Microclimatic changes in cultivating systems for the production of Collard greens baby leaf

Resumen

With the growing demand for products beneficial to human health, olericulturists developed the marketing of baby leaf. Various cultivation environments provide microclimatic changes, which in turn will change the entire development of plants. Thus, the work aimed to study the productive response of collard greens baby leaf in four cultivations systems [low tunnels with plastic (PT) and with sombrite (SB), nonwoven floating system (NW) and natural environment (NE)] and at five harvest times [21; 28; 35; 42 and 49 days after sow­ing (DAS)]. The experiment was conducted in Ponta Grossa - PR, between 09-01 and 10-20-2011. At 14 DAS was held thinning, keeping the density of 500 plants m^-2. At each moment of harvest, it were evaluated the number of leaves per plant (NL), plant height (PH), fresh (FM) and dry (DM) phytomasses of the plants, leaf area index (LAI) and productivity at the final collection point. The average air temperature (Ta) and photosynthetically active radiation (PAR) were monitored in each cultivation environment. Throughout the growing season it was found rapid growth of plants grown under PT compared to SB, characterized by greater accumulation of FM and DM. The baby leaf cultivation in the PT environment showed four days precocity in the harvest in relation to the NW, six days in NE and eight days for plants grown under SB. The low PAR radiation values within the SB environment interfered with the growth and development of the plants grown therein.