Effect of Seed Scarification and Gibberellic Acid Treatment on Seedling Emergence of Sky-Blue Lupine (Lupinus diffusus)

Abstract

The efficacy of various scarification treatments and gibberellic acid (GA3) treatment on seedling emergence of Lupinus diffusus Nutt. (sky-blue lupine) was evaluated. Seed scarified in concentrated sulfuric acid for 90 min followed by immersion in water for 24 hr resulted in the best emergence of viable seed (≈ 41%). Mechanical scarification with sandpaper for up to 30 min did not improve seedling emergence. Immersing seed in 90C (194F) water which was then allowed to cool for 24 hr apparently killed or severely injured the embryos as no seedlings emerged from seeds treated with hot water. There was only 5% seedling emergence for nonscarified seed that were soaked in water at room temperature for 24 hr. Emergence was not improved by soaking scarified seed in 1000 mg/liter (ppm) GA3 for 24 hr prior to sowing the seeds.