Seedling Quality Grading of Cunninghamia konishii in Fujian

In order to establish seedling quality grading standards of Cunninghamia konishii, seedling quality grading standards of C.konishii were studied by using progressive clustering method and mean ± standard deviation method, the proportion, standard and planting effectiveness of different grades of the 2 different methods were analysed and compared, thus suitable grading method and standards were determined. The results showed that it was feasible to use the seedling height and ground diameter as index for grading of C.konishii seedling. There were obvious difference in the grades seedling ratio, the character indexes range of grades, the difference of character indexes between the adjacent grade and the planting effectiveness of C.konishii seedling among using 2 different methods. Seedling height, ground diameter and afforestation seedling survival rate, high growth of C.konishii decreased significantly with the increase of seedling grade by mean ± standard deviation method; seedling height, ground diameter and afforestation seedling high growth of C.konishii decreased significantly with the increase of seedling grade by progressive clustering method, but there was no significant difference in the survival rate of afforestation seedlings between the first and the second grade. Mean ± standard deviation method was more feasible for seedling grading C.konishii by comprehensive the seedling grades ratio, the character indexes range of grades, the character indexes difference between the adjacent grade and the planting effectiveness of all sorts grades, and grading standard was as follows: Seedling with height no less than 47.5 cm and ground diameter above 0.63 cm were classified as the first grade. those with height less than 47.5 cm and above 27.0 cm, and ground diameter lower than 0.63 cm and above 0.36 cm belonged to the second grade. If 1 item of the seedling height, ground diameter does not meet the grade standard, then drop it a grade.