| 1.The effect of biofumigation on the survival of Meloidogyne incongnita in a laboratory conditionThe effect of biofumifgation using Brassica oleracea L. var. caulorapa, B. oleracea var. capitata,B. campestris pekinensis, B. chinensis, B. alboglabra, B. campestris and Spinacia oleracea on the survival of Meloidogyne incongnita were evaluated in the laboratory condition. The results showed that all the seven vegetable can cause the death of the nematodes, in which B. oleracea L. var. caulorapa, have the highest fumigation effect. The mortality of the nematode after 15d in the treatment of 20g B. oleracea var caulorapa mixed with 200g soil was 92.1% while it was 51.9% in the S. oleracea treatment. The mortality of nematodes was 100% in the treatment of Brassica oleracea var caulorapa at 35°C after 9d. Tt was higher than that at 20°C and 30°C. 100% nematodes were killed in the treatments of 25g Brassica oleracea var caulorapa mixed with 200g soil after 15d and of 30g Brassica oleracea var caulorapa mixed with 200g soil afetr 12d. The same resulte were got when 30g B. oleracea var. capitata mixed with 200g soil afetr 15d. The control efficiency increased with incresed dosage of vegetable used and exposed time.2.The impact of temperature on the survival of M.incongnita in vitroThe impact of different temperature on the survival of M.incognita in vitro was tested in the laboratory condition. The results showed that the times of 100% nematodes dead at 25°C,30°C,35°C and 40°C were 30,26,14 and 9d respectively, while at 45°C and 50°C were 15 and 2.3min. Meanwhile, M.incognita was very susceptible to temperature. The time of killing nematodes shorted with a increasing treating temperature, whist the mortality of nematodes at the same temperature rose with increasing time.3.The influence of different temperature on the survival of M.incongnita in soilThe influence of different temperature on the survival of M.incognita in soil was evaluated in the laboratory condition. The results showed that the mortality rate of M.incognita in soil treated 40d at 25°C and 30°C were 91.1% and 90.4%. The nematodes at 35°C were in inhibited state and the mortality of nematodes after treating 40d was 85.3%. However,the times of 100% nematodes dead at 40°C,45°C and 50°C were 4d,170min and 15min respectively. The optimal temperature of M.incognita in soil ranged between 25°C and 30°C. The activity of nematodes was in inhibited state when temperature reached at 35°C. Besides, once temperature was over 40°C, M.incognita was very susceptible to higher temperature.4.The effect of temperature and moisture on the survival of M.incongnita in soilThe mortality of M.incognita at different temperature and moisture was different. On the condition of temperature at 25°C,30°C,35°C and after treating 40d respectively,the mortality of M.incognita with 6% soil moisture content was 80.1%,70.4% and 62.3%,and with 14% soil moisture was 91.1%,90.4% and 85.3%,and with 18% soil moisture content was 95.4%,94.3% and 88.3%. The time of 100% nematodes dead in soil was 4d with 6% and 14% soil moisture content at 40°C, while 170min was found at 45°C. Meanwhile,With 6%,14% and 18% soil moisture at 50°C, the time of all of nematodes killed was 25,15 and 9min. In addition, the optimal survival condition of M.incognita in soil was with 6% soil moisture content and temperature from 25°C to 35°C. The nematodes failed to survival when temperature in soil reached 40°C and under 6% soil moisture. Besides, temperature in soil over 50°C and soil moisture content over 18% were the worst to M.incognita survival.5.The control effect of nematicides on tomato root-knot nematode diseaseThe control effect of different nematicides on the M.incognita,the pathogen of tomato root-knot nematode disease was tested in greenhouse condition with an inoculation method. The results showed that tomato could be effectively protected from nematode infection by 4 kinds of nematicides at different concentration. 40 days later,the Sebufos Rugby GR that had the best prevention effect reached 98.55 and 90.01% at 4 000 and 2 000 gram/667m2 respectively. Secondly Fosthiazate GR was 90.2 and 84.4% at 1 000 and 500 gram/667m2. And then Avermectin GR reached 89.06 and 80.06% at 4 000 and 2 000 gram/667m2. But the lowest effect was found for Carbosulfan GR with only 24.62% at the dosage of 6 000 gram/667m2. Compared to the control, the effect of each nematicide with higher concentration was more effective than the lower one. Both of the disease index and incidence of tomato were significantly reduced. Key words: Root-knot nematode disease; Meloidogyne incongnita; Biofumigation;...
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