Seeds of lettuce cv. Grand Rapids Nacional were pelleted using as a filler, a mixture of sand and microcellulose in equal volume parts, and as a glue, different volumes of water suspension of bentonite and polyvinyl acetate at five proportions (%): 100+0; 75+25; 50+50; 25+75; and 0+100 applied apart, betonite being applied in the first coat layer. After pelleting, seeds were dried at 15 or 36°C and evaluated for germination and seedling emergence. Seed pelleting compound and drying temperature did not affect total germination. Only two pellet formulations showed reduced rate of seedling emergence indicating that differences were not due to the coat formulation and drying process. Independently of seed pellet formulation and drying temperature, the germination of pelleted seed delayed in relation to raw seeds. When sowed in organic substrate and placed under greenhouse conditions, pelleted seeds showed similar germination rate to raw seeds. In this environment, seedlings from pelleted seeds showed normal growth. The fresh and dry matter were similar to those from raw seeds at 20 days after sowing.
Lactuca sativa L.; pelleting, coat; seedling establishment; vigor
