Variations and effects of climate in growth period of Lycium barbarum L. in Ningxia

In order to clarify the characteristics of climate change (1961-2017) in the growing season of Lycium barbarum and its impact on L. barbarum growth in Ningxia, and to provide corresponding data for effective utilization of climatic resources and scientific theoretical basis for the production and decision-making department of L. barbarum, the characteristics of climate change during the growth period of L. barbarum and its effects in Ningxia were analyzed by Mann-Kendall mutation detection, climatic tendency rate and correlation test, based on the observations of 17 meteorological stations in Ningxia from 1961 to 2017. Results showed that warming and drying were the main characteristics of climate change during the growth period of L. barbarum in Ningxia. Over the past 57 years, the average temperature, ≥ 10℃ accumulated temperature and sunshine hours during the growing period of L. barbarum in Ningxia increased due to climate warming, and the linear trend passed 0.001 significance level test. Average temperature changed abruptly around 1990, and increased by 0.7℃ during 1991-2017 compared with 1961-1990. ≥ 10℃ accumulated temperature had the maximum increase rate in 1990s, and abruptly changed in 2003. After that, annual ≥ 10℃ accumulated temperature increased by 370.6℃. Annual sunshine hours increased by 93.9 h in 2005 compared with before 2005. Precipitation showed a weak decreasing trend in 1961-2017. Effects of climate change on the growth of L. barbarum had more advantages than disadvantages. With the increase of air temperature and the rapid rise of air temperature in spring, the germination period of L. barbarum shifted to an earlier date, the total growth period was prolonged, and the yield per unit area was increased, which was beneficial to agricultural production. The decrease of precipitation during fruit ripening and picking period reduced the occurrence of anthracnose and improved the quality of L. barbarum. Furthermore, there was a significant positive correlation between the accumulated temperature from the date of passing 5℃ to the germination stage of L. barbarum, the ≥ 10℃ accumulated temperature and the yield of L. barbarum in Zhongning. Meanwhile, climate warming increased soil moisture evaporation in winter, which lead to an increasing trend on incidence of pests and diseases of L. barbarum. It needs a further research on how to make full use of favorable climatic resources, to avoid or alleviate the adverse effects of climate change on L. barbarum production.