For Cardenas, plant discoloration started around May 1 as the plant turned from a normal green color to a purple shade. Plants were dead by late May and into early June. Cardenas immediately contacted pest control advisor (PCA) John Gracia of AG RX in Santa Maria.

After plant examination, Gracia first thought mites could be the culprit. Yet in March, the miticides Epi-Mek and Acramite were applied to the crop. Due to a heavier than normal whitefly population this spring, Gracia had prescribed the insecticides Courier, Esteem, and Oberon which provided good whitefly control.

“The disease was most likely brought in by the whitefly,” Gracia said.

The whitefly is generally not a major concern in strawberry production in the valley. Yet an increase of strawberry acreage likely increased whitefly numbers.

“In the future, we have to be more aggressive on whitefly control,” Gracia said. “We cannot afford to take the risk anymore.”

Given the situation, Gracia says area-wide grower control of whiteflies is needed to protect the crop.

“If one strawberry grower keeps their field clean but their neighbor doesn’t then none of the fields will stay clean,” Gracia said.

He says additional research is needed on the disease and related viruses.