Publication Date
1989
Description
Seed coatings provide a unique opportunity to supply developing seedlings with a source of nutrients to which each sown seedling has preferential access compared to neighbouring weeds, thus providing the seedlings with a competitive advantage during pasture establishment. A study of commercially prepared nutrient coatings (containing nitrogen [NJ, phosphorus [P] and sulfur [SJ) applied to seeds of perennial ryegrass showed that whilst the S component of the coating was effective, the P component was only partially effective, and the N component was ineffective in alleviating the respective soil nutrient deficiencies (Scott et al., 1985). The successful development of nutrient seed coating technology demands that the coatings are not only effective in promoting growth but are safe to the seed during germination and emergence. Although considerable research has been conducted on the safety of conventionally applied fertilizers to seed germination (e.g. Carter, 1969), little has been reported on the safety of nutrients when applied in coatings to seeds. When calcium phosphates with different w.ater solubilities were applied at several rates to seeds of lucerne (Medicago sativa) and phalaris (Phalaris aquatica), the most soluble form (monocalcium phosphate [MCP]) severely damaged lucerne during emergence whilst relatively little injury was caused to phalaris (Scott and Blair, 1988a). In a subsequent experiment, MCP applied as a seed coating to phalaris at 5 kg P ha-1 was as effective in promoting early root growth as a drilled application of MCP at 20 kg P ha-1 (Scott and Blair, 1988b). Although lucerne was damaged by MCP seed coatings, early seedling growth was markedly increased by a drilled application of MCP whereas less soluble sources produced no increase in early growth. Hence there appears to be a dilemma between safety to emergence (insoluble forms being safe) and efficacy in promoting early seedling growth (soluble forms being most effective). Several experiments were conducted to investigate why the lucerne and phalaris differed so much in tolerance to MCP seed coatings and how injury during emergence might be overcome.
Citation
Scott, J M., "Developing Effective Nutrient Seed Coatings for Grasses and Legumes" (2025). IGC Proceedings (1989-2023). 56.
https://uknowledge.uky.edu/igc/1989/session1/56
Included in
Agricultural Science Commons, Agronomy and Crop Sciences Commons, Plant Biology Commons, Plant Pathology Commons, Soil Science Commons, Weed Science Commons
Developing Effective Nutrient Seed Coatings for Grasses and Legumes
Seed coatings provide a unique opportunity to supply developing seedlings with a source of nutrients to which each sown seedling has preferential access compared to neighbouring weeds, thus providing the seedlings with a competitive advantage during pasture establishment. A study of commercially prepared nutrient coatings (containing nitrogen [NJ, phosphorus [P] and sulfur [SJ) applied to seeds of perennial ryegrass showed that whilst the S component of the coating was effective, the P component was only partially effective, and the N component was ineffective in alleviating the respective soil nutrient deficiencies (Scott et al., 1985). The successful development of nutrient seed coating technology demands that the coatings are not only effective in promoting growth but are safe to the seed during germination and emergence. Although considerable research has been conducted on the safety of conventionally applied fertilizers to seed germination (e.g. Carter, 1969), little has been reported on the safety of nutrients when applied in coatings to seeds. When calcium phosphates with different w.ater solubilities were applied at several rates to seeds of lucerne (Medicago sativa) and phalaris (Phalaris aquatica), the most soluble form (monocalcium phosphate [MCP]) severely damaged lucerne during emergence whilst relatively little injury was caused to phalaris (Scott and Blair, 1988a). In a subsequent experiment, MCP applied as a seed coating to phalaris at 5 kg P ha-1 was as effective in promoting early root growth as a drilled application of MCP at 20 kg P ha-1 (Scott and Blair, 1988b). Although lucerne was damaged by MCP seed coatings, early seedling growth was markedly increased by a drilled application of MCP whereas less soluble sources produced no increase in early growth. Hence there appears to be a dilemma between safety to emergence (insoluble forms being safe) and efficacy in promoting early seedling growth (soluble forms being most effective). Several experiments were conducted to investigate why the lucerne and phalaris differed so much in tolerance to MCP seed coatings and how injury during emergence might be overcome.
