Researchers found that an extract from Cinchona bark, containing the compound quinine, effectively kills rice-damaging fungus Rhizoctonia solani through two mechanisms: starving the fungus of the amino acid tryptophan and disrupting its energy-producing mitochondria. This natural plant-based treatment could serve as an eco-friendly alternative to synthetic fungicides, reducing crop losses from fungal diseases while avoiding the environmental damage and resistance problems associated with chemical pesticides.