By Joel Siegel, USDA San Joaquin Valley Agricultural Sciences Center, Parlier, Calif.
Q: If I plan to double shake my pistachio orchard this season to maximize yields, do I have to be more concerned about navel orangeworm (NOW) control? If so, how should I alter my control strategy?
A: The addition of a second shake is extending pistachio harvest into mid-October. It helps growers capture more harvest but also brings increased threat of navel orangeworm (NOW) damage as multiple generations have more time to develop.
This year’s weather conditions have pushed NOW populations to extremely high levels in many areas. Growers need a NOW control strategy that provides sufficient protection longer into the fall. Consider a three-spray insecticide strategy with alternating modes of action to protect your valuable crop in a high pressure orchard.
Under a three-spray program, the first application is made in mid-July to knock down the population early in the season and prevent buildup of NOW populations. The second spray is applied in early August and the third spray follows in early September.
Activity from late applications with pyrethroid insecticides may not provide enough protection for a late harvest. You need to rotate to alternative chemistries, such as a diamide, for longer-lasting protection, but also consider preharvest interval when planning applications.
The key is to avoid treating successive NOW generations with the same insecticide or insecticides that have the same IRAC group number. Sole reliance on inexpensive pyrethroids is going to backfire in the long run. Last season, farmers who used some pyrethroids back to back didn’t get the necessary control, which cost them at processing.
Consider using one of the newer products (diamide) for the first spray, a pyrethroid for the second spray, and another change in chemistry for the third spray, so you’re not using any single chemistry back to back.
• DuPont™ Altacor® insect control powered by Rynaxypyr®, is an effective anthranilic diamide (Group 28) insecticide that provides long residual control and ovicidal1, ovi-larvicidal, larvicidal and adult activity2,3 on NOW. It is an important part of an effective control program. For resistance management purposes, avoid treating successive NOW generations with the same insecticide or insecticides with the same group number.
1Significant ovicidal activity is observed at varying levels depending on pest species. Activity is maximized when eggs are laid onto treated surfaces.
2Disruption of adult insect behaviors in some pest species (e.g. CM, OFM) such as mate finding, mating, oviposition, feeding, locomotion and orientation.
3Adult mortality is species, application rate, exposure level, and time dependent for NOW (based on lab and field studies).
Always read and follow all label directions and precautions for use when using any pesticide alone or in tank-mix combinations. The DuPont Oval Logo, DuPont™ The miracles of science™ Altacor® and Rynaxypyr® are trademarks or registered trademarks of DuPont or its affiliates.