Comparison of yield characteristics of Independence, a self-compatible almond variety, as affected by the presence of honey bee pollinators

Abstract

Abstract Until recently, all the almond varieties grown globally, have been self-incompatible, a fact that drives the interdependent relationship between almond growers and the beekeepers that provide honey bee colonies for pollination. Recently, almond growers have begun a transition to self-fertile varieties, such as Independence, which do not require genetically distinct pollen to produce kernels. However, this transition often occurs under the impression that due to self-compatibility, one can eliminate the honey bee rentals for pollination and thereby reduce costs for these orchards, but the impact that eliminating rented colonies would have on almond quality and yield are not fully understood. Here, we explore the extent to which yields for Independence variety vary with and without honey bee pollination and across a range of hive stocking densities in the San Joaquin Valley of California. We found that access to honey bee pollination significantly improves nut set and whole tree yields, ultimately resulting in economically meaningful gains to growers. Our economic model shows how specific honey bee hive stocking density recommendations depend on the surrounding landscape and will change as acreage of self-fertile varieties continues to increase over time.