College of Plant Protection, State & Local Joint Engineering Research Center of Green Pesticide Invention and Application, Nanjing Agricultural University, Nanjing, 210095, China.
Plant Dis. 2018 Jul;102(7):1234-1239. doi: 10.1094/PDIS-10-17-1521-RE. Epub 2018 Apr 25.
This study evaluated the use of phenamacril and ipconazole, alone and in mixtures, for the control of rice bakanae disease caused by Fusarium fujikuroi. Mixtures were studied with the goal of reducing the selection of fungicide-resistant field isolates of the fungus. When tested alone, both phenamacril and ipconazole exhibited high antifungal activity against F. fujikuroi mycelial growth; the average EC value for 19 field isolates was 0.1544 μg/ml for phenamacril and 0.0472 μg/ml for ipconazole. A 2:1 mixture of phenamacril and ipconazole caused a slightly synergistic (greater than additive) inhibition of mycelial growth. Inhibition of F. fujikuroi sporulation was highest for ipconazole alone, intermediate with the 2:1 mixture, and lowest for phenamacril alone. Inhibition by phenamacril and ipconazole alone or by the 2:1 mixture was substantially lower for spore germination than for mycelial growth or sporulation. When the total fungicide concentration was <24 g of a.i./100 kg of treated rice seeds, the fungicides, whether alone or in the 2:1 mixture, were not phytotoxic to seeds or seedlings of two rice cultivars. In a greenhouse experiment, the 2:1 mixture of phenamacril and ipconazole at 6 g of a.i./100 kg of treated seeds provided 100% control of rice bakanae disease on two cultivars. Overall, the results indicate that the use of a 2:1 mixture of phenamacril and ipconazole should control rice bakanae disease while reducing the occurrence of fungicide resistance in F. fujikuroi.
本研究评估了单独使用苯霜灵和抑霉唑以及二者混合物防治由藤仓镰刀菌引起的水稻恶苗病的效果。研究混合物的目的是减少镰刀菌田间分离株对杀菌剂的选择抗性。单独测试时，苯霜灵和抑霉唑对藤仓镰刀菌菌丝生长均表现出很高的抑菌活性；对 19 个田间分离株的平均 EC 值分别为苯霜灵 0.1544μg/ml，抑霉唑 0.0472μg/ml。苯霜灵和抑霉唑以 2:1 的比例混合对菌丝生长产生轻微的增效（大于加和）抑制作用。单独使用抑霉唑对藤仓镰刀菌孢子形成的抑制作用最强，2:1 混合物次之，而单独使用苯霜灵的抑制作用最低。苯霜灵和抑霉唑单独或 2:1 混合物对孢子萌发的抑制作用明显低于对菌丝生长或孢子形成的抑制作用。当总杀菌剂浓度<24 g a.i./100 kg 处理水稻种子时，单独使用或 2:1 混合物使用的杀菌剂对两个水稻品种的种子或幼苗均无植物毒性。在温室试验中，苯霜灵和抑霉唑以 2:1 的比例，用量为 6 g a.i./100 kg 处理种子，可使两个品种水稻恶苗病的防治效果达到 100%。总体而言，研究结果表明，使用苯霜灵和抑霉唑 2:1 混合物可控制水稻恶苗病，同时减少藤仓镰刀菌对杀菌剂的抗性发生。
