A team led by Kanazawa University, Japan, discovered that applying the vitamin nicotinamide (NIM) to plants prevents development of fungal disease. Pre-treatment with NIM activates the plant immune response and increases amounts of antimicrobial compounds that suppress the growth of the fungus. The results could lead to novel approaches to tackling crop diseases, potentially replacing toxic fungicide sprays with new, safer ways to stimulate the plant's own defense systems.