Autoria: RIGHI, C. A.; LUNZ, A. M. P.; BERNARDES, M. S.; PEREIRA, C. R.; TERAMOTO, E. R.; FAVARIN, J. L.

Resumo: Water uptake and use by plants are essentially energy processes that can be largely modified by percentage of soil cover, plant type; foliage area and its distribution; phenological stage and several environmental factors. Coffee trees (Coffea arabica - cv. Obatã IAC 1669-20) in Agrforestry System (AFS) spaced 3.4x0.9m apart, were planted inside and along rows of 12- year-old rubber trees (Hevea spp.) in Piracicaba-SP, Brazil (22 42'30" S, 47 38'00" W - altitude: 546m). Sap flow of one-year-old coffee plants exposed to 35; 45; 80; 95 and 100% of total solar radiation was estimated by the heat balance technique (Dynamax Inc.). Coffee plants under shade showed greater water loss per unit of incident irradiance. On the other hand, plants in monocrop (full sun) had the least water loss per unit of incident irradiance. For the evaluated positions average water use was (gH2O.m-2Leaf area.MJ-1): 64.71; 67.75; 25.89; 33.54; 27.11 in Dec./2002 and 97.14; 72.50; 40.70; 32.78; 26.13 in Feb./2003. This fact may be attributed to the higher stomata sensitivity of the coffee plants under more illuminated conditions, thus plants under full sun presented the highest water use efficiency. Express transpiration by leaf mass can be a means to access plant adaptation to the various environments, which is inaccessible when the approach is made by leaf area.

Ano de publicação: 2008

Tipo de publicação: Artigo de periódico

Unidade: Embrapa Acre

Palavras-chave: Absorción de agua, Absorção de água, Agroforestería, Agroforestry, Agrossilvicultura, Café, Coffea, Coffea arabica cv Obatã, Coffee, Cultivo intercalado, Cultivo intercalar, Eficiência, Hevea Brasiliensis, Hevea sp, Intercropping, Luz, Radiación solar, Radiação solar, Rubber tree, Seringueira, Sistema Agroflorestal (SAF), Solar radiation, Transpiración, Transpiration, Transpiração, Transpiração vegetal, Uso da água, Water uptake, Árbol del caucho