Recommendations for Bees Pollinating Almonds

The flush of color the almond bloom brings to valley is a spectacular indicator that a new year is upon us. It is also a time to reflect and congratulate each other on the productivity and hard work of the previous year. Like 2020, 2021 will have its own unique set of challenges. The fall rain growers with drip irrigation rely on to germinate their cover crop in order to feed bee colonies before almond bloom was non-existent this year. Orchards with micro-sprinklers, flood or solid set irrigation that germinated the seed by late October achieved bloom as early as  mid-January. Choosing the right cover crop mix is important. However, depending on the circumstances the timing of planting and germination is often more crucial. Even during a very dry fall and winter, achieving successful cover crops that bloom early enough to feed bees before, during and after almond bloom can be accomplished with very little water. For example, an almond grower In Ceres who planted the PAm Brassica Mix in October and irrigated only once for 24 hours on 10/21/2020 experienced excellent ground coverage and bloom by January 15th!     

The following information will help you accomplish your regular orchard management tasks without posing a risk to bees and their ability to pollinate effectively. The honey bee is a small creature, and attention to small details regarding their health and safety is an important factor in achieving high yields.  

Communication

Growers should communicate with all parties that are involved with pollination. Proper communication will certainly include the beekeeper who is providing the colonies but might also include a bee broker, pest control adviser (PCA) and certified pesticide applicator (CPA). California county agricultural commissioners also play a vital role in the communication chain between growers and beekeeper. All colonies are required to be registered with each county agricultural commissioner upon arrival in that county.
 
The best way to register colonies is by using the Bee Where program. This web based program offers beekeepers a dynamic, real-time geographic information system (GIS) where they can mark colonies with a pin drop in the orchard via a mobile app. Bee Where is useful to growers because their notice of intent (NOI) for material applications allows each county agricultural commissioner to notify each beekeeper in the area which allows them the opportunity to move their colonies.
 
Proper communication helps both grower and beekeeper achieve successful pollination while reducing risk to honey bee colonies and the almonds they pollinate. Starting before bloom, growers and beekeepers should agree upon average frame count per colony, date and location of placement and removal, inspection protocol, and payment terms. A contract is a good way to get the discussion going.  A pollination contract template can be found at the Project Apis m. website.

Pesticide Applications

Many of the pesticides commonly used to protect crops can also harm or kill honey bees. Caution should be taken when applying crop protection products when bees are present.  Always read labels and follow directions. Do not use pesticides with cautions on the label that read “highly toxic to bees,” “toxic to bees,” “residual times” or “extended residual toxicity.” Avoid applying any insecticide during bloom. If a fungicide application is necessary, spray in the evening or at night when bees and pollen are not present. Adjuvants should not be used with fungicides unless stated on the label. 1     

Clean Water for Bees

Photo Courtesy of Blue Diamond Growers

It is common knowledge that bees need nectar and pollen to survive. But adequate access to clean water is an often-overlooked requirement for proper bee health. Even on a day with temperatures that may seem cool to us, a colony packed with 40,000-60,000 bees can easily overheat. Bees collect water and regulate hive temperatures by fanning small water droplets. It’s insects version of evaporative cooling. Standing water on orchard floors may be contaminated with pesticides which could be harmful to bees. Bees accessing other water sources like neighboring pools/fountains may create a nuisance. Providing water is an easy step to manage bees pollinating almonds and avoid complaints from neighbors. This is why Blue Diamond and Project Apis m. have teamed up to create the Water for Bees. This program provides guidance on how to provide clean water hydration stations honeybees need to flourish before and after the almond bloom.
  
Place water near hives as soon as they arrive and use new containers or ones that have been thoroughly cleaned out. A proper “landing” area is essential for successful water collection, so bees don’t drown. This can be achieved with floating cork, marbles, leaves, grass, or straw.  For buckets or drums, most commercial beekeepers use burlap. Burlap, fastened by clothespins, is draped over the sides allowing water to wick up the sides. Change out water if it has been contaminated with pesticides or looks unclean. The recommended rate of water is about a half-gallon for each hive for the duration of pollination, which is roughly equal to: One 55 gallon drum for every 100 hives or, one 5 gallon bucket for every 10 hives.

Bee Nutrition & Forage

Seeds For Bees blooming in an almond orchard, as bees are being placed for pollination in late January, 2021. Photo Courtesy of Christine Gemperle.

Many producers are now looking at cover crops for helping them achieve their goals of improving soil quality, pollinator health and economic viability. This year 47 Blue Diamond growers participated in Seeds for Bees which helped them plant 2,782 acres of bee friendly cover crops. Growers that plant alternative sources of nutrition like blooming cover crops before and during the bloom of their cash crop do so to create a positive feedback loop within the hive. This positive feedback loop helps ensure healthy and more bees for pollination. As pollen is brought back to the hive, the queen lays eggs.  In three days, the eggs hatch into larvae. The immature larvae that beekeepers call ‘brood’ secretes a pheromone that drives adult foragers to go find more protein, in the form of pollen. The smell of the brood pheromone is the hive’s way of communicating the urgency in which bees need to collect resources to support the next generation of bees. Preliminary results from an Almond Board of California funded study conducted by Dr. Elina Niño measures the impact Seeds for Bees cover crops in or near almond orchards has on colonies.2  She found that hives in orchards with access to the PAm Mustard Mix were on average three frames more populous than hives without access to supplemental forage. Planting bee forage cover crops is a great way to get more brood pheromone in the hives you rent for pollination, giving them a boost before the bloom and increasing foraging behavior (pollination).  
 
Increasing bee health is just one of many benefits cover crops bring to an orchard system. The preliminary data shared by University of California researchers regarding these benefits is very exciting. Research shows seed mixes high in legumes can boost nitrogen levels in the soil. Orchards with cover crops had 82 more nitrogen lbs/acre in Merced county and 126 nitrogen more lbs/acre in Kern county, than orchards without cover crops.
 
While it’s hard to say what factor is responsible and it is likely multiple benefits are contributing, the UC study has found orchards with cover crops also have higher almond yields. At the Merced county site yields were 225 lbs/acre higher when compared to control orchards with resident vegetation/weeds. In Kern county the yields were 94 lbs/acre higher when compared to bare soil.
 
While almond growers are finding it increasingly difficult to get reliably strong colonies, beekeepers are facing greater challenges to keep their hives alive. Varroa mites and loss of habitat/poor nutrition are two of the biggest health threats honey bees face in modern beekeeping. To help mitigate other stressors to their bees, beekeepers often look for orchards with supplemental sources of forage for their bees. Planting cover crops that will bloom before and after almonds can help growers attract high-quality beekeepers with healthy hives. Some beekeepers even give growers a discounted rental rate for hives if there is access to supplemental sources of food.

References:

1. Almond Board of California. Honey Bee Best Management Practices For California Almonds. Modesto, CA. http://www.almonds.com/sites/default/files/ALM_189395_HBBrochure_ForWebsite_8_5x11_F5.pdf  
2. Niño, Elina (2016-2017) Longitudinal Evaluation of Honey Bee Colonies on Different Forage Regimes. Almond Board of California Annual Research Report 

​Author:  Billy Synk, Director of Pollination Programs, Project Apis m. 
Billy@ProjectApism.org