What is in this article?:
- Pistachio industry facing tough drought implications
- Infestation jump
- California's drought “will throw out conventional thinking” for the pistachio industry.
He said the jump in infestation was the result of “high heat and a high overwintering population.” Siegel said the pest can weather extreme cold with temperatures as low as 16 degrees, but “some mortality is associated with cold weather and rain that can occur December into February, and we haven’t really had either.”
Among those hard hit in 2013 by the NOW pest was Fresno County, with a level of 1.52 percent of insect damage, the first year the damage had exceeded 1 percent; Kern County at 1.79 percent; Kings County at 2.37 percent and Tulare County at 2.11 percent, only down slightly from 2012’s 2.18 percent.
“The trend is going the wrong way in these drought, high heat years,” Siegel said. “Everybody is making money, but quality is being eroded.”
To combat the trend, he said, growers need to increase sanitation, prevent splits with irrigation management, increase sprays, improve coverage and harvest early and double shake as needed.
Siegel fears the problem could be exacerbated as new plantings come into bearing in the next four years “and we go from islands (of pistachio orchards) to a monoculture.”
“Now is the time to think of insecticides and plan ahead to apply sprays at 2 miles per hour max and at 150 gallons per acre minimum,” he said.
He closed with a quote from Dan Quayle: “The future will be better tomorrow.”
David Haviland, University of California entomology farm adviser with Kern County, took a rare stab at predicting the future for infestation of some pests.
He said infestations from small bugs – such as lygus, calocoris, phytocoris and California buckeye bug – will likely be smaller this year because of a decline in weed growth due to the drought. But those pests may move into pistachio orchards from the foothills earlier, Haviland said.
He believes stink bugs will be a “non-issue” due to use of pyrethroids. As for leaffooted bugs, he said, populations were high but they were hurt by a freeze in December.
For mealybugs, he said, it will be a “normal” year.
Monitoring for all pests and timing sprays properly is a key to insect management, Haviland said. He emphasized a need to be able to distinguish among the different insects and recognize that some can be beneficial. For example, the phytocoris preys on NOW eggs. And the rough shouldered stink bug is a predator that feeds on insects.
To combat the gilli mealybug, he said, growers can use sprays in June against crawlers; prevent spread by washing harvest equipment and monitor at harvest to prevent newly infested fields.
Themis Michailides, plant pathologist with UC Davis, talked of steps growers can take to address Altenaria late blight that include managing irrigation, improving water infiltration, hedging trees to increase orchard ventilation and not using cover crops.
He said several fungicides are registered for use against the disease.
There are also several fungicides that can be used against Botryosphaeria, he said, terming the disease “a sleeping giant” because it can accumulate in older trees and then be “awakened.”
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