Posts Tagged: avocado
Upcoming CAS/UC/CAC Seminar Addresses
Gibberellic Acid Use
The California Avocado Society will host the first of its 2019 California Avocado Growers Seminar Series with workshops focused on mulch and Phytophthora. Dr. Ben Faber, Dr. Tim Spann and Dr. Carol Lovatt will deliver presentations at the seminars.
Dr. Ben Faber, UC Cooperative Extension Soils/Water/Subtropical Crops Farm Advisor, will speak about the benefits of using mulch in avocado groves. Ben will discuss the various types of mulch that can be used, how and when to apply them and the benefits of using mulch in avocado groves.
Dr. Tim Spann, California Avocado Commission Research Program Director, will cover Phytophthora 101. Tim will discuss what phytophthora species affect avocados, how to recognize symptoms of phytophthora infection in avocados and best management practices for dealing with phytophthora.
Dr. Carol Lovatt, UC Riverside Emeritus Professor of Plant Physiology, will discuss the use of gibberellic acid (GA) plant growth regulator on avocados. A special local needs registration was obtained in early 2018 for use of GA on avocado in California. Carol will discuss the benefits of using GA, and when and how to apply it for those growers interested in trying this new tool.
The seminars will be held as follows:
Tuesday, February 5, 1:00 p.m. – 3:00 p.m.
SLO Farm Bureau, 4875 Morabito Place, San Luis Obispo, CA 93401
Wednesday, February 6, 9:00 a.m. – 11:00 a.m.
UC Cooperative Extension Office Auditorium, 669 County Square Drive, Ventura, CA 93003
Thursday, February 7, 12: 30 p.m. – 2:30 p.m.
Fallbrook Public Utility District Board Room, 990 East Mission Road, Fallbrook, CA 92028
And read more about Mulch Myths:
euc and a bit of scrap
SWEEP and Healthy Soils Grants
February 14, 2018
University of California Cooperative Extension
Ventura County Farm Bureau
Ventura Co. Resource Conservation District
CA Dept of Food & Agriculture
Why: Apply for CDFA funding- State Water efficiency and Enhancement Program (SWEEP) and Healthy Soils Program (HSP).Receive up to $100,000 in grant funding to improve your on-farm water and energy efficiency and healthy soil practices through the grant funding programs. During the workshop irrigation specialists will:
- Provide a comprehensive review of SWEEP/HSP and summary of other CDFA Climate Smart Grant programs
- Guide you through the required water savings and greenhouse gas reduction calculations
- Show you how to assemble a strong grant proposal
When: Thursday, February 14, 2019
2:00 PM - 4:00 PM
Where: UC Cooperative Extension office, 669 County Square Dr., Ventura 93003. California Conference room
Presenters: Andre Biscaro, Irrigation and Water Resources Advisor
Jamie Whiteford, Irrigation Specialist, Ventura/Cachuma RCDs
Khaled Bali, Irrigation Specialist, UC Kearney Agricultural Research and Extension Center
Daniele Zaccaria, Agricultural Water Management Specialist, UC Davis
Registration: To register go to: https://www.eventbrite.com/e/sweep-and-healthy-soils-grants-opportunity-workshop-tickets-54711473490
Questions: Contact Andre Biscaro, 805-645-1465, email: firstname.lastname@example.org
Grant info.: Applications are due March 8, 2019 online at
The SWEEP/HSP provides financial assistance in the form of grants to implement irrigation systems that reduce greenhouse gases and save water on California agricultural operations. Eligible system components include (among others) soil moisture monitoring, drip systems, switching to low pressure irrigation systems, pump retrofits, variable frequency drives and installation of renewable energy to reduce on-farm water use and energy.
Please feel free to contact us if you need special accommodations.
Free One-On-One Technical Assistance to Apply for Grant Funds
Need help in developing and /or submitting your project proposal? Schedule your free one-on-one Technical Assistance session, contact your local UC Cooperative Extension Office for additional information at 805-645-1465
The University of California prohibits discrimination or harassment of any person in any of its programs or activities. (Complete nondiscrimination policy statement can be found at http://ucanr.org/sites/anrstaff/files/107734.doc). Inquiries regarding the University's equal employment opportunity policies may be directed to Affirmative Action Contact and Title IX Officer, University of California, Agriculture and Natural Resources, 2801 2nd Street, Davis, CA 95618, (530) 750-1397; email@example.com.
So Many Shot Hole Borers: New Research Charts Four Nearly Identical Species
by Jiri Hulcr, Ph.D., and Jackson Landers
When an insect spends most of its life in total darkness, it doesn't much matter what color it is. So, it comes as no surprise that so many species of bark and ambrosia beetles maintain the same brown hue as they slowly tunnel through wood and feed on a fungus that they carry with them into their trees. This similarity of appearance has been taken to an extreme in what has turned out to be a cryptic species complex. What was once referred to as the “tea shot hole borer” is actually four distinct species who all look almost exactly the same.
The tea shot hole borer first attracted notice from North American entomologists when it appeared in Florida in 2012, appearing harmless. But the beetles were first described as an economically significant pest in Sri Lanka in 1968. In 2009, the beetles were found eating through avocado and street trees in Israel. Then, in 2012 in California, with a bang, avocado trees were being attacked and killed. Given the value of global avocado crops and tea plants, entomologists had to start taking a closer look at these beetles.
