- Author: Brad Hanson
During the last few years, one of my core research areas has included several projects related to preplant soil fumigation in collaboration with a number of UC, USDA-ARS, and industry researchers. I touched on soil fumigants a bit a few weeks ago shortly after methyl iodide was registered by DPR (link to previos post). Today I thought I’d touch upon research results related to minimizing emissions of two of the most widely used methyl bromide alternatives, 1,3-dichloropropene and chloropicrin.
Soil fumigation is used prior to planting a number of high value crops in California. One of the most widely used soil fumigants, methyl bromide,...
- Author: Brad Hanson
Happy New Year!
Today I thought I'd attach a poster presentation from the recent 38th Annual Almond Industry Conference. The attached poster has some information on an ongoing research project in which we are testing thermal disinfestation as an alternative to soil fumigation for management of almond replant disease.
This is not especially a weed research project but has become an interesting area of research because of the high economic and environmental costs of soil fumigation. In second and later generation, trees can be affected by a variety of soil pests including fungal and bacterial pathogens, parasitic nematodes, and other yet-to-be-identified pests that can reduce orchard establishment and early...
- Author: Brad Hanson
This is one part follow up to my previous post on glyphosate resistance and one part test of a tool to imbed articles in the blog.
The above frame has a 2008 report that Anil Shrestha, Kurt Hembree, and I wrote for California Agriculture on our glyphosate-resistant hairy fleabane work. You can click on it to open it in a full-screen reading pane.
I like this document hosting interface and may use it again. If you have problems viewing it in a particular browser, please let me know.
The article can also be downloaded here
Brad
- Author: Brad Hanson
I thought I'd followup on my post last week about herbicide resistant weeds with a little more detail on our recent (and ongoing) work on glyphosate-resistant horseweed (Conyza canadensis) which is also known as mare's tail.
In 2006 and 2007, we conducted research to determine the magnitude of the glyphosate-resistant horseweed problem in the Central Valley. The sampling was focused at that time in the Fresno area but included sampling as far south as Wasco and as far north as Marysville. We published the results of the initial project in 2009 (Weed Science 57:48-53) but the work has also led to several related projects which are ongoing.
In general, we found that:
1. Glyphosate-resistant horseweed was...
- Author: Brad Hanson
Over the last few years, several of my UC Davis, CSU-Fresno, and USDA-ARS collaborators and I have been involved in research related to using steam heat to thermally disinfest soil as an alternative to methyl bromide fumigation. The basic premise of the work is to heat soil to 70C (158F) for about 30 minutes to kill many soil borne pathogens including parasitic nematodes, fungal and bacterial pathogens, and weed propagules (seed and vegetative parts).
It is pretty clear that heat is effective for pest control; however, efficiency (time and fuel) is the biggest sticking point for this to be a viable alternative for a substantial number of growers. Below is a brief...