A novel seed coating formulation for the management of seed-borne diseases

Almost 90% of the world's food crops are grown from seeds. Seed quality is affected by abiotic and biotic factors. Abiotic factors include environmental conditions, while biotic factors arise from bacteria, fungi, viruses, insects, and nematodes. Seed-borne microorganisms cause serious yield losses (approx. 27-42%) and affect large agricultural areas by transmitting them to seasons/regions via contaminated seeds. Therefore, several physical, biological, and chemical seed treatment methods have been developed and used to control seed-borne diseases up to now. Indeed, seed treatment can become the most effective way to eliminate or reduce seed-borne pathogens. However, none of the existing methods has effectively controlled seed-borne endophytic and epiphytic pathogens. This study aims to develop a new seed-coating formulation that eliminates all types of plant pathogens (bacterial and fungal pathogens) from seeds without harming germination. In this study, piroctone olamine (PO) based on a novel chemical formulation developed and used for coating wheat, tomato, and corn seeds. Different doses including 0.4, 0.1, 0.08, 0.05, 0.03, and 0.01% of PO-based formulation were tested against CMM, PSS, PST bacteria and two fungal pathogens like Aspergillus niger and Penicillium sp. in vitro conditions. According to antimicrobial activity test results, seed coating formulations containing different concentrations of PO, except 0.01%, were effective against all microorganisms tested. It was also observed that all endophytic and epiphytic bacteria and fungi species were eliminated on/in seeds treated with PO seed coating formulations. It was observed that the application PO seed coating formulations at rates of 0.4% and 0.1% was almost 100% effective in pathogen control. On the other hand, it was determined that 0.1% PO formulation did not have any negative effects on root and shoot development of treated seeds. This is the first study to show that 0.1% PO-based seed coating formulation may have great potential to eradicate seed-borne pathogens of different crops in agriculture. Therefore, further study is required to evaluate the effect of PO based formulations against viral pathogens in different crop seeds/seeds in vitro and on yield and quality parameters.