Abstract: A field experiment with six sowing dates of potato was conducted in Dingxi of Gansu in 2010, and the growth and yield formation of the potato after sowed at different dates were analyzed, aimed to search for the suitable sowing period of potato in semiarid area of the loess plateau in central Gansu under the background of climate change. With the delay of sowing dates, the whole growth period of potato shortened, plant height had obvious change, and the dates corresponding to the peak values of dry matter accumulation rate per plant advanced. Among the test sowing dates, the potato sowed on May 27 had the largest plant height, leaf area index, and dry matter accumulation and maximum accumulation rate per plant, and the tuber fresh weight showed an Svariation curve of “slow-fast-slow”. The dates corresponding to the peak values of tuber fresh weight accumulation rate were also advanced with the delay of sowing dates. The variance analysis and multiple comparisons of the yield data showed that sowing date was the main factor affecting potato yield which was the highest when the sowing date was May 27. The analysis of the meteorological conditions at different growth stages of potato indicated that the suitable sowing period of potato in semi-arid area of the loess plateau in central Gansu was by the end of May or in early June.

Key words: Jiangsu Province, agricultural area, soil nematodes, community structure.