Author
Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/19/2010 Publication Date: 10/1/2010 Citation: Boyette, C.D., Hoagland, R.E. 2010. Biological control of Hemp sesbania (Sebania exaltata) and Sicklepod (Senna obtusifolia) in soybean with Anthracnose pathogen mixtures. Weed Technology. 24(4):551-556. DOI: 10.1614/WT-08-154.1. Interpretive Summary: Tank mixtures of fungal spores of Colletotrichum truncatum and C. gloeosporioides, (formulated in corn oil and Silwet L-77 surfactant), were evaluated hemp sesbania and sicklepod control. In greenhouse tests, 100% mortality and dry weight reduction of hemp sesbania occurred 5 days after treatment (DAT), while 15 days were required to achieve 100% mortality and dry weight reduction of sicklepod. In field tests using narrow-row (50 cm) soybean plots, a single application of the mixture (similarly formulated) controlled hemp sesbania and sicklepod 94% and 88%, respectively, 8 DAT. Neither fungus controlled their respective weed hosts when applied as aqueous suspensions. Results indicate that tank mixtures of these pathogens can effectively control these major weeds with one application. Technical Abstract: In greenhouse and field experiments conducted over 3 years, tank mixtures of spores of the fungi Colletotrichum truncatum and C. gloeosporioides, formulated in unrefined corn oil and Silwet L-77 surfactant, were evaluated as a mycoherbicide mixture for simultaneous control of hemp sesbania and sicklepod. In greenhouse tests, 100% mortality and dry weight reduction of hemp sesbania occurred 6 days after treatment (DAT), while 15 days were required to achieve 100% mortality and dry weight reduction of sicklepod. In field experiments conducted in narrow-row (50 cm) soybean test plots, a single application of the fungal mixture formulated as described controlled hemp sesbania and sicklepod 94% and 88%, respectively, 9 DAT. Neither fungus, applied as aqueous conidial suspensions, provided control of their respective weed hosts. These results indicate that tank mixtures of these anthracnose-forming pathogens will effectively control hemp sesbania and sicklepod with a single application. |