Fruit quality of west indian cherry irrigated with saline waters under combinations of nitrogen/potassium fertilization

Abstract

West Indian cherry stands out among the fruits cultivated for the pharmacological and alimentary importance, but its quality can be affected by irrigation water salinity and fertilization management. In this context, this research aimed to study the effect of irrigation water of different salinities and combinations of nitrogen and potassium fertilization on the physical and physico-chemical quality of bioactive compounds in West Indian cherry fruits. The experiment was carried out in the field, using lysimeters of 60 L, in the Experimental Area of the Centro de Ciências e Tecnologia Agroalimentar (CCTA) of Universidade Federal de Campina Grande (UFCG), Pombal, PB, in a randomized block design, with treatments arranged in a 5 x 4 factorial scheme, referring to five irrigation water salinities (ECw): 0.3, 1.3, 2.3, 3.3 and 4.3 dS m^-1 and four combinations (C) of doses of nitrogen (N) and potassium (K₂O): C1 = 70% N + 50% K₂O; C2 = 100% N + 75% K₂O; C3 = 130% N + 100% K₂O and C4 = 160% N + 125% K₂O, of the recommended dose for West Indian cherry, with three replicates and one plant per plot consisting of a lysimeter. The cv. Flor Branca grafted on cv. Junco was used in the study. The increase in salinity of irrigation water reduced the size, weight and vitamin C content of the fruits, but, the combinations of N and K fertilization did not affect fruit shape and the content of anthocyanin, carotenoids, pH, titratable acidity, total soluble solids and fruit flavor. Fertilization combinations consisting of C1 and C2 treatments promoted the largest fruit size under irrigation with ECw of up to 1.3 dS m^-1 and greater mass accumulation. Fertilization doses above C2 combinations negatively affected fruit quality.