Although bud break is at least a month or more away, it’s so far, so good for pistachio growers in Kern County, Calif.
“Growers right now are pretty optimistic,” says Craig Kallsen, Bakersfield, Calif., University of California Cooperative Extension farm advisor. “In addition to enjoying good prices, it is also an on year for some growers. So, their yields should be up this season.”
Lack of consistently cold weather this winter has left some growers wondering if their trees have received enough chilling hours, he says. However, thermometers at reporting stations in the southern part of the San Joaquin Valley indicate that, fromNov. 1, 2010, to Feb. 12, 2011, total chilling hours have been adequate
UC statistics show that pistachios require about 800 chill hours at or below 45 degrees. In Kern County, total chilling hours recorded at five reporting stations have ranged from 849 to 1,085 and in Fresno County, from 822 to 947 hours at seven stations.
However, at the two Kings County stations, Stratford has received 837 chilling hours, but just 735 hours have been recorded at the Kettleman location. That’s not far from Avenal, where pistachio grower and processor Keenan Farms is headquartered.
“Despite the readings, what is the quality of this season’s chilling hours?” asks Eric Montemagni, the company’s grower services manager
Rains in December kept crews out of the orchards, delaying pruning for two weeks, he notes. But, those operations, as well as field sanitation were wrapped up, as usual, by the first part of February. Meanwhile growers have also been putting down pre-emergence herbicides.
Last year, pressure on the trees from the two main pistachio pests — plant bugs and navel orangeworms — was very light, Montemagni says. He credits growers with doing a better job of winter sanitation and monitoring insects, which has resulted in better timing of insecticides and more effective control.