A STUDY ON FORECAST OF TEA PLUCKING PERIOD IN SPRING

Sprouting, growing and plucking periods of tea shoots in winter and spring were observed continuously in 1962-87.We released several forecasts of plucking periods to wide tea areas every year.This paper sums up our research results.It contains three parts: 1.We have obtained the temperature of sprouting and the value of accumulated temperature of different species of tea plant from sprouting to plucking periods: extra-early sprouting species-8℃, 134±15.3℃ early sprouting species-10℃, 128.3 ±10.1℃; meidum sprouting species-10-12℃, 137.6 ± 15.7℃; late sprouting species-14℃, 121.8±9.2℃. 2.We have analyzed the relationship between the plucking periods of different species and meteorological factors. Results show the greatest influence of mean temperature,sunshine-hour and rainfall on the plucking period of extra-early sprouting and early sprou-ting species; the next greatest influence on that of medium sprouting species;and the smallest on that of late sprouting species.The mean temperature of February and the first ten days of March are closely interrelated to the plucking period of extra-early sprouting species.The mean temperature of March is closely interrelated to the plucking period of early medium and late sprouting species. 3. We have provided three kinds of methods of tea plucking period forecast in spring. A. method of interval days of growing period; B. method of accumulated temperature; C. method of multiple regression.Long-term productive practice shows that the method of interval days of growing period has the best effects among the three methods and is easy to use in tea areas.