氟菌·霜霉威对烟草黑胫病的防效及其对烟株生长的影响

为探明氟菌·霜霉威防治烟草黑胫病的潜力，本研究采用菌丝生长速率法测定了6种杀菌剂对烟草黑胫病菌丝生长的影响，并通过温室盆栽试验明确了氟菌·霜霉威对烟草黑胫病的防效及其对烟株生长的影响。结果表明，氟吡菌胺与霜霉威盐酸盐以质量比1∶10混用（氟菌·霜霉威）对烟草黑胫病菌丝生长的抑制效果最好，EC₅₀值为0.06 mg/L。温室盆栽试验结果表明氟菌·霜霉威在773.4 g a.i./hm2时，对烟草黑胫病的防效可达81.50%，显著高于甲霜灵（55.75%）和烯酰吗啉（67.83%）的防效。氟菌·霜霉威在提高烟草株高、茎粗、有效叶片数及光合速率等指标优于与甲霜灵和烯酰吗啉，表现出良好的促生效果。施用氟菌·霜霉威后，烟株叶片的多酚氧化酶（PPO）、过氧化物酶（POD）和超氧化物歧化酶（SOD）等防御酶活性显著增加，而丙二醛（MDA）含量降低。本结果表明氟菌·霜霉威可作为甲霜灵和烯酰吗啉的替代药剂用来防治烟草黑胫病。 

The control efficacy of fluopicolide·propamocarb hydrochloride to tobacco black shank and its effects on tobacco growth

This study aimed to determine the potential of fluopicolide combination with propamocab hydrochloride for management of tobacco black shank.The mycelial linear growth rate method was used to ascertain the toxicity of six fungicides to Phytophthora nicotianae.Greenhouse tests were conducted to evaluate the control efficacy of the combination of fluopicolide and propamocab hydrochloride on tobacco black shank and its effect on tobacco plants growth.Laboratory results showed that the combination of fluopicolide and propamocarb hydrochloride (1∶10, m/m) had the best control efficacy with EC50 value of 0.06 mg/L.Greenhouse results showed that the combination of fluopicolide and propamocab hydrochloride at application rate of 773.4 g a.i./hm2 exhibited remarkable control effect against the disease, with control efficacy of 81.50%, better than that of metalaxyl (55.75%) and dimethomorph (67.83%).In addition, the combination was also able to improve tobacco height, stem diameter and photosynthetic rate compared with metalaxyl and dimethomorph, and it displayed a better effect of promoting plant growth.Moreover, the combination of fluopicolide and propamocab hydrochloride increased activities of protective enzymes (polyphenol oxidase, peroxidase and superoxide dismutase) and reduced content of malondialdehyde significantly.The study indicated that the combination of fluopicolide and propamocab hydrochloride could be used as an alternative fungicide to metalaxyl and dimethomorph for management of tobacco black shank.