CAJ | 학술논문

为明确甘肃省黄芪霜霉病的发病规律、防治药剂、经济危害允许水平和防治经济阈值，采用田间定点定期系统调查的方法，对该病害的发病进程以及影响发病的气候因素等进行了研究，采用模型拟合的方法研究了霜霉病病情指数与黄芪产量损失率的最佳拟合模型，选用6种杀菌剂进行了田间药效试验。结果表明：黄芪霜霉病在5月份显症，8月初至9月中旬为盛发期，一直延续到收获。黄芪霜霉病的病情指数随晚间平均相对湿度和病情基数的增加而增加，病情指数增长率随着白天平均温度的增加而增加。4种模型拟合结果表明，对数函数（y ＝33．81lnx－97．15）是拟合霜霉病病情指数（x）与黄芪产量损失率（y）的最好模型；选用60％百泰（5％吡唑醚菌酯·55％代森联）WG 800倍液进行霜霉病的防治时，经济危害允许水平和经济阈值分别为5．65％和17．73。药剂试验结果表明，52．5％抑快净 WG 1500倍液、60％百泰 WG 1000倍液是防治黄芪霜霉病良好的药剂；72％霜脲氰·锰锌 WP 400倍液、75％百菌清 WP 350倍液以及65％代森锌 WP 200倍液对黄芪霜霉病亦有较好的防效，可选择在生产中使用。
위명학감숙성황기상매병적발병규률、방치약제、경제위해윤허수평화방치경제역치，채용전간정점정기계통조사적방법，대해병해적발병진정이급영향발병적기후인소등진행료연구，채용모형의합적방법연구료상매병병정지수여황기산량손실솔적최가의합모형，선용6충살균제진행료전간약효시험。결과표명：황기상매병재5월빈현증，8월초지9월중순위성발기，일직연속도수획。황기상매병적병정지수수만간평균상대습도화병정기수적증가이증가，병정지수증장솔수착백천평균온도적증가이증가。4충모형의합결과표명，대수함수（y ＝33．81lnx－97．15）시의합상매병병정지수（x）여황기산량손실솔（y）적최호모형；선용60％백태（5％필서미균지·55％대삼련）WG 800배액진행상매병적방치시，경제위해윤허수평화경제역치분별위5．65％화17．73。약제시험결과표명，52．5％억쾌정 WG 1500배액、60％백태 WG 1000배액시방치황기상매병량호적약제；72％상뇨청·맹자 WP 400배액、75％백균청 WP 350배액이급65％대삼자 WP 200배액대황기상매병역유교호적방효，가선택재생산중사용。
To determine outbreak occurrence,economic infection level and economic threshold of downy mildew (Peronospora astragalina )on Astragalus membranaceus in Gansu Province,the disease dynamics and the cor-relation between disease and weather conditions were analysed based on data from fixed on-site field investiga-tion and systematic field surveys.A curve fitting technique was used to define the relationship between disease index and yield loss for A.membranaceus .Fungicides to control the disease were tested.It was found that the peak period for downy mildew occurrence was from early August to mid-September,the disease risk index was low after mid-September.Statistical analysis revealed that the disease risk index increased gradually with the increasing mean night relative humidity and disease cardinality.The logarithmic regression model (y =33.81 ln x -97.15)adequately described the relationship between disease index (x)and yield loss (y)of A.membrana-ceus .The economic injury levels for downy mildew on A.membranaceus treated with 5% Pyraclostrobin · 55% Metiram diluted 800 times were 5.65%,and the economic threshold was about 17.73.Sensitivity testing for fungicides showed that 22.5% Famoxadone·30% Cymoxanil diluted 1500 times,5% Pyraclostrobin·55%Metiram diluted 1000 times,8% Cymoxanil ·64% Mancozeb diluted 400 times,75% Chlorothalonil diluted 350 times and 65% Zineb diluted 500 times could be used in rotation to control powdery mildew on A.mem-branaceus .