Electric stimulation promotes growth, mineral uptake, and antioxidant accumulation in kale (Brassica oleracea var. acephala).

Several studies have demonstrated that electric treatment has a positive effect, respectively, on germination, root growth and post-harvest quality. Nevertheless, there is still a lack of research on the effect of electric treatment on growth characteristics and quality of whole plants. Here, we explored the effect of electric fields on two cultivars of kale (Brassica oleracea var. acephala). Three levels of electric current (10, 50, and 100 mA) were applied to the nutrient solution of hydroponically grown plants for three weeks. Kale plants subjected to the electric fields, particularly 50 mA, had higher fresh and dry weights than the control. The absence of an electric field in a Faraday cage caused a significant decrease in shoot and root growth compared with the natural electric field (control). Electrostimulation enhanced nutrient uptake by activating root hair formation and active ion transport. Plants grown under 50 mA contained 72% more calcium, 57% more total phenolic compounds, and had a 70% greater antioxidant capacity than the control. This work provides foundational information regarding the effects of electrical stimulus on plants, which could enable the development of innovative culture technologies to improve crop yields and quality.