執行成果摘要
First weeding and devining of the Camptotheca acuminata test plots was carried out in February of 2012. Weeding was done mechanically in conjunction with manual weeding of the planting holes. Afterward, fertilization was applied and in early March annual trimming for coppice operation to a height 70 cm above ground was carried out. Due to weather factors, the first harvest of leaves was postponed to late May. The fresh leaves were weighted on-site and the average yield was lower than the previous year. In 2011, the highest yielding Fushan strain produced only 79.0 g of leaves in May harvest. The year’s champion, the 2-year-old Hueisun Forest strain produced only 919.7 g from a single tree, merely 61% of the maximum yield of 2010. We deemed that the poorer performance was due to heavy trimming year-on-year and the plots suffered from typhoons and flooding in consecutive years which caused a weakening of tree growth vigor. Up to July 2012, individual tree sampling for camptothecin content indicated that the newly included sampling plants Fushan strain no. 61 produced 6533.3 ppm, the highest camptothecin concentration. Sampling of this year’s trees indicated a extreme high camptothecin content from many individuals, indicating that on-site screening for high content trees still have ample operation range to work with.