Abstract:

The aim is to clarify the optimal irrigation method for daylily in Datong City, Shanxi Province, and provide reference for local daylily cultivation and irrigation management. Four plots of daylily with different irrigation methods were selected by the methods of geographical location selection and irrigation method selection in Yunzhou District, the main production area of daylily in Datong City, Shanxi Province. The selected plots of daylily had a growth age of more than five years, and other field management methods were the same. The development period of each selected sample plant was consistent. Samples were taken at fixed points and times for determination. The differences in growth indicators, material accumulation and yield structure of daylily under drip irrigation, sprinkler irrigation, ordinary water irrigation and dry land were compared and analyzed. Based on meteorological data from 1981 to 2023, the characteristics of temperature and precipitation changes in the main production areas of daylily, as well as the changes in temperature, precipitation, water requirement and water deficit during the growth period (from emergence to the end of flowering) of daylily were analyzed. The results showed that there were differences in growth indicators, material accumulation and yield structure of daylily under different irrigation methods. Among them, the drip irrigation method resulted in the fastest growth, the most material accumulation, the highest yield and the greatest contribution rate of irrigation. The temperature in the main production areas of daylily has increased, while the precipitation and effective precipitation of more than 10 mm during the growth period have decreased, leading to an increase in the times of irrigations during the growth period of daylily. Comprehensive analysis indicated that the precipitation during the growth period of daylily could not meet the growth requirements. In normal precipitation years, three times of irrigations were needed, while in drought years, six to seven times of irrigations were required, and in severe drought years, ten or more irrigations were needed. Drip irrigation is the optimal irrigation method for daylily production in Datong, Shanxi Province, with the best economic benefits.

Key words: Yunzhou District, Datong City, Shanxi Province, irrigation method, daylily, growth indicators, material accumulation, output, irrigation contribution rate