The Influence Of Greenhouse Vegetable Rotation On The Population Density Of Meloidogyne Incognita In Beijing

Popularization of the greenhouse provides more suitable survival environment for root-knot nematodes. Its population can rapidly develop in the shorter period of time, so the root-knot nematodes have become an obstacle to the production of greenhouse vegetables. This present paper study correlative contents with a view on ecology, Including the indentification of the root-knot nematodes species in greenhouse of Beijin area, influence of crop rotation on population dynamic of the root-knot nematodes, biological controls and so on. The results are as follows.1,, Collection and identification of the root-knot nematodes in main production areas of vegetables in Beijing. All sample were identified were M. incognita by Perineum pattern, sequence of ITS.2, The population dynamic of the root-knot nematodes with different crop rotation in 4 tested section.The effect of temperature to the development of the root-knot nematodes: As a whole, the developmental tendency of the root-knot nematodes was on the rise with the change of temperature. In the fields of host plants, the population density of the nematodes was lower in winter but went up in May and June. The population density was highest in autumn and decreased at the begin of November. But the investigation didn't show that the low temperature in winter can completely control the happening and development of the root-knot nematodes.Different crops in the field remarkably affects the population density of the root-knot nematodes: Some plants can cause the decrease of the density, such as shallot,garlic, cole. But capsicum,tomato can bring the great increase of the root-knot nematodes, especially in summer and autumn. The number of the nematodes in the field of cucumber stably maintain a medium standard, which disturbs the common development of cucumber. The population density of the root-knot nematodes of every test section appears significantly different after the crop rotation of one year. For instance, in the B test section of capsicum, the population density of the nematode was highest. The secondary was in the D test section. And in the C test section, there was not clear change in the area of cucumber, while the density sharply decline in the area of shallot, cole and so on.Different ways of crop rotation also affect the upright distribution of the root-knot nematodes: The main reason was the damage of the 2nd-instars to host plants. When host plants were not suit for the infection of the root-knot nematodes, the moving tendency of the 2nd-instars obviously approach the upper soil, such as in the field of shallot, cole, cucumber. Infecting plants with deeper root series, like capsicum and tomato, the 2nd-instars have not the upright moving tendency.3, In experimental conditions, testing the mortality of the root-knot nematode...