Effect of Weed Management Practices and Nitrogen Levels on Weeds, Yield Components and Yield of Bread Wheat( Triticum aestivum L.) at Kulumsa, Southeastern Ethiopia

摘要

A field experiment was conducted to investigate the effect of isoproturon, 2, 4-DEE and their mixtureson weeds, growth and yield of wheat (Triticum aestivum L.) and to find out the economic viability of differentweed management practices under variable nitrogen levels. The treatments comprised post emergence ofisoproturon (1.5 and 2.0 kg ha 1), 2, 4-DEE (0.50 and 0.75 kg ha 1), mixture of isoproturon at 1.0 with 2,4-DEE(0.25 and 0.50 kg ha 1), hand weeding and hoeing at tillering and weedy check each at three N(0,60 and 120 kgha 1) levels in a factorial combination in randomized complete block design replicated three times. The weedcommunity included twelve broadleaved and six grasses with 64.8 and 35.2% relative density, respectively.The weed population decreased whereas weed dry weight increased with increasing nitrogen rate under all theinteractions. Plant height, days to ear emergence and maturity and grains spike 1 were significantly influencedby the main effect of nitrogen and weed management practices. The productive tillers m 2 increased with thesuccessive increase in nitrogen application rates under all the weed management practices. Application ofisoproturon at 1.0 + 2, 4-DEE at 0.5 kg ha 1 interacted significantly with 120 kg N ha 1 and gave highest 1000kernels weight, grain (5489 kg ha 1) and straw (6443.1 kg ha 1) yield and highest net profit (19714 Birr ha 1).