2007 Annual Report
The fungus Colletotrichum gloeosporioides, originally isolated from the weed species, coffee senna, can effectively control a related weed, sicklepod, when fungal spores are formulated in either unrefined corn oil or an invert emulsion. Control of hemp sesbania is also enhanced when fungal spores are applied to weeds in an unrefined corn oil emulsion. We are also currently evaluating MV formulations with reduced trichothecene content that we have developed, and have demonstrated that these formulations retain high weed control efficacy.
Redvine and trumpetcreeper are increasingly problematic in no-till and low-till soybeans in the Mississippi Delta, and are highly tolerant to recommended glyphosate usage rates. We have found that sequential applications of a glyphosate product, followed by an application of MV, will effectively control these weeds. Control of kudzu and other highly invasive weeds may require a combination of management practices. Identifying the ability to co-apply MV with newer herbicides provides greater ability for use of the bioherbicide. We have also discovered a synergistic interaction occurs between certain glyphosate products and Colleototrichum truncatum for improved biological control of hemp sesbania.
Laboratory studies have assessed the compatibility of MV with three herbicides currently being used for control of kudzu: aminopyralid (Milestone), metsulfuron (Escort) and flouoroxypyr (Vista). A good degree of survival of spores was found in tank mix concentrations of Milestone and Escort and was capable of growth in the presence of commercial formulation of these herbicides. Field trials are evaluating efficacy of combinations of the biocontrol fungus with these herbicides for integrated kudzu control.
Boyette, C.D., Jackson, M.A., Bryson, C.T., Hoagland, R.E., Connick Jr, W.J., Daigle, D.J. 2006. Sesbania exaltata biocontrol with colletotrichum truncatum microsclerotia formulated in 'pesta' granules. Biocontrol - Online DOI 10.1007/s/10526-006-9031-7.
Boyette, C.D., Hoagland, R.E., Weaver, M.A. 2007. Biocontrol efficacy of colletotrichum truncatum for hemp sesbania (sesbania exaltata) is enhanced with unrefined corn oil and surfactants. Weed Biology and Management 7:70-76.
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.
Williams, R.D., Hoagland, R.E. 2007. Phytotoxicity of mimosine and albizziine on seed germination and seedling growth of crops and weeds. Allelopathy Journal. 19(2):423-430.
Boyette, C.D., Reddy, K.N., Hoagland, R.E. 2006. Biocontrol of kudzu (Pueraria lobata), redvine (Campsis radicans), and trumpetcreeper (Brunnichia ovata) is synergized by glyphosate. Biocontrol Science and Technology 16:1067-1077.
Boyette, C.D., Hoagland, R.E., Abbas, H.K. Evaluation of the bioherbicide Myrothecium verrucaria for weed control in tomato (Lycopersicon esculentum). Biocontrol Science and Technology 17:171-178. 2007.
Lovelace, M.L., Talbert, R.E., Scherder, E.F., Hoagland, R.E. 2007. Effects of multiple applications of simulated quinclorac drift rates on tomato. Weed Science 55:167-169.
Weaver, M.A., Lyn, M.E. 2007. Compatability of a Biological Control Agent with Herbicides for Control of Invasive Plant Species. Natural Areas Journal 26:264-268.