Microclima e produção de tomate tipo cereja em ambientes protegidos com diferentes coberturas plásticas / Microclimate and cherry tomato production in greenhouses with different plastic covers

AUTOR(ES)
DATA DE PUBLICAÇÃO

2010

RESUMO

In the regions where solar energy is very intense and temperatures are high, the tomato growers use to reduce the incoming solar radiation inside the greenhouses, aiming to promote the temperature reduction, mainly by installing aluminated shading screens inside. However, the use of such covers promotes an intense reduction of the photosynthetic active radiation, bringing negative consequences for yield. Therefore, it is important to characterize the microclimate inside the greenhouses in relation to the cover material used. Based on that, the objective of the present study was to evaluate the influence of different covers on microclimate and the cherry tomato yield and quality in greenhouses, in Piracicaba, state of São Paulo, Brazil. For that, a 50-m greenhouse was divided in two different environments: Environment I - covered with plastic film anti-UV and with thermo-reflective shading screen disposed internally, and Environment II - covered with diffusive plastic film. Both environments were cultivated with two cultivars of cherry tomato (Sweet Grape and Sweet Million), fertilized with two different solutions (K:N relation of 2:1 and 3:1) by fertirrigation. Environment II had 50.3% more availability of solar energy than Environment I. The temperature inside Environment II was slightly higher (5.2 and 2.1% in the first and second cycles) than Environment I, which had similar temperatures to outside condition. The Sweet Grape cultivar produced more small (163 fruit pl-1) and large (341 fruit pl -1) fruits than Sweet Million (102 and 261 fruits pl-1, respectively). The 2:1 K:N solution promoted greater production of small fruit (144 fruit pl-1) fruits than 3:1 (122 fruit pl-1). Plants in the Environment II produced, in average, 146 small fruits per plant and 368 large fruits per plant, whereas the ones in Environment I produced 119 and 235 fruits per plant, respectively. The different environments did not have influence on fruit diameter; however, they promoted differences in the weight of the fruits. Small and large fruits in the Environment II weighted 6.66 g and 11.91 g and in the Environment I they weighted 6.09 g and 11.21 g, respectively. Sweet Million cultivar produced 4.58 kg pl-1 and 3.85 kg pl-1 and Sweet Grape 3.94 kg pl-1 and 3.53 kg pl-1 respectively in the 1st and 2nd cycles. In relation to fruit quality, the environment had influence only on the percentage of acidity and vitamin C content. The ratio K:N 2:1 resulted in a small °Brix difference in relation to the ratio 3:1. The Sweet Million fruits had higher acidity and vitamin C content than Sweet Grape ones. Based on these results, it is concluded that the cover of Environment II (diffusive plastic film) was efficient to keep the temperature and solar radiation in favorable levels for high productivity and quality of both cherry tomato cultivar during the two seasons evaluated.

ASSUNTO(S)

cultivo protegido radiação solar tomate yield solar radiation tomato crop produção vegetal temperature quality temperatura

ACESSO AO ARTIGO

Documentos Relacionados