Seedling suppliers have moved away from “generation” vocabulary for over a decade. Tree improvement foresters have known for years it is not how old the tree is. Instead, it is crucial to understand the genetic performance of an individual family. On average, second-generation loblolly pine families were better than first-generation selections. In theory, third-generation families would represent an improvement over second and first-generation material. But this is not always the case. Some first-generation families still outperform second and even third-generation selections. New categorical designations such as Advanced, Select, and Elite have replaced “generation” and are a part of our modern reforestation language.
The genetic value created from an individual loblolly pine family can be attributed to four main criteria: growth/productivity, fusiform rust resistance, stem straightness, and forking reduction. This criterion applies to Open Pollinated (OP) and Mass Control Pollinated (MCP®) seedlings. OP is synonymous with first, second, and third generation, where we know the mother’s genetic contribution but not the father’s (pollen source). MCP families use the best OP families to make control crosses of known mothers and fathers, providing a much improved seedling.
