除草剂精禾草克和乙草胺对油菜菌核病生防菌盾壳霉生长和寄生的影响

Effect of Quizalofop-ethyl and Acetochlor on the Growth and Parasitism of Sclerotial Parasite Coniothyrium minitans

本文研究了油菜田间常用除草剂精禾草克和乙草胺对油菜菌核病生防菌盾壳霉Conio-thyrium minitans的影响。结果表明它们对盾壳霉菌丝生长和分生孢子萌发均有显著的抑制作用,其中精禾草克对盾壳霉菌丝生长和孢子萌发的抑制中浓度分别为2.95mg/L和7.80mg/L;乙草胺对菌丝生长和孢子萌发的抑制中浓度分别为137.45mg/L和120.90mg/L。精禾草克可以抑制盾壳霉寄生核盘菌Sclerotinia sclerotiorum菌核,当精禾草克的使用量达田间使用浓度时,盾壳霉不能寄生核盘菌菌核;而乙草胺对盾壳霉寄生菌核的影响较小,在田间使用浓度1250mg/L时,盾壳霉仍可寄生菌核;乙草胺和盾壳霉在田间使用浓度条件下混合使用,60d后菌核腐烂指数与单独使用盾壳霉没有显著差异,均大于75。上述结果表明在田间使用量条件下,乙草胺可以和盾壳霉生防制剂混用,而精禾草克不宜和盾壳霉混用。

In this paper,effects of two herbicides,Quizalofop-ethyl and Acetochlor,on mycelial growth,conidial germination and parasitism of sclerotial parasite Coniothyrium minitans were studied.Results showed that both Quizalofop-ethyl and Acetochlor could inhibit the mycelial growth and conidial germination significantly.In mycelial growth inhibition test,the EC50 of Quizalofop-ethyl and Acetochlor was 2.95 mg/L and 7.80 mg/L,respectively.In conidial germination inhibition test,the EC50 of Quizalofop-ethyl and Acetochlor was 137.45 mg/L and 120.90 mg/L,respectively.When treated with recommended dosage,Quizalofop-ethyl completely inhibited C.minitans to parasitize the sclerotia of Sclerotinia sclerotiorum,the fungal pathogen of rapeseed（Brassica napus）,while Acetochlor could not inhibit the parasitization of C.minitans even at the dose of 1250 mg/L in fields.The sclerotial rot index when sclerotia were treated with Acetochlor and C.minitans was not significantly different from that treated with C.minitans alone,both were above 75.Our results suggested that C.minitans and Acetochlor could be mixed when applied in rapeseed fields,which is likely to control weed and stem rot efficiently.