防治大豆疫霉根腐病的药剂筛选

采用实验室测定和温室盆栽方法研究了8种杀菌剂对大豆疫霉菌(Phytophthora sojae)菌丝生长和繁殖的影响及它们对大豆疫霉根腐病的接种防治效果。结果表明,50%烯酰吗啉可湿性粉剂、97%甲霜灵可湿性粉剂和58%甲霜灵锰锌可湿性粉剂对大豆疫霉菌的菌丝生长和繁殖具有很好的抑制作用,该3种药剂能够明显抑制菌丝生长,抑制中浓度(EC50)值依次为0.1208μg/mL、0.1563μg/mL和0.3603μg/mL。浓度为10.0μg/mL时,对孢子囊形成和萌发的抑制率均为100%,对卵孢子形成抑制率分别为64.5%、59.5%和55.0%。接种防治试验结果显示,以上3种药剂喷药后7d防效依次为73.4%、68.8%和60.5%,其余的5种杀菌剂防治效果相对较差。

Fungicides screening for controlling Soybean Phytophthora Root and Stem Rot

The effect of eight fungicides on growth and propagation of Phytophthora sojae as well as their control effects on Phytophthora root and stem rot of soybean under inoculation condition were investigated. The results showed that 50% dimethomorph WP, 97% metalaxyl WP and 58% Ridomil-MZ WP exhibited higher inhibitory action to the growth and propagation of Phytophthora sojae. These three fungicides inhibited the growth of mycelial significantly, the EC50 values were 0.120 8 μg/mL, 0.156 3 μg/mL and 0.360 3 μg/mL, respectively. The three fungicides inhibited sporangium formation and germination completely, and inhibited oospore formation over 55.0 percent under the concentration of 10.0 μg/mL. These three fungicides had higher controlling effect on Phytophthora root and stem rot of soybean than other five fungicides which were 73.4%, 68.8% and 60.5% ,respectively, after 7 d spraying fungcides.