IN YOUR ORCHARD
mummy nuts. Interestingly, cover crops have been shown to reduce the number of NOW. This is thought to be due to changed orchard floor conditions which accelerate the decomposition of mummy nuts on the ground and increased mortality of the NOW larvae. Cover cropping is not a replacement for winter sanitation but can work synergistically with NOW suppression.
pollen and nectar resources that can benefit honey bee health. Flowering cover crops present an opportunity to expand nutritional resources for bees and increase brood stimulation and thus pollination productivity and efficacy. For years, almond growers rightfully asked whether a blooming cover crop would compete with almond blossoms for bee visitation and pollination. This research article showed that a flowering cover crop does not compete with nor decrease pollination effectiveness in almonds. In some instances, the presence of non-almond flowering plants has been shown to improve almond pollination. When bee hives are placed in orchards in the late winter, honey bees will not have yet received the signals to begin growing their numbers and preparing for spring. The first pollen brought into the hive by early foragers serves as that signal. Once the queen bee notices there are new pollen sources, she will begin laying eggs. This stimulates the colony to begin collecting more pollen and nectar. Cover crops — which flower before the almond bloom — kick-start this early foraging behavior, meaning that when the almond bloom time arrives, it’s met by bees that are ready to go rather than just waking up. One of the reasons why almond pollination services have become so expensive is because beekeepers have been forced to start this process of stimulation by adding pollen patties and sugar water at high cost to have hives ready to go when they arrive in the orchards. Just like growers, the more inputs and “touches” to any beekeeping operation, the higher the costs go. Cover Crop Termination and Harvest Managing cover crops for pollinator health may entail some tradeoffs. When 50% of the cover crop is in bloom, the carbon to nitrogen balance in plant matter begins to favor carbon. As less nitrogen is available compared to the amount of carbon, plant matter break down is slowed. Thus, as Project Apis m .’s Seeds for Bees program advises growers, it is imperative to manage the cover crop properly. If the above ground biomass of the cover crop is not properly managed, crop residues may indeed become a nuisance during harvest. Proper management has shown
Seeds for Bees’ Pollinator Brassica Mix blooming with colonies in the orchard. Photo Credit: Project Apis m.
Pollination and Bees Cover crops also provide strong pollination benefits. The vast majority of commercial almond orchards depend on pollination services provided by managed honey bees. However, most almond orchards lack diverse
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ALMOND FACTS
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