Extracellular Fragmented Self-DNA Displays Biostimulation of Lettuce in Soilless Culture

Research is advancing regarding techniques that are based on natural products developed using the plants. Extracellular DNA (eDNA) is a potential alternative that can be used as active material in agronomy. The objective of this study was to evaluate the use of self-eDNA using fertigation in lettuce plants as a biostimulant. Five fertigation treatments were used: 0 (control), 0.025, 0.25, 2.5 and 25 mg self-eDNA per plant. Fertigation was monitored through drainage fraction, pH and EC. The benefits of fertigation were evaluated using water, nitrate and potassium uptake, and growth. There was a significant correlation between fertigation uptake and growth. The highest correlation (R2 = 0.96) occurred between water uptake and growth. There was a quadratic fit between uptake and production parameters and the dose of self-eDNA applied. Mean drainage values showed no significant differences between treatments for EC and pH. The highest values of fertigation uptake (water, nitrate and potassium) and growth were observed at doses of 0.25 and 2.5 mg self-eDNA. Doses lower than 0.25 decreased by 21.3%, while doses higher than 2.5 decreased by 16.4%. Self-eDNA had beneficial effects as a biostimulant and potentially had an appropriate cost–benefit ratio.