Improving Longleaf Pine Seedling Establishment in the Nursery by Reducing Seedcoat Microorganisms
Longleaf pine (Pinus palustris Mill.) seeds are sensitive to damage during collection, processing, and storage. Highquality seeds are essential for successful production of nursery crops that meet management goals and perform well in the field. We conducted a series of tests under laboratory and nursery conditions to evaluate what effect a number of presowing treatments, e.g., soaking, stratification, and coat sterilization, had on the performance of longleaf pine seeds of varying qualities. Test results indicate that removal of fungal contamination from the seedcoats will markedly improve seed germination and seedling establishment in the nursery. Both a 1-hour soak in 30-percent hydrogen peroxide and a 10-minute drench in a 2.5 percent m.l. per liter benomyl solution improved longleaf pine seedlot performance, particularly in seedlots of low to medium quality. Based on seedling establishment 3 months after sowing, other treatments, which included water soaking and stratification, were less effective than sterilants. Because the benomyl drench was as effective as the hydrogen peroxide soak, it is the preferred treatment for controlling seedcoat contamination: it is both more economical and safer for the nursery manager to use. An effort is underway to extend the registration for this seed treatment to Southern States other than North Carolina, where it is currently labeled.