Sponsored by:
www.brandt.co
dynamics. So, it’s important to scout for early splits every year to monitor and keep track of them. Winter sanitation is important, but even good winter sanitation doesn’t mean there won’t be problems with NOW. Nearby or- chards might not have had the same level of sanitation, meaning there could be NOW in the vicinity that create problems. This makes monitoring critical for NOW, especially if there are a lot of early splits. The developing kernel is visible in early splits. NOW will move inside and start feed- ing on the kernel, and the worms can develop very quickly. The pistachio kernel is very nutri- tive, so they can develop faster in pistachios than almonds. If monitoring shows NOW in early splits, growers should begin spray appli- cations. There are enough spray options that growers can rotate through different chemi- cals and reduce the risk of building resistance.
The first generation of the overwintering navel orangeworm emerges in May and the second generation in mid-July. If there are early pistachio splits, they move into them and feed on the kernel. This creates prob- lems when the third generation emerges later in August. If an orchard has a lot of early splits, it is very likely there will be more NOW damage be- cause the worms will reproduce and increase in numbers. As the third generation emerges during hull split, that can result in damage at harvest. So far this year, early splits have been above average. Many growers have made chemical applications because of early splits and NOW activity. Early splits are seasonal. Some years, there are more splits than others. With on-crop years, there tends to be more early splits, but not al- ways. Every ranch and every season has its own
PEST CONTROL ADVISOR
How do navel orangeworms affect pistachios?
Mateo Marquez, Integral Ag Services, Durham
MEMBER
Take Control of Your Nutrition.
Get Started!
www.brandt.co
August 16, 2023 Ag Alert 11
Powered by FlippingBook