What is in this article?:
- Almond bait traps monitor pre-hullsplit NOW levels
- Bait traps
- When to spray
- Many growers are still not using one of the best tools to monitor almonds’ most destructive pest — navel orangeworm (NOW).
When to spray
When to spray remains a judgment call tempered by harvesting.
“If you have your own harvesting equipment, you can make a judgment call on when to begin harvest to avoid harvest time NOW damage,” said Bentley.
However, if a grower is dependent on a custom harvester to shake his trees and get the nuts into the trailers, it is a different story. Protecting the nuts at hullsplit or before takes on much more urgency.
“If you’re a 50 or 100 acre grower, you are the bottom man on the totem pole,” he said. “I would take a more cautionary approach to treating for navel orangeworm.”
Navel orangeworm did not get its reputation as the No. 1 pest in almonds without causing significant damage. However, “You cannot run scared. I hate to say it, but I have seen some horrendous (treatment) recommendations when spraying was completely off timing and in hard shell varieties,” Bentley said.
“Ask questions of the person making the recommendation. Do not be afraid to question the PCA,” he said.
“You want to take care of the problem you have without making unnecessary treatments.”
Leaffooted plant bug has surfaced as a problem this season in southern San Joaquin Valley almond orchards. However, Bentley has not seen the problem in the central part of the state.
Nevertheless, he urged growers and PCAs to be vigilant for the pest which is hard to monitor for its presence, but not for its damage.
“You should try to detect leaffooted plant bug early in the season. You are not going to find the bug as easily as you will the damage,” he warned.
Leaffooted plant bugs often retreat behind leaves when approached. Bentley said growers can use a large, metal garbage can lid to hold bottom side up under large limbs to catch falling leaffooted bugs or stink bugs when the limb is struck by a small bat or broomstick.
Leaffooted plant bug can damage nuts from the nutlet all the way to harvest. It can knock nuts off at bloom; suck juice out of formed nuts and even puncture mature nuts, leaving black spots on the kernel. Bentley said some packers are now discounting nuts for the spots, even though the leaffooted plant bug does not downgrade nut quality.
Leaffooted plant bug is particularly damaging to thin shell varieties.
They aggregate out of an orchard in places like an old shed or in pomegranates. They also can migrate early from pistachios to almonds.
As this year’s heavy tree loads mature toward harvest, limbs touch the orchard floor and become ladders for ants.
Look for colonies in orchards and use baits, if ants are present. “Baits are effective and relatively cheap,” added Bentley.
“Ants climb the limbs, not the trunks,” Bentley pointed out.