Influence of Plastic Covering on the Microclimate in Vineyards in the São Francisco River Valley Region

Abstract Data from field experiments conducted in table grape vineyards variety of Festival in Petrolina-PE in the period fromSeptember 19 to October 12, 2010 were used to evaluate the influence of plastic cover on microclimate conditions ofvineyards in Sao Francisco River Valley region. Three treatments were studied: canopies without plastic cover (WC);with plastic cover positioned at 50 cm (PC50), and at 100 cm (PC100) above canopy. The results indicate that the plasticcover prevented the passage of about 40% of the global and net radiation, retained the relative humidity inside the can-opy, generated an increase of air temperature and marked reduction in wind speed over the canopy of treatment PC50.However, treatment PC100 had a higher incidence of short wavelength and net radiation under canopy (on the berries)than WC and PC50 treatments, resulting in more favorable weather conditions, providing about 40% greater productiv-ityinthistreatment.Therefore,thevineyardwithplasticcoverplacedat100cmabovecanopyrepresentsamoresuitablealternative to the climatic conditions of the region of the Sao Francisco River Valley.