Persistence of ALS inhibiting (Group B) herbicides in alkaline soils of south eastern Australia

摘要

The ALS inhibiting (Group B) herbicides (sulfonylureas, sulfonanilides and imidazolinones) are soil and foliar applied herbicides whose persistence threatens production of rotational crops. This study found that in alkaline soils of south eastern Australia persistence was as little as one month after treatment (MAT) under ideal conditions for metsulfuron or as long as 43 MAT for chlorsulfuron and imazethapyr. While they are prone to leaching the majority of herbicide remained in the top 20 cm of thesoil profile at the low-medium rainfall sites used in this study. In general the product labels provide adequate guidelines for avoiding damage to rotational crops provided that the pH of the paddock is properly assessed.