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Serving: West

Coastal vegetable crops respond to warming trend

After a slow start to the 2007 season, coastal vegetables have been responding to good weather conditions, with strong growth and light overall pest pressures.

With lettuce and cole crop harvests in full swing in the Salinas Valley, area consultants report that orderly harvests resumed following the March freeze that caused some crop delays and bunches in production.

PCAs report some pressure from aphid and thrips, but worms have been light and some say coastal vegetables have been following the statewide trend for lighter overall pressures of major pests — likely a result of the early spring freeze.

“My inputs are substantially lower this year,” Salinas Valley PCA Efren Calaya said at mid-June. “Usually by this time I’m doing five or six sprays. Right now I’m between two or three. We’re seeing low numbers of aphids and thrips, but not enough to shake a stick at.”

As temperatures warmed toward the end of June, sources said plants were responding favorably, but pest pressures were likely to ramp up as well.

“The crops are responding perfectly to this weather,” says PCA Jose Valdez, with D’Arrigo Bros. in the Salinas Valley. “We have been having some trouble with aphids, both green peach aphids and red aphids, and thrips also have been giving us a lot of problems.”

After surprisingly low counts early on, worm pressures were just beginning to show up by the latter part of June as temperatures moved into the high-80s. Diamondback moths were moving into some broccoli and other brassicus fields, but worm pressures in lettuce have been reported light most of the season. Lygus in strawberries were also about two weeks behind where they would typically be this time of year.

Early looper activity in lettuce was quiet this year, and PCAs expect numbers to stay down until late July or August. Warmer weather has meant consultants were making applications for aphids and thrips in lettuce, particularly around the Gonzales area. Valdez says that as plants get larger, aphids become more difficult to control, particularly green peach aphids, which tend to hide under plant leaves, thus avoiding contact with insecticides. Gonzales has been applying imidacloprid or other materials with a 7-day PHI in high water volume to get residual coverage close to harvest.

While temperatures were warming in the inland coastal regions, the more coastal Watsonville and Moss Landing areas, were seeing soil temperatures 3 to 4 degrees below normal, and lettuce crops were still showing some effects from the cool weather, says PCA Gene Spencer.

“In the lettuce varieties that didn’t tolerate the cooler temperatures, yield and quality are down. It’s very variety dependent,” Spencer says. “Where we have hazy conditions, between sun and fog, we’re still getting a lot of in-between weather that causes a lot of tip burn.”

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