Disease Archives - Page 2 of 8 - West Coast Nut



Mite Pressure Up in Walnuts

PCAs and growers reported high mite pressure in walnuts last year, particularly in the Sacramento and northern San Joaquin valleys, according to UCCE Farm Advisors Franz Niederholzer and Luke Milliron as well as Area IPM Advisor Jhalendra Rijal. “Usually, in walnuts, you have some mite activity,” said Rijal, an advisor for the northern San Joaquin Valley. “But usually, it is late in the season. This past year, they started in the early part of the season.” Mite presence late in the season generally is not problematic, Rijal said, given that by then, predatory mite populations have built up and the...

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Winter Prep in Walnuts

December and January provide ideal opportunities for walnut growers to get a head start on weed and disease control programs. In terms of weed control, that may mean laying down some long-residual preemergence herbicides to keep orchard floors clean going into spring. In terms of disease control, the early winter is an ideal time to measure walnut blight inoculum levels and prepare your season-long control strategy. Luke Milliron, UCCE farm advisor for Butte, Glenn and Tehama counties, said most growers have a good sense of the walnut blight inoculum in their orchards from monitoring nut drop the previous May, June...

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Five Things That Worked for Pest Control in 2021 — and a Few Things That Didn’t

PCAs interviewed at the 2021 Crop Consultant Conference and in the field emphasized nutrition, sanitation, tracking degree days and mating disruption as their major tools to keep crop damage low in tree nut crops this year. No surprise that navel orangeworm (NOW) and mite control were their two biggest challenges throughout a hot and dry summer, but they all had strategies that worked as well as some that worked less effectively. What Worked Their five most successful strategies for pest control in 2021 were: Sticking with a Plan “We had a good pest control plan,” said David Vieira, PCA for...

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Biopesticides Complement Traditional Insecticides for Resistance Management and Residue Limits

With biopesticide use, it’s more about returns and less about risk. It is a safe bet that most tree nut growers have heard of biopesticides and their use to control pests and diseases in orchards. Many have questions about biopesticide efficacy and cost compared to their synthetic counterparts. Growers understand that reducing their use of synthetic pesticides while maintaining control of damaging insects and diseases is a positive move, but they also take a hard look at their return on investment. Biopesticides are pest and disease control materials that are derived from plants, microorganisms and other natural substances such as...

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Almond Leaf Scorch: A Periodic Disease in Almonds

An almond disease that has been present in California since at least the 1950s raised concerns last year among growers and UCCE advisors when symptoms began showing up in Sacramento Valley orchards. Although this disease has been present for at least 70 years, UCCE advisors noted that it only surfaces periodically. They also reported that warmer summer and winter temperatures appear to increase disease prevalence. There is a concern that ALS could move from a minor issue for the industry to a potentially serious problem as the climate changes. ALS has predominantly been found in the Sacramento Valley. As reported...

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