The correct option is (b).
Explanation
Harvesting involves cutting a crop after it has matured. Following the harvest, grain seeds must be separated from the stalks and chaff through specific mechanical or manual processes known as threshing and winnowing.Statement-wise Analysis:
- Statement 1 is Incorrect. Threshing is the process of separating the grain seeds from the chaff or stalks. It is performed after harvesting. Sowing is the distinct agricultural process of planting seeds into the soil.
- Statement 2 is Correct. Winnowing is a traditional method used to separate heavier grains from lighter chaff. It utilizes wind or blowing air; the lighter chaff is blown away while the heavier grains fall vertically. This method is typically used by farmers with smaller landholdings.
- Statement 3 is Incorrect. A 'Combine' is a large agricultural machine that integrates two major processes: harvesting (cutting the crop) and threshing (separating the grain). It is not used for irrigation purposes.
Key Takeaway: Threshing separates grain from stalks, whereas winnowing separates grain from chaff using air currents. A Combine harvester automates both harvesting and threshing.