Fruit quality of West Indian cherry under saline water irrigation and nitrogen-potassium fertilization¹

Qualidade de frutos de aceroleira irrigada com águas salinas e adubação com nitrogênio-potássio

HIGHLIGHTS:

The decrease in the size of West Indian cherry fruit reflects the diversion of energy to maintain metabolic activities.

The pH reduction is related to an increase in the total titratable acidity of West Indian cherry pulp.

Water salinity above 0.3 dS m^-1 inhibits the synthesis of bioactive compounds in West Indian cherry fruits.

ABSTRACT

The presence of waters with high salt concentration stands out as a limiting factor for the quality of agricultural production. Thus, this study aimed to evaluate the fruit quality of West Indian cherry cv. Flor Branca, subjected to irrigation with water of different salinity levels and combinations of nitrogen-potassium fertilization, between 630 and 750 days after transplanting in the field. A randomized block design was used in a 5 × 4 factorial arrangement, with three replicates, whose treatments consisted of five values of electrical conductivies of irrigation water - ECw (0.3, 1.3, 2.3, 3.3 and 4.3 dS m^-1) and four combinations of nitrogen and potassium fertilization (70-50, 100-75, 130-100 and 160-125% of recommendation of N and K₂O, respectively). Electrical conductivity of irrigation water above 0.3 dS m^-1 reduces the polar and equatorial diameters, hydrogen potential and flavonoid concentration and increases titratable acidity in West Indian cherry fruits. N-K₂O combination of 70/50% of fertilizer recommendation reduces the effect of salt stress of irrigation water on the anthocyanin concentration in the fruits at ECw of 1.3 dS m^-1 and ascorbic acid at ECw of 3.3 and 4.3 dS m^-1.

Key words:
Malpighia emarginata Sesse & Moc. ex DC.; salt stress; plant nutrition; post-harvest