Chemical Weed Control in Cowpea (Vigna unguiculata)

A field experiment was carried out during 1991 and 1992 at the Research Farm, Punjab Agricultural University, Ludhiana to evaluate the performance of pendimethalin (0.37, 0.56, 0.75 and 0.94 kg/ha) and fluchloralin (0.60, 0.90 and 1.20 kg/ha) herbicides compared with hand weeding and no weeding treatments to control weeds in the seed crops of cowpea (Vigna unguiculata). In both the years, pendimethalin and fluchloralin herbicides at all levels controlled the weeds effectively and significantly reduced the dry matter accumulation of weeds over control. Dry matter of weeds recorded at 25 days after sowing ranged from 0.35 to 0.51 and 0.94 to 1.16 q/ha where pendimethalin was sprayed at 0.94 and 0.75 kg/ha during 1991 and 1992, respectively, in comparison to 9.83 and 21.10 q/ha in control plots during 1991 and 1992, respectively. Pendimethalin and fluchloralin at all levels and hand weeding treatments increased the seed yield over control. Pendimethalin at 0.75 kg/ha produced the highest seed yield of 14.28 to 14.51 q/ha which was 59.5 and 41.1% higher over control during 1991 and 1992, respectively. The effect of weed control treatments was also significant on straw yield, but the straw yield decreased as the dose of herbicides increased.