Plant Protection (Entomology and Plant Pathology)
Domain 8 covers insect pests, diseases and their integrated management in horticultural crops.
Key pests
- Borers: fruit borer in tomato and okra, shoot and fruit borer in brinjal.
- Sucking pests: aphids, jassids, thrips, whitefly, mites.
- Banana pseudostem weevil, citrus leaf miner, mango hopper.
Key diseases
- Powdery mildew (rose, cucurbits), downy mildew (grape, cucurbits).
- Bacterial wilt (tomato, brinjal), citrus canker, Panama wilt of banana, banana bunchy top virus vectored by the banana aphid.
- Damping-off in nurseries.
IPM and spray arithmetic
- Monitor, use economic threshold levels, pheromone traps, yellow and blue sticky traps, and biocontrol agents such as Trichoderma, NPV and Bacillus thuringiensis.
- Rotate chemical groups to delay resistance; respect the pre-harvest interval.
Worked example
A spray at 1.0 mL/L is to be applied at 500 L/ha. Formulation needed = 1.0 x 500 = 500 mL/ha. Reasoning: dose per litre multiplied by spray volume gives the product quantity; follow the label's recommended dilution rather than tank size, and stop spraying within the pre-harvest interval before picking.
Marks-losing traps
- Treating a virus with a fungicide; control the vector instead.
- Confusing nutrient deficiency with disease.
- Ignoring the pre-harvest interval and residue limits.
- Mixing products in one tank without a jar test.