The syndrome of bud necrosis, a storage disease of tulips, is analysed and relationships between several phenomena are described: 1. In ‘White Sail’, bud necrosis occurred in cardboard boxes only when bulbs infected withFusarium oxysporum f. tulipae were present. 2. Buds with symptoms of bud necrosis were open at the tip. 3. Whereas in ‘White Sail’, open buds occurred in boxes only whenFusarium-infected bulbs were present, in ‘Red Champion’, open buds occurred also in well-ventilated open trays with wire-gauze bottoms stored at higher temperatures but withoutFusarium-infected bulbs. In ‘Rose Copland’, open buds were only found exceptionally. 4. In buds with symptoms of bud necrosis, mites were almost always present. 5. In boxes in whichFusarium-infected bulbs were present, ethylene concentrations up to 23 ppm were found.