Wetting agent effects on plant growth
Peat based growing media that dry out usually fail to rewet correctly. Waxes, resins, organic acids, and other chemicals presented in organic media components, principally peat moss and bark, are inherently water repellent. Wetting agents aid in the uniform wetting and rewetting of media. The excessive use of wetting agents added into substrates during formulation or added as a drench may be harmful for plants; however, this depends on the wetting agent type and application rate, plant sensibility and plant growth stage. Very little attention has been paid to the adverse impacts of wetting agents on growth and development of plants. In this study, we evaluated the effect of three commercial wetting agents applied at seven different rates (0, 1, 2, 3, 5, 10, and 20 times the recommended application rate) on the growth parameters of multiple plant species grown in a 100% sphagnum peat-based substrate. Two of the species were grown from seed (Impatiens, Antirrhinum majus) and two other were propagated from rooted cuttings (Calibrachoa, New Guinea impatiens). Adverse impacts of wetting agents occurred at concentrations between 3-10 times the recommended dose, depending on wetting agent type, plant type and plant growth stages. Growers should be aware of the adverse effects of excessive use of wetting agents to prevent damage to their crops.
Reza Nemati , M. and Jeong, Ka Yeon 2017. Wetting agent effects on plant growth. Acta Hort. (ISHS) 1168:63-70
growing media, adverse impact, phytotoxicity