烯丙苯噻唑和氟唑环菌胺复配颗粒剂研究及其对水稻苗期稻瘟病和纹枯病的防效

水稻苗期病害的发生及防治备受关注。为明确诱抗剂烯丙苯噻唑与杀菌剂氟唑环菌胺复配颗粒剂对水稻幼苗的安全性和对苗期病害的防治效果,研制了16%烯丙苯噻唑·氟唑环菌胺复配颗粒剂配方并检测了理化性质,采用高效液相色谱法检测了有效成分含量及其缓释效果,并测定了温室条件下烯丙苯噻唑对水稻幼苗的安全性,以及颗粒剂对水稻稻瘟病和纹枯病的防治效果。结果表明,所制备颗粒剂的各项指标均符合国家相关标准要求。释放动态结果显示:杀菌剂氟唑环菌胺在V甲醇:V水=30:70的混合溶液中释放4 h后,累积释放率(质量分数)即达到峰值33%,且随后趋于稳定;而诱抗剂烯丙苯噻唑则在7 d后累积释放率方达到最高峰值;将两种有效成分复配可实现药剂对作物苗期病害的速效性与持效性协同作用。安全性试验显示,16%烯丙苯噻唑颗粒剂制剂用量不高于150 g/m2时对水稻幼苗安全。人工接菌条件下,试验剂量的烯丙苯噻唑可诱导水稻幼苗产生稳定的抗稻瘟病和纹枯病效果。16%烯丙苯噻唑·氟唑环菌胺颗粒剂对稻瘟病和纹枯病的防治效果在制剂用量150 g/m2剂量下最佳,分别为64.79%和68.32%,实现了1次用药同时防治两种病害的效果。研究结果可为诱抗剂与杀菌剂复配制剂的研发提供理论依据,同时可为缓释颗粒剂的田间科学施用提供参考。

Research of probenazole and sedaxane combined granule and the control efficacy on rice blast and sheath blight at seedling stage

The occurrence and control of rice seedling diseases has been well concerned. In order to clarify the safety and control efficacy of the combination of plant immune inducer probenazole and fungicide sedaxane on rice during the seedling stage, 16% probenazole + sedaxane granule formulation was prepared and the physical indexes of the formulation were measured. Two active ingredients contents in the formulation and the cumulative release rates were detected by HPLC. The safety of probenazole to rice seedlings and the control effect of the combined granules on rice blast and sheath blight were measured. The results showed that the quality of the prepared granules met the national standard requirements. The release dynamic curves of the active ingredient in a 30% (V/V) methanol solution showed that the cumulative release rate of sedaxane was 33% (m/m) after 4 h and then changed very slightly, while 7 d was needed for probenazole to achieve its highest peak cumulative release rate. It indicated that the combined granule might provide a combination of quick-acting and sustained-effect for disease control during the rice seedling stage. The results of safety tests showed that 16% probenazole granule was safe for the growth of rice seedling using the dose of 150 g/m2. A stable resistance of rice seedlings to rice blast and sheath blight was induced by probenazole at the test dosage under the artificial inoculation conditions. The 16% probenazole + sedaxane granule, at the dose of 150 g/m2, exhibited excellent activity for the control of rice blast and rice sheath blight, with the control efficacy of 64.79% and 68.32% respectively. This work has provided a good example for the development of premixtures with plant immune inducers and fungicides, which has also offered a reference for reasonably granules application in field.