Purpose: To assess a reduced pesticide risk system in a Kern County orchard.
Conducted by: Mario Viveros, U.C. Cooperative Extension, Kern County, Walt Bentley, UC Regional IPM Entomologist, Kearney Ag Center, James Brazzle, UC Cooperative Extension, Kern County, and Brian Hockett, Pond-Shafter-Wasco Resource Conservation District.
Cooperator: Thomas Vetsch from Vetsch Farms of California, Inc.
Location: Vetsch Farms of California at Pond.
The Orchard: This orchard consists of two-40 acre blocks of Nonpareil-Fritz-Sonora and two-40 acre blocks of Butte-Mission-Padre. The Nonpareil types and Butte types are caddy-corner to each other in a checker board fashion. (See diagram 1).
Objective: To compare a reduced risk strategy to a normal conventional pest management program.
Treatments: There will be two treatments and two replications in both Nonpareil type and Butte type varieties. The description of the two treatments are as follows:
1. - Conventional Normal Program:
a. Dormant Spray (OP or pyrethroid plus oil)
b. Winter Sanitation (less than one mummy per tree/acre)
c. Bloom and Foliar disease program- based on bloom and foliar development
d. Irrigation - based on grower practices
e. Fertilization - based on grower practices
f. PTB Control - based on dormant OP and June OP sprays
g. NOW Control based on sanitation, May and hull split OP sprays
h. San Jose Scale - Dormant and Crawlers sprays
i. Ant Control - based on OP sprays in Spring or Summer
j. Mite Control - based on Apolo early Spring and/or Omite in the Summer
k. Weed Control - Grower program (pre-emergence herbicides)
l. Resident vegetation on the middles.
2. - Reduced Risk System:
a. Dormant Spray (oil only).
b. Winter Sanitation (less than one mummy per tree/acres).
c. Bloom and Foliar Disease Program (based on weather forecasts).
d. Irrigation - based on stem water potentital.
e. Fertilization (based on June-July leaf analysis, water analysis and yields).
f. PTB Control. Bt sprays in early spring based on emergence.
g. NOW Control based on winter sanitation (less than one mummy per tree/acre.
h. San Jose Scale control - based on oil and IGR sprays.
i. Ant control - harvest with pistachio harvester and dry almond on a black surface.
j. Mite Control - based on a good irrigation schedule which will be generated from stem water potential monitoring. If there is a need to control mites, a reduced risk miticide will be used. Also, low rates of Omite will be considered with the augmentation of predator mites.
k. Weed Control. Only, contact herbicides and reduced width of the herbicide strip.
l. Cover Crops. (barley and other cover crops)
Procedure: Each 40 acre block will be divided into two 20 acre blocks. One will have the normal conventional pest management program and the other will contain the reduced risk program (See Diagram 2).
Navel orange worm, peach twig borer, San Jose scale, mites and ants will be monitored throughout the season. The monitoring will not be exclusive to these pests but also for their predators and parasites. To monitor all these pests, traps will be placed in the orchard at the appropriate time. Water stress will be monitored using stem water potential to establish proper irrigation practices. This is important for mite management, since past research has shown a relationship between water stress and mite problems.
Both the seeded cover crop and resident vegetation will be monitored for parasite and predator insects.
The nutritional status of the orchard will be monitored leaf analysis in June-July. This information will be the basis for an appropriate N-fertilizer program.
Soil moisture and water infiltration rates will be determined to assess the benefits of the cover crops.
At harvest time, we will assess the benefit of using the pistachio harvester in ant control, dust reduction and cost.
Dust control will be evaluated from both resident vegetation and seeded cover crops. Also, harvest efficiency will be determined between these to cover crops.
Temperature records will be kept by a hydrothermograph in the orchard.
Cost records will be kept from all activities in the orchard. They will be used for a cost-benefit study.
Data to be Collected:
Pests and their predators and parasites
1. N.O.W. (traps)
2. S.J.S. (traps and crawlers)
3. PTB (emergence)
4. Ants (wieners)
5. Mites (presence-absence)
Diseases - Spring and Summer
1. Blossom Blight and Brown Rot
2. Shothole
3. Green fruit rot
4. Alternaria leaf spot
5. Rust
6. Hull rot
Weeds on the berm and on the middles
1. Spring
2. Summer
3. Fall
Predator and beneficial insect population . Twice per month, April- November.
Leaf Samples - Nutrition Analysis
1. June-July
Stem Water Potential - once a week April-November.
Dust during harvest. Filter paper on stands.
Drying time for nuts - resident vegetation vs seeded cover.
Residual vegetation - resident vegetations vs. seeded cover.
Efficiency of nut removal.
Sampling for reject evaluation - All varieties
Yields: Nonpareil and Butte
Mummy Counts - Early February
Hydrothermographs - Every week