Postharvest quality and coloration of radish roots under organic fertilization in a semi-arid environment

ABSTRACT The postharvest quality and coloration of radish roots can be compromised by factors such as the type of cropping system and fertilization management. Therefore, the objective of this work was to estimate the postharvest quality indices and color parameters of radish roots in monocropping, as a function of different roostertree (Calotropis procera) biomass amounts, in two cropping seasons in a semi-arid environment. The experimental design used was randomized complete blocks with five treatments and five replications. The treatments consisted of different roostertree biomass amounts: 16, 29, 42, 55 and 68 t ha-1 on a dry basis, incorporated into the soil. In each block, two additional treatments were added, one without fertilization (control) and the other with mineral fertilizer, for comparison purposes with the maximum efficiency treatment. The radish cultivar planted was Crimson Gigante. The radish characteristics evaluated were: pH, soluble solids content (SS), titratable acidity (TA), SS/TA ratio, total soluble sugar content (TSS), vitamin C (CV) and anthocyanin (A) contents, and roots color parameters (L*, C* and h°). The maximum flavor efficiency (SS/TA) and the total soluble sugar content (TSS) were achieved with the incorporation into the soil of 47.24 and 25.27 t ha-1 roostertree biomass, respectively. Higher concentrations of bioactive compounds (CV and A) were obtained when incorporating 35.79 and 45.85 t ha-1 green manure biomass. The color parameters values (L*, C* and h°) in the red radish roots were achieved in the biomass amounts of 40.39, 53.14 and 52.71 t ha-1 of roostertree.