PURPLE NUTSEDGE (CYPERUS ROTUNDUS L.) MANAGEMENT IN COTTON WITH COMBINED APPLICATION OF SORGAAB AND S-METOLACHLOR

Allelopathy can be employed effectively for weed management in different ways; one such aspect may be its utilization for reducing the use of synthetic herbicides. Considering its importance as a natural weed control approach, a study comprising two doses of sorgaab (Sorghum bicolor L. water extract) 12 and 15 L ha(-1) combined with lower doses i.e. and 1/3(rd) (1075, 717 g a.i. ha(-1)) of synthetic herbicide (S. metolachlor) as pre-emergence spray against purple nutsedge was undertaken in cotton (Gossypium hirsutum L.) under irrigated conditions in central Punjab, Pakistan. Label dose of S. metolachlor (2.15 kg a.i. ha(-1)) and untreated treatment were maintained as control. The results of two years field trials revealed that 62-92% purple nutsedge control was achieved from sorgaab application in combination with reduced doses of herbicide. Similarly purple nutsedge dry weight was reduced by 75-88% than untreated control indicating that sorgaab with lower S. metolachlor doses was quite effective in suppressing purple nutsedge.