How can tree breeders get the information needed to make the right decisions in less time?
One useful approach is to examine the results of several generations of tree breeding elsewhere. Some examples of more advanced programs include the loblolly pine tree improvement efforts in the south east USA, the radiata pine breeding program in New Zealand and clonal eucalyptus programs in Brazil. These programs are all in their third generation of breeding and selecting for superior parents and offspring. Actual realized gains from the first two cycles can be inspected to determine the relationship between gains in: • height, • diameter, • individual-tree volume, and • stand volume productivity at rotation age in operational stands where competition control may be stronger than in the realized gain trials. Paired Block Plots Paired block plots compare improved and unimproved families or clones grown for a full rotation under the same environmental and silvicultural conditions. Site productivity differences are accounted for by the paired plots, and they are relatively simple to ins
