Identification Of Pathogenic Nematode On Burdock And Its Control Tactics

Burdock root-knot nematode was a new disease occurred on burdock in resent years. The disease severely reduced burdock yield and quality, limited the development and property of burdock. In this experiment, the disease occurrence law, disease pathogen identification, nematode yearly generation changes and relationship between nematode population density and burdock yield were studied; the resistance reaction of difference cultivars, the control experiment of burdock root-knot nematode were also carried out.1.Through microscope, esterase isozyne electrophoresis and discriminate host inoculability, identified south root-knot nematode(Meloidogyne incognita) was the pathogen, which caused burdock root-knot nematode.2.Investigation host plant of South root-knot nematode, results indicatied that there were 8 branch 42 genus could be infested by south root-knot nematode in Wei fang area.3.The nematode completed four entire generations in one growing season and the duration each generation is about 35 d. Juvenile peak appeared at the first ten days of Jul., the middle ten days of Aug, the middle ten days of Sept. and the last ten days of Oct respectively. The greastest population densities of the nematodes mainly occurred in 0-40 cm layer of the soil below the surface.4. Stipulated the Quarantine operation Method of the exported fresh burdock.5.Once Burdock root-knot nematode occurred, the plant height, stem diameter and leaf area per plant were decreased dramatically. It also showed the symptoms like light leaf color, rotten roots, verruca rhizome and bad quality. The yield would reduce by 30%~50%. Investigation showed thatBurdock root-knot nematode was closely related with soil texture, planting rotation and fertilization, sandiness soil, consecutive planting and excessive potassium might aggravate this disease.6. 19 burdock cultivars were evaluated for resistance to burdock root-knot nematode, Liuchuanlixiang.Baijidachang, Dongbeilixiang and Xinyu88 showed high resistance; Jinchang and Dagen showed middle resistance; Jinhuang and Changbai showed maderate susceptibility. Anyu10 showed high susceptibility.7. Control experiment results showed that an available method to reduce the nematode damage was planted with sun-baked soil and cooperate with 1.8% Abamectin. Results also showed that there was no bad effect on export burdock using Abamectin 20 days before hevest.8. In this experiment, integratation prevention technique were established: high temperature antisepses soil, choose Liu chuan li xiang variety, use 1.8% Abamectin might prevent the Burdock root-knot nematode. There no pesticide remnant in burdock 2 days before hevest using this technique.