Mechanical pollination rarely supplements bee pollination
By CnAgri
Print
Don’t miss the most up-to-date : Macadamia, Pistachio, Almond, Pecan, Hazelnut, and other tree nuts in the Western United States..
“It’s an area of jack rabbits and tumbleweeds,” he said.
For the project, Coelho says Valley Orchard supplied the manpower, tractors, and fuel. There were times, he says, when it was necessary to re-treat parts of the orchard. Overall, he found the results “not real positive” when it came to showing significant improvement in pollination.
Increasing almond acreage has increased the overall demand for hives, while chronic honey bee health issues limit hive supply. Interestingly, research into “blowing” pollen onto trees is hardly new. The research paper cites a 1966 research trial.
When asked why research might have been going on so long ago – before the health scourge for bees – Fichtner speculated it might have been because the almond industry was growing and was uncertain whether there would be the availability of the thousands of hives brought into the state from around the nation.
Several research studies have demonstrated that techniques for blowing pollen onto trees have no benefit as a supplement on fruit set or yield.
Fichtner said, “If you have good bee activity, there’s no benefit. It’s a total waste of money. In a rare event it could help.”
To address the efficacy of mechanical pollination as either a supplement or replacement of bees, replicated field trials were conducted in the southern San Joaquin Valley in 2014 and 2015.
Pollen, sourced from Wood Colony and Fritz varieties, was applied twice to test rows at 30-40 percent bloom and 50-60 percent bloom, and at three different experimental rates - 0, 23.5 and 70 grams per acre.
40 interesting facts about ethanol
Cotton’s use of natural resources
Precision Planting launches FurrowJet
Nut set was measured in the Fritz and Monterey rows. There proved to be a higher nut set on the west than on the east side of the rows.
A 2015 study focused on Nonpareil and Monterey varieties. Three treatments were included: no mechanical or bee pollination, mechanical pollination only, plus bee and mechanical pollination.
Pollen was suspended in a Pollen-Tech proprietary liquid matrix applied with an electrostatic sprayer from Electrostatic Spraying Systems, Inc., Watkinsville, Ga.
For the no-pollination research, nylon mesh bags were placed over branches as bee barriers. Immediately prior to mechanical pollination, paper bags were placed over nylon mesh bags to prevent mechanically-applied pollen deposition on flowers.
Mesh bags were removed from branches for mechanical pollination only. Nylon bags were immediately replaced to prevent pollination.
Pollen was applied at approximately 60 percent bloom. Due to spray rig failure, full mechanical pollination was only achieved on the Monterey test row. No results were reported for Nonpareil.
Only a 1.3 percent nut set was achieved in the bee exclusion treatment. Mechanical pollination alone resulted in a 17 percent nut set. The bee-inclusion treatment, which included both bee pollination and any supplemental pollen distributed by mechanical pollination, resulted in 57 percent nut set.
Fichtner said the bee-exclusion study will be repeated in 2016, but 2014 results do not suggest that mechanical pollination significantly supplements bee pollination. She added that it is important to note that environmental conditions vary “between orchards and years.”
