Medicament Control Of Atractylodis Macrocephalae Root Rot And The Investigation Of Resistance Introductions

Atractylodes macrocephala Koidz belonging to the family of Compositae is one kind of perennial herb.Its hypertrophic root and stem dried are used as drugs. Produced mainly in Zhejiang, it is also introduced into the southwest of China,especially Youyang and Xiushan in Chongqing as well as Bao Xing in Sichuan.Root rot caused by Fusarium lateritium is its major disease which usually leads a great yield loss of up to 50% in Baoxing. During the period of 2010-2013,the disease have restricted the local economic development. This paper studied the incidence conditions,introductions’ resistance and the biological control.The results are as follows:1. Incidence conditions of Atractylodis macrocephalae root rotThe incidence rate of continuous cropping is significantly higher than rotate cropping. The incidence from the dryland continuous cropping(59.60%) was higher than the paddy fields’(46.40%).Results from dilution method of plate counting indicated the spore load was higher in continuous cropping soil than rotation soil.The upper 10cm of the continuous cropping soil had the lagest spore load among different kind of soil,indicating the primary infection source from the soil.Different soil types had different impacts on the disease. Clay can induce a high incidence(86%),while sand had a negative effect on the incidence(42%).High temperature and rainfall are favored by the disease, like July and August.2. Discussion of indoor laboratory experiments and field controlAgent tested had significant inhibition effects especially with mixture of bacillus and resistance inducer which had inhibition effects on both spores germination(98.77%) and mycelium growth(87.50%). Results from field test indicated that mixture of bacillus and resistance inducer had good control efficiency in both application methods of seed soaking(60.85%) and spraying(68.87%),while the latter had better control efficiency with the single agent application.3. Biological character and resistance test of the introductionsThe growth period of all of these introductions was different from the local cultivars’ except NO.5. Introduction NO.6 stayed longer in seeding stage and pour seedling stage. No.1-4 were different from local cultivars in plant height, leaf characteristics and the plant stem diameter. Introduction NO.6 had a high production of 1043.19kg/667 m2 with low incidence of 7.30%,which was increased by 41.41%.