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Water-Corn Oil Emulsion Enhances Conidia Germination and Mycoherbicidal Activity of Colletotrichum truncatum

Published online by Cambridge University Press:  12 June 2017

Grant H. Egley  and
C. Douglas Boyette
Grant H. Egley
Affiliation:
South. Weed Sci. Lab., Agric. Res. Serv. U.S. Dep. Agric., Stoneville, MS 38776
C. Douglas Boyette
Affiliation:
South. Weed Sci. Lab., Agric. Res. Serv. U.S. Dep. Agric., Stoneville, MS 38776
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Abstract

A water-corn oil (unrefined) emulsion has promise as a carrier for application of the mycoherbicide, Colletotrichum truncatum. We investigated this formulation (normal emulsion; oil in water) for influences on conidia germination, appressoria formation, and mycoherbicidal activity of C. truncatum. Germination of conidia after application to hemp sesbania leaves was increased from 30% in water alone to 92% in the water-corn oil emulsion (water:oil, 1:1, by vol). The emulsion did not affect appressoria formation. of the several other oils tested, safflower seed oil enhanced in vitro germination but did not enhance germination and mycoherbicide activity when the conidia-emulsion formulation was applied to hemp sesbania leaves. Application of C. truncatum conidia in the unrefined corn oil emulsion to hemp sesbania seedlings resulted in 89 to 97% control of the weed after a 24 to 72 h dew delay. The emulsion enhanced mycoherbicide efficacy by stimulating conidia germination by protecting the conidia during a dew-free period, hence, increasing weed infection when a dew occurred.

Keywords

Hemp sesbania [Sesbania exaltata (Raf.) Rydb. ex. A. W. Hill] #3 SEBEXColletotrichum truncatum (Schw.) Andrus and MooreBiocontrolmycoherbicidefungal pathogenhemp sesbaniacorn oilSEBEX
Type
Special Topics
Information
Weed Science , Volume 43 , Issue 2 , June 1995 , pp. 312 - 317
Copyright
Copyright © 1995 by the Weed Science Society of America 

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References

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