The Research Of Processing Tomato Root Rot Identification And Prevention In Xinjiang

Isolating and Identifing to the Pathogen from 111 processing tomatoes root-rot disease samples in Xinjiang.The results show that the disease was caused by complex pathogenic fungi which were pythium,fusarium,Rhizocton and Phytophthora. pathogenicity indicated Pythium aphanidermatum had a higher virulence than others in seedling stage , causing damping-off, which belonged to preponderant fungus; Next was Rhizoctonia solani. But in the middle-later period of growing, Fusarium oxysporum and Fusarium solani's isolation frequency was the most high, they separately caused wilt and root rot at the processing tomato.Tomato Fusarium wilt is one of new disease,though occuring originally,it caused serious reduction of tomato output. we should take highly regard. In addition,inoculation test of processing tomato don't get easily success like cotton Fusarium wilt,its condition and way of inoculation need farther study。The biological characteristics of the four fungi were studied in the dissertation The suitable pH range for the four fungi growth was pH5-11.the optimum PH range is PH6-8,the mycelial growth is worse at PH5.The optimum temperature for the growth of pythium,fusarium, Rhizocton and Phytophthora is 30-35℃,20-25℃and25-35℃respectively. Different medium tests show that mycelia of pythium,Phytophthora and Fusarium grow well at PDA,CMA and PSA, respectively.Through the winter test showed pythium and Phytophthora can live by oospores,but Fusarium by Clamydo spores.The test also had shown that there were no processing tomato cultivars resistant to pythium and Rhizocton, however ,a cultivars resistant to the Fusarium fungi is HongFan. Some processing tomato cultivars in market belong to sensitive,such as 87-5,UC-82,ShiHong series,HongYun LiYuan8# and so on ,presently.The effect of 10 fungicides against 4 pathogens of processing tomato root rot showed 70%wp genfuling,80%wp Thiram&ziram ,95%wp hymexazo1 and 72%wp Metalaxyl-MZ are superior to others.Due to processing tomato root rot is a typical soil disease,its pathogeny species are great,spread way are wide,resistant variety lacking and control of fungicides is difficult,it is difficult to get to perfect effect for any single prevention measure,taking mostly integrative control combining agriculture control with many measures at present。...