防治大豆疫霉根腐病的药剂筛选

SCREENING OF FUNGICIDES FOR CONTROLLING PHYTOPHTHORA ROOT ROT OF SOYBEAN

在离体条件下测定了 8种内吸性杀菌剂对大豆疫霉菌菌丝生长的抑制作用。甲霜灵、甲霜灵锰锌、安克锰锌、杀毒矾、霜脲锰锌、克露和加瑞农为有效杀菌剂 ,霜霉威不具有抑菌效果。甲霜灵的 EC50 值为0 .4 870 μg/ m L,抑菌效果最好 ,安克锰锌、甲霜灵锰锌的 EC50 值分别为 1.4 2 6 1μg/ m L和 1.76 97μg/ m L,效果次之。在活体条件下 ,甲霜灵和甲霜灵锰锌能完全抑制大豆疫霉菌对感病大豆品种的侵入 ,并具有较长的药效期 ,安克锰锌、杀毒矾和霜霉威虽然具有明显的防治效果但药效期很短。大豆疫霉菌菌株间对甲霜灵锰锌的敏感性存在差异 ,但这种差异与菌株来源没有相关性 ,EC50 平均值为 1.830 2μg/ m L ,没有发现耐药性菌株。在我国黑龙江省目前缺乏有效抗病品种的情况下 。

Effect of 8 systemic fungicides on growth of Phytophthora sojae was investigated in vitro. Among the tested chemicals, seven of them effectively inhibit the groth of P.sojae except propamocarb hydrochloride. The EC 50- values for inhibition of mycelial growth by metalaxyl, dimethomorph mancozeb, metalaxyl mancozeb, oxadixyl mancozeb, cymoxanil mancozeb, curzate-M8 were 0.4870 μg/mL, 1.4261 μg/mL, 1.7697- μg/mL, 11.0996 μg/mL, 10.2114 μg/mL and 8.0294 μg/mL respectively. Metalaxyl had the lowest EC 50- value and exhibited highest inhibitory action to P. sojae. In vivo, metalaxyl and metalaxyl mancozeb completely inhibit the infection of P. sojae to susceptible soybean cultivar, and the efficacy lasted for a longer; In addition dimethomorph mancozeb, oxadixyl mancozeb and propamocarb hydrochloride had better controlling efficacy, however, they had short time of action. The sensitivity of 15 isolates of P. sojae from different locations to metalaxyl mancozeb was tested, no tolerant isolate was found. At present, the resistant to Phytophthora soybean cultivars are not available, applying metalaxyl mancozeb to control this disease may be an alternative and effective way.