Construction of Eucalyptus smithii Seed Orchard

Eucalyptus smithii seed orchard is constructed through thinning and reconstruction of their family test stands. Two superior provenances and twenty superior families were selected in family selection test, which account 28.6% of total provenances and 22.7% of total families respectively. The timber volume hereditability of provenance, family and individual is 0.869, 0.609 and 0.986 respectively. The result indicates that individual and provenance selection is better than family selection. The genetic increment of superior provenance and superior family is 0.246 and 0.276 respectively. The actual average increment of family is 45.3%. There is no significant difference in wood density between superior and inferior families. There are about 340 trees per hectare left after orchard constructed through two times of thinning on family test stands. The results of test on promoting Eucalyptus smithii blooming and bearing show that fertilizer and blooming promoter are benefit for earlier blooming, bearing and increasing amount of flowers and fruits. The flowering and bearing percentage of families treated with fertilizer and blooming promoter is three times that of the control. The average flowering and bearing percentage of seven and half year old individuals in the orchard is 24.6% and it is estimated that the percentage will increase in the rate of 15.5% per year. The provenances with high flowering and bearing percentage are 18676 and 18688, which are inferior provenances. And provenances with low flowering and bearing percentage are 18682 and 17131, which are superior provenances. The flowering and bearing percentage of inferior provenances is 2.1 times that of superior ones. The flowering and bearing percentage of superior families is 65%, which is 2.3 times that of average of all families, 28.6%. Inferior provenances bloom and bear fruits earlier than superior ones. While within families, superior families bloom and bear fruits much earlier.