2.3.6 Comparative effect of botanicals and different control
materials on mango fruit anthracnose
One hundred and fifty (150) green matured mango fruits were
randomly collected from the sampling areas. The fruits were
mixed together and later subdivided into 10 parts of 15 fruits each
with each fruit representing a replicate. Each part containing 15
numbered fruits was treated separately with botanicals (water or
ethanol extraction), hot water and fungicide (benomyl). One part
was treated with sterile distilled water to serve as control. For
botanicals, the fruits were soaked in aqueous plant extract for 30
minutes and air-dried. For heat treatment, the fruits were soaked
in hot water at 55oCelsius for 5 minutes as described by [25].
Benomyl 50 per cent w/w at 100 grams per 100 liter of water was
sprayed over the fruits and completely covered with sterilized
paper towels while in the case of control treatment; the fruits were
thoroughly washed and soaked in sterile distilled water for 30
minutes and air dried. The treated fruits for each treatment were
arranged in separate boxes laid out in a completely randomized
design layout and allowed to ripen for 16 days under humid
condition. The fruits were each examined for anthracnose lesions
every other day beginning from the sixth day after treatment when
ripening has commenced until the sixteenth day. Fruit
anthracnose was assessed using the standards for the
assessment of fruit anthracnose of mango proposed by [4]. Scale
1 to 5 was used, where scale 1 represents no fruit lesions, 2
represents 1 to 3 lesions, 3 represents 4 to 6 lesions, 4
represents 7 to 15 lesions and 5 where more than 30 per cent of
fruit surface is covered with lesions. Disease index (number of
infected fruits), and anthracnose rating (percentage of disease
ratings on the average) was then obtained by the following
formula: