Evapotranspiration and crop coefficient of Heliconia psittacorum L x H. spathocircinada (Arist) under greenhouse conditions.

Abstract

A study was conducted in greenhouse conditions located in an experimental station, in the State of Ceará coast and had as objective the estimation of evapotranspiration and crop coefficient for Heliconia psittacorum L x H. spathocircinada (Arist), cultivar Alan carle. The evapotranspiration (ETc) was estimated using soil water balance method. A class A pan evaporation was used to estimate the reference evapotranspiration (ETo). It has been used a class A pan evaporation installed inside the greenhouse and another one outside, from an agrometeorological station located 500 m from the experimental area. Using the ETc and ETo data, the crop coefficient (Kc) was determined for each crop development stage. The crop evapotranspiration average was 2.2 mm.day-1. The crop coefficients (Kcs) from reference evapotranspiration estimated by the class A pan evaporation in the greenhouse were higher than those from the estimated ETo using the class A pan evaporation located at the agrometeorological station. Thus, the average values of crop coefficient for initial, crop development and flowering stages were 0.41, 0.78 and 1.26 respectively, when using inside pan evaporation and 0.29, 0.60 and 0.92, when using outside pan evaporation data.