Start Early With Hull-Split Sprays for NOW Control

Almond at hull split
Joel Siegel, Ph.D., entomologist, USDA Agricultural Research Service

More Almond Acres, More Pest Pressure

Almond acreage has increased in recent years, with many new trees being planted in existing almond-growing areas. This increase in the number of trees has the potential to increase NOW populations, which means growers need to do a better job of pest management.

In the southern part of the San Joaquin Valley, NOW pressures have become heavier and more predictable and growers have adjusted their product rotation and application techniques, notes Joel Siegel, Ph.D., entomologist, USDA Agricultural Research Service. “Growers on the northern end of the valley, where NOW appearance had been more sporadic, are seeing more regular and longer NOW pressures and need to alter their budgets and spray plans accordingly.”

Scout and Treat for NOW Control

Growers should begin monitoring trees in mid-June for early signs of hull split, says Siegel. “Protecting the nut crop from second-generation NOW egg-laying is critical at hull split, and the first spray should be made at or before 1 percent hull split.

It’s better to err on the side of caution and make the first application several days early than to be several days late, he adds. “Almond blanks split about five days before intact almonds, so that’s a good sign to prepare for the first application.  DuPont™ Altacor® insect control is a good option because its duration of activity provides some flexibility in that first application, and it can be applied again 10 to 14 days later for optimal results.”

In areas with heavy NOW pressure, employing two 4.5-ounce applications of Altacor® powered by Rynaxypyr® made 10 to 14 days apart, beginning at early hull (1 percent hull split) is an effective way to combat NOW. This “two-shot” strategy allows growers to apply two layers of residual protection to almond hulls and shells that are at various stages of splitting and exposure, providing a one-two punch against second-generation NOW.

Steps for Managing Heavier NOW Pressure

  • Start monitoring for hull split at the edges of the orchard, where trees get the most sunlight and heat.
  • Get good spray coverage. That may require slowing down to ensure thorough coverage to the tops of tree canopies.
  • Adjust spray budget. Increased NOW pressure and an additional generation within the season will likely require another pass or two.
  • Don’t cut corners. If NOW populations aren’t controlled, they could impact this season’s crop yield and quality and make insect pressure that much worse next year.
  • Develop a resistance management plan. Rotate insecticide modes of action to ensure successive generations of the same pest aren’t treated with insecticides belonging to the same group.
  • Know what your neighbors are doing. NOW can easily fly up to 3 miles (10 times farther than codling moth) so coordinating treatment timings with neighboring producers can make control more effective for everyone.

Great Fit at Early Hull Split

Altacor® is effective against NOW and other damaging insects, including peach twig borer and oriental fruit moth. It provides ovicidal,1 ovi-larvicidal, larvicidal and adult activity2,3 on NOW for flexible, lasting residual control. While strong on NOW, Altacor® is soft on predators and parasitoids, and will not flare spider mites or cause other secondary pest problems.

In areas with heavy NOW pressure, employing two 4.5-ounce applications of Altacor® 10 to 14 days apart, beginning at early hull (1 percent hull split) is an effective way to combat NOW. This “two-shot” strategy allows growers to apply two layers of residual protection to almond hulls and shells that are at various stages of splitting and exposure, providing a one-two punch against second-generation NOW.

1Significant ovicidal activity is observed at varying levels depending on pest species. Activity is maximized when eggs are laid onto treated surfaces.
2
Disruption of adult insect behaviors in some pest species is observed (e.g., codling moth, oriental fruit moth) 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).
DuPont Altacor® is not available in all states. See your local DuPont sales representative or retailer for details on availability.
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