| In recent years, the damage of root knot nematode (RKN) on vegetables has been very serious in China. Chemical nematodicides are mainly used to control RKN in many regions, because nonchemical methods or products were not provided to manage the disease. In the present, more attention on the safety of food and environments has been paid, so biological reagents for controlling RKN have been studied by many people. The research interests have been conducted:1) monitoring occurrence of RKN in Beijing,2) identifying dominant species of RKN using molecular analysis,3) testing the susceptibility of main vegetable species to RKN in Beijing,4) analyzing the control efficiency of two plant fumigants bamboo vinegar and horseradish on the RKN in the laboratory and comparing the efficiency of them with popular chemical nematodicides on RKN,5) detecting the integrating management efficiency of RKN by combining two plant fumigants with fresh corn straw and cow dung. The results gained in the paper were as followings:1. The occurrence of RKN had two peaks in Beijing:from April to July and from September to December. ITS analysis shows that dominant species of RKN was Meloidogyne incognita. Fourteen species from 7 families of main vegetables were significantly susceptible to RKN in Beijing.2. The bamboo vinegar and horseradish gave significant efficiency on controlling M. incognita. The LC5o of two plant fumigants on M. incognita was 0.0035μg/mL and 1.32E-05μg/mL, respectively; which were lower than those of fosthiazate and chloropicrin. The control efficiency of the two plant fumigants on J2 of M. incognita and disease indexes were 34.62%,62.23%, and 42.64%,72.39% respectively, which were almost the same to those of the control chemicals.3. The biomass straw made the soil temperature increase. When the usage dose is 8000kg/400 m2, the temperature of soil at 30cm depth raised by 6.88℃ and the rate of J2 at lethal temperature of 55℃ raised from 0 to 0.95%. The efficiency of the biomass straw on J2, disease indexes and percentage of diseased plants were 90.94%,97.19% and 79.50% respectively, and the output of plants increased by 57.11%.4. The efficiency of the integrating management on RKN by combining two plant fumigants with fresh corn straw were much higher than those of chloropicrin and control. The efficiency of two plant fumigants on J2, disease indexes and incidence were 98.87%,92.47%,90.78% and 96.38%,88.7%, 85.87%, respectively. The physical and chemical properties of the soil were improved and the organic matter and nitrate nitrogen of soil increased by 27.5%,43.21% and 20.78%,39.13%, respectively. The biological indexes of the plants increased; the gross output increased by 32.26% and 26.78%, respectively. The nutrient values of the vegetables were improved; especially the crude fiber decreased by 23.89% and 19.04%, respectively.5. The disease indexes on plants incited by RKN and biological properties of RKN showed close correlation with the soil physical and chemical properties. J2 was negatively correlative with organic mass(R=0.987). Disease indexes were positively correlation with mass salt of soil(R=0.417), and negatively correlative with organic mass, nitrate nitrogen of soil, and soli temperature(R=0.998,0.689, and 0.899, respectively). Percentage of diseased plants was positive correlative with mass salt of soil(R=0.878), and negatively correlative with organic mass, soli temperature, nitrate nitrogen of soil (R=0.978,0.956, and 0.752, respectively). Output of plant products were positively correlative with organic mass and soli temperature(R=0.841,0.737), and negative correlative with mass salt of soil(R=0.621). Reducible Vc was positively correlative with organic mass (R=0.949). Crude fiber was negatively correlative with organic mass(R=0.680).The results will be beneficial for controlling vegetable diseases caused by RKN with scientific, safe and high efficient technologies in Beijing, Tianjin, Hebei, or other provinces in China in the future. |
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