丙环唑对水稻纹枯病菌的抑制作用及对纹枯病的防治效果

摘要

The control effects of propiconazole to rice sheath blight were studied through laboratory tests, potted plant tests and field trial tests. The results showed that propiconazole could strongly inhibit mycelial growth in vitro, with an EC50value of 0.045 μg/mL,and strongly inhibited sclerotium production. After propiconazole treatment, the pathogenicity of R. Solani decreased obviously. Propiconazole could be easily absorbed by the leaves and roots of rice, and transmited into the stem and the leaf of sheath. Propiconazole exhibited fine protective and curative effects in controlling rice sheath blight in potted plant tests and had a long persistence effect on R. Solani on rice. In the field trial tests, propiconazole was sprayed at 150 g a. I. /hm2, and showed 89.15% control effect a-gainst sheath blight. Propiconazole was safe to the rice plants at the tested dosage. Propiconazole exhibited excellent control efficacy against rice sheath blight, which could provide a basis for controlling rice sheath blight and scientific application of fungicides in the field.%为明确丙环唑对水稻纹枯病的防治作用,通过离体抑菌试验,温室盆钵试验和田间试验研究了丙环唑对水稻纹枯病菌的抑制作用和对纹枯病的防治效果.离体抑菌试验表明,丙环唑能够强烈抑制水稻纹枯病菌(Rhizoctonia solani)的菌丝生长,EC50为0.045 μg/mL,并能够强烈抑制菌核产生,但不能抑制菌核萌发.温室试验表明,纹枯病菌经丙环唑处理后,致病力随药剂浓度提高而显著减弱；丙环唑可以很好地被水稻叶片和根系吸收,并输送到水稻的茎部和叶鞘；丙环唑对水稻纹枯病具有保护和治疗作用,400 μg/mL丙环唑处理水稻,抑制病斑长度分别达到82.16％和76.61％,并随药剂处理浓度的降低而降低；丙环唑对立枯丝核菌有较长的持效期,800 μg/mL处理水稻11 d后再接种的防效为40.10％.田间药效试验表明,25％的丙环唑乳油在有效剂量150 g/hm2下3次喷药后14 d的防效达到89.15％,丙环唑在本试验剂量范围内对水稻安全.表明丙环唑对水稻纹枯病有很好的防治作用,可为生产上防治水稻纹枯病和科学用药提供依据.