Cloning strategy for Chinese-fir (Cunninghamia lanceolata (LAMB.) HOOK.) suggested by early test results

Fifteen cuttings from each of 252 donors, originating from seedlings from a seed-orchard of an appropriate provenance were taken and rooted in spring 1991. The stecklings were planted in Hubei in a randomized complete-block d esign; seedlings from a local source were used as controls. About 15% of th e least-desired clones were rogued from the test plantations in each of the third and sixth years. It was found that: (1) the height, diameter and volume growth of the steckl ings were consistently and significantly higher than those of the seedlings over the years; (2) the absolute growth difference between the seedlings a nd the stecklings increased with age dramatically; however, the gain as a p ercentage of current size decreased rapidly; (3) there were significant dif ferences among clones and roguing raised the average performance of the ste ckling population; (4) early-late correlation coefficients in growth were l ow. The results indicated that: (1) clonal selection can be done while timber-p roduction plantations are, growing, so that increases in later plantation p erformance and the development of clonal varieties can be achieved incremen tally over time by roguing in the cutting orchard; (2) early selection of a very few clones is likely to be less effective than retaining more clones for later selection approaching or at rotation age; (3) a very few clones t hat have not been well studied should not be used in operational practice.