Noni is a crop of Asian origin that has piqued the interest of Brazilian farmers because of its properties in herbal folk medicine and its high commercial value. However, there is little information about the crop management in general, and particularly on the irrigation of the crop in Brazil. The objective of this study was to define what localized irrigation system (drip or micro sprinklers) and water depth that provide the best vegetative growth of noni plants. The experiment was conducted from May 2009 to March 2010 in the city of Trairi, Brazil. We used a split block experimental design, with two irrigation systems (drip and micro sprinklers) arranged in vertical lines. Within each line, five irrigation levels, corresponding to the application of fractions of the reference evapotranspiration (ETo) 40% 60% 80% 100% and 120%, were distributed in five blocks. For the micro sprinkler irrigation system, the corresponding slides were: 109.3 mm, 135.8 mm, 187.9 mm, 227.8 mm and 297.7 mm, respectively, and for the drip irrigation system, they were: 83.4 mm, 123.7 mm, 166.5 mm, 204.7 mm and 254.4 mm, respectively. The noni vegetative growth was influenced both by the irrigation systems and the depths of irrigation applied. The application of irrigation depths equivalent to 227.8 mm, which corresponds to 100% of ETo with the use of micro sprinklers, provided the largest gains in stem diameter, plant height and canopy diameter.
Morinda citrifolia L; Micro irrigation; Irrigation management
