Promoting Red Elm (Ulmus rubra Muhl.) Germination with Gibberellic Acid

摘要

Red or slippery elm (Ulmus rubra Muhl.) is valued by many Native American tribes for its food, fiber, and medicinal uses and as ceremonial fuelwood; however, nursery propagation is hindered by a lack of large seed trees due to Dutch elm disease, caused by the fungus Ophiostoma ulmi (Ophiostoma ulmi Busiman) and poor germination of collected seed. The objective of this study was to evaluate the effect of using gibberellic acid (GA(3)) to improve red elm seed germination. Studies were conducted for 2 years with two seed sources, both nonstratified seed and seed stratified for 45 or 90 days, soaked in GA3 concentrations ranging from 0 to 2,000 ppm. Seed viability ranged from 80 to 94%; however, germination ranged from 13 to 88% for nonstratified seeds. In 2010, GA3 up to 1,000 ppm improved germination of nonstratified seeds; however, GA3 decreased germination of stratified seeds. In 2011, GA3 improved or had little effect on germination. Use of GA3 should improve red elm seed germination, particularly if stratification is not used.