# Eco-friendly alternatives to seed chemical coating: agro-industrial byproducts as seed treatments with long-term effects on growth and reproduction

## TL;DR

This study explores eco-friendly seed treatments using agro-industrial byproducts as alternatives to harmful chemical coatings, showing positive effects on plant growth and reproduction.

## Contribution

The study introduces agro-industrial byproducts as a sustainable and effective alternative to chemical seed treatments.

## Key findings

- AIBW-treated seeds showed enhanced root growth compared to non-soaked and chemical-treated seeds.
- AIBW treatments increased grain weight per spike by up to 34.3% compared to controls.
- Metabolic analysis revealed increased amino acid tryptophan in seeds from AIBW-treated plants.

## Abstract

Synthetic chemical seed treatments, while effective, often raise significant environmental and health concerns. These concerns stem from the use of hazardous chemicals such as fungicides and insecticides that, besides posing risks to workers, have broader environmental impacts. These hazardous chemicals can leach into the soil and water systems, disrupting ecosystems, harming beneficial organisms, and entering the food chain. Agro-industrial byproducts/wastes (AIBWs) represent an abundant, environmentally friendly resource with potential for seed treatments. We focused on AIBWs that are produced in enormous amounts and do not pose potential hazards since they are commonly used to feed animals as well as food additives for humans, including wheat bran (WB), wine pomace (WP), and brewer’s spent grain (BSG). We investigated the effects of imbibing wheat seeds in water-soluble extracts of AIBWs or coating seeds with a biopolymer supplemented with AIBW substances on wheat growth and reproduction. As controls, we used water-soaked (WS) and non-soaked (NS) seeds, as well as chemically Celest Top-coated seeds. Petri dish assays showed that seeds imbibed in AIBW extracts exhibited enhanced post-germination growth as compared to NS seeds. Thus, while 81% of NS seedlings produced up to 3 seminal roots (SRs), 84% of WB and 64% of Celest Top seedlings produced 4 and 5 SRs. Net-house experiments revealed that Celest Top and AIBW extracts had a positive effect on reproduction as compared to NS, displaying 17.4%, 14.5%, 30.3%, and 34.3% increases in grain weight per spike in Celest Top, WB, GP, and WP, respectively. Metabolic analysis of seeds derived from treated plants revealed variation in metabolite profiles with a notable increase in the amino acid tryptophan. We utilized the nature-sourced polysaccharide carboxymethylcellulose (CMC) to coat seeds with AIBW substances derived from GP, referred to as CMC-GP. The results indicated that CMC-GP and Celest Top enhanced root growth, displaying 2- and 1.5-fold increases in fresh and dry weight, respectively, as compared to NS and CMC-coated seeds. Thus, AIBWs appear to provide cost-effective, eco-friendly alternatives to the hazardous chemical seed coatings, whether applied via imbibition or coating, while aiding in waste valorization within the circular economy.

The online version contains supplementary material available at 10.1186/s40643-025-01000-5.