Aspectos fisiológicos e rentabilidade de mamoeiro UENF/Caliman 01 sob diferentes lâminas de irrigação.

Abstract

Irrígation is a practice much used in fruit crop in the brazilian Northeast, including the papaya crop in order to increase their productivity. Wishing to know the productive potential of hybrid papaya under irrígation, an experiment was conducted to evaluate their physiological changes and yield under different irrígation leveis, seeking subsidies for irrigated agriculture in sertão paraibano. The work was done in the Campus IV, at the Center of Human and Agricultural Sciences, State University of Paraíba, located in Catolé do Rocha - PB. Were tested four irrigation leveis (50, 75, 100 and 125 % of ETo) and the reference evapotranspiration calculated by Penman-Monteith model. Was used the papaya (Carica papaya L.) UENF/Caliman 01, planted in single rows, in the spacing 4.0 m x 2.0 m, irrigated by drip. The experimental design used was randomized blocks with six repetitions and three plants per plot. The variables studied were: stomatal conductance (gs), CO2 assimilation rate (A), transpiration (E), instantaneous water use efficiency (EUA), internai C O2 concentration (Ci), instantaneous carboxylation efficiency (A/Ci), initial fluorescence (Fo), maximum fluorescence (Fm), variable fluorescence (Fv), quantum efficiency of photosystem II (Fv / Fm), fruit mass (MF), number of fruits (NF), yield and fruit profitability, transverse diameter (DT) and longitudinal diameter (DL), pulp thickness (EP) (cm), externai appearance (AE) and internai appearance (AI), soluble solids (SS), titratable acidity (AT), pulp pH and SS/AT. The water leveis does not have significant effect on gas exchange of papaya UENF/Caliman 01. The quantum efficiency of PSII showed higher values with use of 100 % of ETo not being influenced among the times evaluated. Best qualitative índices of the fruits were obtained when the papaya was irrigated with 100 % of ETo. In the levei 4 (125 % ETo) obtained the maximum yield (66.59 mg ha"1) and according to the economic analysis carried out showed that the cultivation of papaya has a higher economic return with the application of this treatment. The hybrid UENF/Caliman 01 can be cultivated in the region of sertão paraibano with replacement rate between 100 and 125 % of ETo, without compromising on growth performance, physiological, qualitative and economic of the crop.