GLYPHOSATE CONTROLS RUST DISEASES IN GLYPHOSATE-RESISTANT WHEAT

Authors: FENG, P - MONSANTO CO.; CLINTON, W - MONSANTO CO.; BALEY, J - WASHINGTON STATE UNIV.; BUNKERS, G - MONSANTO CO.; ALIBHAI, M - MONSANTO CO.; Paulitz, Timothy; KIDWELL, K - WASHINGTON STATE UNIV.

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/20/2005
Publication Date: 5/20/2005
Citation: Feng, P., Clinton, W., Baley, J., Bunkers, G., Alibhai, M., Paulitz, T.C., Kidwell, K. 2005. Glyphosate controls rust diseases in glyphosate-resistant wheat. Phytopathology. 89: S29

Interpretive Summary:

Technical Abstract: Glyphosate is a broad spectrum herbicide with very attractive environmental properties and has been used in glyphosate-resistant crops for efficacious control of weeds. Glyphosate inhibits 5-enolpyruvyl shikimate 3-phosphate synthase which is a key enzyme in the synthesis of aromatic amino acids in plants, fungi and bacteria. The current studies showed that glyphosate provided both preventive and curative activities against Puccinia triticina and Puccinia striiformis, which cause leaf and stripe rusts in wheat, respectively. Rust control was demonstrated at multiple plant growth stages with a glyphosate spray rate of 0.84 kg/ha which is the typical use rate for weed control. Leaf rust control by glyphosate was not mediated through induction of 4 common systemic acquired resistance genes. A field test under realistic stripe rust pressure confirmed the preventive and curative activities of glyphosate. Our results suggest that disease control is through a direct action of glyphosate on the rust fungi.