Evaluate the physiological and sanitary quality of bean and maize seeds treated with Ocimum gratissimum extracts and eugenol-pure oil nanoemulsion

The study aimed to assess the fungicidal potential of ethanolic and dichloromethane extracts from Ocimum gratissimum leaves and eugenol-pure nanoemulsion in the preservation and viability of bean (Phaseolus vulgaris L.) and maize (Zea mays L.) seeds during storage. Seeds were soaked in 5mg/mL ethanolic extract solution, 5mg/mL dichloromethane extract solution, and 5% eugenol nanoemulsion, followed by storage in plastic containers at room temperature for 60 days. Fungi presence was noted in the seeds, prompting evaluation. Methyl thiophanate was used as a positive control and water as a negative control. Vigor analysis used filter paper as a substrate pre- and post-storage. Effects of extracts on seed germination, germination speed index, first germination number, emergence, emergence speed index, root length, and stem length were also analyzed. The fungal diversity analysis demonstrated the presence of Aspergillus, Penicillium, and Rhizopus fungi in all treatments. For beans, eugenol nanoemulsion (4.4%) showed greater pathogen reduction, while for maize, ethanolic (40.4%) and dichloromethane (43.0%) extracts were more effective. Post-storage, bean seeds treated with ethanolic extract displayed a 98.6% germination rate, while maize seeds had an 84.6% rate. However, both dichloromethane extract and eugenol nanoemulsion negatively impacted seed vigor in both crops. Results suggest that ethanolic extract from O. gratissimum leaves could be a viable alternative for protecting seeds from fungi during storage while maintaining germination ability.