UC Delivers

Mite devastating date crop is foiled

The Issue

Riverside County is the number one producer of dates in California as well as the nation but successful, economical production is limited by Banks grass mite (BGM), the leading pest of dates in the state. Sulfur is the only registered pesticide for use in controlling BGM. However, sulfur disrupts natural enemies and no longer controls BGM. Alternative chemicals must be found.

What Has ANR Done?

Dr. Peggy Mauk, UCCE Riverside County, was asked by area growers to find an alternative pesticide for controlling BGM. In one year of testing products she came up with an alternative pesticide, Savey. Meanwhile, Drs. Tom Perring (UCR) and Carmen Gispert (UCCE, Riverside County) investigated why sulfur was no longer effective in controlling BGM.

The Payoff

New miticide saves date crop, mites resist sulfur.

After one season of testing, Dr. Mauk was able to get EPA to approve an emergency registration for Savey in California for the following season.

The miticide, sprayed with water once early in the season, gives season-long control. In the first year of its introduction, nearly 50% of the growers used it. Three years later over 90% of growers had traded in their dusting machines for sprayers so that they could use Savey.

Since Savey's introduction there no longer are nuisance or health issues that were provoked by dusting sulfur. From pesticide applicators and field workers to packing line workers, injuries and illnesses due to sulfur exposure have been nearly eliminated. Savey not only gives season-long control but is easy on the natural enemies (good bugs) and overall crop quality is ideal.

Drs. Perring and Gispert determined that the mites had developed high resistance to sulfur which was why it no longer gave adequate control.

Clientele Testimonial

Albert Keck, Chairman, California Date Commission: "The California date industry has benefited greatly from the attention provided to it by the UCCE. Through the recent efforts of Dr. Peggy Mauk, the industry has successfully combated a devastating mite infestation, which if left unresolved would certainly have led to the demise of the industry."

Contact

Supporting Unit: Riverside County

Dr. Peggy A. Mauk
County Director/Subtropical Horticulture Advisor
21150 Box Springs Rd., Ste 202
Moreno Valley, CA 92557
909-683-6491 ext. 221