Pencycuron防治水稻纹枯病的研究

Pencycuron*是一种苯脲类型的新型杀菌剂.离体抗菌谱试验表明,Pencycuron对Rhizoctonia Solani,特别是对Pellicularia Sasakii具有特异的抗菌活性.该药剂在含药琼脂培养基上低浓度下对P.Sasakii菌丝的扩展也表现出极强的抑制作用,而且可引起菌丝体形态异常.此点,与井岗霉素有相似之处.室内植株测定表明,Pencycuron抑制菌丝侵染作用明显优于井岗霉素,抑制病斑扩展作用比井岗霉素差.防治水稻纹枯病的侵染有稳定的持久性,可达35天以上,而井岗霉素不足14天.因此,该药是一种以长效性为特征的保护性杀菌剂.室内人工模拟降雨测定,施药后50分钟,淋洗20mm雨量,效果明显受到影响.田间试验与室内结果一致.

Studies on Pencycuron to Control Rice Sheath Blight

Pencycuron is a novel fungicide of phenylurea type. The fungicide spectrum of pencycuron in vitro showed that the com pound had specific antibiotic activity to Rhizo-ctonia solani, particularly to Pellicularia Sasakii . Pencycuron also displa-yed a strong inhibitory effect on the P sasakii mycelial development on agar plate amended with the compound at low concentrations, and induced its morphological disorder in mycelial development. The effect property is almost the same as that of Validamycin.The result shown in glass-house test indicates that the in hibitory effect of Pencycuron on hypha infection is remarkably better than that of Validamycin, but the inhibitory effect on the development of lesion is weaker than Validamycin. Pencycuron has remarkably stable persistency in preventing the infection of rice sheath blight its effect lasting more than 35 days, while Validamycin, less than 14 days. Therefore, Pencycuron is a protective fungicide with stadle persistency. The efficacy was affected obviously, when the rice plants in the glass-house wece showered with artificial rain-fall at a level of 20 mm 50 min after the chemical treatment,The result of field tests is the same as that of the glasshouse.