IMPROVED CULTIVATION OF LETTUCE WITH A LOW COST SOILLESS SYSTEM IN INDIGENT AREAS OF NORTHEAST BRAZIL.

The purpose of this research was to determine the performances of lettuce (Lactuca sativ L.) using low cost soilless gardens in peri-urban areas of the city of Teresina (Piaui-Brazil). In the suburbs of main cities, the introduction of gardening activities may be a sustainable tool to reduce poverty and improve food security. However, due to low access to fertile land horticultural production is constrained. The introduction of low cost hydroponic gardens may be a sustainable way to launch horticultural production in roof, terraces and courtyard. The proposed soilless system are constituted by sloped lines of plastic bottles connected together into a closed pipeline. Four experiments were conducted between June and September 2007, applying the following factorially combined treatments: 1st experiment - garden orientation (west-east vs. east-west), two nutrient solutions (namely Maceiò and La Molina) and three cultivars (“4 Estacoes”, “Elisa” and “Banchu”); 2nd experiment - two nutrient solutions (Maceiò and La Molina) and four cultivars (“Grand Rapids”, “Solaris”, “Veronica” and “Isabella”); 3rd experiment - two nutrient solutions (Maceiò and La Molina) and two cultivars (“Veronica” and “Red Comet”); 4th experiment - the garden slope (17, 22, 27%) and two cultivars (“Veronica” and “Red Comet”). The experimental design consisted of entirely randomized subdivided plots. Plant growth was measured at different phenological stages. Moreover, three times per week, N-Tester measurements were performed on young unfolded leaves. At harvest main biometric measurement were conducted. Period from sowing to harvest was particularly short (44 days), and yield reached 3,7 kg m-2.