Abstract:

Taking the 7 d daily average temperature during the coldest period of winter as the main indicator and precipitation as the auxiliary indicator, the revised Puccinia striiformis f. sp. tritici overwintering meteorological index and geographic information system (GIS) were used to carry out overwintering climatic zoning of wheat area in eastern Gansu Province. The 6 main overwintering areas were southern Longnan, northern Longnan, Weihe River basin and Guanshan area, southern Longdong Loess Plateau, northern Qingyang City and southern Longzhong. The 7 d average temperature during the coldest winter period of 6 main overwintering areas was 0.6, -4.1, -6.5, -8.3, -9.0 and -9.8℃, respectively, which generally occur in the first and second ten-days period of January, and the lower limit of the altitude that could not be overwintered was respectively 2500, 2000, 1800, 1600, 1200 and 1800 m. Compared with the 1980s, the upper limit of the altitude rose 200-400 m in Longdong and most of Longnan, and extended west and north to the southern Longzhong below 1800 m and the northern Qingyang City below 1200 m. The easy overwintering areas were mainly distributed in the Bailong River basin below 2100 m in southern Longnan and eastern Gannan Prefecture, 1600 m in northern Longnan and 1400 m in Weihe River of Tianshui City. The overwintering area was between easy overwintering and non-overwintering, the largest area was the southern Longdong Loess Plateau, and the least areas were northern Qingyang City and southern Longzhong.

Key words: Gansu, Hedong area, Puccinia striiformis f. sp. tritici, overwintering, refining, climatic zoning