INTEGRATED AND ECONOMICALLY VIABLE WEED MANAGEMENT IN SOYBEAN (GLYCINE-MAX) - WHEAT (TRITICUM-AESTIVUM) CROP SEQUENCE

A field experiment was conducted during 1987-88 and 1988-89 to study t he weed-control efficiency, production potential and economic feasibil ity in soybean [Glycine max (L.) Merr.]-wheat (Triticum aestivum L. em end. Fiori & Paol.) cropping system at Jabalpur. The dominant weed flo ra were awnless barnyard grass [Echinochloa colona (L.) Link] (21.57%) , umbrella grass (Cyperus iria L) (20.34%) and false daisy [Eclipta al ba (L.) Hassk.] (9.15%) in soybean; and small canary grass (Phalaris m inor Retz.) (38.96%), lambsquarters (Chenopodium album L.) (8.03%), to othed medick (Medicago hispida; syn M. denticulata Willd.) (6.83%) and scarlet pimpernel (Anagallis arvensis L.) (6.43%) in wheat. Though ex cessive tillage with tractor- or bullock-drawn implements improved the weed-control efficiency in both the crops (57 or 51% in soybean and 5 7 or 52% in wheat), it deteriorated the soil structure (bulk density) besides utilizing additional energy and the resultant higher cost of p roduction. Among different tillage practices, seedbed preparation with rotovator (1 pass) proved more economical and safe for maintaining so il structure. Drilling of seeds in rows resulted in higher profitabili ty (2.14) compared with broadcast sowing because of increased yield of 115 kg/ha soybean and 176 kg/ha wheat with the same investment of inp uts. Hand-weeding and herbicidal control were equally effective in con trolling the associated weeds, but the latter proved more economical.