The performance of six lettuce cultivars of the American group, under hydroponic system "NFT" was evaluated in Marechal Cândido Rondon, Paraná State, Brazil. The experiment was performed from June to August 2001, in randomized blocks designed, with four replication and six treatments, constituted by cultivars Lorca, Tainá, Havem, Empire 2000, Lucy Brown and Kaesar. Yield of fresh mass and dry matter of the shoot, concentration and accumulation of macro and micronutrients were evaluated. 'Lorca' and 'Havem' presented larger production of fresh matter. These cultivars presented smaller concentration of Ca and Cu in relation to the others cultivars. The concentration of nutrients in the shoot was not different among cultivars for N, P, K and Mn. For Ca, Mg, Cu and Zn, bigger variation in the concentration was observed. No statistical difference was observed among cultivars for the extraction of N and P, while for the other evaluated nutrients, the cultivars Lorca, Havem and Empire 2000 were superior, being also the ones which produced more fresh and dry matter.
Lactuca sativa L.; yield; soilless-culture; mineral nutrition
