Modelos para estimar o acúmulo de fitomassa de alface em hidroponia

摘要: The protected and hydroponics cultivation are increasing in Brazil, demanding a better knowledge of crop performance this environment. Plant dry matter accumulation as function solar radiation, temperature, relative humidity other weather parameters greenhouse is different when compared with field cultivation. With the purpose proposing models to characterize temporal variation leaf total production hydroponics-grown lettuce (Lactuca sativa L.) determine flowering period maximum rate plant development (relative degree-days), radiation effective thermal index, two experiments (Spring Autumn) were carried out greenhouse, at Santa Maria, Rio Grande do Sul State, Brazil. Growth useful obtaining basic information on ´ environment interactions, maximizing use resources well as, define best form management. cultivar Vera was chosen its earliness. Models proposed estimate accumulation, where results for obtained using degree-days, characterizing importance air temperature vegetative phase reproductive. yield quality seeds evidenced high potential technique.