Effect of land configuration and weed management in onion (Allium cepa)

A field experiment was conducted to examine the effect of different planting patterns and weed management practices on weed growth and productivity of onion (Allium cepa L.) during rabi 2006–07 and 2007–08. The experiment was laid out in split-plot design with planting patterns of onion in main-plots (flat and raised bed planting with or without rice straw incorporation) and weed management practices viz., pendimethalin @ 0.75 kg/ha, oxyflourfen @ 0.225 kg/ha, fluchloralin @ 1.125 kg/ha, two hand weedings and control (unweeded) in sub-plots. Weed population and dry matter accumulation of weeds under different planting patterns and straw management techniques remained unaffected throughout the crop growth period and at uprooting. Yield attributes and bulb yield were not significantly influenced by planting patterns. Population and dry matter accumulation of weeds were significantly reduced with the application of oxyflourfen, pendimethalin and two hand weedings, when compared with fluchloralin and unweeded control during both years of investigation. Application of oxyflourfen gave the highest bulb yield, which was at par with pendimethalin and two hand weedings. These treatments gave significantly more bulb yield than fluchloralin and unweeded control. The highest net returns obtained with flat bed sowing with rice straw incorporation. Among the different weed control treatments, the maximum net returns of 185.6×10³/ha with BCR 7.63 registered with oxyflourfen. Unweeded control treatment recorded the lowest net returns of 94.3×10³/ha with BCR 4.10.