Study On The Different Ways Of Soil Disinfection To Prevent And Control Of Fusarium Wilt And Root-knot Nematode In Cucumber

Soil-born diseases is one important factor of monocropping obstacle. To get more economic interests, cucumber, tomato and other vegetables with high interests are planted on the same land year after year. Because of this, soil-born diseases, such as Fusarium wilt(Fusarium Oxysporum f.sp.Cucumerinum) and root-knot nematode (Meloidogyne spp.), are becoming more and more serious and have limited the healthy and sustainable development of facility agriculture. So, study on the ways to control of Fusarium wilt and root-knot nematode is very important. In this study, cucumber was used as material to investigate the effects of different levels of temperature, water and calcium cyanamide and their crossover treatments on Fusarium wilt and root-knot nematode. And a preliminary evaluation on biosafety of this soil disinfection ways was did. The main results are as follows:1. Calcium cyanamide had a good kill effect on root-knot nematodes. The higher of the concentration, the better of the effect. When the concentration was2g/Kg, it could kill the root-knot nematodes completely. But when the concentration was too high, it would hurt the cucumber plants, making the value of net photosynthesis and root activity of cucumber significantly reduced, MDA and activity of PAL and Antioxidant enzyme elevated. While the concentration was too low, it could not have a obvious effect on root-knot nematode. The kill rate of calcium cyanamide was only42.40%when the concentration was0.25g/Kg. At the same time,0.5g/Kg concentration of calcium cyanamide had a93.26%kill rate and it did not have a negative effect on plants.These results suggested that calcium cyanamide could kill the root-knot nematodes effectively when its concentration is0.5g/Kg (about55-60Kg/acre) and will not hurt the plants.2. On the basis of determining the best concentration of calcium cyanamide, we took a step forward to study on the effect of different levels of temperature, water and calcium cyanamide and their crossover treatments on Fusarium wilt and root-knot nematode. High temperature, waterlogging and calcium cyanamide had a certain extent of inhibition effect. High temperature+waterlogging+calcium cyanamide treatment had the best effect, which can kill the Fusarium Oxysporum and root-knot nematode almost completely. And, at45/39℃, temperature was the main effect factor. While at19/13℃,26/20℃,33/27℃and39/33℃, waterlogging and calcium cyanamide played a major role. This indicate that we can use the control way of high temperature+waterlogging+calcium cyanamide treatment to get better effect.3. Studied on the effect of different levels of temperature, water and calcium cyanamide and their crossover treatments on bacteria, fungi and actinomycetes.Through plate counting method, we obtained that, in the early days of treatment, high temperature, low temperature,waterlogging and calcium cyanamide all could kill bacteria in a certain extent. The higher of the temperature, the more the bacteria was killed. And high temperature+waterlogging+calcium cyanamide had the best effect. Low temperature and calcium cyanamide had no effect on fungi on1day after treatment. On3td day, calcium cyanamide began to work. High temperature+waterlogging+calcium cyanamide also had the best effect on fungi. Except of waterlogging+calcium cyanamide treatment, other treatments had no effect on actinomycetes. After11days of treatment, the numbers of bacteria, fungi and actinomycetes all tended to or had been back to control. The results demonstrated that all of these treatments had no great impact on soil microbial after11days. So11days could be the safety interval of these soil disinfection ways.