My UC colleagues are understandably critical of my strong support for mating disruption, since they have not yet developed data to support its performance in pistachios. My question to you is – do you want to wait three years for the data on a concept that has successfully reduced economic pest damage in all the other crops in which it has been implemented?
Mating disruption is currently used for oriental fruit moth in shipping fruit, and codling moth control in apples, pears, and walnuts.
Codling moths love apples and pears. In non-mating-disrupted orchards, if you get five moths a week you can have a potential disaster. Unlike NOW in nut crops, codling moth is attracted to pome fruits constantly, so their populations have to be kept very low. If you read about these crops on the UCIPM website, it states that mating disruption works best in large orchards, square in configuration.
It also states that mating disruption is not a stand-along program.
In these highly sensitive crops, properly selected and timed insecticide sprays are necessary to keep codling moth populations below economic injury levels. The IPM website also states that sanitation is a must to reduce overwintering insect populations.
Now, I do not have the data to support the following statement, so I offer it as my strong opinion:
Community-wide implementation of mating disruption in pistachios is a very powerful tool. In combination with winter sanitation and properly timed and executed insecticide sprays, it is the most powerful NOW program we have for long-term suppression of lepidoptera pests. We have no reason to suggest that NOW, a lepidopteran insect, will behave any differently than codling moth or oriental fruit moth.
In fact, we have pistachio growers who have implemented the above program, and they report dramatic reductions in NOW damage at harvest in orchards with high pest pressure. If you are suffering excessive NOW damage in your pistachios, I believe you owe it to yourself to use all the tools available to suppress this insect, because the damage penalties from the processor are only going to get tougher, resulting in substantial loss of income.
Why does this not make sense? Do you think this year is the one in which NOW is going to give you a pass? Do you want to wait until it is proven without a doubt that mating disruption is an effective NOW management tool in pistachios?
As you contemplate your response, please remember one aspect of NOW that has changed dramatically over my career – the vast amount of nut crop acreage, especially almonds, provides a continuum for sustaining NOW populations.
As soon as NOW gets done infesting the almonds, they are coming after you when the almonds are harvested. You are messing with Jaws, and need a bigger boat.
I will stand on stage and eat a pair of dirty underwear if properly employed mating disruption fails in pistachios. Thus far, growers who have implemented it as one additional tool – with proper monitoring and insecticide supplementation – have reported less damage at harvest and increased income sufficient to pay for the additional cost.
Ultimately, we seek long-term suppression of NOW in the San Joaquin Valley. I believe sanitation, mating disruption and professional insecticide treatments are the way to accomplish this.