Pyrithiobac Combinations Control Red Morningglory (Ipomoea coccinea) and Devil's-claw (Proboscidea louisianica) in Non-Transgenic Cotton (Gossypium hirsutum)

Abstract

Standard and reduced rates of pyrithiobac, prometryn, and diuron applied preemergence (PRE) alone and in combination and followed by pyrithiobac POST were evaluated for red morningglory and devil’s-claw control in non-transgenic cotton. Preemergence applications of prometryn or diuron controlled red morningglory no more than 27% and devil’s-claw no more than 47%.  Preemergence combinations of prometryn or diuron plus pyrithiobac controlled red morningglory and devil’s-claw as much as 75%.  Prometryn or diuron plus pyrithiobac followed by pyrithiobac postemergence (POST) controlled red morningglory 88 to 91% and devil’s-claw 81 to 100%.  Red morningglory control was similar with reduced rates (0.8 lb ai/A) of prometryn or diuron plus pyrithiobac PRE followed by a reduced rate (0.047 lb ai/A) of pyrithiobac POST.  Cotton yields were greatest when PRE combinations were followed by pyrithiobac POST.