In today’s Almond Matters, brought to you by Valent, dormancy provides an opportunity to protect orchards against overwintering pests. Field Market Development Specialist with Valent USA, Todd Burkdoll said that dormant applications can be very effective against pests like San Jose scale, navel orangeworm, and peach twig borer.
“Typically, it’s dormant oil and an insecticide, or insecticides. With the demise of the organophosphates and Lorsban, Asana is a good alternative to that,” Burkdoll noted. “Then at the same time Esteem is an IRG, insect growth regulator, and very effective on scale. Basically, you can put it on any time of the year but putting it on now when there’s nothing to intercept the spray, you’re going to maximize coverage.”
Application of contact materials is most effective when there are fewer obstacles such as leaves to interfere with applications. Burkdoll said that the recent rains that came through California also provide an advantage for making applications in the orchards.
“You don’t want to spray them when they’re dry. You want to spray them when they’re hydrated. Having the bark wet, and trees wet, and some moisture out there helps with a lot of different things, but you’ll get better coverage that way,” Burkdoll explained. “The trees are already wet; they’re not soaking up everything into the bark with the spray. It’s going on and getting to where you need it to be.”
Failure to adequately address overwintering pests can create significant problems for growers when temperatures warm back up. For scale in particular, Burkdoll said there is not much activity in the wintertime. However, the pest presents considerable risks for growers in the spring. “The females have laid their eggs and they’re going to have crawlers coming out and so there can be exponential growth pretty rapidly. You can get limb dieback; actually, you can get scaffold dieback if you leave it untouched and don’t treat anything,” Burkdoll noted.
Listen to the report below.