- Author: Chris M. Webb
Ventura County Cooperative Extension’s Oleg Daugovish will hold a free commercial grower vegetable production and water management meeting Thursday, December 9 from 7:30am to 12:30pm. The meeting will be held at Freedom Center, 516 Eubanks Road in Camarillo.
Scheduled meeting topics are:
- Vegetable pathogens: recent and persistent pathogens of vegetable crops
- Weed control with drip activated herbicides in celery and cabbage
- Precision weed management tools in vegetable crops
- Update on Ag waiver regulations for the LA/Central Coast region
- Soil and water analyses, results and implications for Ventura County vegetable fields
- Best management practices for fertilizer management in coastal vegetable crops
- Insect pest management in warm and cool season vegetables
Lunch will be provided, and continuous education credits have been requested from DPR (Department of Pesticide Regulation).
For special arrangements, for questions or to register please contact Oleg Daugovish at (805) 645-1454 or at odaugovish@ucdavis.edu. Additional details can be found here.
- Author: Chris M. Webb
UC’s Nursery and Floriculture Alliance (UCNFA) has a variety of trainings, workshops, and webinars on topics of importance to the nursery and floriculture industry. Some of the education opportunities are free and others at a cost. Workshops and trainings are held throughout the state.
In November the ABC’s of Fertilizer Management will be held in Ventura County. On November 1 the topic will be taught in English and on November 2 in Spanish.
Education credits will be offered for the conditional waiver programs for the Central Coast and Ventura/Los Angeles Regional Water Quality Control Boards and for Certified Crop Advisors.
Click on the above links for details and to register.
- Author: Chris M. Webb
Improving water quality is an important step towards building and maintaining sustainable natural ecosystems. We can all help reach water quality improvement goals by making small changes in our behavior. Small changes multiplied by many people make a big difference!
What is urban runoff? Urban runoff is the water that washes away all the chemicals we use, which then flows into storm drains and creeks and then out to the ocean. These chemicals include: home pesticides, fertilizers, cleaning products, oil and many other products. Urban runoff is a significant contributor to poor water quality.
This rainy season is a good time to think about our contributions to urban runoff and to make some small changes. Here are some good places to start:
- look into ways to reduce home pesticide use
- learn about composting to improve soil quality and possibly reduce the need for fertilizers
- find safer alternatives for cleaning products.
- keep mechanical equipment in good repair.
Our office has great resources to help further improve water quality.
A collection of "green sheets" designed to help people make small changes to improve water quality
Management Practices to Portect Water Quality: A Manual for Greenhouses and Nurseries
Orchard Water Quality Management
Please contact our office if you would like further information.
- Author: Chris M. Webb
Today Ventura County Cooperative Extension Farm Advisor, Ben Faber shares some of his knowledge of avocados with us.
The only treatment that should be done rapidly after a freeze is whitewashing. Often the most severe damage following a freeze results from sunburn of exposed twigs and branches after defoliation. Temperatures do not have to be extremely high to cause sunburn. A white latex paint that has been diluted with water so that it can be sprayed is the easiest way to whitewash. The whitewash needs to be white on the tree, so don’t add too much water.
Pruning should be carried out to prevent secondary pathogens and wood decay organisms from slowing tree recovery. Again, however, there should be no rush to prune. Premature pruning, at the very least, may have to be repeated and, at the worst, it can slow tree rehabilitation. It should be remembered that when pruning, all cuts should be made into living wood. Try to cut flush with existing branches at crotches. Do not leave branch stubs or uneven surfaces. Tools should be disinfected in bleach or other fungicide before moving on to the next tree.
Irrigate carefully! Remember that when leaves are lost, obviously evaporation from leaves is greatly reduced, and, therefore the amount of water required is also greatly reduced. A frost-damaged tree will use the same amount of water as a much younger or smaller tree. Over irrigation will not result in rapid recovery. Instead, it may induce root damage and encourage growth of root rotting organisms. This is particularly true for avocados. Irrigation should be less frequent, and smaller amounts of water should be applied until trees have regained their normal foliage development.
Fertilization of freeze-damaged trees should be carefully considered. There is no evidence to indicate that frozen trees respond to any special fertilizer that is supposed to stimulate growth. If trees are severely injured-with large limbs or even parts of the trunk killed-nitrogen fertilizer applications should be greatly reduced, until the structure and balance of the tree become re-established. Trees should be watched for evidence of deficiencies of minor elements. Deficiencies of zinc, manganese, copper, and iron are most likely to develop.
- Author: Chris M. Webb
Ventura County UCCE Farm Advisor, Ben Faber shares his knowledge of avocados. Today’s topic:
The most important thing you can do before planting is assess the pH of the soil before planting. Avocados are very sensitive to soil pH greater than 7. Their uptake of iron and zinc can be terribly compromised and they will suffer. Correcting the soil pH prior to planting is the easiest way to approach the problem, rather than trying to correct it later when the tree is in the ground. Otherwise, it becomes expensive and takes a long time to correct the problem without killing the tree. Elemental sulfur (not popcorn sulfur) in pellets is the easiest way to accomplish this. Watering and waiting for the sulfur to make the change and then checking to make sure the pH is really down takes about 6 months.
As for nutrients, though, the most commonly required ones are nitrogen and potassium. These can be applied as either organic (fish, soybean, manure, etc.) or synthetic forms (urea, ammonium sulfate, potassium sulfate, etc.) or a combination. The thing to remember is that the tree likes small, frequent amounts of nutrients because of its shallow root system. And because it is a subtropical plant, it goes quiescent in the winter and when the soil is cold. So nutrient applications like nitrogen are best applied when soils are warm, from spring though fall.
Newly-planted trees do not need supplemental nutrients, they are loaded up from the nursery and the young root system can easily burn until it gets established. In the first year, use the equivalent of 1 ounce per tree of nitrogen in 4- 5 applications over the spring/fall. The following year double that amount and do so for each succeeding year for the next 5 years. The more small applications you make the less total nitrogen fertilizer you will use. Use the equivalent amount of nitrogen whether it is a synthetic source or an organic source. Once the tree has started to develop a thick leaf mulch, it is possible to back off on nitrogen applications because now the mulch is contributing some of the nutrients. In many garden situations where mulch is maintained, by year 10 the nutrient status is self-sustaining and nitrogen fertilizer may not be needed at all. Just keep an eye on the leaf color to make sure it stays green, indicating adequate nitrogen.
When the avocado starts bearing fruit about year three, it may need potassium. This is not necessary in all situations throughout the state, but the harvested avocado fruit contains twice as much potassium as nitrogen and when the fruit is removed the tree can start showing potassium deficiency symptoms. This can be analyzed at a lab, but probably the best thing to do is just apply potassium sulfate at an equivalent rate to nitrogen or to use triple 15 fertilizer to meet both the nitrogen and potassium needs. Organic growers can use organic potassium sulfate or kelp. Although phosphorus is used by avocados, there are no documented cases in California where supplemental phosphorus needs to be applied.