David Doll5 CommentsSeptember 13, 2014Insects

Scale and Lower Branch Dieback in Almonds

Written by Gurreet Brar, UCCE Farm Advisor (Nut Crops), Fresno & Madera Counties This summer we observed many cases of lower branch dieback in almond trees (like the one shown in picture). In many cases these symptoms were found to be associated with high scale populations. Diagnosis of such branches revealed that San Jose Scale and Walnut Scale caused lesions beneath the bark resulting in death of the tissue. These scales suck plant juices from the inner bark by inserting their mouthparts into twigs and injecting a toxin. When the populations become high enough, the numerous lesions may coalesce and cause the whole branch to die. Uncontrolled populations can kill branches within 1-3 years. San Jose Scale can be found on most, if not all, almond varieties. Walnut scale seems to like Monterey variety more than the others.

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David Doll4 CommentsJune 26, 2014Insects

Speed Doesn’t Kill Part 3: Economics

There has been a lot of research focusing on spray rig speed and spray coverage. Work by Jack Dibble back in the 70s-90s indicated that the best coverage is achieved at 1.5 MPH, and was the basis of the compromised recommendation of 2.0 MPH. This work has since been repeated by Dr. Joel Siegel (along with several collaborators) and Dr. Ken Giles and colleagues at Arbuckle, CA, and has indicated that at higher speeds, control of navel orangeworm (NOW) is lost in the upper canopy of the tree (>15′ high). This, interestingly enough, is where the majority of the crop is located. A few articles have been posted on this in the past (Speed Doesn’t Kill, Speed Doesn’t Kill, part 2).

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Franz Niederholzer0 commentsDecember 19, 2013Horticulture, Insects

Pruning Can Improve Pest Control

A replicated field trial in mature Non-pareil almonds at hull split using a diamide insecticide (Altacor®) measured better navel orange worm (NOW) control in the tops of pruned vs unpruned trees.  As regulatory and/or resistance issues with key pests (navel orange worm, alternaria, etc.) move the almond industry towards selective pesticides that require excellent coverage to deliver effective pest control, growers may want to review pruning options for young and mature trees with an eye to improving spray coverage in the upper tree canopy.    

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David Doll2 CommentsOctober 22, 2013Insects

2013 Navel Orangeworm Insecticide Efficacy Trial (Merced Co.)

We have completed our data analysis of our 2013 navel orangeworm trial from an orchard near Le Grand, CA. Below is the report: Objective:  To evaluate the efficacy Brigade (bifenthrin pyrethroid), Proclaim (Emamectin benzoate), Brigade+Proclaim, Altacor (rynaxypyr), Entrust (spinosad), Intrepid (methoxyfenocide), and two different rates of Intrepid Edge™ (spinetoram and methoxyfenozide, GF 3028) for control of navel orangeworm (NOW) timed at Monterrey hull-split in California almonds.

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David Doll6 CommentsMay 10, 2013Insects

Leaffooted Plant Bug

I have been several calls in regards to leaffooted plant bug (Leptoglossus clypealis and L. occidentalis). Damage has been reported from various areas of the county, with significant damage observed within some blocks. Leaffoted plant bugs get their name from the leaflike features found on the back legs of the large nymphs and adults. Adults are about 1 inch long and have  a yellow or white zigzag line across their back. Females lay eggs in strands which are often found on the sides of almonds or pistachios.

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David Doll3 CommentsApril 27, 2013Insects

NOW Biolure – 2 Different Moths in Trap

I have been hearing multiple reports of high counts of Navel Orangeworm (NOW) moths trapped with the new Suterra Biolure. We have placed our traps and have had high trap counts as well. In our liners, however, we have found two different moths – one being NOW  (Amyelois transitella) and the other being a meal moth (Pyralis farinalis). Both of these moths are within the same family (Pyralidae) and can be confused. 

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David Doll1 CommentApril 12, 2013Insects

Managing Mites in Almonds with Abamectin

Written By David Haviland, Kern County UCCE Entomology Advisor For more than a decade abamectin has played a key role in mite management programs in California almonds.  When applied properly, early-season abamectin treatments typically provide good mite control through hull split, and in some cases throughout the season.  Unfortunately, recent reductions in the cost of abamectin have led to unnecessary use, and sometimes abuse, of abamectin-based products.  This has led to more and more cases of unsatisfactory mite control at a time when mite management has taken an elevated importance due to increased adoption of pyrethroids for control of navel orangeworm.  This article covers several considerations that should be made while using abamectin to insure that it works effectively and consistently. 

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David Doll0 commentsApril 3, 2013Insects

Are the “Wild” Almonds Near You Harboring Navel Orangeworm?

Written by Bob Johnson – Almond Board UCCE Farm Advisor Intern As I drove down a county road near Arbuckle in the south Sacramento Valley, I noticed a significant number of mummies in the “wild” almonds growing in the ditch. With winter sanitation becoming much of the focus in NOW control, I wondered how many worms were overwintering in that patch of roadside almonds with commercial almond orchards on both sides of the road.  I pulled over and checked.  Of the trees that contained mummies, if it had a soft shell it was packed full of NOW. Dave Doll’s blog post in November stressed the importance of winter sanitation and presented recent data from Brad Higbee (Paramount Farms) and Joel Siegel (USDA-ARS). Their data provides suggested sanitation standards of no more than 2.0 mummies per tree in low pressure areas and less than 0.7 mummies per tree in higher pressure areas, to keep NOW damage below the 2% industry standard. What about one tree that contains hundreds of mummy nuts and is just on the other side of the fence? If sanitation is your goal, a quick drive around to identify trees with significant mummies along the roadsides near your orchard might be worth the time. Not every “wild” almond presents a problem, as some are hardshells and most contain no mummies, but you might consider removing those that do.

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David Doll0 commentsMarch 23, 2013Insects

New video for managing almond pests using the year-round IPM program

Not sure what you should be doing to manage pests for the upcoming season?  Check out the year-round IPM program for almonds on the UC IPM web site. Need help using it?  UC IPM has just published an online video to help you manage almond pests using the year-round program. How to Manage Almond Pests Using the Year-Round IPM Program is a narrated how–to guide written for growers, PCAs, and others who work in almonds, showing what needs to be done throughout the season to stay on top of pest problems.

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