Evaluation of meteorological elements and lettuce (Lactuca sativa, L.) yield related to geographic orientation of polyethylene greenhouse.

• Autor(a) principal: SOUZA, C. M. P. de
• Data de Publicação: 2002
• Outros Autores: KLAR, A. E., DUENHAS, L. H.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da EMBRAPA (Repository Open Access to Scientific Information from EMBRAPA - Alice)
• Texto Completo: http://www.alice.cnptia.embrapa.br/alice/handle/doc/151593
• topic: Cultivo; Alface; Estufa; Evaporação; Irrigação

This experiment was carried out at the Agricultural Engineering Department, FCA/UNESP, Botucatu-SP aiming to stady the geographic orientation influence of two plastic tunnels (East/West and North/South based on the magnetic North) on lettuce plant (Lactuca sativa L, cv. Elisa) behavior and on the evaporation distribution uniformity inside the tunnels. The plants were sowed on 05/05/1999, transplanted on 05/29/1999 and havested on 06/31/1999. Temsiometers were used to monitore soil water potentials. A drip irrigation system was used. Both tunnels received A Class pan and thermohygrograpes in the center and 3 m apart small evaporimeters set at 3 heights (0.50 m, 1.00 m and 1.50 m). Through geostatistical analysis, there was not neither spatial dependency nor spatial variability of evaporation in both tunnels. However, the height of evaporimeters showed statistical differences: the 1.50 m height evaporimeter had slower evaporation than those from other heights. The air temperature, relative humidity and vapor pressure deficit averages were not statistically significant in both greenhouses when they were compared to those from the outside. A Class pan evaporation values were higher outside the tunnels than inside them, but there were no differences between both tunnels for this varieble. The lettuce plant yild was not influenced by tunnel orientation, but there were significant differences on plant yield among beds inside each tunnel.