PGR Now Available for Aerial Applications of Almond Orchards in California

PGR Now Available for Aerial Applications of Almond Orchards in California

Valent U.S.A. LLC announced the label expansion for ReTain plant growth regulator for California in the form of a soluble powder for inclusion of aerial application for almond bloom. This new use provides growers and workers with application flexibility during a tight almond bloom window.


ReTain extends the viability of almond blooms and offers more opportunity for flowers to be pollinated, which greatly improves nut set and yield potential. In aerial application trials conducted in 2016 and 2017 with ReTain on nonpareil almonds, nutmeat yields increased by 312 pounds — or a 12.2% yield increase — over the untreated check. Applications were made via fixed-wing or rotary-wing aircraft at application volumes ranging from 15 to 20 gallons per acre.

“Time is critical for growers at bloom,” says Tom Caruso, Tree Nut Crop Marketing Manager for Valent. “ReTain has proven to be the trusted technology for almonds; and with aerial application, growers are able to reach more orchard blocks much faster and more effectively in order to boost nut set and yield potential.”

ReTain works by reducing ethylene production in almond flowers and delaying flower and stigmatic senescence. This results in flowers being viable longer, which allows more time for pollination to occur. Field studies have demonstrated that ReTain extends the life of an almond bloom by 43% over the untreated check.

ReTain can be applied between 10% and full bloom; however, the recommended application timing is between 30 to 60% bloom, and the aerial application allows growers to pinpoint that optimal timing for best results. ReTain offers an easy-to-use rate of one water-soluble pouch per acre. In addition to aerial applications, ReTain can also be applied by ground, via air blast sprayer at the recommended spray volume of 100 to 200 gallons per acre.

For more information on applications, see this story on applications during a wet year.