Effects of Seed Tuber and Soil Borne Inoculum on Potato Growth and Its Dry Rot Occurrence

【Objective】 To provide the basis for the comprehensive prevention and control technology of potato dry rot in Ningxia, the influence of infection source on the growth of potato and the occurrence of potato dry rot were studied, and the control effect of pre-sowing fungicide seed treatment on potato dry rot was studied. 【Method】 Two methods of seed tuber- and soil borne inoculums were used, and seed tube was treated with or without fungicides. The effects of different treatments on potato growth and potato dry rot were evaluated by field experiments. 【Result】 Seed tuber- and soil borne inoculums had an impact on potato growth and the occurrence of potato dry rot. The seedling emergence rate of seed tuber borne inoculum T1-1 treatment was 89.55%, and the plant height was 54.19 cm, which were lower than those of other treatments. The average number of diseased potatoes of progeny tubers treated with T1-1 was 8.95, the incidence rate was 34.00%, and the disease index was 20.64, which were much higher than those of other treatments. With the increase of soil borne inocula, the growth index of potato showed a decreasing trend, while the incidence of potato dry rot showed an increasing trend. The growth index of potato treated with fungicide seed dressing was higher than that without seed dressing, and the incidence of potato dry rot was lower than that without seed dressing. 【Conclusion】 Seed tuber borne inoculums is a key factor that causes the occurrence of potato dry rot. Seed dressing with fungicides could reduce the occurrence of potato dry rot.