Abstract:

To develop refined meteorological services for autumn Osmanthus in Chengdu, and establish a meteorological forecast model, this research used mathematical statistics to study the relationship between the pre-flowering period and flowering period of Osmanthus and the meteorological factors, and established the prediction model of the initial flowering period of Osmanthus in combination with the Osmanthus growth characteristics based on the phenological observation of Osmanthus and meteorological data in Chengdu from 2004 to 2016. The results showed that: with abundant rainfall before flowering, when the sliding average temperature on the 5th day passed 23℃, Osmanthus entered the first flowering period in 3-6 days. During the flowering period, there was an alternation of sun and rain with the daily average temperature ranging from 20℃ to 24℃. The number of rainy days, precipitation and sunlight were the main meteorological factors influencing the duration of flowering period. The initial flowering period of Osmanthus was positively correlated with the highest temperature in late February, sunshine duration in late February and rainy days in late July, but negatively correlated with rainfall in late October and rainy days in late May. The prediction model of the flowering period of Osmanthus in Chengdu had a high historical fitting rate and a good forecast effect, which could predict the flowering time 20 days in advance. The study could be used for the medium and long term forecast of the early flowering period of Osmanthus and provide accurate meteorological service for the appreciation of Osmanthus in Chengdu.

Key words: Osmanthus, flowering period, meteorological index, forecast