Study On Introduction, Cultivation Andlarge Scale Production Of Famous High-Quality Dahlia

Dahlia is one of the flowers which have the most types in the world. Its flowers are big, various and colorful. Dahlia not only has numerous types and long colony inflorescence, but also has some value for medicine. In spring of 1996, more than 170 types of Dahlia were introduced from Lintao County of GanSu Provence to Xi'an Botanical Garden by the author. After more than 10 years of cultivation and study, many achievements have been achieved in propagation, cultivation, field management, prevention and cure of diseases and pests, and storage in winter, etc. The conclusion of the research includes mainly the following two aspects.Firstly, the relationships among the height of plant, the time of bloom and the diameter of flower were studied under the same cultivation time and method. There is obvious relationship between the height of plant and the time of blooming. Most short types bloom earlier, and many high types bloom late. There is certain relationship between the diameter of flower and the height of plant. The big flower is more than the small one in the high types, but the small one is more than the big one in the short types. In addition, there is no clear relation between the diameter of flower and the time of blooming. No matter the variations are big, middle or small types, they are evenly distributing over earlier or later blooming types.Secondly, some key techeniques of potted Dahlia were proposaled, i.e., select the short variations, cultivate seedlings of cutting, choose suit potts and soil, regularly fertilize, irrigation control, and use of hormones to contol the growth. In addition, the following teqeniques can be used also to improve the growth of potted Dahlia: cut the root partially, fill the pot step by step, bury the pot halfly in the earth, and cultivate the seedlings of cutting with top sprout or bud.Thirdly, techniques of control of the florescence of Dahlia were mastered. The techniques related to bringing forward the florescence include keeping the plant in green house in advance, propagating by root-division, and keeping the plant has only one stem and one bud without cutting the head bud. The techniques related to postponing the florescence include keeping the plant at a cool place, propagating by stem-cutting, cutting the head buds two or three times, and cultivating cross-breed variations. Techniques such as starting the seedling cultivation at the end of summer or the beginning of spring, keeping the plant in green house and ensuring it enjoys sun / light illumination at least for 12-14h per day in winter can make Dahlia flowers at the spring Festival. Similarly, techniques such as starting the seedling cultivation at the end of spring, keeping the plant in green house and ensuring it enjoys sun / light illumination at least for 12-14h per day since the beginning of March, and putting the plant outside after the middle of April can make Dahlia flowers at the the beginning of May.