What is in this article?:
- Many growers are still not using one of the best tools to monitor almonds’ most destructive pest — navel orangeworm (NOW).
California’s 750,000 acres of bearing almond orchards are heavily laden with what is projected to be another record crop.
It was just a decade ago when prophets of doom were saying the industry would collapse economically when the crop topped 1 billion pounds.
Since that ominous prediction, it has exceeded the billion pound mark nine out of the last 10 seasons. It is slowly climbing to the breathtaking pinnacle of 2 billion pounds in a season, a seemingly unimaginable level 10 years ago.
This year’s crop is estimated to be 1.75 billion pounds, and marketers say they’ll need every pound to meet a growing worldwide demand for California almonds.
The rocket ride to this season’s projected crop has also been equaled on the price side. When the naysayers were predicting the billion pound meltdown, the average price to growers averaged less than $1 per pound. Over the past decade, the average has not fallen below $1 per pound. The average over the past seven years has been almost $2 per pound.
It has been a series of crops obviously worth protecting, and overall growers and PCAS have done that well. However, University of California IPM entomologist Walt Bentley said many growers are still not using one of the best tools to monitor almonds’ most destructive pest — navel orangeworm (NOW). Failure to evaluate whether NOW poses a threat often results in unneeded sprays, he said at an almond management field day sponsored by the San Joaquin Sustainable Farming Project.
Bentley told growers and PCAs in Joe Del Bosque’s almond orchard west of Firebaugh, Calif., that almond meal bait traps will not provide pinpoint number treatment thresholds. However, they can provide a good overview of the presence or absence of NOW population levels and whether to treat to protect almonds before hull split.
The first line of defense against NOW is to destroy overwintered mummy nuts, almonds that were left hanging on the tree after harvest. These are perfect habitat for overwintering NOW. Removing them by shaking dormant trees and destroying the mummies is highly recommended. A lack of a winter sanitation project is an invitation for NOW damage without spring or hullsplit sprays.
NOW survive in these mummies and when the new crop hulls split, it is dinner time.
“Navel orangeworm will not get into your new crop in May,” but growers are protecting that crop when they control overwintered moths laying eggs, he said. That is not necessarily news to growers, who have been reluctant in the past to treat earlier than hullsplit because older pesticides could flare other pests like spider mites.
Bentley said newer, reduced risk insecticides do not spawn secondary pests and good coverage of these could have a significant impact on overwintered NOW before new crop hullsplit.