Quality in the pepper under different fertigation managements and levels of nitrogen and potassium1 Qualidade do pimentão sob manejos de fertirrigação e diferentes níveis de nitrogênio e potássio

The rational use of nutrients is of fundamental importance for obtaining high productivity of high nutritional quality. This work was developed with the aim of evaluating the quality of pepper fruit grown under different fertigation managements and different levels of nitrogen and potassium. The experimental design was of randomised blocks in a 3 x 6 factorial scheme with four replications. The treatments resulted from the combination of three fertigation managements (M1-based on the rate of absorption; M2-monitoring the conductivity of the soil solution; M3-monitoring concentrations of N and K ions in the soil solution) with six levels of N and K (N0K0, N50K50, N100K100, N150K150, N200K200 and N300K300) as a percentage of the recommended dosage for the crop under conventional fertigation (M1) or hydroponics (M2 and M3). Fruit quality was evaluated for the following characteristics: pH, soluble solids, titratable acidity, vitamin C content and the ratio of soluble solids to titratable acidity. The different fertigation managements only affected the levels of soluble solids (SS) and titratable acidity (TA), reducing the SS and TA. The variables under study were adjusted for the levels of N and K using quadratic models.