Control Effect Of Plant Growth Promoting Bacterium And Fungicides On Oats Smut Pathogen

In present paper, biological characteristics of pathogens, inhibition effect of pathogenteliospore germination by17kinds of fungicides and16kinds of bio-control bacteria,security application dose for two kinds of oat varieties(Dingyou4and Yan2007) weremeasured based on oat powder smut fungus (Ustilago avenae) and covered smut fungus (U.Levis). The main results were obtained as follows:1. Both two kinds of Ustilago spp. had the highest teliospore germination in water agarculture-medium; meanwhile, they had a high humidity requirement, and began to germinatewhen relative humidity (RH) was more than90%, and their germination rates were lessthan10%; Illumination time and pH had not obvious influence on teliospore germination.The adaptive germination temperature, pH value, carbon and nitrogen sources of Ustilagoavenae teliospore were20-25℃,4-7, glucose and peptone respectively; The suitablegermination temperature of Ustilago hordei teliospore were20-30℃, the effect of pH onteliospore germination was not obvious. Glucose, chloride ammonium, urea and glycinehad a inhibit influence to Ustilago hordei teliospore germination.2. Effect of common fungicides on Ustilago spp. pathogen had reduced significantly, onlyTriadimefon, Carbendazim, Thiophanate methyl(Ri Cao), Quintozene(PCNB) on Ustilagoavenae, Carbendazim on Ustilago hordei pathogens inhibition ratios were high, but theirconcentrations of fungicides were double on recommended dosage, their dosages were400g/hm2,4500g/hm2,2400g/hm2and267g/hm2currently respectively. threeconcentrations of Oxine copper(400g/hm2,300g/hm2,200g/hm2), Azoxystrobin(225g/hm2,150g/hm2,75g/hm2) and Prochloraz(500times liquid,1000times liquid,2000times liquid), Flusilazole (60g/hm2) and Difenoconazole (1000times liquid) of New typefungicides had higher preventions and suppression rates on Ustilago spp. pathogen thanfrequently-used fungicides; three concentrations of Ethylicin(1500times liquid,3000timesliquid,4500times liquid) and Ding Zi carvacrol (3000g/hm2) of botanical fungicides hadsuppression rates on Ustilago spp. more than90%. The inhibition ratio of Chitosan (3000g/hm2) for Ustilago avenae was obviously.3. Triadimefon1(400g/hm2), Triadimefon2(200g/hm2), Carbendazim1(4500g/hm2)and PCNB1(267g/hm2) of frequently-used fungicides, three concentrations of Oxinecopper(400g/hm2,300g/hm2,200g/hm2), Azoxystrobin3(75g/hm2), Flusilazole1(60g/hm2) of new type fungicides, Ethylicin3(4500times liquid), Chitosan1(3000g/hm2) and Ding Zi carvacrol1(3000g/hm2) of botanical fungicides had no influnces and low toxicityon oat seed, the same as their growth. Therefore, these fungicides could be used to controlUstilago spp.. Meanwhile, three concentrations of Prochloraz(500times liquid,1000timesliquid,2000times liquid), Hexaconazole1(325g/hm2), Hexaconazole2(195g/hm2) andPropiconazole＋Difenoconazole1(225g/hm2) of new type fungicides had large toxicity ontwo oat varieties, so they could not prevent oat diseases by seed dressing. The testedfungicide as Lentinan had a less toxicity on oat, and it could be used to control other oatdiseases.4.5kinds of tested fungi (Trichoderma koningii, Phanerochaete sp.,25(Trichoderma sp.),22-1(Trichoderma sp.),22-2(Trichoderma sp.)) had a different degree inhibiting effect onthe growth of4kinds of pathogenic fungi (4H (Rhizoctoni sp1.)、Fusarium oxysporumf.Niveum, Rhizoctonia solani, Fusarium oxysporum), but the suppression effect ofRhizoctonia solani was low compared with other pathogenic fungi, the inhibition ratio forother pathogenic fungi were more than65%. The germination of Ustilago spp. teliosporewas inhibited by22-1and25; The tested actinomyces included FX1, FX2and F1-4had ahigh inhibition ratio on pathogenic fungi, while FX1and FX2on Ustilago spp. teliosporegermination rate reached more than95%simultaneously; The tested bacteria such as XX2,XX5and XX6had some inhibitory effect on pathogenic fungi, and the inhibition ratios ofUstilago hordei teliospore by XX5, XX6,170,191,92and LHS11were100%, theinhibition ratio of Ustilago avenae teliospore by XX5, XX6,92and170more than60%.