Crown rot of banana

Crown rot of banana

    Causal organism: Botryodiplodia theobromae, Colletotrichum musae, Botryodiplodia theobromae, Fusarium roseum, Verticillium theobromae and Acromonium sp.
    Symptoms
    • The disease is implicated in the more severe form in the main stalk rot in which splitting of stem occurs.
    • The disease is a problem when shipment is done in boxes only and not in bunches. Most of the deheaded bunches are susceptible as they are cut from main stalk and dipped in water for removal of latex. Softening and blackening of crown tissue during ripening of fruits are the first symptoms.
    • The fungus also extends through cushions and causes finger stalk rot and finger dropping.
    • It is some times associated with fruit spots and blemishes and in most varieties causes extensive finger tip rot.
    • The infection originates in or immediately below the decayed perianth or styles and spreads uniformly along the fruit and cause a progressive brownish black discoloration and softening of the pulp.
    • The skin becomes soft, black, wrinkled and encrusted with pycnidia. Infection may lead premature ripening of the fruits.

    Etiology

    • Asexual fruiting body is Pycnidia and up to 5mm in diameter.
    • Conidia are asexual spores, thin walled at first which become thick walled, mycelia.

    Mode of spread and survival:

    • Primary source of inoculum: Dormant mycelia
    • Secondary source of inoculum: Soil and airborne conidia.

    Epidemiology

    • Temperature at 250 - 300 C, high relative humidity and wounds are the predisposing factors.

    Management

    • Avoid and injury to the fruits, use of resistant varieties, storage of fruits at 100 C, dipping of fruits in 100 -400 ppm benomyl solution are some of the controlling method.

Last modified: Wednesday, 18 January 2012, 9:26 AM