小麦黑胚病药剂防治研究

为了有效防治小麦黑胚病,室内测定了8种不同杀菌剂对小麦黑胚病菌(A lternaria a lternata)的抑菌效果。试验结果表明,敌力脱对小麦黑胚病菌菌丝生长抑菌活性最强,EC50为3.38 m g/kg;烯唑醇、世高抑菌效果也较好,EC50分别为6.61和6.89 m g/kg。代森锰锌对病菌孢子萌发抑菌活性最强,EC50为0.25 m g/kg;麦叶净、福美双、烯唑醇抑制效果也较好,EC50分别为0.30、0.80和1.76 m g/kg。通过两年田间试验发现,22%麦叶净W P 600倍液喷雾对小麦黑胚病防效最好,平均防效达80.59%;其次为25%敌力脱EC 1 000倍喷雾,两年平均防效为74.97%;22%麦叶净W P 800倍和12.5%烯唑醇1 500倍液喷雾也有较好的防效,两年平均防效均超过60%。从防治时期和次数试验结果来看,扬花后5 d喷药防治效果最好,随着施药时间延迟,防治效果也随之下降;两次施药效果明显优于一次施药。

Study on the Chemical Control of Wheat Black Point

The inhibiting effect of 8 fungicides on the pathogen of wheat black point(Alternaria alternata) was tested in vitro. The results indicated that Tilt(Propiconzole)had the best inhibiting effect on the hypha growth of pathogen, EC_(50) is 3.38 mg/kg; Diniconazole and Score(Difenoconazole)also had good inhibiting effect on the hypha growth of pathogen with EC_(50) 6.61 mg/kg and 6.89 mg/kg. In inhibiting spore germination. The effect of Mancozeb is the best with EC_(50) 0.25 mg/kg, Maiyejing,Thiram and Diniconazole also have good inhibiting effect,with EC_(50) are 0.30 mg/kg,0.80 mg/kg and 1.76 mg/kg, respectively. The results in field experiments for two years indicated that the effect of spraying 22% Maiyejing WP with diluted 600 times was the best one,with 80.59% control effect averagely. The second was spraying 25% Tilt EC with diluted 1000 times,with the average control effect was 74.97%; the effect of spraying 22% Maiyejing WP with diluted 800 times and spraying 12.5% Diniconazole WP with diluted 1500 times also were preferably,that the control effect were over 60% averagely. The effect of spraying 22% Meiyejing WP on controlling wheat black point at different stage and time indicated that 5 d after flowering stage was the optimum control stage, the later spraying would lower effect. The effect of twice spraying is better than once.