不同施肥水平对紫花苜蓿霜霉病抗病性的研究

Study on the effect of different fertilizer rates applied on resistance of alfalfa downy mildew

在定西九华沟利用田间自然发病条件,以当地紫花苜蓿品种———庆阳苜蓿为材料,研究了不同施肥水平对紫花苜蓿霜霉病抗病性的影响。结果表明,苜蓿霜霉病在田间的症状有4种表现:褪绿斑型、霉叶型、叶片畸变型、系统性症状型,其平均发病率在57 0%～88 8%,病情指数为19 1～44 3。通过对发病率和病情指数2项指标进行统计分析,发现不同的施肥水平对苜蓿霜霉病抗病性差异不显著。

The relationship between different fertilizer rates applied and resistance of Qingyang alfalfa to Alfalfa downy mildew(Peronospora aestivalis Syd DC) were evaluated in Jiuhuagou ,Dingxi county , Gansu province  The result showed that there are 4 field symptoms: green fade spots, mould leaves, leave aberration and systematic symptom The incidence varies between 570%～888%, disease index is 191～443 Statistical analysis of disease incidence and index indicated that there was no significant difference in fertilizer rates applied affecting alfalfa downy mildew resistance