The experiment was carried out at the Department of Soil Sciences of the Universidade Federal de Lavras - UFLA, from June to August 2002, with the objective to evaluate the productivity, the nutritional state and the quality (size class) of lettuce cultivars grown with calcium silicate in greenhouse. The experimental design was disposed in blocks with four replicates, in factorial arrangement with additional treatments: 3 x 4 +3, composed by three lettuce cultivars: Raider (group crisphead lettuce); Regina (group butterhead lettuce) and Vera (group looseleaf lettuce) and four calcium silicate rates (0, 410, 1.000 and 2.000 mg dm-3), additional treatments were composed of the application of calcium carbonate of 1.000 mg dm-3 for the three cultivars. The nutritional status of lettuce was evaluated by Diagnosis and Integrated Recommendation System. The application of calcium silicate fertilizer did not increase the growth of the plants and did not improve the concentration of nutrients in lettuce plants; but improved the lettuce nutritional status for Si and increased the percentage of leaves healthy. The application also increase Mn concentration, due to high content of Mn in the silifértil® fertilizer. The three varieties of lettuce behaved as non-accumulation plants of Si.
Lactuca sativa L.; plant nutrition; siderurgical residue
