But in the past two years,Congjiang orange industry has faced a series of problem: the decline in the quality of fruit,income is reduced for input increasing and output decreasing,orchards increasing output without increasing income;market is narrowed by the plenty of imitated "Congjiang orange";farmer s interest of planting Penggan is decreased.

In vitro system for the regeneration of mature internodal stem segments of Ponkan (Citrus reticulata Blanco);

Study on the selection of new variety Heping ponkan;

Lipeng No. 2, a new Ponkan mandarin cultivar;

The climatic factors influencing the occurrence of citrus yellow shoot trees are studied by using the climatic data of the Congjang Meteorological Bureau(the day-to-day temperature,precipitation,evaporation and number of consecutive rainy days) from May to October,1981 to 2005.

The optimal processing technology of citrus-milk was ascertained: quantity of citrus ponki juice is 20%, quantity of defatted milk powder is 2.

The perfume essential oil in ponkan peel was extracted by ameliorated simultaneous distillation extraction.

Determination of Zine Content in Congjiang Citrus by Flame Atomic Absorption Spectrometry;