Many taxonomists eventually came around to the idea that they were looking at three identical species rather than one: the tea shot hole borer (from southern Southeast Asia), the Kuroshio shot hole borer (originating in the Pacific Islands), and the polyphagous shot hole borer (presumed native to northern Southeast Asia). A 2017 paper authored by Richard Stouthamer and his team from the University of California, Riverside, first designated those three clades and established common names for them.
The four newly delineated species of the Euwallacea fornicatus species complex are, from left to right, E. fornicatior, E. fornicatus, E. whitfordiodendrus, and E. kuroshio. The wood-boring beetles known as various kinds of “shot hole borers” are so similar in morphological characteristics while also variable in body dimensions that their appearance can't be reliably used for differentiating specimens. (The four shown here vary in size but some of their cousins within each species can all range from 1.8 to 2.9 millimeters long.) New research has used molecular genetic techniques to identify the different species within the complex. (Photo credit: Demian Gomez)
And read more from the folks at UC:
It is that time of year and we should be alert to threat of freezing weather and damage to trees. Last winter was one of the warmest on record, but there was still a sneak cold blast around December 25 that caused some problems in some areas. Wet winters tend to have lower frost threats, and even though wet is forecast for this winter, the forecast is erratic, as usual. That still leaves January which historically is when most of our damaging frosts occur. Fox Weather on the CA Avocado Commission is forecasting some cold weather coming up, so growers need to be prepared for the worst.
Here are some links to frost information, preparing for frost and managing frost damage to trees.
A Frost Primer
The forecast is for north winds, which often means cold, dry air and often with winds. Winds mean no inversion and no warm air that can be introduced at ground level to warm trees. If this occurs, running a wind machine can make the damage worse. Wind machines and orchard heaters work on the principle of mixing that warmer air higher up – 20-100 or so feet higher than ground level which has colder air. When temperatures drop, the air is dry (wet-bulb temp below 28 deg F) and there is no inversion, running a wind machine can just stir up cold air and cause worse conditions (freeze-drying). It's better to not run the machine. The only thing left to do is to run the microsprinklers during the day so that the water can absorb the day's heat. Then turn the water off before sunset so that evaporative cooling from the running water isn't accentuated. Then when temperatures drop near 32 at night and the dewpoint is much below that, it's time to start the water again and let it run until sunrise (when risk is less). Running water works even if the water freezes. This is due to the release of heat when water goes from liquid to frozen state. This 1-2 degrees can mean the difference between frost damage and no damage. Also, ice on fruit and leaves can insulate the fruit. As the ice melts at the surface of the plant, it releases heat, protecting the plants. If there is not sufficient water to run the whole orchard, it's best to pick out the irrigation blocks that are the coldest or the ones you definitely want to save and run the water there continuously. Running the water and turning it off during the night to irrigate another block can lead to colder temperatures in both blocks.
Keep warm this winter.
and check out this Wind Machine You Tube:
Wind Machine frost
“Wood chip mulches will decrease soil nitrogen and spread pathogens” A Misunderstanding that is addressed below by:
Chalker-Scott, L. , Extension Specialist And Associate Professor, Washington State University
Downer, A.J., Farm Advisor, University of California
With chronic drought and/or record-breaking summer temperatures making it increasingly important to conserve water, many gardeners and groundkeepers are using landscape mulches. The ideal landscape mulch not only moderates soil temperature and conserves water, but also:
- reduces compaction;
- provides nutrients;
- enhances plant growth;
- provides habitat for beneficial insects;
- helps control weeds, pests and disease; and
- reduces the need for pesticides and fertilizers.
In addition, landscape mulches should be readily available, affordable, and easy to apply and replace. A review of the literature on landscape mulches (Chalker-Scott, 2007) determined that organic mulches are overall the best choice, with deep layers of coarse woody material providing most or all of the above-listed benefits. Arborist wood chips (created from leaves and branches chipped up by tree service companies) are a particularly good option as they are generally inexpensive and easy to obtain anywhere trees are managed.
Fortunately, none of these concerns are validated by research. Here are some brief explanations (Chalker-Scott, 2007) targeted to our audience:
- Wood chips will not draw nitrogen from the soil unless they are incorporated into it. When used as mulch, arborist chips have no effect on underlying soil nitrogen levels, except to increase them over time.
- Wood chip mulches, even those made from diseased trees, will not transmit pathogens to healthy plant roots. If diseased chips are incorporated into the soil they could infect plant roots, but field evidence of this is rare. Arborist chips that are stockpiled even for a few days undergo severe pathogen reduction through microbial attack within the pile (Downer et al., 2008).
- Wood chips, or any other organic mulch, will not change the pH of the soil. The soil volume is vast, and any acidification would occur only at the mulch-soil interface where it would quickly be neutralized.
- Wood chips, even those made from black walnut or cedar, will not kill landscape plants. There is no reliable evidence that chemical inhibition from decaying wood actually occurs in a landscape situation.
- Wood chip mulches do not lend themselves to tunnel building like landscape fabric and other sheet mulches do: they collapse. Termites do not eat wood chips unless they have no choice; they are negatively affected by some of the chemicals wood contains. In fact, arborist chip mulches house a number of beneficial insects and other species that naturally control pests.
For arborist wood chip mulches to be the most effective (Chalker-Scott, 2007), they should be:
- coarse – no less than ½” diameter – so water and air can move freely through them;
- applied as soon as possible after chipping both to maximize the materials available to microbes and to capture the nutrients released by their activity in the soil; and
- maintained at a depth of at least 4” to prevent weed growth.