Story by John Holland
The rented bees arrived to find quite a feast in Mike Silveira’s almond orchard north of Oakdale.
He had sown mustard seeds between the tree rows in the fall, and by mid-January, they had burst out in flowers full of pollen and nectar for the bees to eat. This helped them gain strength for the almond pollination, now well under way up and down the Central Valley.
Silveira is among about 150 almond growers taking part in this research effort for the bees, which have struggled with disease and other challenges over the past decade.
“If you have this for a month before the almond bloom, then you build up a lot of bees,” said pollination researcher Christi Heintz, executive director of the sponsoring group, Project Apis m. It is named for Apis mellifera, the scientific name for the European honeybee, the species at issue.
Almonds are among the top-grossing farm products in the Northern San Joaquin Valley and statewide, and the largest users of commercial colonies in the nation each year. About 1.7 million bee boxes are delivered to the orchards for the pollination, which runs from mid-February to mid-March.
Beekeepers expect to lose some of their colonies each winter, but many have had much larger losses in recent years. Researchers say the causes could include diseases, parasites, trucking stress, pesticides or poor nutrition where drought has reduced flowering plants. Even when rain is abundant, winter does not provide much food.
“Those are times of dearth for bees, when there isn’t much for them to eat,” said Heintz, who works out of Tucson, Ariz., and previously was with the Almond Board of California, based in Modesto.
Heintz talked about the effort during a visit Wednesday to Silveira’s orchard, on 40 hilly acres along Twenty-Six Mile Road. The seeds he sowed came free from Project Apis m., which operates on about $100,000 in grants each year. The mix includes a few varieties of mustard, which put out yellow flowers before the almond bloom, and clover, which bear red, white or purple flowers afterward.
Heintz said the diverse food in the orchard, combined with nearby drinking water, “is exactly what we need. This is a bee spa.”
Almond blooms still are the favored food for the bees, she added, and they will not fill up on the supplemental plantings at the expense of pollinating the crop.
The effort so far covers only about 3,000 of the 860,000 acres of almonds in California, but Heintz said she would like to see it become a common practice. She is collecting data on how the supplemental food sources affect nutrition, colony population and other factors.
Silveira has taken part for two years. He said some almond growers might worry about these plants taking soil moisture from the trees, but that has not been a problem. He also noted that the mustard and clover protect the ground from erosion and take up nitrate from fertilizer, reducing the risk of tainted groundwater.
Silveira plans to mow the plants when the flowering in done, so they will decompose well in advance of the almond harvest. The nuts are shaken to the ground by machines, and growers do not like to have too much debris lying there.
Silveira rented the colonies from Hughson-area beekeeper Kevin Peavey, who is taking part in the effort for the first time this year.
“The bees are going to have more pollen and nectar to gather,” Peavey said. “The more they are fed, the stronger they are.”