Water stress due to regulated deficit irrigation can cause almonds to split earlier, moving up the timeline for possible navel orangeworm access to the inshell almonds.

Joel Siegel, research entomologist with the USDA’s Agricultural Research Service, Parlier, Calif., warns growers they had better be prepared to treat earlier for NOW.

“Earlier hull split could change the dynamics of the navel orangeworm population,” he says. “If they are searching in the canopy and find new crop nuts on which to lay eggs, instead of mummies in the canopy or on the ground, survival will be greater, depending on maturity of the kernel inside the nut.”

Earlier and more extensive scouting to determine treatment thresholds also makes sense with earlier hull split