The Competitive Ability of Avena spp. and Alopecurus myosuroides Huds. Influenced by Different Wheat (Triticum aestivum) Cultivars

摘要

Field experiments were conducted at Havza and Gelemen to evaluate the effect of different densities of Avena spp. and Alopecurus myosuroides Huds. on wheat cultivars Bezostaja and Kate-A-I. As expected the semi-dwarf cultivar Bezostaja was shorter than Kate-A-I in all weed densities, indicating that plant height was not correlated with competitiveness under the experimental conditions. The mean yields of Bezostaja and Kate-A-I in the weed-free plots in 2000-2001were 3420 kg ha-1 and 3360 kg ha-1, respectively. Both species caused decreases in wheat yield with increasing density. While 20 Avena spp. per square reduced the yield by 13.3% in Bezostaja, yield losses of 18.6% were observed in Kate-A-I for the same density. The competitive ability of Avena spp. with wheat cultivars was highly variable. Taking these yield losses into consideration, the competitive ability of Bezostaja with Avena spp. was higher than that of Kate-A-I. Similar results of yield loss were also observed in A. myosuroides. Wheat shoot dry weights consistently decreased with increasing weed density. However, there was no correlation between wheat cultivars and weed species. Kate-A-I has more competitive ability for the formation of biomass due to its height.