In the 2021 growing season, hot and dry conditions across the Central Valley led to an increase in pest populations, with the ever-challenging navel orangeworm (NOW) being one of those pressures. In addition to the drought conditions, wildfires swept across the West Coast, and in some orchards the smoke formed a barrier between the sunlight and the trees. This led to almonds not being able to dry as quickly, giving NOW moths the chance to increase their populations.
With the challenges Mother Nature threw our way in 2021, and if the drought continues, it’s anticipated NOW populations will be high in 2022. When left uncontrolled, a single female NOW can produce at least 150 eggs. It’s important growers use strategies that not only protect against larvae but also control NOW at all life stages. After all, a couple of moths can produce an infestation within a very short amount of time. An infestation can cause a loss of 30-40% of an orchard’s yield and create quality issues that reduce the price a grower can receive for their almond crop. Remember, damage in the field is twice what is assessed on the grade sheet because severely damaged nuts are eliminated before grading.
TO HELP REDUCE GROWERS’ NOW RISK IN THE COMING SEASON, CONSIDER SHARING THE FOLLOWING TIPS WITH YOUR GROWERS:
DON’T SKIMP ON SANITATION.
Sanitation is the first line of defense in any NOW management plan and will be key for 2022 due an increased mummy load from unharvested nuts due to weather. Shaking or poling first and then destroying any mummies that have fallen to the ground at the end of the season can prevent NOW from taking hold in the off-season or at least significantly reduce the potential for an infestation during the growing season. Beyond this step, control is all about a strong insecticide plan.
PERFECT INSECT CONTROL SPRAY TIMING.
“If a grower planned their insect control applications based on calendar year 2021, those growers likely applied too soon,” said Issa Qandah, technical services manager for FMC. “If a spray occurred at the end of June into the first 10 days of July, not only did they miss the contact to the growth stages of NOW, but in some areas the nuts at this time were still closed because of the weather, which does not protect the vulnerable nut tissue of the plant.”
It’s important growers use multiple sprays and time them properly to ensure all nuts are protected from NOW, even if they open at different rates. Almonds are at a higher risk as the hull opens more and even more during ripening. So it’s critical to time and layer sprays to help prevent damage from NOW.
"A selective insecticide such as Altacor® insect control is a good fit for that key early hull split application,” said Joel Siegel, Ph.D., research entomologist with the USDA Agricultural Research Service and coordinator of the USDA NOW Research Program. “It is highly toxic to larvae when ingested, has good activity against NOW eggs and also has activity on adults. In addition, growers can make two Altacor insect control sprays 10-14 days apart to protect newly exposed, vulnerable nut tissue.”
Siegel recommends applying Altacor insect control powered by Rynaxypyr® active at the full 4.5 oz./A rate when making back-to-back sprays 10-14 days apart. He also notes growers should never skip a row and spray at a speed of 2 mph.
PAY ATTENTION TO THE NEIGHBORS.
“If you notice a grower’s neighbors are starting to shake nuts off their trees, that will stir the NOW population up, and they will begin moving to adjacent orchards,” says Siegel. “If their neighbor is shaking eight to nine days before they do, make sure they’re taking a look at their own orchards and their nut vulnerability and plan accordingly.”
TO LEARN MORE ABOUT ALTACOR INSECT CONTROL AND HOW IT CAN HELP PROTECT YOUR GROWERS’ ALMOND ORCHARD FROM NOW, VISIT YOUR FMC RETAILER OR ALTACOR.AG.FMC.COM.
Always read and follow all label directions, precautions and restrictions for use. Some products may not be registered for sale or use in all states. FMC, the FMC logo, Altacor and Rynaxypyr are trademarks of FMC Corporation or an affiliate. ©2021 FMC Corporation. All rights reserved. 21-FMC-0742 10/21