Pistachios Archives - West Coast Nut



Taking the Mystery Out of Rootstock Selection in Pistachios

Interest in planting pistachio trees continues to grow in California, but many growers, even those with experience in pistachio production, may not be aware of all the basics of rootstock selection for their orchards. UCCE Tulare County farm advisor Elizabeth Fichtner said she receives many questions from new growers about pistachio rootstocks, including differences between seedlings and clones and how they are produced. Fichtner’s presentation at the annual Statewide Pistachio Day was directed at answering many of the questions and “demystifying rootstocks.” In the past 10 years, Fichtner said, there has been an overlap in tree nut production, with walnut and almond growers moving into planting pistachios. The terminology used in rootstock production is not uniform across all nut crops and can be confusing to new growers. Rootstocks comprise the roots and crown of trees and are selected for certain horticultural characteristics as is the scion that is grafted to...

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Understanding Physiological Effects of Winter Chill in Pistachios

Gurreet Brar hopes to determine not only what it will take to boost pistachio yields following warm winters, but the reason why trees fail to produce in the absence of winter chill and whether and why treatments improve yield. The understanding, Brar said, will help researchers provide a science-based solution to what has become a persistent problem in recent years: low chill accumulation in winter months. Brar, an assistant professor in the Department of Plant Sciences at California State University, Fresno, is in the midst of four-year study analyzing several issues surrounding chill requirements in pistachios. Among issues he is studying: How trees respond to changes in temperature, or the physiology of chill accumulation and dormancy break in pistachios; and how pistachio trees respond to horticultural oil, an input that growers use to offset low chill accumulation. Researchers in Brar’s lab are collecting flower buds from early January through March...

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What We Know About Winter Chill and Pistachios

Eighty-degree days in the month of November did not send California pistachio trees into their winter rest period on schedule. With harvest at an end and irrigations done to fill soil profile, the trees were primed to enter their needed dormant stage, but warm days and barely cold nights are not conducive to sending pistachio trees into dormancy. (Editor’s note: the end of the month brought some welcome cold to pistachio growing regions in the San Joaquin Valley. How the remainder of the dormant season plays out is yet to be seen.) Industry Research Industry research has determined a lack of sufficient hours below 45 degrees F affects the nut crop that develops in the spring. There can be poor fruit bud development, delayed or strung out bloom and poor overlap with pollinators. The ability to set a crop can be affected as well as maturity timing resulting in need...

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Winter Prep for Pistachios

Almonds and walnuts may be California’s heavy hitters in the tree nut market, but pistachios also hold a valuable place, even if this crop experiences less of the spotlight, and has less research that finely tunes the growing processes. “There’s no step-by-step guide because everyone does different things,” says Craig Kallsen, University of California Cooperative Extension (UCCE) farm advisor specializing in citrus and pistachios. Even though there aren’t any hard and fast rules about pistachio orchard best practices, there are a few things growers can do to ensure their orchard remains healthy during the winter months. Slowing Growth A significant step in the preparation for winter for pistachios begins in August when the water gets turned off. This is especially important for young trees under six years, and in areas where there is not a significant transition from summer to winter, as these trees suffer from juvenile winter...

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Postharvest Pistachio To-do List

When the last truckload of pistachios rolls out of the orchard, it’s not the time to relax—it’s time to prepare for a successful harvest next year. Guidelines for postharvest pistachio management by University of California (UC) Davis researchers cover all postharvest activities necessary to ensure a quality crop for the next year. Pest control and crop advisors also have their own checklists that cover specific challenges and growing conditions in their individual orchards. Evaluate IPM Plan Since insect pests and diseases are often the cause of poor yields and quality in a nut crop, a postharvest evaluation of the current integrated pest management (IPM) plan for an orchard is in order. Spray application times, additional control activities and monitoring records prior to control and after should be reviewed. Orchard sanitation remains the cornerstone of pest management in pistachios, as it is proven to reduce numbers of navel orangeworm (NOW) in...

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