What is the impact of salicylic acid (SA) on the total phenolic compounds and antioxidant activity in Swiss chard (Beta vulgaris L.) under different irrigation treatments?

Total phenolic compounds and antioxidant activity are important indicators of the nutritional quality of vegetables. Phenolic compounds have strong antioxidant properties and are linked to various health benefits. The study evaluated the effects of different irrigation treatments and foliar application of SA on these parameters in Swiss chard.

From: "Effects of foliar application of salicylic acid on physiological and qualitative parameters in differently colored Swiss chard (Beta vulgaris L. ssp. cicla) under an aquaponic system", Journal of Agriculture and Food Research, Volume 22, August 2025, 102140

The study found that the total phenolic content showed little variability and was not significantly influenced by the irrigation treatments. However, the application of SA had varying effects depending on the irrigation treatment. For instance, SA combined with the 50/100 treatment increased total phenolic content in white chard. Regarding antioxidant activity, no significant effects were observed from the applied treatments. Red chard exhibited higher antioxidant activity compared to white chard, likely due to its higher concentration of betalains. These findings suggest that SA can influence phenolic content and antioxidant activity, but the effects depend on the specific irrigation treatment and chard variety.