Defoliation levels on gas exchange and composition of grape clusters cv. Italia.

• Autor(a) principal: SOUZA, E. R.
• Data de Publicação: 2014
• Outros Autores: RIBEIRO, V. G., DANTAS, B. F., LIMA FILHO, J. M., ONO, E. O.
• 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/991544
• topic: Ttaxa de assimilação; Crescimento baga; Uva; Vitis Vinifera; Grapes

The objective of this study was to evaluate the influence of defoliation on gas exchange of vine leaves at different phenological stages, and also in the development of clusters and berries of cv. Italia in the Valley of Submédio San Francisco. It was performed four levels of defoliation (5, 10, 15 and 20 leaves kept in production branch) and nine repetitions. The assessments of gas exchange (CO2 assimilation rate (A, ?mol CO2 m-2 s-1), transpiration rate (E, mmol water steam m-2 s-1), stomatal conductance (gs, mol m-2 s -1), water use efficiency (USA ?molCO2; mmol H2O)-1, carboxylation activity of the ribulose enzyme 1,5-diphosphate carboxylase (Rubisco) and leaf temperature were determined in four phenological phases (60, 72, 84 and 106 days after pruning). It was also evaluated: yield per plant (kg plant-1), diameter (mm), length (mm) and volume (mL) average of berries; soluble solids content (°Brix) and titratable acidity. Results revealed no significant differences between the levels of defoliation in the traits studied during the development stages of the berries, indicating that removal of leaves did not affect the gas exchange process of the leaves opposed to the cluster.