ReTain Increases Yields

ReTain Now For Aerial Use in Almonds, To Extend Bloom Time

By Patrick Cavanaugh, Farm News Director

ReTain plant growth regulator from Valent is now registered for aerial use in almonds.

“ReTain was registered for use on almonds this past growing season, and this past winter, California Department of Pesticide Regulation registered it for aerial use, so now it can be applied by air as well as a ground applications,” said Pat Clay, a field development manager with Valent USA.

“It really helps with making a timely application across large acreage.  ReTain works best when applied at 30 to 60 percent bloom and being able to go by air allows for more ground to be covered as well as target those applications to that specific bloom time,” he explained.

ReTain extends the viable bloomed time in almonds.

“ReTain reduces ethylene production on the almond flower,” Clay said. “Ethylene is responsible for senescence (aging) of the floral organs, particularly the stigmatic surface. So by applying ReTain, it’s extending the viability of the flower by about a day-and-a-half to two days.”

“With aerial applications, we’ve seen the yield increase greater than 300 pounds per acre on Nonpareil almonds,” Clay said.

Other crops have been using ReTain with great results.

“It has been used in apples for harvest management and cherries for very similar use to what we’re using it for in almonds. It has also been used widely in walnuts for pistillate flower abortion,” Clay explained.

Project Apis m. Helps Almond Growers Empower Bees

Project Apis m. Helps Almond Growers Empower Bees

With Free Flowering Forage

By Patrick Cavanaugh, Deputy Editor


Christi Heintz, executive director for Project Apis m. (PAm), elaborated on the message she presented at the annual Almond Conference last month in Sacramento, “Our purpose at the Almond Industry Conference was to meet growers and talk to them about planting additional forage before and after almond pollination. These are times of dearth when honey bees are not getting the nutrition they need and beekeepers have to feed tremendous amounts of sugar syrup or high-fructose corn syrup to keep the bees alive,” Heintz said.

Project Apis m.Established as a non-profit organization in 2006, PAm has the goal of funding and directing research to enhance the health and vitality of honey bee colonies while improving crop production. Heintz explained PAm.—named after Apis mellifera, the scientific name for the European honey bee—offers farmers free mustard mix for pre-almond bloom or clover mix for post-almond bloom to extend the season of nutrition availability for bees when they are most vulnerable. The increase in forage also benefits bees by providing additional natural and more diverse sources of nutrition resulting in better pollination and increased crop yields.

Heintz wants more growers to take part in the program. She reemphasized, “Honey bees love almonds, but we worry about those times just before and just after bloom. If you can get something going before bloom, you’ll get bee colonies that want to go out and forage for pollen, and they will be in great shape for almond pollination,”Heintz said.

Heintz enthusiastically urges growers to get involved by contacting PAm at and ask about forage seed mix to plant for honeybees. Growers can also go to the Project Apis m. website and to their web page For the Almond Grower.

Heintz has managed research, including pollination research since 1979, and has focused on honey bees since 2006. She also manages the Environmental Sustainability Program and production research for the Almond Board of California.