Silage Tarps, in Combination with Roller-crimping or Mowing, Effectively Terminate a Cowpea Cover Crop

Cowpeas ( Vigna unguiculata ) are popular as a warm-season, nitrogen-fixing cover crop in US vegetable production. However, terminating this cover crop is challenging. Silage tarps, which are black plastic sheets used as groundcovers to kill weeds and any other living vegetation, could be an alternative for farmers trying to terminate cowpeas. An experiment was conducted at the Meigs Horticulture Research Farm in Lafayette, IN, USA, in 2024 to explore the utilization of mowing and roller-crimping followed by (fb) silage tarps for cowpea termination. Treatments consisted of mowing or roller-crimping alone, mowing fb tarping, roller-crimping fb tarping, cultivation fb tarping, and glyphosate (1530 a.i./ha). Chlorophyll content index (CCI) measurements at 2 weeks after treatment (WAT) were 0.09 CCI for mowing fb tarping, 9.5 CCI for roller-crimping fb tarping, 10.6 CCI for glyphosate, 27.8 CCI for mowing alone, and 37.6 CCI for roller-crimping alone. By 3 WAT, all treatments involving tarping resulted in 100% visual cowpea termination. Glyphosate (92%) did not completely terminate cowpea at 3 WAT; however, it was greater than mowing alone (45%) and roller-crimping alone (31%). Weed density 3 WAT was highest with mowing alone (3.05 weeds/m 2 ) and roller-crimping (1.78 weeds/m 2 ), while all treatments with tarps had 0 weeds/m 2 . These results suggest that cowpeas can be terminated by cultivation, roller-crimping, or mowing treatments fb tarping for 3 weeks.