Development Of A New Seed Coating Formulation For Medicago Sativa

Lucerne (Medicago sativa), as a perennial forage legume, plays an important role in pasture livestock production, improving soil quality and control of soil and water erosion. Diseases, especially soil- and seed-borne diseases, are one of the limiting factors of lucerne production and utilization. Lucerne seedling diseases could be controlled and pasture establishment could be improved effectively by seed coating with fungicide and rhizobium. Forage seed coating is a common practice in developed countries. However, the core of the seed coating techniques is normally protected by the patient. There is an urgent need of seed coating technique in China. The objectives of the present experiments are to develop seed coating formulation and techniques which allow the fungicides and rhizobium could be applied to lucerne seed with one operation. A series of experiments were conducted in the laboratory and glasshouse. Fungicides and adhesives were evaluated and selected, their optimum dosages were determined. Seed coating formulation was then developed. The formulation was subsequently tested with 7 seed lots harvest from 1999-2005 at tongwei county, Gansu province, China. The measurement of coated seeds included seed laboratory germination, seedling emergence rate, plant height, number of nodules, herbage dry matter yield and root biomass. The results showed that compared with those of non coated the seed germination percentage increased by 3.3-19.0% with the average of 5.7%, the seedling emergence rate increased by 1.1-11.3% with the average of 6.4%, the plant height increased by 7.1-17.7% with the average of 13.6%, whereas the herbage dry matter yield increased by 18.7-63.6% with the average of 34.0%, and the root biomass increased by 50.0-139.0% with the average of 77.4%. The results mentioned above indicated clearly that the lucerne establishment and herbage production were improved significantly by the seed coating formulation developed. Field trials under various environmental conditions will be undertaken to test the effectives of the seed coating formulation.