Strong interest in one of the state's more drought tolerant crops drew a large crowd to the annual state-wide Pistachio Day held Jan. 15 at the Visalia Convention Center. "There used to be a lot of familiar faces at these, but there are a lot of new faces now", said Madera pistachio grower Larry Lowder during a break in the presentations.

Presentations by University of California Cooperative Extension advisors focused on some of the more pressing issues in the pistachio industry. Water supply concerns for many growers, especially those who rely on canal water, were addressed by UC irrigation specialist David Goldhamer. "Pistachio trees will survive without water, but they can't give high production", he Goldhamer said. Goldhamer outlined some of the extensive research on water needs in pistachio trees done over the past several years in the Kettleman City area. Knowing the trees are tolerant to water stress, Goldhamer said they evaluated the sensitivity of each stage of growth to water stress.

Of the three stages of crop growth, the most critical time for water stress, he said, is the third - late July to harvest. Goldhamer said nuts will be smaller, there will be a decrease in shell split and total yields could be reduced by two-thirds. During earlier growth stages and post harvest, he said, the trees can weather deficit irrigation. The ideal time to save water is the six weeks from May to July when there is not much going on with the nut crop.

Kern County advisor Craig Kallsen provided information on new pistachio varieties, one that has potential to spread out the crop's narrow harvest period. That is an important consideration, he said, because 98% of the trees in production now are the Kerman variety, and there will be increasing demand for labor and equipment during the harvest period. The Golden Hills variety, which was released in 2005, he said, matures two weeks to 10 days earlier than the Kerman. The hotter temperatures of late July also cause a higher percentage of splits, an important consideration in pistachios.

"We will get in a bind if we keep only planting Kerman", Kallsen said. The variety uses the male pollinator variety Randy, which is also earlier than the pollinator for the Kerman variety. It produces good quantities of pollen, Kallsen said. Another advantage to the early harvest is possibly evading some damage from the navel orange worm by missing the third flight of the season. Comparing yields, Kallsen said the Golden Hills averaged 7,600 pounds per acre with 45 percent more edible split. During tests from 2002 to 2007 the Golden Hills produced 943 more pounds per acre in Kern County. He said Madera area yields were less.

Another variety being tested is the Kalehghouchi, an Iranian variety that Kallsen said is also early maturing. Nut size is this variety's advantage. There is no yield advantage, he added, and while it is a little earlier than the Kerman in maturing, it will not appreciably spread out harvest. USDA entomologist Joel Siegal reported on the 2007 attack of the navel orange worm. "It was an epidemic. It inflicted more damage than expected", Siegal said.

He noted that almost a third of all loads delivered to processors last year had 2 percent navel orange worm damage. As a result, he said, loads were rejected or downgraded, plus growers had the increased cost of field sanitation. On the processor side, there were added costs to remove damaged nuts, along with quality concerns. Siegal said one of the biggest problems the pest can cause for the California pistachio industry is a loss of competitive advantage.

Another pest that appears to be spreading through the state's pistachio producing regions is Ferrisia gilli, or Gill's mealybug. David Haviland, a Kern County entomologist said about 5,000 acres in 10 counties were infested last year. The pests can cause staining of shells and an increase in closed shells and "sticktights." Haviland said the pest is easily spread from orchard to orchard by harvesting equipment because pest activity is high at that time. There is potential for biological control, he said, but due to permethrin sprays in pistachios, mealybug predators are usually wiped out.

Although California's pistachio industry has made huge gains in acreage in the past 10 years, growers experienced a loss last year when the state marketing order California Pistachio Commission was dissolved. In its place is the newly organized California Pistachio Research Program. It was approved by a near unanimous vote by growers. The program will be funded by a mandatory one-quarter cent per pound assessable weight of pistachio.

The program is authorized to conduct research on propagation, production, harvesting, handling and preparation for market and to educate producers on the research results. There is no advertising or volume control components in the program. The voluntary Western Pistachio Association is expected to handle some of those duties, although assessments won't equal those of the commission.