- Author: Rachael Freeman Long
- Author: Ian Grettenberger
- Author: Michael Rethwisch
- Author: Dan Putnam
An important change has come to California insect management tools and strategies for alfalfa and other crops.
As of January 1, 2019, new restrictions on the use of chlorpyrifos (e.g., Lorsban and other products) for alfalfa in California have been imposed. This is likely to impact grower practices and strategies to address pest resistance issues.
According to CA-DPR (California Department of Pesticide Regulation), chlorpyrifos can only be used in alfalfa under the following permit conditions:
Chlorpyrifos (e.g., Lorsban) permit conditions (CA) for alfalfa:
- For control of alfalfa weevils, blue alfalfa aphid, and cowpea aphid (no other pests).
- The size of an...
As you're thinking about winter weed management in alfalfa production, keep in mind the need for common groundsel control.
Groundsel (Senecio vulgaris) is highly toxic to livestock at all growth stages because it contains pyrrolizidine alkaloids (PA) which can cause chronic and irreversible liver disease in animals. Cattle and horses are most sensitive to the PAs, followed by pigs and chickens, and then sheep, goats and turkeys, which are the least sensitive to PA toxicity. Younger animals are typically more sensitive than adults. Therefore, the identification and control of groundsel in forages is important for preventing livestock PA poisonings.
The first step in developing a successful weed management program is being able to properly identify the species that are infesting a field. But why? Why is weed identification so important? Simply stated, because not all weeds are created equal. Species differ with respect to their emergence timing, life history traits, competitive interactions with the crop, potential to harm livestock, and sensitivity to available herbicides, among many other characteristics. Consequently, the type and timing of weed control events need to be designed to target problematic species so that control is maximized, weed seed return to the soil seedbank is minimized, and crop yields are protected.
Unfortunately, weed identification is not always a...
- Author: Michelle Leinfelder-Miles
UC Cooperative Extension will host the SJC and Delta Field Crops Meeting on Thursday, January 17, 2019 from 8:00am to 12:00pm. The meeting location is the Cabral Agricultural Center in Stockton (2101 E. Earhart Ave., Stockton, CA 95206). The meeting will include presentations related to alfalfa and forages. Coffee and light refreshments will be provided.
The agenda is attached at the bottom of this post, and is as follows:
8:00am Doors Open and Sign In
8:15am Nitrogen Stabilizers in Silage Corn, Michelle Leinfelder-Miles, UCCE San Joaquin/Delta Counties
8:45am Measuring the Interaction between N Demand and Water...