Relationship analysis on phenological characteristics of Paeonia ludlowii with its main meteorological factors

Paeonia ludlowii distributed in Tibet Nyingchi area was taken as research object, and such main phenophase as sprout period, leaf-expansion period, flowering period were observed from 2012 to 2013. The results showed that: (1) The bulbil began germinating in mid March, and the plant got into growth period; (2) The buds began swelling at the end of March to early April, the flowers opened in early or mid May, and the plant entered flowering peak in middle or late May. Then the plant entered the fruit growing period. (3) Mid-late June to mid-September was the fruit maturity stage, the fruit began to fall after that. We found that there were significant correlations between phenophase phase and temperature index: pentad average temperature of 4.1could be regarded as the temperature index for the beginning of germination period. The plant entered in flowering period when pentad average temperature was 10 , the effective temperature exceeded 5 at flowering phase was not less than 325, the cumulative sunshine hours before flowering was less than 470 h. The average temperature in young fruit period amd fruit maturity period were above 15 and 17, respectively. And the average temperature in fruit abscission period was 13. When the average temperature was less than 6 in November, P. ludlowii wetn into dormancy. Key words: Nyingchi; Paeonia ludlowi; phenophase; meteorological factor; temperature