茶轮斑病体外抑制试验及大田防治效果

Effects of commonly used fungicides on Pestalotiopsis theae under laboratory and field conditions

[目的]筛选安全高效防治茶轮斑病的杀菌剂。[方法]采用菌丝生长速率法和孢子萌发法分别测定武夷菌素、多抗霉素、春雷霉素、枯草芽孢杆菌、戊唑醇对其菌丝和分生孢子的抑制作用,在此基础上开展大田防治试验。[结果]戊唑醇、枯草芽孢杆菌对菌丝抑制作用较强,春雷霉素对分生孢子有较强的抑制作用。戊唑醇3 000～5 000倍120 h对菌丝抑制率为100%,枯草芽孢杆菌500倍和2 000倍120 h对菌丝抑制率分别为90.25%和83.71%。春雷霉素400～1 200倍对分生孢子抑制率为100%。戊唑醇5 000倍+春雷霉素1 000倍对菌丝和孢子抑制率分别达到100%,枯草芽孢杆菌1 000+春雷霉素1 000倍对菌丝和孢子抑制率分别为60.77%和100%。大田试验结果表明,戊唑醇、戊唑醇+春雷霉素、春雷霉素与枯草芽孢杆菌交替使用3个处理的防效分别为78.64%、77.48%和73.76%。[结论]生产中可采用430 g·L^(-1)戊唑醇SC 5 000倍+6%春雷霉素WP 1 000倍或者6%春雷霉素WP 1 000倍与100亿芽孢·g^(-1)枯草芽孢杆菌WP 1 000倍交替使用2个配方进行防治。

[Objective]The aims of present study was to screen the safe and efficient fungicide for Pestalotiopsis theae control.[Methods]In this study,mycelium growth rate and spore germination methods were employed to analyse the inhibitory effects of five fungicides,including wuyiencin,polyoxin,kasugamycin,bacillus subtilis,and tebuconazole,on mycelium growth rate and spore germination of Colletotrichum camelliae Massea under laboratory condition.Base on the results,field trials were carried out.[Results]The results showed that both tebuconazole and bacillus subtilis strongly inhibited mycelium growth,while Kasugamycin showed strong effect on spore germination.The inhibition rates of tebuconazole diluted by 3 000x to 5 000x produced 100% inhibition activity on mycelium growth in 120 h post treatment,while it was 90.25% and 83.71% for bacillus subtilis diluted by 500x and 2 000x,respectively,during the same testing time interval.At the same time,Kasugamycin diluted by 400x and 1 200x produced 100% inhibition activity on spore germination.When tebuconazole at 5 000x dilution was mixed with Kasugamycin at 1 000x dilution,the mixture exhibited 100% inhibitory activity on both mycelium growth and spore germination,while when the combination of both bacillus subtilis and Kasugamycin were at 1000x dilution,the inhibition rates of mycelium and spore were 60.77% and 100%,respectively.The field trials indicated that the control effects of tebuconazole,mixture of tebuconazole and kasugamycin,and mixture of kasugamycin and bacillus subtilis were reached up to 78.64%,77.48%,and 73.76%,respectively,when these three solutions were alternately applied in the field.[Conclusion]To effectively control Pestalotiopsis theae in the field practice,two fungicide combinations could be adopted,which are 430 g·L^-1 tebuconazole SC 5 000x mixed with 6% Kasugamycin WP 1000x and 6% Kasugamycin WP 1 000x combined with 10 billion spores·g^-1 bacillus subtilis WP 1 000x.