NIR spectroscopy: a tool for determination of maturity stage of sweet cherries and their quality after different irrigation doses

We aimed to develop a fast alternative for fruit analysis using near infrared spectroscopy and to determine the impact of irrigation regimes on the development and quality of sweet cherry cultivar 'Sweet Early'. Three treatments of irrigation were proposed depending on the water dose: ETc0 (not irrigated); ETc50 (restitution of 50% evapotranspiration) and ETc100 (full evapotranspiration restitution). Vegetative growth expressed by trunk cross-sectional area, yield, harvest maturity, fruit diameter, firmness, and soluble solids were monitored. The numerical values of these parameters were paired using the TQ Analyst software with the NIR spectra measured using spectrometer Antaris II. We also created calibration models. The most important indicators were the coefficient of determination and the ratio of prediction to deviation. Near infrared spectrometry enabled prediction of firmness and soluble solids. The determination coefficient of more than 0.9 was achieved. The regulated deficit irrigation ETc50 and ETc100 treatments delayed the time of fruit ripeness. Difference was found among the qualitative parameters of the fruits depending on the irrigation treatment.