Weed management in spring-planted sugarcane (Saccharurn oficinarurn)-based intercropping systems

Abstract

Field studies were conducted during spring seasons of 2000-01, 2001-02 and 2002-03 on a sandy loam soil to evaluate relative profitability of intercropping spring-planted sugarcane (Saccharum officinarum L.) with greengram [Phaseolus radiatus (L.) Wilczek], blackgram [Phaseolus mungo (L.) Hepper] and okra (Abelmoschus esculentus L.) in 1:l ratio as compared to its sole cultivation and to assess the efficacy in these intercropping systems. Four weed-control treatments, viz. unweeded control, two hand-hoeings (30 days after sowing and after harvest of intercrops), pendimethalin @ 0.75 kglha as pre-emergence and trifluralin @ 1.0 kg1 ha as pre-plant to intercrops. These were tested in randomized block design (RBD) with three replications. The data of 3 years showed that intercropping of okra reduced the cane yield by 8.1% compared with sole sugar- cane. However, this intercropping system recorded the highest mean cane-equivalent yield (74.2 tonneslha) as well as net returns (Rs 37,461lha) among the cropping systems. The net returns under sole sugarcane yere R s 24,9501ha. Uncontrolled growth of weeds reduced the yield of sole sugarcane by 26.7%. One pre-emergence application of pendimethalin @ 0.75 kglha or pre-plant incorporation of trifluralin @ 1.0 kglha recorded effec- tive control of annual weeds and gave cane yield, intercrop yield and net returns comparable to two hand- hoeings. These herbicides, however, did not show their herbicidal effect on Cyperus rotundus.