- Author: Jodi Azulai
- Posted by: Brooke Jacobs
UC IPM has completed another tutorial about using the degree-day tools on our Web site to go along with Walt Bentley's presentation about degree-days to time insecticide applications in fruit and nut orchards.
Peach twig borer larvae damage growing shoots and their feeding creates shallow channels and surface grooves in the nutmeat. Accumulating degree-days let's you know the best time to manage peach twig borer—when peach twig borer larvae are young and before they have chewed their way into shoots where they're protected from insecticides.
According to the Almond Pest Management Guidelines, put out pheromone traps to determine the biofix:
- Place one peach twig borer pheromone trap per 20 acres (but never less than two traps in smaller orchards) by March 20 in the southern Central Valley and April 1 in northern areas.
- Monitor twice a week to identify the biofix date (when the first male is trapped in April).
- Start accumulating degree-days on the biofix date.
Monitor trees for shoot strikes in mid-April. Make sure strikes are caused by peach twig borer and not Oriental fruit moth. If several strikes are seen in each tree by late April, a spring insecticide application may be necessary. Time it to kill first-generation larvae before the majority of them chew their way into shoots:
- 300 to 400 degree-days after biofix, if applying insect growth regulators
- 400 to 500 degree-days after biofix, if applying conventional insecticides
For more information about peach twig borer see the UC Pest Management Guidelines for almonds. For more information on degree-days visit our degree-day web page.
- Author: Brooke Jacobs
Our second annual Pomology extension course finished with a fun, and only slightly rainy, four day field tour throughout California. Course instructors Professor Ted DeJong (Professor, UC Davis), Carlos Crisosto (Cooperative Extension Specialist) and I drove twelve passenger vans north to Corning, south to Hanford, and many points in between. Thirty of the students from the first week of our course stayed on to tour a wide range of UC experiments, processing and packing facilities, nurseries and orchards.
This year our field tour was jam-packed with help from our UC ANR farm advisors and specialists. I would like to thank the following UC ANR advisors and specialists for contributing interesting and unique stops to our field tour.
- Franz Niederholzer, UCCE Farm Advisor and Director of the Nickels Soil Lab
- Bruce Lampinen, Walnut and Almond UCCE Specialist
- Bob Beede, UCCE Farm Advisor Emeritus
- Mike McKenry, Nematologist Emeritus at Kearney Agricultural Research & Extension Center
- Deborah Golino, UCCE Specialist and Director of Foundation Plant Services
Allan Fulton (Irrigation and Water Resources Advisor) deserves a special thank you for braving the pouring rain to talk to our group about two new almond irrigation experiments he started recently. Thank you Allan!
Below are photos from just a few of our field tour stops. We hope to see you in the class next year! E-mail our registration coordinator Penny Stockdale (pastockdale@ucdavis.edu) right away to reserve a spot.
Bob Beede (UCCE Farm Advisor Emeritus) and Professor Ted DeJong in the pistachio block at the Kearney Agriculture Research & Extension Center
Bruce Lampinen (UCCE Walnut and Almond Specialist) describing ongoing walnut research projects at the Nickels Soil Lab in Arbuckle, CA.
Mike McKenry (Emeritus Nematologist at Kearney Agriculture & Research Extension Center) showing students the results of a large field experiment testing for differences in root structure and size as a result of different fumigation treatments.
Jeff Colombini with Lodi Farming, Inc discussing innovative orchard management practices. Jeff was recently named "Grower of the Year" by the Good Fruit Grower. Congratulations Jeff!
- Author: Brooke Jacobs
We had a fun and intense week in the second annual extension course “Principles of Fruit and Nut Tree Growth, Cropping and Management” at the UC Davis Conference Center. On Thursday morning Professor DeJong (Plant Sciences Department, UC Davis) discussed the process of fruit growth and development with the class. After that Professor Brown (Plant Sciences Department, UC Davis) explained the basics of tree nutrient uptake and fertilization. In the afternoon the class toured Wolfskill Orchard in Winters, CA and had dinner at the famous Buckhorn Steakhouse in downtown Winters.
On Friday Dr. Carlos Crisosto (UC ANR and UC Davis) lead a series of lectures on harvest, fruit maturity and postharvest biology. During Dr. Crisosto's section of the course students had the opportunity to measure fruit maturity and and participate in a sensory panel demonstration.
This week the class is on a field tour of California. More updates to come!
Professor DeJong leading the class visit to Wolfskill Orchard in Winters, CA:
Carlos Crisosto's Friday lecture on fruit quality:
Principles of Fruit and nut Tree Growth, Cropping and Management, Class of 2014!
- Author: Brooke Jacobs
Our second annual pomology extension course, Principles of Fruit and Nut Tree Growth, Cropping and Management, is underway at UC Davis. New and experienced growers working with all of the common fruit and nut crops grown in California are attending. In the first three days we have had a chance to learn about tree growth, pruning, pollination, root growth, irrigation and tree water use from a team of UC experts.
We spent Monday and Tuesday mornings in lecture learning about tree growth, bearing habits, chilling, dormancy, flower anatomy and pollination. On the first two afternoons our lead instructor, Professor DeJong (Plant Sciences Department, UC Davis) teamed up with Kevin Day (Farm Advisor in Tulare County and stone fruit expert) to teach pruning and root growth in the field.
On Wednesday Professor Shackel (Plant Sciences Department, UC Davis) gave us a thorough introduction to tree water use and irrigation with lectures and practical worksheets. In the afternoon everyone had the chance to learn how to measure plant water stress using a “pump-up” pressure bomb developed by Professor Shackel.
Hands on pruning demonstration and root excavation at the UC Davis teaching orchard:
Measuring plant water stress using a pressure bomb:
- Posted by: Brooke Jacobs
- Author: Jodi Azulai, UC Statewide IPM Program
Imagine a pesticide sprayer smart enough to hit trees and turn off between them. What would that mean for your wallet? What would it mean for the rivers and streams near your orchard? View On Target, a video that shows how smart sprayer technology is helping farmers manage orchard pests with clever results:
- Substantially reduced pesticide use and cost
- Less pesticide movement to rivers and streams
- Full tree coverage
- Same efficacy as conventional sprayers
- Ease of use
- Valuable application data
Walt Bentley, retired UC IPM Advisor, narrates this video showing a smart sprayer in action.
Smart sprayer technology is based on the use of high frequency sound waves. An onboard computer directs sound waves toward trees. When sound waves are returned, a target is detected and the computer triggers nozzles to spray. When sound waves are not returned, a gap is identified, prompting the program to turn off nozzles.
Find the video on the UC IPM Mitigation Pesticide Hazards page at http://www.ipm.ucdavis.edu/mitigation/index.html. Scroll down to the second bullet under “Before application.” Remember this page the next time you plan a pesticide application. It will help you consider practices that minimize environmental and efficacy problems.