Studies On The Occurrence And Control Techniques Of Corn Stalk Rot In Heilongjiang Province

The objective of this paper was to study the occurrence of corn stalk rot through theinvestigation of the incidence and yield loss damaged by the disease. to study the controltechniques of the disease in order to explore the effective measures to protect ecologicalenvironment.1.The study on species of pathogen showed that Pythium graminicola, Pythiumaphanidermatum and Pythium inflatum were the dominant species of pathogen which theisolation frequency was high and the pathogenicity was strong, the isolation frequency ofpathogen was related to the variety of culture medium and disease grade of diseased plant.2.The study of inoculation technique of pathogen indicated that several inoculationmethods could induce incidence of corn stalk rot. The root and pith inoculation could displaythe typical symptom, the soil inoculation before sowing was better.3.The investigation of the occurrence and the damage of corn stalk rot suggested that thecorn stalk rot was a widespread disease in Heilongjiang province, the disease ratio was relatedwith corn varieties, meteorological condition and cultivation, the incidence was up to 75%. Ifthe sowing was earlier and the planting density was more, the disease grade of plant grown 3rows in 140 cm ridge width was more than that of 2 rows.4.82 corn varieties were identified for the resistance to corn stalk rot, the result showedthat there were 15 high resistant varieties(lines), accounting for 18.29%, 18 resistantvarieties(lines), accounting for 21.95%, 13 middle resistant varieties(lines), accounting for15.88%, 20 middle susceptible varieties(lines), arcounting for 24.39%, 10 susceptiblevarieties(lines), accounting for 12.2%, 5 high susceptible varieties, accounting for 244%.5.The determination of induced resistance showed six induced strains of Fusarium couldinduce com resistance to corn stalk rot. The induced protection caused by F1 for P.graminicola was the best, the effects of F1 injection and soil inoculation were 100% and 98%respectively The induced protection caused by F5 for F.graminearum was the best, theinduced effects of the forenamed methods were all 100%. The effect of immunity wereinfluenced by induced methods, the effect of soil inoculation before sowing was the best andits protection period could be kept conger, which could improve the agronomic character ofcorn. When the lag period was 16 days, the induced effect after 63 days challenge inoculationremained 100%. The best lag period of soil inducing inoculation was 16 days. for injectioninoculation it was 10 days.6.The results of the diseased control by plant nutritional substances showed that Kfertilizer could control the disease and increase corn yield. The suitable rate of K fertilizerapplication was 225 kg/hm2 at a prerequisite for normal application rate of urea and(Nmp:PO+ Si fbolizer could contrl corn stalk rot. Both Si fereilizer and ZnSQ hadallbihon to Mum.7.The seed beatment by fungicide could effectiveIy control corn stalk rot. ThrOugh fieldexPeriments, several fOrmulas Of chenyi9al fungicides were screened. they were 70%ThOPhanate-methyl WP+50% Thha WP, l5% Triadimefon WP+50% Thiram WP and 2%Tebuconazole DP. their contrOl effectS at seedling were 7l.43%, 66.63% and 7l.43o/oresPeCtively In M-up the contrOl dri wer 94'94%, l00% and 92.56% respechvelyName: Mei, LiyanSPeCialIy' Plant patholOgyAdvisor: Wen, Jingzhi...