UCCE Ventura County- Blogs
New Avocado Herbicide
Rely® 280 Herbicide Available for Use in California Avocado Groves
The California Department of Pesticide Regulation has approved the herbicide Rely® 280 (glufosinate-ammonium) for use in avocado groves in California. Rely® 280 is a post-emergence broad-spectrum herbicide for use against broadleaf and grassy weeds. Glufosinate-ammonium is an excellent alternative to glyphosate, especially for those weeds that have developed glyphosate resistance.
The California Avocado Commission provided funding for Dr. Peggy Mauk, extension professor for subtropical horticulture at the University of California-Riverside, to conduct efficacy trials with glufosinate-ammonium and the IR-4 program provided funding for the required phytotoxicity (crop safety) trials. “Glufosinate-ammonium is an effective broad-spectrum herbicide,” said Mauk. “The weed that is the biggest problem here in Riverside is mare's tail or hairy fleabane ( Erigeron bonariensis). Glufosinate will kill it depending on the application timing and size of the plants. Treating for weeds is also going to be seasonal…the spring is usually worse because spring rains bring a lot of weeds, especially this past year.”
Currently, growers must have a copy of the DPR approved supplemental label in their possession when using Rely® 280. The DPR-approved label has a stamp on it with the wording "LABELING ACCEPTABLE State of California Department of Pesticide Regulation Pesticide Registration" and can be downloaded here. This supplemental label expires on December 1, 2025, and BASF, Rely® 280's manufacturer, anticipates that all old product will be used by that date and new product with avocado listed on the package label will be fully in the supply chain by that date.
Dr. Mauk's phytotoxicity trials found minimal damage, assuming sound application practices are followed. “Spray applications should not be made when there is a breeze,” Mauk emphasized. “If the wind carries the herbicide onto the plants, there can be some leaf discoloration. The discoloration appears as occasional purple spots on the leaves. There is not widespread damage. We also never saw any discoloration on the avocado fruit.”
General questions about this registration can be directed to CAC's Research Director Dr. Tim Spann at tim@spannag.com or 423-609-3451. For specific questions regarding the use of Rely® 280 growers should contact their Pest Control Advisor.
palmer amaranth
Future Green Careers for New Graduates
Future Design Gives New Graduates Hope Spring usually brings an abundance of colorful blossoms and excitement for high school and college graduates everywhere. In the past, graduates celebrated their hard-earned achievements, ready to carve their own...
Steven Abraham-unsplash
Snakeflies
Watch out ACP, Persea Mite, Avocado Thrips. Here comes Snake Fly. Not a snake. And not a fly. But a snakefly. It's always fun to be reminded that there are lots of different predators out there, and this one is one of the more voracious. Although because of its slow reproductive cycle, you don't see a lot of them until you start seeing them all over the place. Here's one that came up in a recent text message.
Photo: Jane Delahoyde
Snakeflies are related to lacewings (order Raphidioptera, rhaphidiids). The adult has a long thorax and can raise the head above the rest of the body which gives it the appearance of a snake ready to strike. Snakeflies are found world-wide, but only in western North America on this continent. Larvae live under the bark of forest, ornamental and fruit trees, including avocado and citrus. They can be helpful predators in fruit orchards. Adults also are predaceous. They would work in concert with other predators for control of Asian Citrus Psyllid and avocado mite and thrips.
Hosts
Larvae feed on wood-boring insects, small insects such as aphids and caterpillars, and various insect eggs, often feeding on insects and mites found in leaf duff. Snakefly adults feed on aphids or other small, weak prey.
Life stages
Egg -The egg is elongated and cylindrical with a small appendage at one end.
Larva - The larva is long and flattened with a black shiny head and prothorax and three pairs of legs. It can be from 1/2 to almost 1 inch (12 to 25 mm) long and is a mottled reddish or grayish color.
Pupa -The pupa is active and not enclosed in a cocoon.
Adult - Snakeflies have four membranous wings which are held roof-like over the body when at rest. The wings, which have many veins, are from 1/4 to 2/3 inch (6 to 17 mm) long. The prothorax is elongated. The female is usually slightly larger than the male and has a long tail-like ovipositor.
Life history
Most species have one generation each year but take 2 to 3 years to complete their life cycle. The larva overwinters in a small depression on the bark surface covered by small pieces of bark. After pupation under the bark, adults emerge and disperse in search of prey. They can be seen in orchards throughout the season.
Adult snakeflies are territorial and carnivorous organisms. They are diurnal and are important predators of aphids and mites. Pollen has also been found in the guts of these organisms and it is unclear whether they require pollen for part of their lifecycle or if it is a favoured food source. The larvae of many raphidiids live immediately below the bark of trees, although others live in crevices in rocks, among leaf litter and in detritus. Here they feed on the eggs and larvae of other arthropods such as mites, springtails, spiders, barklice, sternorrhynchids and auchenorrhynchids. The actual diets of the larvae vary according to their habitats, but both larvae and adults are efficient predators.
What predates/parasitizes snakeflies?
Birds eat them. They predate each other making it difficult to raise in an insectary. And they are parasitized by wasps.
Cover Crop Field Day - May 28
Come learn about what cover crops grow in Ventura and how they can be managed
The first half of the event will take place Hansen REC featuring 19 diverse cover crop s and croip crop mixes with unique features and benefits. The second half will take place at the Rodale Institute COC showcasing the innovative roller crimper as it efficiently terminates cover crops
Samples of Avocado Sunblotch Needed
Tree Samples Needed for Avocado Sunblotch Viroid Disease Study
Avocado sunblotch viroid is an established disease in California that causes symptoms on all plant parts including leaves, stem, seeds, roots and flowers. Asymptomatic infection also occurs. Those trees, which are referred to as symptomless carrier trees, contain higher concentrations of ASBVd compared to symptomatic. Existence of asymptomatic trees and the uneven distribution of viroid in the tree make the identification of ASBVd symptoms in young trees challenging and problematic. Therefore, accurate symptom identification and the distribution of ASBVd in symptomatic and asymptomatic plants and disease detection are of great importance.
Dr. Fatemeh Khodadadi, Assistant Professor of Extension and Assistant Plant Pathologist at the University of California-Riverside, is conducting a research project on optimizing a fast and reliable detection method for ASBVd. As part of the study, her team is seeking to sample symptomatic and asymptomatic trees from avocado orchards in California. California avocado growers who are dealing with this disease in their orchard or are aware of orchards, ranches or groves harboring this disease, are invited to contact Dr. Khodadadi at 845.901.3046 or fatemehk@ucr.edu.
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