机构地区: 西北农业大学植物保护系
出 处: 《西北农业大学学报》 1993年第1期51-56,共6页
摘 要: 利用田间自然虫源级别辅以人工控制培养,使形成虫量梯度,以研究油菜蚜虫混合种群对油菜植株生长及产量的影响。结果表明,在蚜量达500头/百株以上时,影响趋势明显加大,特别在5000~7000头/百株和7000头/百株以上时,株高、叶面积、分枝依次减少41.6%,50.4%和69.5%;71.3%,51.1%和76.3%;产量损失73.0%和96.3%。并建立了其影响的动态模型。通过对油菜产量构成因子的通径分析,明确了产量损失主要是由于蚜虫危害造成批荚率的提高。因此,在油菜生长后期防治虫害的同时,还应采取降低批荚率的农艺措施。 The influence of plant growth and yield losses caused by rape aphids were analysed based on several density combined treatments made by additional inoculation or partial pesticide control over natural populations. The results showed that the damage caused by rape aphids had some clear restrains on rape, when the total number of aphids per 106 plants was over 500 especially over 5000-7000 and over 7000, the rate of plant height, the leaf area and the number of plant branch decreased by 41.6% and 50.4%, 69.5% and 71.3% and 51.1% and 76.3% in proper order, the rate of the yield losses decreased by 73.0% and 96.3%. The dynamic models for affecting plant growth and yield losses caused by rape aphids were established. Through the analysis of path coefficients of the construction of rape yield at the damage of rape aphids showed that the determinative factor affecting the yield losses was the increase in the blighted pods. In the later period of rape growth, agronomic measures, should be adopted to reduce the blighted pods.