Irrigação no cultivo orgânico de alface utilizando Irrigás, tanque Classe A e um sistema automático de baixo custo

Abstract

The objective of the present research was to compare an low cost controller with two other techniques of irrigation management, Irrigas system and Class A pan, in the cultive of lettuce (Lactuca sativa L.),concerning operability of systems, equipment costs, applied depths and crop yield data. The cultivation was developed in a randomized complete blocks design with four treatments randomized in six replicates. The treatments were characterized by the system Irrigás, Class A pan (TCA) and the use of automatic irrigation of low cost device (AAI) in two different soil water tensions (9.0kPa and 12.0kPa). Data of irrigation depth, water use efficiency and production variables leaf area, fresh and dry weight of shoots, diameter and height of the head were evaluated. There wasn’t significant difference between treatments for any of the production variables evaluated (P>0.05) and total irrigation depths were related to different management practices and close to the evapotranspiration estimated reference (ETo) accumulated in the period. The water use efficiency in treatments TCA, AAI/9kPa, Irrigás, AAI/12kPa were, respectively, 241.4, 217.9, 205.5 and 267.1kg ha-1 mm-1, while the productivities were, respectively, 32.80, 28.86, 28.80 and 35.45Mg ha-1. The results obtained are close to values reported in the literature, allowing to conclude that the evaluated methodologies were efficient for growing lettuce and thus the method chosen would depend on the availability of skilled manpower and also of the level of farmer training.