- Author: Sonia Rios
- Posted by: Gale Perez
From the Topics in Subtropics blog ¦ Oct. 21, 2022
Control of weeds has always been a major economic cost in subtropical fruit production because of favorable climate that allows for weed germination and year-round growth. The use of chemical weed control has increased dramatically due to labor costs, equipment costs, product costs and availability, the shift to more narrowly spaced tree rows, and installation of low volume irrigation systems that prohibit the operation of mowing or tillage equipment under the tree canopy area (Futch 2001).
However finding herbicides that are labeled for certain subtropical crops can be a bigger challenge. UC Weed Science has updated the Subtropical Crops herbicides usage chart for California growers (2020). It also seems that preventive programs are most frequently overlooked as a method of weed control. Preventive programs entail the use of such practices as sanitation, spot spraying, or hand labor to prevent the source of weed infestation (seed and/or vegetative) from widespread dissemination throughout a given area. By removing the undesirable weed species prior to seed development, dissemination by wind or mechanical transport on equipment can be effectively delayed.
Before herbicide application, growers should survey the grove and determine the stage of growth and type of weeds for that given location. Many products do not provide control of emerged species, thus requiring the application of more than one product to provide both preemergence and postemergence protection. Rotation of soil-applied herbicides should also be considered to prevent the buildup of resistant annual and perennial weeds. The resistant species may not be evident initially; however, if the same herbicide and cultural program is maintained, over time their populations may build up until they infest the entire grove and become the dominant weed species.
Herbicide damage to foliage and fruit has also been noted when herbicides were applied under windy conditions or use of improper equipment allowed the materials to contact areas other than the weeds or soil. Please make sure to follow the label's direction and use caution.
Attached is a chart listing of herbicides registered for avocado, citrus, date, kiwi, fig and pomegranate, along with the Big Trees' herbicides. Check out how many more are available on almond than avocado. Both start with an A.
* * * * *
Sonia Rios is the UC Cooperative Extension Riverside and San Diego Counties Area Subtropical Horticulture Advisor.
Original source: Topics in Subtropics blog ¦ Oct. 21, 2022
T&V herbicide registration chart 2020-March
![Herbicide Registration on California Tree and Vine Crops chart (March, 2020) Herbicide Registration on California Tree and Vine Crops chart (March, 2020)](/blogs/blogcore/blogfiles/95593.jpg)
- Author: Sonia Rios
Control of weeds has always been a major economic cost in subtropical fruit production because of favorable climate that allows for weed germination and year-round growth. The use of chemical weed control has increased dramatically due to labor costs, equipment costs, product costs and availability, the shift to more narrowly spaced tree rows, and installation of low volume irrigation systems that prohibit the operation of mowing or tillage equipment under the tree canopy area (Futch 2001).
However finding herbicides that are labeled for certain subtropical crops can be a bigger challenge. UC Weed Science has updated the Subtropical Crops herbicides usage chart for California growers (2020). It also seems that preventive programs are most frequently overlooked as a method of weed control. Preventive programs entail the use of such practices as sanitation, spot spraying, or hand labor to prevent the source of weed infestation (seed and/or vegetative) from widespread dissemination throughout a given area. By removing the undesirable weed species prior to seed development, dissemination by wind or mechanical transport on equipment can be effectively delayed.
Weed control programs will vary from location to location within the state and can even vary within a given site based upon specific conditions such as soil type, variety, method of herbicide application, and the presence of specific weed species.
Before herbicide application, growers should survey the grove and determine the stage of growth and type of weeds for that given location. Many products do not provide control of emerged species, thus requiring the application of more than one product to provide both preemergence and postemergence protection. Rotation of soil-applied herbicides should also be considered to prevent the buildup of resistant annual and perennial weeds. The resistant species may not be evident initially; however, if the same herbicide and cultural program is maintained, over time their populations may build up until they infest the entire grove and become the dominant weed species.
Herbicide damage to foliage and fruit has also been noted when herbicides were applied under windy conditions or use of improper equipment allowed the materials to contact areas other than the weeds or soil. Please make sure to follow the label's direction and use caution.
Attached is a chart listing herbicides registered for avocado, citrus, date, kiwi, fig and pomegranate, along with the Big Trees' herbicides. Check out how many more are available on almond than avocado. Both start with an A.
