Crop Pests, Diseases and Weeds: notes

Pests and Diseases

• Pest: an animal that damages crops, such as aphids, stalk borers, armyworms and quelea birds.
• Chewing and sucking insects: chewing insects make holes; sucking insects drain sap and spread viruses.
• Disease causes: fungi, bacteria and viruses. Rust and blight are fungal.
• Weed: a plant growing where it is not wanted. It competes for water, light and nutrients.

Control

• Cultural: rotation, clean seed, early planting, field hygiene.
• Biological: natural enemies such as ladybirds eating aphids.
• Chemical: pesticides and herbicides. Follow the label, wear protective clothing and keep to the waiting period before harvest.
• Integrated control: a mix of methods that cuts chemical use.