Submitted to: Weed Technology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 12/23/2009
Publication Date: 5/7/2010
Publication URL: hdl.handle.net/10113/43443
Citation: Williams, M., Boerboom, C.M., Rabaey, T.L. 2010. Significance of Atrazine in Weed Management Systems of Sweet Corn. Weed Technology. 24:139-142. Interpretive Summary: This research provides a contemporary assessment of weed management systems being deployed in sweet corn. Selective herbicides are relied on heavily, and atrazine is the single most important herbicide in use. Applications of atrazine preemergence account for a majority of the herbicide amount applied; however, postemergence atrazine applications are common. Our work shows that loss of atrazine would directly impact two-thirds of the sweet corn production area in a given year. If atrazine were phased out completely, we hypothesize the greatest burden would be to those growers who 1) are relying less on tillage for weed control, 2) have particularly weedy fields, 3) have early season crop production, and 4) grow sweet corn in diverse rotations with other vegetables. No herbicide with economic and agronomic benefits equal to atrazine exists. Regardless of atrazine’s future, additional research is necessary to develop weed management systems meeting the demands for sustainability. The impact of this work is that it provides an assessment that will help frame the questions for future research on weed management in sweet corn.
Technical Abstract: Knowledge of weed management systems being used by sweet corn growers, including the role of atrazine in these systems, is poorly characterized. Management records of 175 fields throughout the major sweet corn production areas of the Midwest were surveyed from 2005 to 2007. Seventy-four percent of sweet corn fields in the Midwest were grown in rotation with soybean or corn (field corn, seed corn, and sweet corn). Interrow cultivation was used on 48% of fields, and atrazine use was higher in those fields without interrow cultivation. A majority of fields (54%) received both PRE and POST herbicide applications, with 66% of fields receiving one or more applications of atrazine at an average total use rate of 1.345 kg ai/ha. Mesotrione was applied below the registered use rate in two-thirds of the fields in which it was used POST. Atrazine use in sweet corn was highest when the preceding crops were other vegetables, compared to when the preceding crops were soybean or corn. Application of selective herbicides are relied on heavily in U.S. sweet corn production, accounting for 94% of total weed management expenditures which average $122.57/ha. Growers using atrazine spent an estimated $7.50/ha on the herbicide.