Between-row Mowing Systems Control Summer Annual Weeds in No-till Grain Sorghum

Abstract

In previous research, use of PRE soil residual herbicides was reduced 50% in no-till corn and soybean by banding herbicides over crop rows followed by mowing weeds growing between rows two times. The research goals were (1) to determine whether such between-row mowing systems adequately controlled weeds and prevented grain yield loss in other competitive field crops, such as no-till grain sorghum, and (2) to compare broadcast herbicide treatments with between-row mowing systems. PRE atrazine plus dimethenamid at relative rates of 0.75× and 1× (where 1× = 1.7 plus 1.3 kg ai/ha, respectively) were band-applied over rows shortly after planting followed by two between-row mowings close to the soil surface. In 2 of 3 yr in Missouri, this system controlled giant foxtail and common waterhemp as well as broadcast herbicides in no-till sorghum. In 2 of 3 yr, between-row mowing systems also prevented yield loss in no-till sorghum as well as both broadcast herbicides at the same rates and the weed-free check.Nomenclature: Atrazine; dimethenamid; giant foxtail, Setaria faberii (L.) Beauv. SETVI; common waterhemp, Amaranthus rudis Sauer. AMATA; corn, Zea mays L. ZEAMX; sorghum, Sorghum bicolor (L.) Moench SORVU ‘Northup King GS10’and ‘Pioneer 84G62’; soybean, Glycine max (L.) Merr.