Is it possible to enhance the concentrations of valuable compounds by reduced nitrogen supply in several vegetable species?
Among all mineral elements, nitrogen (N) is most important in plant nutrition. Reducing the N application below recommended levels reduces leaching into the groundwater and may thus be beneficial for the environment. It is known that N starvation can lead to increased concentrations of secondary metabolites. However, little attention has been paid to the effects of N limitation on the content of carotenoids and anthocyanins. Two vegetable species rich in carotenoids (spinach, tomato) and two vegetable species rich in anthocyanins (red cabbage, purple carrot) were chosen for this study. The N supply applied to these vegetable species was according either to recommendations or reduced by 50%. The effects on yield and quality of the harvested products were investigated. Neither yield nor secondary metabolites of tomato were affected by reduced N supply. In spinach, the marketable yield was higher in the control treatment compared with reduced N supply but there were no effects on carotenoid concentration. The yield and the anthocyanin concentration of red cabbage were not affected by reduced N application. Similarly, in two purple carrot cultivars, yield reductions were not observed with 50% N, and effects on the anthocyanin content were variable. The results confirm that N supply could be reduced for several vegetable crops without negative effects on yield or the concentrations of valuable secondary compounds.
Schmidt, L. and Zinkernagel, J. (2015). Is it possible to enhance the concentrations of valuable compounds by reduced nitrogen supply in several vegetable species?. Acta Hortic. 1106, 55-60
purple carrot, red cabbage, spinach, tomato, anthocyanin, carotenoids