Lettuce quality in greenhouse with different technological levels

Resumo

Technologies for protected lettuce (Lactuca sativa) crop have been gaining ground in scientific studies, in search of alternatives which increases productivity, quality and loss reduction in the production of the most consumed leafy vegetable in Brazil. Greenhouses provides to crops controlled conditions of temperature and relative humidity, to held within the optimal ranges for plant development and ensuring thermal comfort. This research work assesses the influence of greenhouses with different technology levels (natural ventilation, red shade net and evaporative cooling system) on lettuce grown and quality attributes. The study was held at FEAGRI/UNICAMP, conducting a 45-days growth cycle of green and ruby ‘mimosa’ lettuce seedlings in pots with pine bark substrate drip-irrigated with nutrient solution. At the end of the cycle, plants were assessed in terms of their physical and physico-chemicals atributtes and chlorophyll and anthocyanin contents. Red shade net intensifies red spectral band and promotes high rates of vegetative and radicular growth. Leafy vegetable growing in greenhouses with shade net enhances bioactive compounds and pigments synthesis, in addition to thermal comfort conditions, increases anthocyanins content. Better quality atributtes are achieved in thermal comfort provided by using evaporative cooling system for vegetable crop in greenhouses.