香蕉枯萎病田间发病株的高效灭菌方法筛选

为筛选有效防控香蕉枯萎病菌扩散蔓延的灭菌方法,采用含毒介质培养法测定咪鲜胺和多菌灵不同配比对枯萎病菌的毒力作用以筛选最佳混配液,比较最佳混配液与生石灰、草甘膦、咪鲜胺的平板抑菌和大田灭菌效果,并研究了大田不同施用方式对最佳混配液灭菌效果的影响。结果表明,咪鲜胺与多菌灵体积比为10∶1时得最佳混配液,可显著提高对香蕉枯萎病菌的抑制效果,增效系数为1.53,EC50值最小,为0.025 mg/L;4种药剂的EC50值由大到小为草甘膦生石灰咪鲜胺最佳混配液。1 000 mg/L最佳混配液喷施于大田病株5 d后根际土壤病菌含量下降了95.93%,10 d后球茎病菌含量减少了71.88%,综合灭菌效果显著优于其它处理。此外,应用打孔灌药法可显著提高最佳混配液对大田病株的灭菌效果,施用5 d后球茎病菌含量减少了95.95%。表明以打孔灌药法施用1 000 mg/L最佳混配液灭菌效果显著且操作便捷,易于推广应用。

Sterilization of diseased plants infected with Fusarium wilt disease in banana fields

To control the spread of Fusarium oxyporum f. sp. cubense (FOC), sterilization of bananaplant infected with the disease should be done. The inhibitory activity test of the mixtures of prochloraz and carbendazim at different mixing ratios against FOC was determined by the plates containing fungicides and the synergistic ratios were calculated according to Wadley formula. Then, the effects of quicklime, glyphosate, prochloraz, and the best mixture of fungicides were investigated on the PDA plates and diseased bananas, and the effects of different treatments with the best mixture of fungicides were tested. The synergistic interactions against FOC of the mixtures of prochloraz and carbendazim were observed at the ratio of 10:1, and the synergism ratio was 1.53, and the EC₅₀ of the best mixture of fungicides was 0.025 mg/L, significantly smaller than that of other reagents tested. The FOC on the rhizosphere and banana corms sprayed with 1 000 mg/L the best mixture of fungicides decreased 95.93% after five days, and 71.88% after ten days, respectively, significantly higher than that of other reagents tested. Moreover, perfusion with the best mixture of fungicides after perforation on the banana cauloid was significantly better than spraying with the best mixture of fungicides. The FOC from banana corms treated with the best mixture of fungicides after perforation decreased 95.95% after five days. The sterilization method was efficient and convenient for controlling Fusarium wilt disease in banana fields.