Seed Priming of Winter Annual Cover Crops Improves Germination and Emergence
- Sieglinde Snapp *,
- Richard Price and
- Maureen Morton
Enhancing soil-protecting living cover over the winter is an important challenge in temperate row crop production. This note reports on novel findings for cover crop seed priming, a process of controlled hydration and drying. The effects of seed priming over durations of 0, 2, 4, 8, 12, 24, and 36 h were evaluated for four species that varied in seed size and germination characteristics: cereal rye (Secale cereale L.), perennial ryegrass (Lolium perenne L.), hairy vetch (Vicia villosa Roth), and oriental mustard (Brassica juncea L.). A logistic function modeled response was used to quantify onset of germination, time to 50% germination (t50), maximum germination rate, final germination percentage (K), seedling emergence, and establishment in laboratory germination paper and soil core assays. Rye seed germinated rapidly regardless of priming treatment. Under the optimum environmental conditions of a laboratory germination assay, the smallest seeded cover crop, perennial ryegrass, was the only species to show a final germination response that was higher in primed (86%) than untreated seed (78%). However, seed germination rates of three species were influenced by priming: 50% germination was reached 8, 6, and 9 h earlier in hairy vetch, mustard, and perennial ryegrass, respectively. Compacted soil assays showed that priming (24 h) improved seedling emergence by 36% and 57% for hairy vetch and perennial ryegrass, respectively, compared with untreated seed. These results were consistent across experiment runs. Seed priming shows promise as a new technology for improving cover crop establishment in compacted soil.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
Copyright © 2008.