Developing a precision pollination strategy for tree fruit

Probir Kumar Das

The current pollination process for tree fruit crops relies upon pollinators (i.e., bees) and pollenizers (i.e., trees as sources of compatible pollen). Pollination success in fruit crops is variable and threatened by the global decline in honeybee (Apis mellifera) populations and perennial challenges with pollenizers and their management (e.g., density, distribution, pollen compatibility, bloom overlap, harboring disease). The objective of the current research was to develop a precision pollination system for tree fruit, based on electrostatic field application of pollen suspensions, that is capable of replacing the current pollinator + pollenizer model. The role of potential suspension constituents was assessed by evaluating apple (Malus domestica Borkh.), sweet cherry (Prunus avium L.) and pear (Pyrus communis L.) pollen germination in vitro following incubation of 5, 30 and 60 minutes in suspension. After 60 min, pollen germination of all genotypes was reduced 15-20% in water alone. Pollen germination was significantly greater (3-4 fold) after 60 mins incubation in suspensions containing component A (1-2%, w/v), B (0.05-1%, w/v) and C (0.075%, w/v) compared to water alone media. Field trials with electrostatic application of pollen suspensions revealed that, a single supplementary application of pollen (i.e., applied in addition to normal pollination processes) was sufficient to improve fruit set. In sweet cherry, ‘Tieton’ fruit set was increased by 10-15% compared to natural open pollination. This was due apparently to nearly 3-fold greater pollen deposition on the stigma. A replacement pollination (i.e., in the absence of pollinators and pollenizers) treatment of two applications of pollen suspension was as effective as natural open pollination in ‘Bing’ – tree yield was 4.8 and 3.3 kg/tree for natural and replacement pollination, respectively. Replacement pollination on ‘Gala’ apple limbs improved fruit set between 56% and 75% compared to open-pollinated control limbs. In ‘Jazz’ apple, a replacement pollination treatment induced fruit set of 40 – 65% despite the absence of any bee-mediated pollination. Combined, these lab and field tests provide promising evidence for the potential for precision pollination systems for tree fruit.

Developing a precision pollination strategy for tree fruit

Files and links (1)

Abstract

Metrics

Details