The control of Asian rust by glyphosate in glyphosate-resistant soybeans.
BACKGROUND
Glyphosate is a widely used broad-spectrum herbicide. Recent studies in glyphosate-resistant (GR) crops have shown that, in addition to its herbicidal activity, glyphosate exhibits activity against fungi, thereby providing disease control benefits. In GR wheat, glyphosate has shown both preventive and curative activities against Puccinia striiformis f. sp. tritici (Erikss) CO Johnston and Puccinia triticina Erikss, which cause stripe and leaf rusts respectively.


RESULTS
Laboratory studies confirmed earlier observations that glyphosate has activity against Phakopsora pachyrhizi Syd & P Syd which causes Asian soybean rust (ASR) in GR soybeans. The results showed that glyphosate at rates between 0.84 and 1.68 kg ha(-1) delayed the onset of ASR in GR soybeans. However, field trials conducted in Argentina and Brazil under natural infestations showed variable ASR control from application of glyphosate in GR soybeans. Further field studies are ongoing to define the activity of glyphosate against ASR.


CONCLUSIONS
These results demonstrate the disease control activities of glyphosate against rust diseases in GR wheat and GR soybeans.
Feng
Paul C C
PC
Monsanto Co., 700 Chesterfield Pkwy W., Chesterfield, MO 63017, USA. paul.feng@monsanto.com
Clark
Celeste
C
Andrade
Gabriella C
GC
Balbi
Maria C
MC
Caldwell
Pat
P
D001487:Basidiomycota / Q000502:physiology*; D005659:Fungicides, Industrial; D005998:Glycine / Q000031:analogs & derivatives*; D053209:Herbicide Resistance / Q000235:genetics; D010935:Plant Diseases; D013025:Glycine max / Q000235:genetics / Q000382:microbiology*; D000097797:Glyphosate
D005659:Fungicides, Industrial; D005998:Glycine; D000097797:Glyphosate