TITLE:
Red Rice Control and Soybean Tolerance to S-Metolachlor in Association with Glyphosate
AUTHORS:
Carla Rejane Zemolin, Luis Antonio de Avila, Dirceu Agostinetto, Guilherme Vestena Cassol, Marlon Bastiani, Rodrigo Pestana
KEYWORDS:
Crop Rotation, Weed Control, Crop Injury, Application Timing
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.5 No.13,
June
26,
2014
ABSTRACT: Red rice is one of
the major troublesome and difficult weeds to control in rice production
regions. The introduction of the Clearfield® technology allowed
producers to control red rice using rice genotypes tolerant to the
imidazolinone herbicides. However, because the consecutive use of this
technology red rice biotypes have evolved resistance to imidazolinone
herbicides, the rice-soybean rotation has been an alternative used by
producers to control this weed. This system allows the use of herbicides with
different modes of action to control red rice, such as S-metolachlor. Thus, greenhouse
and field experiments were carried out during the 2011 to 2012 and 2012 to 2013
growing seasons to evaluate: 1) sensitivity of imidazolinone-resistant red rice
to S-metolachlor; 2) red rice control
and soybean tolerance in response to associations of S-metolachlor and glyphosate. In greenhouse, S-metolachlor effectively controlled both susceptible and
imidazolinone-resistant red rice in preemergence. In field, preemergence
applications of S-metolachlor
provided greater red rice control in comparison to S-metolachlor alone in early postemergence. The association of S-metolachlor with glyphosate did not
improve red rice control in preemergence application. However, association of S-metolachlor with glyphosate
significantly improved red rice control in early postemergence applications. S-metolachlor injury to soybean
increased with early postemergence applications. These results indicate that S-metolachlor effectively control
imidazolinone-resistant red rice in rice-soybean rotation.