Transpiration in mango using Granier method.
Vellame L. M., Coelho Filho M. A., Paz V. P. S.
Author Affiliation: ESALQ/USP, Av. Pádua Dias, 11, C.P. 9, CEP 13418-900, Piracicaba, SP, Brazil.
Revista Brasileira de Engenharia Agrícola e Ambiental 13 : 516-523
Abstract : A study was conducted to evaluate Granier's method (heat dissipation probe) for mango crop and to determine the viability of its use under field conditions and to adjust the equation of sap flow (SF) on the basis of lysimeter measurements. The work started with three seedlings of mango cv. Tommy Atkins cultivated in recipients that were placed on a weighing platforms which functioned as lysimeters. The sapwood area (SA) was determined through pigment application. Transpiration measurement by lysimeter were conducted in recipients and sap flow estimates with heat dissipation probe (HDP). This probe and a stem heat balance sensor were installed in one branch of the adult plant. Using original coefficients of Granier's equation, the method underestimated sap flow by 31% daily in relation to the transpiration. Modifying empirical parameters of equation SF=0.00017k1.231SA, the mean error was of -1.4% with good precision (R2=0.89). HDP and stem heat balance method showed good agreement.