Garbage compost effects on lettuce production

Abstract

Heavy metals, potassium and sodium absortion and production of lettuce cultivars fertilized with garbage compost were evaluated. The experiment was carried out in a greenhouse with pot-transplanted cultivars of Brasil 48, Grand Rapids, Vitória Verde Clara and Regina 71, fertilized with the following compost doses: 0, 17.5, 35.0 and 52.5t.ha^-1. Freshmatter production of leaves was influenced by cultivars and compost doses, being Regina 71 and Vitoria Verde Clara the most productive when 17.5t.ha^-1 dose was applied. Compost doses increased significantly Zn, Cu, Mn, K, and Na concentration in lettuce drymatter, and the different cultivars affected Pb, Zn, Cu, K and Na concentration in the drymatter. Cultivars and compost doses interacted as for Cu, Mn, K and Na. Concentration of K and Cu in lettuce leaves was considered normal, while Mn and Zn were low and Na and Pb were high, when the latter exceeded the limit allowed by Brazilian legislation for consumers of vegetables in natura