Effect of stabilised hydrogen peroxide on seed germination and seedling growth and its implication for managing drip irrigation

The use of hydrogen peroxide (H2O2) is recently recommended for use in drip irrigation particularly for cleaning of drip emitters. Relatively less known are the effects of H2O2 in irrigation water on seed germination, seedling growth and establishment. We evaluated two hydrogen peroxide products, with varying levels of stabiliser, over a range of peroxide concentrations (10-5000 ppm), in-vitro (petri dishes) seed germination and seedling growth for ten crop species. Germination of the tested seed species was not impacted negatively by H2O2 concentrations up to 5000 ppm. Positive effects on seed germination were found for mung bean, egg plants, okra, leek and rocket at H2O2 100 ppm. Root and shoot growth were impacted more negatively by H2O2 treatments particularly at higher concentrations and for the highly stabilised H2O2 product in all crops except for corn, which is likely due to persistence of peroxide in the germination media for longer duration with stabilised H2O2 product. We conclude that stabilised H2O2 products up to 1000 ppm do not negatively impact seed germination in general and improve seed germination in some species. Negative impacts on root and shoot growth were largely associated with higher concentrations (1000 and 50000 ppm) and for some species root and shoot growth were enhanced by stabilised H2O2 at lower concentrations. Therefore, continuous injection of H2O2 at lower concentrations in irrigation water for the field crop is unlikely to negatively impact the seed germination and seedling growth. © 2019 International Society for Horticultural Science. All rights reserved.