Different rootstocks, irrigation, and nutritional management on the quality parameters of Montenegrina mandarins (Citrus deliciosa Tenore) cultivated in Vale do Caí region, South Brazil

The objective of this work was to evaluate the qualitative parameters of Montenegrina mandarin fruits under different water and nutritional management, combined with two rootstocks, in the Vale do Caí region.The experiment was conducted in the city of São Sebastião do Caí, South Brazil, at UCS Campus.The experiment was bifactorial with two varieties of rootstocks (Poncirus trifoliata L. and Swingle citrumelo) and three cultivation systems (conventional, irrigated, and fertigated), completely randomized, with three replicates for each treatment.Fifty fruits were evaluated for average fruit mass (AFM), longitudinal and transverse diameters (Ø); 10 fruits for juice content (Jc), soluble solids content (SS), total titratable acidity (TA), ratio, and ascorbic acid content.The variables transversal Ø, AFM, Jc, SS, and ratio were not significantly influenced by the adopted treatments.Irrigated plants presented higher TA when compared to conventionally managed and fertigated plants.Swingle citrumelo presented greater longitudinal fruit Ø compared to P. trifoliata.Montenegrina fruits grafted to P. trifoliata presented a higher concentration of ascorbic acid compared to Swingle citrumelo fruits.For the conditions of Vale do Caí, with the climatic conditions of the years 2018/2019, would not be necessary to make use of irrigation and fertigation technologies to increase fruit quality.