Citrus/Avocado Herbicide Update
With the rains, and in those area where fire took out the competition, weeds are coming back in their glory. Mustard has painted the hills yellow. The question comes up, what to do about all that wild growth. Mechanical control, such as discing or whipping can work great. Sometimes chemical control is the only answer. A recent request for an alternative to glyphosate (Round-up) control of marestail (horseweed, Conyza canadensis) which is similar to hairy fleabane (Conyza bonariensis), came to the office from a lemon grower. Glyphosate just wasn't controlling it. And it's been a problem for a while, even in tank mixes with paraguat and old-line weed killer. The alternative might be a newer material, such as saflufenacil (Treevix) which has been recently added to the herbicides that can be used on citrus.
As always before doing "vegetation management" it's best to identify the plant that is the problem
Identify the problem plant (weed)
http://wric.ucdavis.edu/information/weedid.htm
or if you know what the plant is, go directly to a listing of the weeds
Listing of weeds, their biology and control
http://wric.ucdavis.edu/information/info_spec_weed.htm
- Susceptibility of Winter Weeds to Herbicide Control (9/08)
- Susceptibility of Spring/Summer Weeds to Herbicide Control (9/08)
Or you can go in reverse order and look at your tree crop and see what herbicides are listed
Listing of herbicides by tree crops, including avocado and citrus
http://wric.ucdavis.edu/PDFs/T&V_herbicide_registration_chart.pdf
conyza canadensis