NOW Infestations Still an Issue for Growers South of Madera

Brian German Industry, Pest Update

Navel Orangeworm (NOW) levels have improved, but NOW infestations continue to be a significant issue for growers that are south of Madera County.  Efforts to combat the pest were increased this year after dealing with sizable numbers of NOW populations that were seen last season.

“2018 levels are definitely better than the 2017 levels, but in the south valley, from Madera County south we’re still seeing some pressure.  On average, it’s within about a tenth of a percent of where it was a year ago,” said Director of Member Relations for Blue Diamond Growers Mel Machado.  “So better reactions, better controls in the north.”

NOW Infestations

Courtesy: UC ANR

Control methods such as mating disruption have proved to be most effective when other growers in the immediate area are also participating in the process.  “With two and a half million acres of habitat out there, between almonds, walnuts, and pistachios, it’s going to take a unified effort to really control things,” said Machado.

The expense involved with attacking Navel Orangeworm infestations is a worthwhile investment when considering the consequences of not actively addressing the issue.  “The example I use is 10 percent rejects, which there were people at 10 percent levels last year, people who had never been over two in their lives lived between 8 and 12,” Machado said.  “At 10 percent, on a 2,500-pound crop, at $2.50 a pound, it’s $1,700 an acre in losses.”

An important aspect to consider when combatting NOW is correct calibration of sprays and applying materials in an effective manner to have the biggest impact on pest populations.  “There’s a lot of expense in control; a lot of time and money invested in getting proper control, you got to make sure that machine’s doing the job correctly,” Machado noted.

A multifaceted approach to NOW populations that includes mating disruption, application treatments, and effective sanitation techniques will provide the largest benefits for controlling the pest.  “If I can take out a lot of that population with sanitation, it makes my treatments more effective.  And I really think that the mating confusion, again, will take out another layer of worms to make that final treatment more effective,” said Machado.


Listen to Machado’s interview below.


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Brian German

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Ag News Director, AgNet West