Mango trees are affected by a number of pests of which the hopper is a major and serious threat during the flowering season. If uncontrolled they can cause severe damage. Theses insect pest also damage the crop by secreting a sweet sticky substance called honey dew.
Shade and high humidity conditions favor its multiplication. Such conditions prevail in old, neglected and closely planted orchards. The female lays 100- 200 eggs on the mid rib of tender leaves, buds and inflorescences. The life cycle of the pests is 12 to 17 days.
Apart from the hopper- sooty mould complex, powdery mildew and anthracnose diseases are also damaging..
The symptoms of the powdery mildew can be noticed on the inflorescence, stalk of the inflorescence and leaves forming a white superficial powdery growth on these parts.
Anthraconse can be observed on leaves, petioles, twigs and blossoms. Oval to irregular brown spots of various sizes can be observed scattered all over the leaf surface.
In almost all the districts mango growers have started spraying chemicals. Farmers are cautioned not to use these chemicals which will create pest resurgence in the later phase of the growth. It is advisable to include one fungicide along with the pesticides for effective management .
The following strategies will help
— Keep orchards clean. Prune overcrowding and over lapping branches during August- September.
— Collect and destroy affected inflorescence or sticky inflorescence
— Install light traps at 1 trap/hectare. At the time of flower initiation spraying of Imidacloprid 17.8 Sl @ 0.4 ml/litre + wettable Sulphur at 2 g/litre will be effective.
— After 50 per cent flowering spray Phosalone 35 EC at 1.5 ml/lit + wettable Sulphur at 2 g/litre of water.
— If the incidence of pests is observed again, then it is recommended to spray carbaryl 50 WP @ 2g/litre + wettable sulphur at 2 g/litre of water
—Two sprays of Carbendazim @ 1 g/lit at 15 Days interval is recommended to control leaf and blossom infection of anthracnose if noticed.
M. Selvarajan, B. Usha Rani and A.Vijayasamundeeswari
Department of Fruit CropsHorticultural College and Research InstituteTNAU, Periyakulam