Anthracnose (a fungal infection) is the most prominent disease that mango producers must combat.
In the field, anthracnose can cause a direct loss of fruit and, if left untreated in harvested fruit, the blemishes it produces can make mangos hard to market. It is a fungal disease caused by Colletotrichum gloeosporioides.
Aanthracnose symptoms occur on leaves, twigs, petioles, flower clusters (panicles), and fruits. On leaves, lesions start as small, angular, brown to black spots that can enlarge to form extensive dead areas.
Dark spots
Ripe fruits affected by anthracnose develop sunken, prominent, dark brown to black decay spots before or after picking and may drop from trees prematurely.
Most green fruit infections remain latent and largely invisible until ripening. Thus fruits that appear healthy at harvest can develop significant anthracnose symptoms rapidly upon ripening.
A second symptom type on fruits consists of a “tear stain” symptom, lending an “alligator skin” effect and even causing fruits to develop wide, deep cracks in the epidermis that extend into the pulp.
Lesions on stems and fruits may produce conspicuous, pinkish-orange spore masses under wet conditions.
Wet, humid, warm weather conditions favor anthracnose infections in the field. Spores (conidia) of the pathogen are dispersed passively by splashing rain or irrigation water.
Mangement
Prune trees yearly and remove fallen plant debris from the ground.
Wider plant spacing will inhibit severe epidemics. Intercropping with other types of trees that are not hosts of mango anthracnose will inhibit epidemics.
Periodic fungicide sprays. at the right time are very critical for adequate disease control.
Sprays should begin when panicles first appear and continue at the recommended intervals until fruits are about 11?2–2 inches long.
Spraying at every 14–20 days depending on the weather with 1.0 per cent Bordeaux Mixture or 0.1 per cent Carbendazim (50WP) or 0.1 per cent Methyl thiophenate (70 per cent ) will control the foliar anthracnose.
MALLIKARJUN KENGANAL
HEMAVATI RANEBENNUR & A.S. BYADGI University of Agricultural Sciences, Dharwad, Karnataka
