| Tomato plays an important part in structure of food all over the word because of good tasty and rich nutriment. However, with the increasing multiple cropping index and replanting, the soil-borne diseases in tomato become more and more serious, especially in greenhouse, which has been one of most important diseases influencing the production and quality of tomato, the diseased plants were taken in part of tomato production areas in Shandong province and separated to identify as well as fungicides and some volatiles were used to determine the toxicity on pathogens and conduct experiments in field trial. The results below:1. The distribution of three soil-borne diseases in part of tomato production areas in Shandong province was investigated. The bacteria wilt in tomato variety of in Dongliangfu of Tai’an city and the Fasurium wilt in tomato variety of in Shenxian of Liaocheng city were the most serious in incidence and index of diseases, the incidence83%and72%, respectively while incidence of resistance TY-3in Shouguang just6%. The tomato crown and root rot in Dongdawu and Xizhu of Tai’an city were serious, the incidence of which were51%and46%, respectively. Morphology of tomato crown and root rot on different medium showed that tomato crown and root rot grew fastest in oatmeal agar and slowest in SNA only in which were larger falciform conidium produced while larger fusiform conidium in other medium.2. The result of bioactivity of fungicides on tomato crown and root rot by measuring growth and germination of spores showed that carbendazim, prochloraz, difenoconazole, tebuconazole and triflumizole had a good bioactivity on pathogen, indicating appication value. The toxicity of carbendazim and prochloraz were higher than that of rest, whose EC50value were0.077mg/L and0.016mg/L, respectively. The inhibiting effect of prochloraz on mycelial was best, which could completely inhibite spores germination at the concentration of1mg/L while carbendazim couldn’t act as well as inhibite mycelial, only at the concentration of10mg/L could carbendazim completely inhibite spores germination.3. The result of bioactivity of volatile on mycelia of tomato crown and root rot and germination of spores showed that trans-2-hexenal,trans-2-octenal,trans-2-eptenal and chloropicrin had high bioactivity on pathogen of tomato crown root and rot. Among them, the toxicity of chloropicrin was highest, which could completely inhibit the growth of mycelia at the concentration of10mg/L. Only at the concentration of25mg/L could trans-2-hexenal,trans-2-octenal reach that extent trans-hexenaltrans-2-octenal, chloropicrin and benzothiazole could inhibit the growth of the pathogen in soil while the rest of the volatiles promoted the growth of that, the toxicity of chloropicrin was highest, the percentage of which was55.80%, followed by trans-2-hexenal,trans-2-octenal, and benzothiazole, which were33.81%、29.90%and25.91%, respectively.4. The result of bioactivity of disinfectors on pathogen of tomato bacteria wilt by inhibition zone showed that the bioactivity of Streptomycin were highest, followed by C8-10, whose width inhibition zone were52.50mm and25.25mm, respectively.5. The result of bioactivity of volatiles on pathogen of tomato bacteria wilt by seal-pad showed trans-2-hexenal, trans-2-octenal, trans-2-eptenal and chloropicrin had high bioactivity on pathogen of tomato bacteria wilt, chloropicrin highest among them.6. The result of determination of fungicidal and/or fungistatic activity of volatile compounds showed that volatile compounds had fungistatic activity at low concentration but fungicidal activity at high concentration.7. The result of field trial of five fungicides on tomato crown root and rot showed that triflumizole had good effect compared with other treatments, which could completely prevent occurrence of pathogens at low or high concentrations. The stem and root treated by triflumizole grew best, followed by difenoconazole, and that of prochloraz worst, which might be relationship with less dosage. |
PDF Full Text Request