- Posted by: Gale Perez

Congratulations to UC Davis weed science graduate student Erika Escalona (Fennimore Lab) for winning 1st place in the student poster presentation category at the 2024 California Plant and Soil Conference on Feb. 6-7, 2024 in Fresno, CA.
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Evaluating Bacterial Diversity in Steam Fumigation Treatments in the Salinas Valley's Lettuce Fields
Erika Escalona, University of California, Davis; Steve Fennimore, UC Cooperative Extension, Weed Specialist, Salinas; Department of Plant Sciences, University of California, Davis; J.S. Rachuy, Department of Plant Sciences, UC Davis; Cristina Lazcano, Department of Land, Air and...
- Author: Trina Kleist
- Posted by: Gale Perez

AI-trained machines slash labor costs
Experimental robots are reducing the costs of hand-weeding by learning the difference between weeds and lettuce. In addition, steam can clear the soil of fungi and spores that cause lettuce and spinach to wilt, reducing the need for chemical herbicides in the bargain, according to the latest research by Steve Fennimore and his lab at the UC Davis Department of Plant Sciences.
Fennimore, a professor of Cooperative Extension, presented his findings at a recent meeting of the California Leafy...
/h2>- Author: Bob Johnson
- Posted by: Gale Perez

From the weekly newspaper for California Agriculture, Ag Alert • Dec. 2, 2020 • California Farm Bureau Federation
Advisors seek practical use of steam in weed control
By Bob Johnson
Steam-treating a shallow band of soil within the seed line before planting may offer, when combined with advanced cultivators, an economical weed control option for organic farmers and conventional growers looking to reduce herbicide use.
University of California specialists said their research in Salinas Valley vegetable fields this year showed the technique can significantly reduce weed pressure...
/h2>- Author: Nelly Guerra
- Author: Steven Fennimore

Despite the tremendous need, there are currently no preemergence herbicides that are organic-compliant. Steam injected into the soil such that the soil temperatures reach >140°F for 15-20 minutes will kill weed seed in the soil. The effect of this reduction in the seedbank viability results weed control in the treated area that persists for several weeks or months, similar to the effects of a preemergence herbicide.
Two studies were conducted at the USDA Hartnell Farm at Salinas, CA during July to September 2020. Steam was applied to raised beds using a custom-built steam injector. Prior to seeding lettuce, steam was applied in a 4-inch wide band to a depth of 3 inches deep. The steam was supplied by a SF-20 Sioux steam...