Evapotranspiration and crop coefficient of Alpinia purpurata

Abstract

The lack of information about Alpinia purpurata water needs is a limiting factor for the crop implementation and productivity increase, especially in arid and semi-arid regions. This work had as objective to estimate the evapotranspiration and crop coeffi cient of Alpinia purpurata, grown in a screen greenhouse condition at the coast region of Ceará State, Brazil. The crop was grown at Embrapa Agroindústria Tropical experimental station, Paraipaba, Ceará. The water balance method was used in a controlled soil depth of 0,60 m. The Alpinia purpurata red cultivar was planted in a 0,90 m x 2,00 m spacing. Both organic and mineral fertilizations were done each three months. The field was microsprinkler irrigated. The accumulated evapotranspiration during the period was 291,0 mm, which represented an average of 2,4 mm d^-1. The observed crop coefficient (Kc) variations were due to climate conditions and crop development stages. The Kc average values, from ETo estimated from a class A pan evaporation installed inside the greenhouse, were 0.72; 1.07 e 0.77 for initial, crop development and blossom stages respectively.