Abstract:

To give full play to the role of disease-resistant cultivars in the prevention and control of the stem base rot of sweet potato, different cultivars including ‘Zheshu 255’ were identified and screened and subsequently the characteristics of the selected disease-resistant cultivars were observed and the main cultivation techniques were studied using disease-resistant identification in disease nursery, production demonstration and multi-point verification methods. The results showed that ‘Zheshu 255’ planted in the area where sweet potato stem rot occurred were strongly disease-resistant and the disease incidence was low. The above ground part of ‘Zheshu 255’ grew faster at the early stage, but the tuberlization of this cultivar was late; the stems were long and thin; the number of tubers per plant was about 3; the harvest began in late October and the rate of large-and-medium sized tubers with spindle shape was high. The sweet potatoes were soft and nice in taste with light-red skin and orange-colored meat and general-storability. In the research, cutting density, urea consumption and potassium sulfate consumption were selected as three main agronomic factors, and the field was arranged with a single-lattice design, and the regression mathematical model of three test factors on the yield and net output value was established. The model analysis shows that the cutting density of 42000-48000 plants/hm², the topdressing urea of 185-210 kg/hm², and the basal fertilizer potassium sulfate of 225-300 kg/hm² are appropriate for ‘Zheshu 255’ under the experimental conditions.

Key words: Sweet Potato, Disease-resistant Cultivar, Stem Base Rot of Sweet Potato, ‘Zheshu 255’, Characteristics, Cultivation Techniques