关键词: 镉, 镉, 作物, 富集, 机制

Abstract: Based on the meteorological data of 7 stations in Pingliang form 1971 to 2010, the variation characteristics of late frost and Spring temperature was analyzed. On the basis of the phenological observation data in Kongtong from 1987 to 2013, the response characteristics of late frost to apple phenophase was also analyzed. The results showed that there were obvious regional differences of late frosts end date and late frosts lasting days in study area. The late frost end date delayed and the late frost lasting days increased from east to west. Since the late 90 s, except in individual years, the late frosts end date advanced at the rate of 13.4d/40y. The average temperature in spring, average minimum temperatures and average maximum temperatures showed an linear upward trend since 1971 under the background of global warming, the accumulated temperature of ≥10 ℃ increased too. The growth periods of apple’s bud burst, developing leaves, flowering ,etc. had advanced about 10-13 days. The bud burst earlier had increased the damage chance of freezes to fruit tree’s bloom in spring. Furthermore, the late frosts end date delayed in individual years and the duration of process increased made more freezing risk on apple.