<p>Most Californian pistachio growers have received the required amount of chill hours this season, though some are questioning whether they were of sufficient quality to ensure a good harvest.Pistachios need around 800 hours of temperatures below 45 degrees F, between November 1st and February 15th. Andy Anzaldo, general manager of grower relations for Paramount Farms, Lost Hills, Calif. says that man hours were recorded, except for in a few isolated areas.“For the first time in a long time, the vast majority of those hours came in January and February compared to November and December,” he says. “There’s a theory in the industry that it’s more important for good dormancy to get more hours in the first half of the chill than later. We’ll be able to test that theory with the bloom this year.</p> <p>“There’s some concern that the warm afternoon temperatures may have negated the chilling effects of the much cooler morning temperatures,” Anzaldo says. “Again, we’ll know more when the trees bloom.”It maybe that this year's bloom does not occur until the second half of April, around two weeks later than usual. This will reduce the risk of frost damage, as the later the blossom the safer it is.</p> <p>This year is an off year for California orchards, though it is thought the yield may still be more than expected. In 2012, California’s on-year production averaged about 3,100 pounds per acre. That’s 500 pounds less than usual for an on-year crop.At the same time, though, last year’s moderate on-year yields may have left the trees with enough energy to produce above-average off-year yields this time. Or, so goes another industry theory, Anzaldo notes.One strictly non-theoretical industry development last year was the extensive amount of damage to California’s pistachio crop caused by the navel orangeworm.One reason for the heavy navel orangeworm damage last year was the higher-than-normal overwintering NOW population from the 2011 season, Anzaldo says.</p> <p>Record heat last July and August compounded the problem. The hot weather caused an unusually large number of hulls to shrink and split, allowing the larvae easy access to feed on the nuts.The worm exacted a heavy toll from growers last year. Processors rejected 1.9 percent of the nuts they received due to damage from the insect. That’s nearly 2 percent of the crop for which growers received no payment.“Paramount growers lost an average of $375 an acre or 11 cents a pound from navel orangeworm damage associated costs,” Anzaldo says. “On an industry-wide basis that represents a total loss to growers of about $60 million dollars on last year’s 552-million pound crop.”</p> <p> </p>