Artificial pollination of kiwifruit (Actinida chinensis Planch. var. chinensis)(Ericales: Actinidiaceae) results in greater fruit set compared to flowers pollinated by managed bees (Apis mellifera L. (Hymenoptera: Apidae)

Authors: ABBATE, ANTHONY - Auburn University; Campbell, Joshua; WILLIAMS, GEOFFREY - Auburn University

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 2/16/2023
Publication Date: 3/20/2023
Citation: Abbate, A.P., Campbell, J.W., Williams, G.R. 2023. Artificial pollination of kiwifruit (Actinida chinensis Planch. var. chinensis)(Ericales: Actinidiaceae) results in greater fruit set compared to flowers pollinated by managed bees (Apis mellifera L. (Hymenoptera: Apidae). Journal of Economic Entomology. 116(3):674-685. https://doi.org/10.1093/jee/toad044.
DOI: https://doi.org/10.1093/jee/toad044

Interpretive Summary: New cultivars of kiwi have been developed for the southeastern United States. However, the best management practices required to achieve pollination to ensure adequate fruit development is unknown. In other countries where kiwi is commonly grown, managed honey bees and bumble bees are commonly used to pollinate plants. We tested whether honey bees and bumble bees would be good pollinators in the southeastern United States for kiwi. Overall, we found that managed honey bees and bumble bees woefully under-pollinate these cultivars and artificial pollination is needed to develop marketable fruit. These data will assist kiwi growers in the southeastern United States grow and develop high crop yields of marketable fruit.

Technical Abstract: Due to a lack of knowledge on the pollination requirements of kiwifruit cultivars grown within the United States, farmers simultaneously implement multiple pollination methods, like rental of managed bee species or artificial pollination, to achieve high fruit yields. However, implementing multiple pollination methods is costly and possibly an inefficient use of resources. We assessed the contribution of two managed bees (Apis mellifera and Bombus impatiens) to the pollination of kiwifruit by 1) determining the relative abundance of kiwifruit pollen collected by foragers of each bee species, and 2) comparing fruit set among insect and artificially pollinated flowers through an insect exclusion experiment. A significant difference was observed between mean relative abundance of kiwifruit pollen carried in the corbicula of A. mellifera and B. impatiens, with B. impatiens carrying on average 46% more kiwifruit pollen than A. mellifera. Artificially pollinated kiwifruit flowers set significantly greater numbers of fruit per flower at four weeks post bloom and at harvest compared to insect pollination, wind pollination, and a control. Kiwifruit producers experiencing similar conditions to ours should focus on artificially pollinating their crops rather than relying on managed or wild insects for kiwifruit pollination. Future research should comparatively evaluate other methods of artificial pollination to determine their effectiveness and efficiency in the pollination of kiwifruit grown within the United States.