The Gentiana Septoria

The auther studied the occurrence rules and the species of gentiana spot blotch pathogen in Shannxi and also established the effective controlling measures on agricultural measure, soil treatment, seedling treatment, fertilizer treatment and germicides control and studies on the effect of these measures on incidence of gentiana spot blotch.First, this experiment proved that the gentiana spot blotch was caused by The pathogen which was identified as Deuteromycotina subphylum, Hgphomycetes class, Hyphomycetales order, Dematiaceae family, Alternaria Nees ex Wallr species.In this paper, the relation of the occurrence of gentiana spot blotch and cultivating factors had been studied. The method of graded counting had been used to investigate the relations of gentiana spot blotch and the following factors: the grade of seedling, the cultivated density, the cultivated time,the preceding crop,sunshading. The results showed that gentiana spot blotch was reliefed when the following measures were applied: the first or second grade seedling was cultivated;the cultivated density was reasonable(40plant/m~2); cultivatation began at autumn; interplanted technology was applied; rotation; the preceding crop was corn.The effect of gentiana spot blotch on the output and quality of Gentiana macrophylla Pall was studied in this experiment and this proved that it is necessary to prevent the occurrence of the gentiana spot blotch.Spraied three germicides on seedling bed in order to prevent the occurrence of the gentiana spot blotch. In this experiment, the seedling was soaked by different germicide before transplanting in order to control gentiana spot blotch, the results showed that thiophanate methl and mancozeb had better effect.