Soft spray program for pears
Though a no-organophosphate codling moth control program is more expensive at first, it’s not long before growers are saving money, says Bruce Kiyokawa, a pest control advisor with Chamberlin Distributing Company in Hood River, Oregon.
Kiyokawa works with several pear growers who are participating in an areawide codling moth program in Hood River. The first year of using mating disruption makes pest control more expensive, but the second year it’s a wash, he says, because growers are not applying as many pesticides. By year three, they start saving money.
“I think probably the impact of not spraying is getting to be larger now, with the price of labor and fuel,” he said. “It’s probably saving two to three trips with sprayers going through the orchard by doing this.”
Most growers in the program are using a full rate of NoMate or Isomate pheromone dispensers (400 dispensers per acre). After that, they do nothing unless trap catches exceed the treatment threshold. If a spray is needed during the growing season, most are using Altacor (rynaxypyr), which Kiyokawa says appears to be effective against codling moth without being disruptive to beneficial insects. Last season was the sixth year of the project for half the growers and the fourth year for the rest. He estimates that no more than 15 percent of the growers applied Altacor and none applied it more than once.
Growers report that control of their other key pest, pear psylla, has improved since the areawide program began. Kiyokawa said growers have an aggressive control program up to bloom time, but are cautious about applying pesticides after that stage.
They typically apply oil and sulfur at the delayed-dormant stage and an adulticide, such as endosulfan, to catch the psylla returning to the orchard after the winter. After endosulfan is phased out next year, they will be left with the option of using Nexter (pyridaben). Few growers in the area use kaolin clay for psylla control.
“Then, for the most part, we’re just playing a waiting game to see if psylla come up,” Kiyokawa said. “If they don’t, we do nothing. If they do, we may come in with Ultor.”
Ultor (spirotetramat) also appears to be quite selective and not harmful to natural enemies, he said. Perhaps half the growers have been using this product.
The option to use Altacor or Ultor when needed has been the key to helping growers transition to the softer program, he added. “Otherwise, we would be in big trouble trying to go soft off the bat. I think Ultor will always be somewhat of an important tool because I don’t think we’re always going to see low pear psylla populations. I think they go in cycles.”