Agriculture — CROP PRODUCTION

Subtopic: Crop harvesting

Harvesting is the process of collecting crops from the field when they are mature and ready to eat or store. Good harvesting keeps food safe, increases profit, and reduces waste. These notes are for students in Kenya (age 13).

1. Why harvesting is important

• To get food and grain ready for market or home use.
• To prevent losses from pests, birds, mould and bad weather.
• To keep seed quality for next planting season.

2. When to harvest (signs of maturity)

Different crops show different signs. Harvest too early and yield is small; too late and grains/roots may be damaged.

• Maize: Leaves and husks dry and brown; kernels are hard and full (black layer at kernel base).
• Beans: Pods dry and brown; seeds rattle inside when shaken.
• Potatoes: Tops (plants) yellow and die back — then lift tubers carefully.
• Rice: Panicles change from green to golden; grains are hard.
• Cassava: Usually harvested 8–12 months after planting (depends on variety).

3. Common harvesting methods in Kenya

• Hand-picking (vegetables, fruits).
• Cutting with a sickle or knife (maize, sorghum).
• Uprooting (potatoes, cassava, sweet potatoes).
• Mechanical combines (large farms for maize, wheat where machines are available).

4. Steps in harvesting and post-harvest handling

1. Prepare tools: Clean and sharpen sickles/knives; have bags and containers ready.
2. Cut or collect: Harvest when dry and avoid rainy days if possible.
3. Transport: Move crops quickly to a clean, dry place—avoid piling on wet ground.
4. Threshing: For cereals, separate grain from stalks using flails, animals, or machines.
5. Winnowing: Remove chaff and light debris by gently tossing grain in the air or using a fan.
6. Drying: Dry grains on raised mats, tarpaulins or drying floors in the sun until safe moisture is reached.
7. Cleaning & grading: Remove broken grains, stones and small impurities; sort good quality grain for seed.
8. Storage: Store in clean, dry bags or airtight containers; use PICS bags, silos or clean granaries to protect from pests.

5. How to reduce losses after harvest

• Harvest at the right time and avoid rainy days.
• Dry crops well and protect from morning dews (cover at night).
• Use clean storage containers and good hygiene to stop insects and mould.
• Keep storage away from walls and floor to reduce moisture and rodents.
• Use simple pest control: good sanitation, rodent traps, or approved safe chemicals when needed.

6. Safety for harvesters

• Wear gloves and closed shoes to avoid cuts and bites.
• Keep sickles and knives sharp and handle them carefully.
• Drink water and rest — harvesting is physical work under the sun.
• Lift sacks properly: bend knees, not back, to avoid injury.

7. Simple student activities (school garden)

• Identify mature maize/beans in the school garden and explain why they are ready.
• Practice threshing a small handful of grain and winnowing with a tray or basket.
• Weigh a small batch of maize every day while drying and record the change to learn about moisture loss.
• Design a simple raised drying mat using local materials (bamboo and mat).

8. Easy infographic (harvest flow)

9. Short checklist for harvest day

• Tools cleaned and sharpened?
• Containers and tarpaulins ready?
• People assigned to tasks (cutting, collecting, drying)?
• Plan to avoid rain and dew?
• Place to store crop after drying prepared?

10. Glossary (simple)

Threshing

Separating grain from stalks or pods.

Winnowing

Using wind or a fan to remove chaff from grain.

Maturity

When a crop is ready to harvest.

Post-harvest loss

Food lost after harvesting due to pests, moisture or poor storage.

For more help, ask your teacher or local agricultural extension officer. They can show local signs for harvest and safe storage methods.