The disease is characterized by the development of a dry, gray to black rot at the tip of the fruits. The fungal growth actually starts at the flowering stage and compromises the ripening process of the fruits. The affected areas are covered by grayish fungal growth that looks like the ashes at the burnt end of a cigar, thereby the common name. In storage or during transport the disease may progress to involve the whole fruit, resulting in a "mummification" process. The fruits have a abnormal shape, mold is apparent on their surface and lesions are clearly visible on the skin.
Cigar end rot is a disease of banana caused mainly by the fungus Trachysphaera fructigena and sometimes another fungus (Verticillium theobromae). It is transported via wind or rain splashes to healthy tissues. The fungus attacks bananas in the flowering stage during the rainy season. It infects the banana through the flower. From there, it later spreads to the tip of the fruit and causes a dry rot that is similar to the ash of a cigar, thereby the common name. The infection is common in the early days after the emergence of the fruit and in warm moist conditions, especially in high altitude areas and in plantations in shade areas.
Sprays based on baking soda can be used to control the fungus. To make this spray, dissolve 100 g of baking soda with 50 g of soap in 2 liters of water. Spray this mixture on infected branches and on nearby branches to prevent infection. This increases the pH levels of the surface of the fingers and inhibits the growth of the fungus. Copper fungicide sprays might be effective, too.
Always consider an integrated approach with preventive measures together with biological treatments if available. Usually the disease is of minor significance and it seldom requires chemical control. Affected bunches can be sprayed with mancozeb, triophanate methyl or metalaxyl once and be covered with plastic sleeves afterwards.