The North Carolina State University – Industry Cooperative Tree Improvement Program has followed two major lines of development: (1) Production seed orchards to supply large quantities of genetically improved stock, (2) research clone banks to be used as a gene pool for advanced-generation seed orchards.Results from current progeny tests reveal the occurrence of parent trees with strong general combining ability and occasional outstanding specific combinations. Thus, many of the best trees selected from open-pollinated or pollen-mix progenies would be half-sibs or full sibs. It is, therefore, essential that the parentage of trees used in advanced-generation orchards be known if the presumed detrimental effects of inbreeding are to be avoided. A conscious effort must be continuously made to maintain a broad genetic base for advanced-generation breeding populations.Where the cost of testing in terms of time and money is critical it is important to use a progeny-testing scheme that: (1) gives an assessment of parental breeding value, and (2) provides unrelated families of known parentage from which selections for advanced-generation orchards can be effectively made. The tester design satisfies these criteria for organizations having several orchards, each with different testers, so that material can be freely exchanged for future generations. A suggested alternative for organizations with limited resources or specialty orchards is a partial diallel design.