Almond Matters: Lack of Rain Affecting Preemergent Efficacy

Brian German Almond Matters, News from our Sponsors

In today’s Almond Matters, brought to you by Valent, the dry conditions in California appear to have affected preemergent efficacy in many orchards. Field Market Development Specialist for Valent USA, Todd Burkdoll indicated that at least a quarter-inch to a half-inch of rainfall is ideal for activating preemergents in the soil. Many of the few rain events California received were considerably less than that benchmark, compromising many preemergent efforts.

Preemergent Efficacy

“The biggest detriment is not having enough rainfall to drive that into the soil and get it activated,” said Burkdoll. “Because if it’s up on the surface you can get photodegradation. You can get actual physical movement and disturbance in the soil from vehicles, from people, from whatever. That can also interfere with a good preemergent herbicide barrier.”

Growers are beginning to see indicators of a lack of preemergent efficacy in their orchards. The absence of rainfall, combined with windy conditions physically moving those herbicide applications are creating issues for many growers. “Weeds are coming through. Summer annuals are starting to pop up everywhere and you’re seeing the effects of good herbicide absorption into the soil and poor absorption into the soils,” Burkdoll noted.

Some growers will have more of an issue this year with weeds, requiring a more vigorous approach with post-emergent applications. There are a variety of tools available to growers to address mounting weed pressures in orchards. While preemergent efficacy may have been compromised and created more weed issues than usual, Burkdoll notes that it’s all part of the overall cycle of addressing weed pressures.

“Some people call it ‘weed control,’ I call it ‘weed management’ because basically weeds never really go away, they come back,” said Burkdoll. “You can have a preemergent application in the fall and the winter and then you come back with post-emergent applications to do clean up to keep weeds at bay, to keep them down to a level that doesn’t interfere with your farming.”

Listen to the report below.