![herbicides on trees 2020 herbicides on trees 2020](/blogs/blogcore/blogfiles/95349.jpg)
- Author: Ben Faber
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![IMG 2037 IMG 2037](/blogs/blogcore/blogfiles/49173.jpg)
- Author: Sonia Rios, Area Subtropical Horticultural Advisor
Jim Downer, who is based in Ventura County touched base on tree pruning- understanding plant responses to an important management tool. Downer, suggested several tips, such as paying attention to branch biology that structural pruning is crucial, you also want to conserve healthy canopy foliage, and most of all don't thin trees just to thin. By keeping up with pruning from the beginning, you can make less invasive smaller cuts and save money. Smaller cuts can also reduce the amount of surface area that is exposed to the elements that can cause disease.
Ben Faber, advisor based out of Ventura and Santa Barbara Counties spoke on specific avocado pruning techniques and challenges growers may face. He reminded the growers, avocado trees can get extremely tall. Taller trees may be hazardous to pickers that are working on ladders, this may also slow down the picking processes, especially along the steep hillsides. The main thought on everyone's mind, how much space does a tree really need to be the most productive? During this discussion, Faber spoke of Emeritus UC Farm Adviser, Gary Bender's higher density planting trial in San Diego. Instead of the standard distance of twenty feet apart, he ran a trial where he planted trees ten feet apart. Then, instead of letting the trees grow tall, which is the standard practice, he pruned them regularly to keep the trees short and fat. The study has been a huge success yielding nearly 13,000 pounds of Hass avocados per acre. Usually farms in the southern California are yield between 6,000 to 7,000 pounds per acre.
Growers had a chance to interact and speak with the lectures, other UC advisors and other members of the Avocado Commission and Society. We hope to see everyone at the next seminar in August, all growers welcome, no RSVP needed, and it's FREE!
Seminar coming up: Current Hot Topics in Avocados-Farm advisors will discuss current hot topics in the avocado industry, specific to the growing regions in each seminar location:
- SanLuisObispo -MaryBianchi, UC County DirectorandHorticultureFarmAdvisorforSanLuisObispo County
- Aug 4, 2015 at 1:00pm - 3:00pm, San Luis Obispo, CA, UC Cooperative Extension Office Auditorium, 2156 Sierra Way
- Ventura - Ben Faber,UCFarmAdvisorforVentura and Santa Barbara Counties
- Aug 5, 2015 at 9:00am - 11:00am UC Cooperative Extension Office Auditorium, 669 County Square Dr. Ventura, CA
- Fallbrook - Sonia Rios, UC Area Subtropical Horticulture Advisor for Riverside and San Diego Counties -Aug 6, 2015 1:00pm - 3:00pm
Fallbrook Public Utility District Board Rm., 990 East Mission Rd., Fallbrook, CA
![20150604 140708 (1) 20150604 140708 (1)](/blogs/blogcore/blogfiles/30315.jpg)
- Author: Ryan Krason
For those that have attended our Water School meetings, the time is finally here! Our new self assessment app "Know Your H20 is now available on the iTunes Store for free! Right now there are only a self assessment for Tree Crops but we will be working in the near future to create sections for Greenhouses & Nurseries, Animal Agriculture, and Commercial Turf & Landscape. We'll let you know as those become available.
App Description
Water quality laws and regulations are putting a heavy burden on agriculture nationwide. Although Agriculture is not the only concern, runoff from agricultural properties can contain contaminant levels that exceed water quality standards. Runoff from agricultural operations can pick up and carry natural and man-made pollutants, including fertilizers, salts, pesticides and sediments to lakes, rivers, wetlands and beaches.
Certain growing practices can contribute to water quality problems, however, Best Management Practices (BMPs) can be utilized to minimize the impact of agriculture on water quality.
This Self-Assessment Application will help you assess your growing practices and their potential impact on water quality. It will also provide suggestions for Best Management Practices that can help to solve your water quality problems.
Download the App click here.
App Development by Touch This Media, LLC
![Icon-02 Icon-02](/blogs/blogcore/blogfiles/15102.jpg)
![Screen-shots Screen-shots](/blogs/blogcore/blogfiles/15978.jpg)