Triticale competitive ability with annual ryegrass (Lolium rigidum Gaudin) as affected by variety, sowing rate and row spacing

摘要

One strategy for dealing with herbicide resistant weeds is to identify strongly competitive crop cultivars that suppress weed growth and/or withstand the competitive effects of weeds. Triticale (X Tritico-secale Wittmack) is often ranked as more tolerant to environmental stresses than wheat (Triticum aestivum L.), however, little is known about varietal differences in its competitive ability with weeds. Annual ryegrass (Lolium rigidum Gaudin) is one of the most serious weed species in Australian cereal cropping largely because it has evolved herbicide resistance, is widespread and competes strongly with grain crops. A field trial was conducted to examine the competitive ability of four triticale cultivars and one wheat cultivar against annual ryegrass as influenced by row spacing (15 or 30 cm) and sowing rate (50 or 100 kg ha~(-1)). Cultivar Bogong had the highest grain and biomass yield of the triticale cultivars in the ryegrass-free treatment. In contrast, cultivars KM 10 and Tuckerbox demonstrated greater competitive ability than the other triticale cultivars by sustaining smaller growth reductions when grown with ryegrass (10.4 and 8.5% biomass reduction, respectively). No interactions were observed with row spacing and sowing rate. The comparative wheat cultivar Spitfire had a lower grain yield and biomass than the triticale cultivars in both ryegrass treatments. There appears to be scope for utilising triticale competition in weed management, however, the optimal agronomy may vary with thecultivar.