Deposition of Polymeric Layers on Seeds using Plasma Technology and their Effects on Germination Processes

Abstract

One of the consequences of climate change is an increase of micro-organisms in contact with seeds. As resistance to pesticides increases, this could lead to serious public health issues. In recent years, the use of chitosan in agriculture has increased because it has antibacterial effects and is environmentally friendly. Because chitosan has weak hydrophilic behaviour, a modification of its surface properties is necessary to make it usable. To obtain these modifications, the application of atmospheric plasma can be useful as it allows the introduction of new hydrophilic groups into the outer layer of a seed without altering its overall structure. For this reason, this study investigated the effect of chitosan deposition on melon seeds subjected to atmospheric dielectric barrier discharge plasma activation. Surface analysis of the treated melon seed revealed that the order of plasma application and chitosan concentration influenced the homogeneity of chitosan deposition. Water absorption and germination studies of the treated seeds showed a modulation in the time and amount of germination under normal irrigation conditions (3 ml) due to the low capacity of these seeds to absorb water. However, the delay in germination is favourable at high irrigation conditions (10 ml). Treatments that slightly worsen the hydrophilicity of melon seeds favour their germination under conditions of abundant irrigation, thus simulating an environment of continuous precipitations