Black mold occurs in both colored and white onions in the field, during transit, and at storage. The causal fungus attacks many fruits and vegetables through wounds or during ripening.
Symptoms and Damage
Among the symptoms of black mold are black discolorations on the bulb and shallow lesions on the outer scales. Streaks of black mycelia and spores develop beneath the outer dry scales. In the advanced stage of the disease, the entire surface of the bulb turns black.
Cause
Aspergillus niger Tiegh.
Management Practices
Cure the onion bulbs quickly and provide good ventilation. Store in a cool place and not in boxes or bags.
Harvest the bulbs at maturity. Cure the onions quickly.
Storage condition should be cool and dry, with good ventilation.
Do not store bulbs in boxes or bags. Store the bulbs at 1-10oC.
Avoid bruising of bulbs during harvest, storage, and transit.
Source
PhilRice, 2007. Integrated Pest Management in Rice-Vegetable Cropping Systems. Maligaya, Science City of Muñoz, Nueva Ecija.
