Stanislaus County Almond Pest Management Alliance Project 

2002 Progress Report, Nov. 27, 2002

Roger Duncan, UCCE Farm Advisor, Stanislaus County; Walt Bentley, IPM Advisor, UC Kearney Agricultural Center, Parlier; Joe Reis, Field Technician, Stanislaus County UCCE; Merlyn Garber, grower; Art Bowman, pest control advisor, Salida Ag Chem

Objectives of the Stanislaus County Almond Pest Management Alliance project:

·        To scientifically evaluate the long-term effectiveness and economic viability of less broadly toxic pest management programs.

·        To extend gained information to the almond industry.

·        To demonstrate IPM monitoring techniques and decision-making processes.

We have completed our fourth season in the Stanislaus County PMA trial.  The original three pest management regimes were maintained similar to the first three years (grower’s standard practice and two “reduced risk” treatments).  The only difference in 2002 was that Omite was used for mite control in all plots.  Because reject levels have been very low for all pest management regimes throughout the trial, a fourth, “untreated” program was added in 2001.  Each pest management program is replicated three times within a 120 acre Nonpareil: Carmel orchard west of Modesto.  Each plot is approximately 13.5 acres in size.  The treatments are:

1)                  Grower’s Standard Practice: (fairly common in the Northern San Joaquin Valley).

¨       A dormant application of Asana^® (a pyrethroid), 6 gallons of oil, & 8 lb. Kocide^®.

¨       A May spray with an organophosphate (Lorsban).

¨       Lorsban for ant control.

2)                  Soft Program #1:

¨       A dormant application of copper & oil (no insecticide).

¨       A “bloom” spray of Success^® at ~ 30% PTB emergence (piggy-backed with fungicides).

¨       A May spray of Confirm^®.

¨       Clinch^® (Abamectin) bait for ants if monitoring deems necessary.

3)                  Soft program #2:

¨       A dormant application with oil only.

¨       Two “bloom” applications of Bt (@ ~20% PTB emergence & ~ 80% emergence).

¨       Two May sprays of Bt (300-350 & 450-500 DD after biofix).

¨       Esteem^® bait for ants if monitoring deems necessary.

4)                  “Untreated”:  only mites and ants are controlled if necessary. 

¨       No dormant copper, oil, or insecticide application.

¨       No bloom insecticide applications.

¨       No May or hull split sprays.

¨       Esteem^® bait for ants if monitoring deems necessary.

Overwintering nuts (“mummies”) were removed and destroyed in all treatments to reduce overwintering naval orangeworm.  Cover crop management, fertilization, and fungicide treatments were the same for all treatments other than no dormant copper was applied in “soft program #2” and the “untreated” areas.

Monitoring:

Each plot had two PTB pheromone traps, two San Jose Scale pheromone traps, four sticky tape traps for S.J. scale crawlers, and two NOW egg traps for a total of 120 traps in the trial.  Peach twig borer and naval orangeworm traps were checked twice weekly while San Jose scale pheromone traps were monitored bi-weekly throughout the season (March through September).  In addition, mites and mite predators were monitored bi-weekly with the presence / absence leaf sampling technique.  Ants were monitored twice using hotdog bait.  In the fall, spurs were sampled to monitor San Jose scale populations.

Results:

Pest and beneficial arthropod populations were very low throughout the season, regardless of treatment.  There were no differences between treatments in peach twig borer trap catches, naval orangeworm egg laying, spider mite numbers, San Jose scale trap catches, or scale parasitoids. Spur samples collected after each growing season have shown almost no San Jose scale present in any of the treatments. Due to our error, we were only able to secure harvest samples from one of the three treatment replications.  Analysis of these samples showed only 1 out of 500 kernels (0.2%) with ant damage in Treatment #1 and 2 out of 500 kernels (0.4%) with ant damage in the Treatment #2.  All other samples were zero for ant, NOW and PTB feeding damage.