Research was conducted to determine the minimum number of between-row mowings necessary to control annual weeds, chiefly giant foxtail and common waterhemp, without corn yield loss. Over 2 yr in Missouri, the between-row mowing systems that were evaluated consisted of a 38-cm band of PRE atrazine plus metolachlor at 2.2 plus 2.2 kg ai/ha applied over corn grown in 76-cm rows shortly after planting followed by one, two, or three between-row mowings close to the soil surface. Based on rated total weed control, between-row total weed cover, and corn yield, the weed-free check was statistically indistinguishable from a treatment in which banded PRE herbicide was followed by only one between-row mowing, late, when weeds were relatively large. When mowed once at 52 to 64 days after planting (DAP), giant foxtail and common waterhemp were greater than 85 cm tall. The yield was not increased by mowing earlier or more than once.
Nomenclature: Atrazine; metolachlor; giant foxtail, Setaria faberii (L.) Beauv. #3, SETFA; common waterhemp, Amaranthus rudis Sauer. #3 AMATA; corn, Zea mays L. ‘Pioneer 3379’ #ZEAMX.
Additional index words: Alternative weed control, banding, banded application, cutting, mechanical weed control, nonchemical weed control, reduced rate herbicide.
Abbreviations: BR, between row; IR, in row.
