|Bresnahan, G - NORTH DAKOTA STATE UNIV|
|Dexter, A - NORTH DAKOTA STATE UNIV|
Submitted to: Sugarbeet Research and Extension Reports
Publication Type: Proceedings
Publication Acceptance Date: February 26, 1999
Publication Date: N/A
Technical Abstract: Imazethapyr (Pursuit) is a selective herbicide used to control grass and broadleaf weeds in soybean. Imazethapyr has been shown to carryover into the years after the year of application, which may result in injury to rotational crops. Carryover has been primarily observed in low pH soils that have high organic matter and clay contents. The carryover may be due the increased sorption in these soils. The objects of the present study were to determine the effect of soil pH on imazethapyr carryover to sugarbeet,and to determine whether increasing soil pH would decrease carryover. Two years after imazethapyr application to pH 5.8 soil, the remaining imazethapyr residues reduced sugarbeet yield by a factor of 3. In fields limed to pH 7.7, the remaining imazethapyr residues only decreased sugarbeet yield by 15 percent. The results of these experiments suggest that raising the pH of low pH soils with lime will increase sugarbeet yield, although raising the pH did not totally prevent sugarbeet injury from imazethapyr 2 yr after application.