[Response of cotton seeding date to climate warming in Northern Slope Economic Zone of Tianshan Mountain, China].

Based on the meteorological date acquired from 11 meteorological stations in Northern Slope Economic Zone of Tianshan Mountain during 1971-2010 and by using the methods of linear regression, t-test technique and IDW interpolation, this paper analyzed the spatial distribution of each ten-day average temperature from late March to late April and beginning date of ≥ 12 °C to understand the effect of climate change on the cotton seeding date. Results showed that each ten-day average temperature from late March to late April increased by 0. 8, 0. 5, 0. 1 and 0. 5 °C . (10 a)-1, but the beginning date of ≥12 °C advanced by 0.5 d . (10 a)-1 during 1971-2010. All meteorological elements in this research ascended abruptly in the 1990s. The abrupt climate change made each ten-day average temperature increasing by 2.5, 1.9, 1.1 and 1.5 °C, to 7.2, 10.0, 13.2 and 15.6 °C, respectively from late March to late April. The high values of each ten-day average temperature from late March to late April expanded the scope of main cotton producing areas in Northern Slope Economic Zone of Tianshan Mountain, such as Wusu, Sawan and Manasi, and the low values were observed in Urmuqi. The spatial distribution of the beginning day of ≥12 °C was significant different in different regions. During this study period, the early beginning dates of ≥ 12 °C expanded the scope of Jinghe and Manasi as cotton producing areas, and the late beginning dates of ≥ 12 °C narrowed to areas around Urumqi. With the advance of the beginning day of ≥ 12 °C, the seeding date of cotton could start from 22nd to 28th April in most of the counties, and mulch cover could bring forward the suitable sowing date to 15th through 21st April.