Allelopathic influence of Eucalyptus leaves on growth and development of Corn (Zea mays), Peanut (Arachis hypogea), and Morning glory (Ipomoea spp.) in Brazil

We studied the effects of Eucalyptus leaves on the germination, growth and development of indigenous morning glory (Ipomeoa ssp.), corn (Zea Mays L.) and peanut (Arachis hypogea L.) in Lab. Bioassays and pot culture. Seeds were sown in pots soil mixed with Eucalyptus leaf material (Was the leaf material collected from Brazil or USA?) at 1 and 10 % (w/w) to assess effects on germination and seedlings weight. The pots were irrigated to fully moisten the paper with 1% and 10% leaf aqueous extracts to evaluate their effects on germination and seedlings growth. The allelochemicals in Eucalyptus leaves inhibited both the germination and growth of test crops, with indigenous plants showing the strongest inhibition. Phenols were detected in leaf extracts using the ferric chloride test and Folin-Ciocalteu method. Higher concentrations of Eucalyptus leaf extracts had higher amounts of phenols, which significantly reduced the seeds germination and growth. These findings suggested that Eucalyptus allelopathy hindered the crop establishment, posing ecological and economic challenges for Brazilian farmers.