Disease-reducing Effect of Calcium Salts Against Postharvest Diseases of Mango (Mangifera indica L. cv. Carabao) Fruits

Abstract

Mango fruits (Mangifera indica L. cv. Carabao) are susceptible to fungal infection, resulting in postharvest diseases. Chemical pesticides are used for disease management but may have a health impact and are costly. Therefore, alternatives to chemical control are necessary to minimize health risks and losses due to postharvest diseases. This research presented the disease-reducing effect of calcium salts, calcium chloride (CaCl2) and calcium carbonate (CaCO3), against mango stem end rot (SER) (sometimes caused by Lasiodiplodia theobromae) and anthracnose (caused by Colletotrichum gloeosporioides sensu lato). In in vitro assays, mycelial growth of both pathogens was significantly reduced with increasing CaCl2 and CaCO3 concentrations. Spore germination of L. theobromae was significantly decreased by calcium salts. In contrast to CaCO3, higher CaCl2 concentrations stimulated spore germination of C. gloeosporioides. SER infection was higher than anthracnose during the dry season while anthracnose was higher during the wet season. Calcium salts reduced SER infection 7 d after treatment (DAT) in both dry and wet seasons. However, they were ineffective against the disease at 10 DAT when mango fruits were produced during the wet season. Treatments with 1 and 5 % CaCl2 and 1, 3, and 5 % CaCO3 provided a similar degree of control as the hot water treatment (HWT; 10 min dip at 55°C). HWT also delayed symptom development. The treatments did not affect fruit ripening and slightly prolonged saleable life. Further studies must be done on the benefits of calcium salts as postharvest disease management for mango.