Tropical and subtropical fruits (2+1)

Pests and Diseases

PESTS
Stem borer (Isocrata tetraonis)

The grub of this small beetle bores into bark of the Sapota trunk and feeds on the living tissue inside the bark. The chewed bark is seen on the hole.
Control measures

1. Kill the insect by thrusting a stiff wire into the tunnel.
2. Plug the hole with a wad of cotton in kerosene at 0.1 percent and plaster with wet mud. This treatment creates suffocation inside the hole or tunnel which results in death of the insect inside.

Leaf minor

The tiny caterpillar of a greyish moth mines into the surface of young leaves. Affected leaves curl up, mines are seen on the surface of leaves and sometimes caterpillars are found inside the mines. Later on, affected leaves get destroyed, dry up and fall.
Control measures

• Spray once or twice Dimethate (30ml in 18 liters of water) or Malathion (30ml in 18 liters of water)

Mealy bug: (Phenacoccus icerjoides)

It is sucking insect. It is a small, over in shape with a cottony white, waxy on the under surface of leaves and base of the fruit near the fruit stalks. They suck the sap and secrete large quantities of sugary sub stones. Leaves have a block coating which gives thema sickly appearance.
Control measures:

• Spray dimethoate at the rate of 30ml in 18 liters of water.
• Try to keep free sapota plantation from red onts because these help in distributing mealy bugs from one tree to another. Red ants are effectively controlled with a dusting of a mixture of BHC 5 percent with sulphur in the proportion of 2:1.

Scale insects: (Pulvinaria psidil)

They suck the sap by infesting along the sides of midrib and surface of leaves and twinges. These scales are green or grown in colour and oval shaped.
Control measures

• Spray Dimethoate or Malathion at 30ml in 18 liters of water.
Fruit borer (Virachola isocrates)

Borer attacks on fruits and some times buds which can easily be detected by seeing the latex which comes out on the surface of the infested fruits, the latex later crystallizes.
Control measures

1. Spray 0.05 Malathion
2. Spray 0.01% Fenvalerate/0.01% endosufan.


DISEASES

Leafspot: (Phoecophleospora indica)

The causal fungus results in dark brown, the adjacent spots on leaves. When infection is severe, the adjacent spots become large irregular whitish patches. In severe caser, the defoliation of leaves may be noticed.
Control measures:

1. Spray -78 @0.2% at an interval of 30 days.
2. Grow resistant varieties like Co-1, Cricket Ball. The varieties Co-2 & Kalipatti are torerant, but calcutta round is susceptible.



Sooty mould

Sooty mould is incited by Capnodium sps : The causal fungal disease develops on the honey like excretion by scale insects and mealy bugs.
Control measures
1. Spray Zineb @ 40 g in 18 liters water .
2. Spray starch solution (100 g M in 18 liters of water). Starch forms the flakes which eventualy drop off the leaves.