TITLE:
Effect of imazethapyr application timing in kidney and white bean
AUTHORS:
Nader Soltani, Robert E. Nurse, Peter H. Sikkema
KEYWORDS:
Dry Bean; Phaseolus vulgaris; Preemergence; Preplant-Incorporated; Postemergence Herbicides; Sensitivity; Tolerance
JOURNAL NAME:
Agricultural Sciences,
Vol.4 No.12,
December
17,
2013
ABSTRACT:
A total of twelve field trials (6 with kidney bean and 6 with white bean) were conducted over a three-year period (2010 to 2012) at various locations in Ontario to evaluate the tolerance of kidney and white bean to imazethapyr applied preplant incorporated (PPI), preemergence (PRE), and postemergence (POST) at 37.5, 75 and 150 g·ai·ha-1. Imazethapyr applied PPI or PRE in kidney or white bean caused 0%-1%, 0%-4%, and 0%-9% injury at 1, 2, and 4 weeks after application (WAA), respectively. However, the injury was transient and had no adverse effect on shoot dry weight, height, seed moisture content, and yield of kidney or white bean except for shoot dry weight which was reduced 32% with imazethapyr applied PPI compared to the weed free control in white bean. Imazethapyr applied POST in kidney or white bean caused as much as 17%, 18%, and 11% injury at 1, 2, and 4 WAA, respectively. There was no adverse effect on shoot dry weight, height, seed moisture content, and yield of kidney or white bean except for imazethapyr applied POST which increased seed moisture content 1.9% compared to the weed free control in white bean. Based on these results, there is an adequate margin of crop safety in dry bean to imazethapyr applied PPI or PRE at 37.5 or 75 g·ai·ha-1 in kidney and white beans. However, there is not an adequate margin of crop safety for imazethapyr applied POST at rates higher than 37.5 g·ai·ha-1 in kidney and white bean.