential to increase productivity of a broad range of horticultural fruit and nut crops, and to manage the risk of reliance on current insect pollination services. To date, commercial MP systems have been developed for only a few crops (e.g., kiwifruit and date palm), suggesting that innovation in the use of MP systems has been stymied. Here, we review published and ‘grey’ literature to investigate the feasibility of MP systems of economically important tree fruit and nut crops. This review found that, whilst MP systems are a commercial reality for a wider range of fruit crops (e.g., sweet cherry) than nut crops (e.g., almond), promising results have been achieved at the experimental scale. Further we identified that the key barriers for progressing MP systems more widely include knowledge gaps in pollination biology, particularly of emerging fruit and nut species that are grown outside their native distributions, and access to proprietorial knowledge gained by commercial operators. What continues to remain unclear is detailed knowledge of the commercial development of MP systems and therefore, the opportunities to apply this knowledge to other tree crops where effective pollination limits yield and quality.

Validating a multi-locus metabarcoding approach for characterizing mixed-pollen samples

“…Entomophilous pollination, the process by which insects collect and disperse pollen produced by flowering plants, is foundational to the structure of many terrestrial landscapes and success of agricultural systems [ 1 – 5 ]. The mutualistic interaction between producers and primary consumers is beneficial to both parties; entomophilous (insect-dispersed) plants intrinsically rely on insects for successful reproduction—female gametes are sessile, and thus require deposition of male gametophytes by external means [ 6 ].…”

Artificial Pollination Technologies: A Review

“…Field-scale artificial pollination of pipfruit, stonefruit, almonds, and date palm have also been explored in the literature, with early work also occurring in tree nuts, recently reviewed by Eyles et al [25]. In apple, field-scale trials began early on, involving spray planes [26], broadcast tractor sprayers [27], and even explosives [26]-although often with disappointing results, showing little or no improvement in yield or quality.…”

“…In apple, field-scale trials began early on, involving spray planes [26], broadcast tractor sprayers [27], and even explosives [26]-although often with disappointing results, showing little or no improvement in yield or quality. Recent work has favoured handheld devices, as well as sprayers and blowers mounted on vehicles, which have shown yield benefits across a number of crops [25,28]. Generally, uptake of artificial pollination has been modest to date but is accelerating as technology moves out of the lab.…”

Influence of Different Liquid Spray Pollination Parameters on Pollen Activity of Fruit Trees—Pear Liquid Spray Pollination as an Example

“…Worldwide, insect pollinators enhance approximately 7-8% of the total value of agricultural food production and 35% of fruit yields [3]. This shows that the requirement for insect pollinators is greater in fruit [4]. However, with the growth of intensive agriculture during the past century, the variety and abundance of insect pollinators have been rapidly decreasing [3,5].…”

“…Most mechanical pollination use liquid spray pollination (LSP), which is quick, simple, and can even be done using currently available sprayers [15]. It is extremely convenient to carry out pollination operations using existing sprayers, newly improved sprayers, or even knapsack hand sprayers [4,12].…”