Hydroponic cultivation of lettuce varieties under optimized organominerals nutrient solution with the SOLVER/ Cultivo hidroponico de cultivares de alface em solucoes nutritivas organominerais otimizadas com a ferramenta SOLVER

The study aimed to evaluate the cultivation of lettuce varieties in floating type hydroponic system with nutrient solutions optimized by the SOLVER tool of the Microsoft Office Excel. The experiment was conducted at the Center of Environmental and Agricultural Sciences Center of the Paraiba State University, adopting an entirely randomized experimental design arranged in factorial scheme 4 x 3, with three repetitions. The factors were 4 nutritient solutions (S1 = 100% mineral solution; S2 = 90% mineral solution + 10% organic solution; S3 = 84% mineral solution + 16% organic solution and S4 = 78% mineral solution + 22% organic solution) and 3 lettuce varieties (C1--Crespa; C2 --Monteiga and C3--Ruby). The plant height, stem diameter, number of leaves, the length of the root, fresh matter weight and the dry matter weight of the lettuce were evaluated. The organominerals solutions promoted a greater resistance to variation of the pH and replaced partially the mineral solution. The best biometric and production means were observed for the Crespa and Monteiga varieties and for the mineral solution, mineral solution + 10% of organic solution and mineral solution + 22% of organic solution. Key words: Lactuca sativa L. fertilizer optimization Objetivou-se, com este trabalho, avaliar o cultivo de cultivares de alface em sistema hidroponico tipo floating com solucoes nutritivas otimizadas pela ferramenta SOLVER, do Microsoft Office Excel. O experimento foi conduzido no Centro de Ciencias Agrarias e Ambientais da Universidade Estadual da Paraiba adotando-se o delineamento experimental inteiramente casualizado disposto em esquema fatorial 4 x 3, com tres repeticoes. Os fatores foram 4 solucoes nutritivas (S1 = 100% de solucao mineral; S2 = 90% de solucao mineral + 10% de solucao organica; S3 = 84% de solucao mineral + 16% de solucao organica e S4 = 78% de solucao mineral + 22% de solucao organica) e 3 cultivares de alface (C1--Crespa; C2--Manteiga e C3--Rubi). Avaliaram-se a altura da planta, o diametro caulinar, o numero de folhas, o comprimento da raiz, a massa da materia fresca e a massa da materia seca da alface. As solucoes organominerais promoveram uma resistencia maior a variacao do pH e substituiram parcialmente a solucao mineral. As melhores medias biometricas e de producao ocorreram para as cultivares Crespa e Manteiga e para as solucoes mineral, mineral + 10% de solucao organica e mineral + 22% de solucao organica. Palavras-chave: Lactuca sativa L. fertiliz