DC current treatment dramatically shifts leaf harvest toward marketable quality in leafy vegetables.
Applying DC current to soil via plate electrodes increases total leaf biomass and simultaneously reduces non-marketable leaves by up to 77%, concentrating yield into the sellable fraction. The effect is accompanied by elevated mineral density (Ca, Zn, Mg) and improved dry matter — a compound quality and quantity benefit for vegetable crops.
In a greenhouse trial applying 8V or 16V DC via stainless steel plate electrodes for 10 hours per day over 12 days, Solanum scabrum (African nightshade) showed a striking improvement not just in total yield but in harvest quality composition. Marketable leaf count increased +55.3% at 8V and +29.1% at 16V, while non-marketable leaves collapsed by -77.2% and -64.9% respectively. Leaf fresh weight rose +11.5% to +14.4%, and leaf dry weight rose +24.2% at 16V — indicating more biomass with higher dry-matter concentration per gram.
Mineral enrichment accompanied the yield gains: leaf calcium +27.5% at 16V, stem zinc +244.4% at 16V, and stem magnesium +15.6% at 16V. These mineral shifts reflect electroosmotic ion migration driven by the applied current — the electric field actively pulls cations through soil and root tissue into the plant. The result is a crop that is simultaneously heavier, more marketable, and more nutritionally dense.
For subsistence and smallholder contexts where African nightshade is a critical micronutrient source, this combination — more sellable leaves with higher Ca and Zn — represents a meaningful improvement in both farm economics and food security outcomes.
Source: Gogo et al., Journal of Applied Botany and Food Quality 89 (2016), pp. 60–67. DOI: 10.5073/JABFQ.2016.089.007