INTEGRATED WEED MANAGEMENT AND NITROGEN IN INDIAN MUSTARD (BRASSICA-JUNCEA) AND THEIR RESIDUAL EFFECT ON SUCCEEDING GREENGRAM (PHASEOLUS-RADIATUS)

An experiment was conducted on Vertisol of Navasari during 1989-90 and 1990-91 to study the effect of weed-control practices and nitrogen in Indian mustrard [Brassica juncea (L.) Czernj. & Cosson] and their res idual effect on succeeding greengram (Phaseolus radiatus L.). Ten weed -management treatments were laid out in split-plot design with 3 repli cations. The greengram crop was superimposed in summer with 2 levels o f nitrogen in split-split-plot design. Though higher yield was obtaine d with weed-free condition, comparable yield was recorded with 2 hand- weedings, pendimethalin alone or supplemented with hand-weeding owing to effective weed control. Higher yield was also obtained with 90 kg N /ha but remained at par with 75 kg N/ha, indicating better utilization of applied N. Higher uptake of nutrients (NPK) was recorded with weed -free condition and graded doses of N. Likewise, higher oil yield was obtained with these treatments. The weed-management practices as well as nitrogen application followed in preceding Indian mustard crop did not leave any residue to affect the yield of succeeding crop of greeng ram adversely or favourably. However, the seed yield of greengram was significantly increased with 20 kg N/ha.