WINTER COVER CROPS SOWING SYSTEMS FOR PLANTING LETTUCE

Resumo

Soil cover species as well as the sowing system can interfere with the production of dry matter (straw) and the development of further crops. The objective of this study was to evaluate sowing systems for black oat (Avena strigosa schreb) and white lupine (Lupinus albus) species as cover crops, dry matter production and their influence on lettuce yield, americana and curly varieties. Two experiments were conducted, one for each cultivar of lettuce. The research was composed of eight treatments, in factorial 4x2, evaluated in randomized blocks, with five replications. The first factor was four coverages (black oat, white lupine, black oat + white lupine and spontaneous vegetation) and the second, two sowing systems (manual and mechanized). The desiccation of cover crops was performed 47 days after planting, measuring the amount of dry matter (straw) produced in the area. After 30 days from desiccation, curly and americana lettuce were grown under the straw. Lettuces were evaluated for fresh mass, shoot height and head diameter. White lupine and black oat + white lupine provided superior development of lettuce, although black oat combined with manual sowing system, is the most suitable as soil cover due to its high dry matter yields.