Newsletter Archives - Page 3 of 42 - West Coast Nut



Step-By-Step Diagnosis of Tree Disorders

It takes critical evaluation of the tree and the environment to correctly diagnose disorders in an orchard. In a presentation for the virtual 2020 UC Pistachio Production Short Course, Richard Heerema, New Mexico State University Extension pistachio and pecan specialist, outlined a step-by-step guide to field diagnostics. The process is meant to determine the cause of an abnormality and requires a team effort that includes the grower or farm manager, extension advisors and diagnostic clinic. The list of biotic causal agents includes fungi, bacteria, viruses, phytoplasma, nematodes and insects and mites. Abiotic causes of tree disorders include soil moisture extremes,...

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Rootstocks Evaluated for Nematode Susceptibility

The reputation of pistachio trees being resistant to plant-parasitic nematodes stems from times when different rootstocks were used. With the changing parentage of current and future rootstocks, careful investigations need to be done to prevent the development of highly susceptible rootstocks. “We are trying to determine which rootstock parents have susceptibility. While some Pistacia species likely have an above-average proportion of nematode-susceptible plants, it is not that clear in others,” said Andreas Westphal, UC Riverside nematologist. Pistachio orchards are generally planted on heavier ground that is less likely to have high population densities of some plant-parasitic nematodes. Other species like...

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Walnut Scale Can Lead to Higher BOT Infection Rates

Walnut scale and Botryosphaeria (BOT) are not new issues in walnut production and separately can affect tree health. Their interaction, with scale providing openings for the fungal invasion, is gaining attention. UCCE Farm Advisor Elizabeth Fichtner reported that walnut scale feeding causes lesions on tree shoots and spurs. The lesions can open the site for BOT infection. Scale on a prior year’s growth may predispose new growth to disease. Walnut trees with scale infestations are 60% to 70% more prone to BOT infection, Fichtner wrote. Walnut scale is an armored scale where the cover is separate from the body. Walnut...

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Temperatures May Affect Hull Split Timing

Fluctuating temperatures this spring may serve as a warning to almond growers and PCAs that timing hull split sprays for navel orangeworm control could be challenging. Almond Board of California reports that it is important to anticipate hull split and time spray applications for navel orangeworm control as well as prevention of peach twig borer damage and hull rot. Early hull split is when the hull begins to separate at the suture. If the second generation of NOW is emerging from the mummies, the nut volatiles released at hull split signal the female NOW to lay eggs on the suture....

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2022 Almond Acreage and Crop Reports Released

California’s almond acreage continues to grow, but at a gradually slowing rate, according to two new reports released in April by the Almond Board of California and USDA National Ag Statistics Service. While the number of almond orchards removed also increased over the previous year, it was not enough to offset the overall acreage gains. Meanwhile, the NASS subjective crop report released May 12 predicted the almond crop harvested in 2022 will come in at 2.8 billion pounds, 4% below last year’s record 2.92 billion pounds. Forecasted yield is 2,040 pounds per acre, 8% below the 2021 yield of 2,210...

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