吡唑醚菌酯及三唑类杀菌剂对番茄颈腐根腐病的防治效果

Control Efficacy of Pyraclostrobin and Triazole Fungicides Against Tomato Crown and Root Rot

目的】评价吡唑醚菌酯与戊唑醇、丙环唑、氟硅唑等防治番茄颈腐根腐病的应用潜力。【方法】采用菌丝生长速率法和孢子萌发法分别测定吡唑醚菌酯、戊唑醇、丙环唑、氟硅唑4种杀菌剂抑制番茄颈腐根腐病菌(Fusarium oxysporum f.sp.radicis-lycopersici)菌丝生长、分生孢子萌发及芽管伸长的毒力。通过温室盆栽试验,采用灌根处理法,于施药后7、15 d测定番茄幼苗株高和茎粗的增加量,评价杀菌剂对番茄植株生长的安全性;在室内,利用盆栽番茄,采用先接菌后施药的方法,测定施药后7、15和30 d药剂对番茄颈腐根腐病的防治效果;在田间,同样采用灌根处理,分别于施药后60、90和150 d调查番茄颈腐根腐病发病情况及最终番茄产量,评价不同杀菌剂对番茄颈腐根腐病的防治效果以及对番茄产量的影响。【结果】吡唑醚菌酯对番茄颈腐根腐病菌菌丝生长、孢子萌发及芽管伸长均表现出较高的毒力,EC_(50)分别为0.055、0.012、0.010μg·m L^(-1),其次为丙环唑,EC_(50)分别为0.058、0.060、0.011μg·m L^(-1)。戊唑醇抑制菌丝生长的作用强,对孢子萌发及芽管伸长的毒力较低,EC_(50)分别为0.075、0.255、0.455μg·m L^(-1);氟硅唑抑制分生孢子芽管伸长的毒力高,而抑制菌丝生长与孢子萌发毒力相对较低,EC_(50)分别为0.013、0.078、0.457μg·mL^(-1)。戊唑醇25、50 mg a.i./株、丙环唑5、10 mg a.i./株、氟硅唑5、10 mg a.i./株均显著抑制番茄幼苗株高,增加茎粗,吡唑醚菌酯30、60 mg a.i./株处理则均无影响。温室盆栽接种试验中,药后30 d,吡唑醚菌酯60 mg a.i./株防治效果最高,为87.12%,丙环唑10 mg a.i./株次之,防治效果为82.17%,戊唑醇50 mg a.i./株与氟硅唑10 mg a.i./株的防治效果分别为79.40%与71.67%。田间施药后90 d,吡唑醚菌酯60 mg a.i./株防治效果最高,为90.36%,戊唑醇50 mg a.i./株与丙环唑10 mg a.i./株次之,分别为84.20%与82.55%,氟硅唑5 mg a.i./株防治效果最低,为65.06%。而至施药后150 d,各处理防治效果均显著降低,戊唑醇50 mg a.i./株最高,为40.40%。最终产量统计,吡唑醚菌酯60 mg a.i./株处理增产率最高,为50.63%,丙环唑5 mg a.i./株最低,为-2.61%。【结论】吡唑醚菌酯、戊唑醇、丙环唑、氟硅唑4种杀菌剂抑制番茄颈腐根腐病菌菌丝生长的毒力相近,吡唑醚菌酯对孢子萌发及芽管伸长的毒力高于3种三唑类药剂。吡唑醚菌酯、丙环唑及戊唑醇均可用于设施内番茄颈腐根腐病的防治,吡唑醚菌酯60 mg a.i./株的防治效果最高,对植株安全且增产显著,而丙环唑与戊唑醇应注意控制使用剂量。

【Objective】The objective of this study is to evaluate the potential efficacy of pyraclostrobin as well as tebuconazole,propiconazole and flusilazole against tomato crown and root rot,which caused by Fusarium oxysporum f.sp.radicis-lycopersici.【Method】The laboratory toxicity of 4 fungicides to mycelial growth,conidial germination and germ tube elongation of F.oxysporum f.sp.radicis-lycopersici were determined by mycelial growth rate and conidial germination methods.In greenhouse pot experiment,the root-irrigation method was used to treat tomato seedlings.At 7 d and 15 d after treatment,the increment of plant height and stem diameter was measured to evaluate the safety of fungicides on tomato seedlings.In the laboratory,the method of first inoculating and then applying fungicides was adopted.The control efficacy of fungicides on tomato crown and root rot at 7,15 and 30 d after application was investigated,respectively.In field experiment,same root-irrigation method was used to investigate the incidence of tomato crown and root rot at 60,90 and 150 d after treatment and the tomato yield statistic,and to evaluate the efficacy of fungicides against the disease in field and the effect on yield of tomato.【Result】Pyraclostrobin showed high toxicity to mycelial growth,conidial germination and germ tube elongation of F.oxysporum f.sp.radicis-lycopersici,with EC50 of0.055,0.012 and 0.010μg·mL^-1,followed by propiconazole,EC50 was 0.058,0.060,0.011μg·mL^-1,respectively.The inhibitory effect of tebuconazole on mycelial growth was strong,and the toxicity of tebuconazole to conidial germination and germ tube elongation was relatively low,with EC50 of 0.075,0.255 and 0.455μg·mL^-1,respectively.The toxicity of flusilazole to conidial germ tube elongation was high,but the toxicity of flusilazole to mycelial growth and conidial germination was low,with EC50 of 0.013,0.078 and 0.457μg·mL^-1,respectively.Tebuconazole at 25,50 mg a.i./plant,propiconazole at 5,10 mg a.i./plant and flusilazole at 5,10 mg a.i./plant significantly inhibited tomato seedling height and increased stem diameter,but pyraclostrobin at 30,60 mg a.i./plant had no effect on tomato seedling.In greenhouse pot experiment,30 days after treatment（DAT）,pyraclostrobin had the highest control efficacy（87.12%）on this disease at 60 mg a.i./plant,followed by propiconazole 10 mg a.i./plant,the control efficacy was82.17%,and the control efficacy of tebuconazole at 50 mg a.i./plant and flusilazole at 10 mg a.i./plant was 79.40%and 71.67%,respectively.At 90 DAT in field experiment,the best control efficacy on the disease was 90.36%by pyraclostrobin at 60 mg a.i./plant,followed by tebuconazole at 50 mg a.i./plant and propiconazole at 10 mg a.i./plant,which was 84.20%and 82.55%,respectively.The lowest one was flusilazole at 5 mg a.i./plant（65.06%）.At 150 DAT,the control efficacy of each treatment on the disease significantly declined,just tebuconazole at 50 mg a.i./plant was 40.40%.According to field statistics,pyraclostrobin at 60 mg a.i./plant had the highest yield in field,the increased production rate was 50.63%,and propiconazole at 5 mg a.i./plant was the lowest,with the rate of-2.61%.【Conclusion】Pyraclostrobin,tebuconazole,propiconazole and flusilazole had similar toxicity on F.oxysporum f.sp.radicis-lycopersici mycelial growth,however,pyraclostrobin had higher toxicity on the conidial germination and germ tube elongation of the pathogen than the other three fungicides.Pyraclostrobin,propiconazole and tebuconazole could be used to control tomato crown and root rot in greenhouse.The control efficacy of pyraclostrobin at 60 mg a.i./plant was the highest,which was safe and increased production significantly.However,the dosages of propiconazole and tebuconazole should be concerned before application.