Submitted to: Proceedings of Horticultural Industry Show
Publication Type: Proceedings/Symposium
Publication Acceptance Date: February 8, 2007
Publication Date: May 1, 2007
Citation: Webber III, C.L., Sandtner, S.J., Webber, C.L. 2007. Hydrogen peroxide as a soil amendment for greenhouse nasturtium production (Tropaeolum majus L.). Proceedings of Horticultural Industry Show. 26:140-144.
Interpretive Summary: Hydrogen peroxide, H2O2, occurs naturally in animals and plants, and can help protect plants from diseases or signal the plant concerning stress. In addition to its use as a disinfectant for humans and in water purification, hydrogen peroxide is approved for the control of plant diseases. Hydrogen peroxide is used to control diseases on plant leaves, roots, and cuttings. The soil can also be treated with hydrogen peroxide before a plant is started in the soil. There are also common reports that hydrogen peroxide provides additional growth benefits beyond its ability to control diseases and help the plant deal with stress. The objective of this research was to determine the effect of soil applications of hydrogen peroxide solutions on plant growth and flowering. Container grown nasturtium seedlings cv. Scarlet Glean Improved were irrigated with either distilled water, tap water, or hydrogen peroxide solutions. The hydrogen peroxide treatments included adding 1.3, 13, or 26 teaspoons of hydrogen peroxide to a gallon of distilled water. Distilled water was used to be sure there wasn"t something else in the water that was helping or hurting the plants. Hydrogen peroxide applications did affect the nasturtium leaves, stems, roots, and flowers. Nasturtium leaves and stems, and the total plant (leaves, stems and roots) dry weight were greater when using 1.3 teaspoons/gallon than the 13 teaspoon/gallon. Twenty-six teaspoons/gallon resulted in more root growth than using 1.3 teaspoons/gallon. Flowering was also better when using 1.3 teaspoons/gallon than either 13 or 26 teaspoons/gallon. The results indicate that watering with 1.3 teaspoons of hydrogen peroxide/gallon of distilled water did provide growth and flowering benefits to nasturtiums grown in containers, although the results were not as great as the non-scientific reports would suggest. The difference between our results and what many people generally report may be the benefit of hydrogen peroxide decreasing or eliminating diseases in the soil containers rather than it directly helping the plant grow better.
Technical Abstract: Hydrogen peroxide, H2O2, is a highly reactive oxidizing agent naturally occurring in plants and animals. Plants produce hydrogen peroxide to destroy either infected plant cells or the pathogens within a plant. Hydrogen peroxide also acts as a stress signal to plants. It is approved for the control of microbial pests, fungi and bacterial that cause plant diseases and it is applied as a foliar spray, as a dip for cuttings and roots, and as a pre-planting soil treatment to prevent or control plant pathogens. There are also anecdotal reports that hydrogen peroxide provides additional growth benefits beyond its actions related to plant infection or plant stress. The objective of this research was to determine the effect of soil applications of hydrogen peroxide solutions on plant growth and flowering. Container grown nasturtium cv. Scarlet Glean Improved seedlings were irrigated with either distilled water, tap water, or hydrogen peroxide solutions. The hydrogen peroxide treatments included 0.005% H2O2 (1X), 0.05% H2O2 (10X), and 0.1% H2O2 (20X), which are equivalent to 1.3, 13, and 26 tsp/gallon of 3% hydrogen peroxide. The foliage and root fresh and dry weights harvested at 22 days after initiating treatment (DAIT) and the fresh weights at 33 DIAT were not significantly different as a result of the hydrogen peroxide concentrations. Hydrogen peroxide concentrations significantly impacted the foliage, root, and total dry weights at 33 DAIT. The 1X concentration of hydrogen peroxide produced significantly greater amounts of nasturtium foliage and total plant dry weights at 33 DAIT compared to the 10X concentration, but it was not significantly different from the distilled and tap water applications. The 20X root dry weights were significantly greater than all other treatments except the 1X hydrogen concentration. The 1X concentration produced significantly greater total number of flowers than either the 10X or 20X concentrations and 64 and 57% greater numbers of flowers than the distilled and tap water treatments. The results indicate that watering nasturtiums at the tested hydrogen peroxide applications rates did provide slight growth and flowering benefits to nasturtiums grown in containers, although the results were not as great as anecdotal reports would suggest. The most likely explanation for the anecdotal reports of dramatic growth stimulus of hydrogen peroxide watering solutions may be a result of hydrogen peroxide decreasing or eliminating diseases in the soil containers rather than it serving as a direct stimulus to the plant.