Bulb decay can be caused by many common fungi including Botrytis cinera, Penicillium species, Aspergillus species, as well as species of Fusarium. These fungi are common in the environment and infect bulbs through injuries caused by insects or improper handling. Only intact, undamaged bulbs should be stored or planted. Discard any bulbs with signs of fungal infestation. Store bulbs in a dry, cool area in onion bags or loose layers of peat or hay. Bulbs can be treated with hot water to eliminate pathogens or dusted with an appropriate fungicide (thiophante methyl, iprodione, captan) before planting.