The Bio Brief

Harvesting is an important step in crop production. The process of cutting and collecting a mature crop is called harvesting.

• Crops are cut close to the ground or pulled out
• Most cereal crops take about 3–4 months to mature

Crop growth

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Crop maturity

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Harvesting

Methods of Harvesting

1. Manual Harvesting

• Done using a sickle
• Commonly used by small farmers
• Requires more time and labour

Diagram idea:

Sickle

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Cutting crop

2. Machine Harvesting

• Done using a harvester
• Saves time and labour
• Used in large fields

Threshing

After harvesting, grains are separated from the chaff (dry straw).
This process is called threshing.

• Chaff is the dry outer part of the grain
• Threshing can be done:
  • By machine
  • By traditional methods

Harvested crop

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Threshing

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Grains + Chaff

Combine Machine

• A combine is a machine that:
  • Harvests the crop
  • Separates grains from chaff (threshing)
• It is both a harvester and a thresher

Combine machine

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Harvesting + Threshing

Winnowing

• Used by small farmers
• Separates grain from chaff using wind
• Lighter chaff is blown away, heavier grains fall down

Diagram idea:

Grain + Chaff

     ↓ (wind)

Chaff blows away

Grain falls down

Quick Summary Table

Process	Purpose	Tool/Machine
Harvesting	Cutting mature crops	Sickle / Harvester
Threshing	Separating grains	Combine
Winnowing	Removing chaff	Wind

Summary Flow Chart

Crop matures

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Harvesting

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Threshing

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Winnowing

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Clean grains