It Behooves Blueberry Growers To Protect Pollinators

It Behooves Blueberry Growers To Protect Pollinators

Managed bee hive boxes around a blueberry field

Place managed hives adjacent to a blooming blueberry crop.
Photo by Jason Deering

Blueberry production is on the rise in Florida, from the number of acres in production to the number of new operations and increased popularity in specialty operations like organic and U-Pick farms.

Like many crops in Florida, blueberries are dependent on bee-pollination to set fruit. It is really very simple — the more bees that visit a flower, the more pollen grains that will be transferred from the male stamen to the female, resulting in more fertilized ovules. This equals a larger, more even ripening fruit and demonstrates why pollination is so critical for the grower to understand and manage.

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Blueberries (Vaccinium spp.) are more adept to buzz pollination, a vibrating act performed by bumble bee species and other native pollinators that literally shakes the pollen from the flower. However, the availability and abundance of these native pollinators are often not enough to support pollination needs for larger or commercial operations. This is where managed pollinators come into the picture.

Management Matters

Most growers rent managed honey bee colonies for pollination services during the bloom period. The recommended stocking rate is two to five hives per acre, and with upwards of 50,000 bees per hive, it is no question that honey bees can get the job done. The bloom window is relatively short, with abundant flowers that require pollination within approximately three days after opening. However, it is important that honey bees be placed onto the site only after target crop reaches 5% to 10% bloom.

Honey bees forage on the closest, most abundant forage source until it is exhausted. Placing honey bees before the target bloom will leave the bees foraging on the next best source and not the blueberries, even if they are open. Communication between the grower and the beekeeper is crucial to ensure sure hives are ready and placed on site at the correct time relative to bloom.

The time period that honey bees are on site for pollination can pose a number of other challenges beyond timing of hive placement for both the beekeeper and the grower. Blueberry growers face the challenges of pollination itself: bad weather, wind, rain, and sudden blooms can all interfere with bees being available during that crucial bloom time. This is on top of fluctuating market prices and the need to manage pest pressures from insects, mites, and diseases that are often controlled using pesticides, which can pose risks to honey bees and other pollinators. Because both bee pollination and insect control are essential to the success of blueberry production, it is important that both beekeepers and growers work together to reduce these risks.

Safety First

A 2016 survey from the Florida Department of Agriculture and Consumer Services (FDACS) shows many growers are proactively taking steps to ensure honey bees on site are safe. That’s good news for native pollinators, too, as there are up to 20 different species assist with blueberry pollination in Florida. There are many things that can be done to reduce the risk of pesticides to bees while on crop. Many growers adjust the timing of pesticide applications to when bees are not foraging, i.e. after dusk; even when not indicated by label language. Growers can choose products that have less toxic active ingredients or have less bee-restrictive language on the label. Other practices include reducing the overall number of sprays during bloom or performing certain treatments prior to bloom where possible.

These practices, and more importantly their communication and agreement between the beekeeper and the grower, are really what ensures a safe pollination season for bees and blueberries. Many of these operations are utilizing pollination contracts or agreements. These may include details like hive strength, timing of hive placement, pesticide use, and method of contact if any emergency applications may become necessary (liabilities, costs, feeding etc.).

Food For Thought

Although counterintuitive to some, honey bees can and should be supplemented with sugar syrup (a nectar substitute) during pollination. Bees collect an insignificant amount of nectar from blueberries as they mainly gather pollen. Honey bee hives need both nectar and pollen to keep producing more bees, and more bees equals more pollination. Therefore, it is perfectly acceptable to discuss feeding supplements with contracted beekeepers.

Other factors to consider may include where within the field the hives are placed; it is important to keep them away from irrigation nozzles, out of the way of turning equipment, clear from roadways and foot traffic, clearly marked for all farmworkers, in areas not subject to drift, and not in the middle of the rows. Honey bee foraging behavior allows the hives to be placed adjacent to the blooming crop, up to 500 yards away.

Lastly, it has become more and more common to see growers reserve, plant, or install some type of native forage on their property. Supplying abundant and diverse forage will not only supplement honey bees and build stronger colonies, but it supports the nesting of native bees year after year.

Florida has a wealth of knowledgeable blueberry growers, beekeepers, UF/IFAS researchers, FDACS staff, and programs like Integrated Crop Pollination that are working together to build a stronger blueberry industry. From communicating information and interpreting pollination needs to reducing pesticide risks and providing diverse native forage, there are many ways Florida growers are taking the lead to ensure that both the bees and the blueberries are getting the protection they need.