Question

A 3.6 m combine harvester was tested over a crop strip of 20 m length and the following data were obtained while testing: Total material left over walker = 8.5 kg
Free seed over walker = 100 g
Unthreshed seed over walker = 50 g
Total material left over shoe = 5.5 kg
Free seed over shoe = 250 g
Unthreshed seed over shoe = 80 g
Total seed collected in the grain tank = 16.5 kg The grain yield (tonne ha\(^{-1}\)) and cylinder loss (%) are:

• A. 2.36 and 0.77
• B. 4.24 and 0.29
• C. 6.28 and 0.47
• D. 8.05 and 2.82

Hint:

Grain yield can be calculated by dividing the total seed collected by the area of the field, and cylinder loss is calculated as the unthreshed seed percentage.

Answer 1

The Correct Option is A

Step 1: Calculate the grain yield.
The area of the field is: \[ \text{Area} = 20 \, \text{m} \times 3.6 \, \text{m} = 72 \, \text{m}^2 \] The grain yield in tonnes per hectare is: \[ \text{Grain yield} = \frac{16.5 \, \text{kg}}{72 \, \text{m}^2} \times 10000 = 2.36 \, \text{tonne ha}^{-1} \] Step 2: Calculate the cylinder loss.
The cylinder loss is the ratio of unthreshed seed over walker and shoe to the total seed collected: \[ \text{Cylinder loss} = \frac{50 \, \text{g} + 80 \, \text{g}}{16.5 \, \text{kg} \times 1000} \times 100 = 0.77% \] Final Answer: \[ \boxed{2.36 \, \text{tonne ha}^{-1} \, \text{and} \, 0.77%} \]