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ARS Home » Southeast Area » Stoneville, Mississippi » Biological Control of Pests Research » Research » Publications at this Location » Publication #202627
Title: Myrothecium verrucaria as a Bioherbicide, and Strategies to Reduce Its Non-Target Risks

Author
item Hoagland, Robert
item Weaver, Mark
item Boyette, Clyde

Submitted to: Allelopathy Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/28/2006
Publication Date: 1/10/2007
Citation: Hoagland, R.E., Weaver, M.A., Boyette, C.D. 2007. Myrothecium verrucaria fungus: A Bioherbicide and Strategies to Reduce Its Non-Target Risks. Allelopathy Journal 19(1): 179-192.

Interpretive Summary: The fungus Myrothecium verrucaria (MV), originally isolated from sicklepod, kills kudzu and several other important weeds, thus it has potential as a bioherbicide. Under greenhouse conditions MV caused 100% death to kudzu seedlings, and 90 to 100% control of older kudzu plants in naturally infested and experimental kudzu plots, respectively. In environmental chamber experiments, MV caused greatest reductions of kudzu plant biomass production at moderately warm temperatures (30° C). Responses of various non-target, young, woody plant species from several plant families to MV applications ranged from non-susceptible to moderately susceptible. Although MV possesses desirable bioherbicidal traits such as high virulence and the ability to control several species of weeds, this isolate also produces undesirable mycotoxins. Research data are presented and discussed in terms of future approaches to possibly reduce or eliminate these mycotoxins to develop a safe and efficacious bioherbicide.

Technical Abstract: Studies were conducted on a Myrothecium verrucaria (MV) strain, originally isolated from sicklepod (Senna obtusifolia L.), that exhibits bioherbicidal activity against kudzu [Pueraria lobata (Willd.) Ohwi] and several other weeds. Treatments of MV plus the surfactant Silwet L-77 caused 100% mortality to kudzu seedlings under greenhouse conditions, and 90 to 100% control of older kudzu plants in naturally infested and experimental kudzu plots, respectively. MV caused greater reductions of kudzu plant biomass production at 30° C, compared to 20 or 40° C when tested in environmental chamber experiments. Responses of various non-target, young, woody plant species from several plant families to MV applications ranged from non-susceptible to moderately susceptible. Bioassays of MV on seed germination and early growth of sicklepod and hemp sesbania [Sesbania exaltata (Raf.) Rybdb. Ex A.W. Hill] demonstrated that hemp sesbania was more sensitive than sicklepod to the fungus. Although MV possesses desirable bioherbicidal traits such as high virulence and the ability to control several species of weeds, this isolate also produces undesirable mycotoxins(trichothecenes). Research data are presented, as well as some discussion of future approaches to possibly reduce or eliminate these mycotoxins to develop a safe and efficacious bioherbicide.