Interaction of Pyrithiobac and Graminicides for Weed Control in Cotton (Gossypium hirsutum)

• Published in: Weed technology 2003-07, Vol.17 (3), p.461-466
• Main Authors: GRICHAR, W. James, BESLER, Brent A, BREWER, Kevin D, LEMON, Robert G
• Format: Article
• Language: English
• Subjects: Amaranth; Biological and medical sciences; Broadleaf weeds; Checks; Cotton; Fundamental and applied biological sciences. Psychology; Herbicides; Parasitic plants. Weeds; Peanuts; Phytopathology. Animal pests. Plant and forest protection; Weed control
• ISSN: 0890-037X; 1550-2740
• DOI: 10.1614/WT02-028

Field studies were conducted from 1996 through 1998 to evaluate control of broadleaf signalgrass and slender amaranth by clethodim, fluazifop-P-butyl, and fluazifop-P-butyl plus fenoxaprop-P-ethyl applied alone, in combination with pyrithiobac, or sequentially with pyrithiobac. Broadleaf signalgrass control with graminicides alone was 75 to 100%. Although broadleaf signalgrass control with clethodim was not reduced by pyrithiobac, control with fluazifop-P-butyl and fluazifop-P-butyl plus fenoxaprop-P-ethyl was reduced by pyrithiobac. Pyrithiobac controlled slender amaranth 85 to 100% when applied alone. However, slender amaranth control by pyrithiobac was inconsistent when pyrithiobac was applied in mixture or sequentially with graminicides. A reduction in slender amaranth control may have resulted from a combination of reduced graminicide efficacy and interference caused by broadleaf signalgrass with slender amaranth (pyrithiobac alone). Cotton yields were highest when pyrithiobac was applied 24 h after graminicides.