Coffee water use in agroforestry system with rubber trees.

• Autor(a) principal: RIGHI, C. A.
• Data de Publicação: 2008
• Outros Autores: LUNZ, A. M. P., BERNARDES, M. S., PEREIRA, C. R., TERAMOTO, E. R., FAVARIN, J. L.
• 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/511362
• topic: Sistema Agroflorestal (SAF); Coffee; Rubber tree; Árbol del caucho; Cultivo intercalar; Coffea arabica cv Obatã; Hevea sp; Absorción de agua; Agroforestería; Radiación solar; Transpiración; Agrossilvicultura; Cultivo intercalado; Café; Seringueira; Radiação solar; Transpiração vegetal; Absorção de água; Hevea Brasiliensis; Agroforestry; Intercropping; Coffea; Solar radiation; Transpiration; Water uptake

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.