A Linuron-Free Weed Management Strategy for Carrots
The development of a linuron-free weed management strategy for carrot production is essential as a result of the herbicide re-evaluation programs launched by the Pest Management Regulatory Agency in Canada for herbicides registered prior to 1995 and the recent discovery of linuron resistant pigweed species in Ontario. In 2016 and 2017 field trials were conducted in one of Ontario’s main carrot growing regions on high organic soils. Pigweed species seedlings were effectively controlled with pre- and post-emergent treatments. Selected post-emergence treatments were applied at the predetermined biologically effective dose (≥90% control of pigweed seedling) achieving excellent crop selectivity and commercially acceptable pigweed seedling control under field conditions. This study demonstrated clearly that an alternative linuron-free strategy can be developed for carrots. The novel strategy of exploring the potential to utilize the biologically effective dose of selected herbicides to achieve crop selectivity and control of pigweed seedlings was verified.