HOW SEED ORCHARD CULTURE AFFECTS SEED QUALITY - EXPERIENCE WITH THE SOUTHERN PINES

Tree improvement programs have influenced significantly the quality of southern pine seeds produced when compared to collections from native stands. Seed orchard management practices such as fertilization can i ncrease seed size and reduce seed dormancy. These result in the need f or less complex pregermination treatments. Repeated cone collections f rom the same clones facilitate collections according to ripening (cone specific gravity), which can improve seed germination and storage. Ho wever, cultural practices may result in seed properties that are more sensitive to damage during processing procedures and result in lower q uality unless special care is provided during this stage of handling. The effect of orchard management practices on seed quality also varies by species, with loblolly pine being less affected than longleaf pine .