When the majority of petals in your orchard have fallen, it may be time to remove honey bees. Alternative forage, such as this field of mustards, gives bees another source of food, keeping them from traveling to other crops in the vicinity that may be contaminated with pesticides.When the majority of petals in your orchard have fallen, it may be time to remove honey bees if you do not have alternative forage. University of California recommends bee removal when 90% of the flowers on the latest blooming variety are at petal fall.1 Once petals have fallen, no pollination is taking place, and bees that forage outside the orchard (up to 4 miles), seeking alternate food sources and water, will have a higher risk of coming in contact with insecticide-treated crops.
Staggered Pollen Release
During bloom, blossoms release pollen for about four days after they open. When temperatures are above 55° F, pollen is released when the anthers split open, or dehisce. Not all anthers will open at once; this happens in progression. Typically, the pollen that is released each day is collected by bees by mid-afternoon. The pollen-receiving structure, the stigma surface, is receptive to fertilization for about five days after a blossom opens. But, fertilization is most successful when pollination occurs during the first few days that a flower is open.
When 90% of the flowers on the latest-blooming variety are at petal fall and no pollination is taking place, it is in the best interest of the bees to have beekeepers remove the colonies, regardless of the presence of petals or of nectar-foraging bees. Unfortunately, even if bee removal timing may be included in the pollination agreement, keep in mind that beekeepers can’t always be available — or don’t have an alternative location to move the bees to.
Bee Forage Benefits
However, if you have planted bee forage, there is no rush to remove the bees from your orchard once they are finished pollinating your most recent variety. Not only does planting forage on your operation provide a food source for honey bees after pollination, it also provides benefits to your almond tree acreage growth and other improvements to your orchards,2 including:
- Improved soil fertility
- Improved water infiltration
- Improved soil moisture conservation
- Fixed nitrogen
- Increased organic material
- Increased beneficial insects
- Soil stabilization and erosion control
If you do not plant forage and opt to have your beekeeper remove the bees after pollination, it is still recommended to check with the county agricultural commissioner before making insecticide or other pesticide applications, since bees may still be foraging in neighboring orchards or in other crops nearby.
For more information, please visit Almonds.com/BeeBMPs.
1. Mussen, E. 2014. When to leave almond orchards. UC Apiaries newsletter, Mar./Apr. 2014.
2. Growers’ Guide for Planting Forage for Honey Bees, Project Apis m. (2013).
