Root system distribution and vegetative characteristics of Prata type bananas under different irrigation strategies

This study aimed to analyze the root system distribution and vegetative characteristics (pseudo-stem perimeter, plant height, number of leaves and the leaf area) in ‘Dwarf-Prata’ and ‘BRS-Platina’ in their third production cycles under different five irrigation strategies. The vegetative characteristics were measured at the flowering stage and the root sampling was done after the harvesting in the third production cycle. The irrigation depths (ID) were obtained by the model ID= K × AF × ETo, where K is an empirical transpiration coefficient, AF is the leaf area of Dwarf-Prata’ plants and ETo is the reference evapotranspiration. Irrigation strategy 5 was based on the crop evapotranspiration, ETc = ETo × Kc, where Kc is the crop coefficient. Drip irrigation was used, with two laterals per plant row and emitters with flow rate of 8 L h-1, which were spaced out at 0.5 m, totaling 10 emitters per plant. The irrigation strategies based on crop evapotranspiration and on the model ID = K × AF × ETo, with K ranging from 0.2 to 0.65, exhibited similar values for vegetative characteristics, as well as for the root length density (RLD) in Prata type banana; however, higher RLD is found in deeper layers when using a lower K coefficient. The ‘Dwarf-Prata’ displays taller plants, longer pseudo-stem perimeter, higher number of leaves and larger leaf area than the ‘BRS-Platina’, although both exhibit similar root distribution.   Key words: Musa species, root, irrigation management, water deficit, semiarid, leaf area.