Timing is critical during pollination, including this year when rain and cold limited bee flight hours.
Last year’s approval of ReTain, a Valent plant growth regulator (PGR) the company says can extend almond bloom by about 43 percent or close to two days, came in time for California growers to begin product use early this year.
Product trials in California orchards from Bakersfield to Chico showed an average 7 percent improvement in yield when compared to the control (not used), according to Patrick Clay, Valent field development manager.
Studies predominantly in Nonpareil varieties suggested a range of 24-65 percent improved nut set, based on 37 trials throughout the California almond growing region.
In some cases, yields bumps of 15 percent-plus occurred in a well-managed Nonpareil orchard near Delano.
Some Nonpareil trees near Livingston, already producing over 4,000 average pounds per acre, saw a 6.8 percent yield boost or about 285 pounds per acre, Clay said.
On average across 32 sites, Valent says Retain use in Nonpareils included a 185 pound-per-acre increase to over 2,700 pounds per acre, when compared to untreated blocks.
According to Valent, ReTain can be applied between 10 percent bloom and pedal fall, though Valent recommends a window of 30-60 percent bloom for optimal results. Applications are okay by ground. Clay says Valent is working with the California Department of Pesticide Regulations to gain label instructions on aerial applications, and expects those on the 2018 label.
Clay says ReTain has been successfully used without negative impacts to honeybees.
Valent representatives reported ReTain use during California meetings which included updates on other company products, including Quash fungicide and Chateau herbicide, plus Valent’s product line of foliar and soil insecticides, fungicides, herbicides, nematicides, plus a soil and plant health product.