In today’s Almond Matters, brought to you by Valent, storms that came through California brought much-needed rainfall to much of the state. Two days of wet weather brought multiple inches of rain to most of California. Field Market Development Specialist for Valent USA, Todd Burkdoll noted that it’s fortunate the rainfall came now and not when trees are blooming.
“Rain right now is actually a good thing because the trees are still dormant. If it comes during bloom, then you’ve got problems with potential for disease. Moisture conditions for disease are enhanced,” said Burkdoll. “But right now, it’s actually a good thing.”
Increased moisture in orchards can provide ample opportunity for fungal infection. Risk for bloom-time diseases is dependent on a number of factors. Rainfall and temperatures will be the primary driver for what types of disease pressure may appear in orchards. Burkdoll said that he does not typically worry about potential disease pressures until the trees leaf out.
“You can put a dormant copper on there to knock out inoculum. If you had it on with all this rain, it got washed off anyway. So, you’ll probably have to go back and reapply with a chlorothalonil, copper program, mancozeb, or other topical contact materials,” Burkdoll explained. “For the most part, most of your fungicide programs start at bloom or prior to bloom with bud swell and we’re not quite there yet.”
While out in some orchards recently in Kern County, Burkdoll noted that the early varieties he observed were still a few days away. He expects to begin seeing signs of bloom over the next 10 days or so. Rainfall coming during bloom can create a multitude of concerns for growers. Getting moisture in newly emerged tissue can increase the potential for fungal infections.
“Bloom blight can come in and infect blossoms at that time. But that’s if it stays wet and moistures there,” said Burkdoll. “If it dries up with nice sunny days the potential for any disease is dependent upon environment. So, if you take the environment out of the equation then the disease potential goes away as well.”
Listen to the report below.