DefinePK

Research Objective

To assess the effect of field operating conditions and maturity characteristics of wheat on the threshing performance of a locally developed wheat thresher during the 2017-18 wheat seasons.

Methodology

A locally fabricated wheat thresher, consisting of feeding/threshing, sieving/cleaning, and power transmission/transportation units, was tested. The experiment involved three wheat varieties (Seher 2006 (V1), Faisalabad 2008 (V2), Lasani 2008 (V3)), three harvesting stages (early, mid, late, corresponding to moisture contents M1, M2, M3), and three feeding rates (FR1: 41 kg/min, FR2: 47 kg/min, FR3: 52 kg/min). Dependent parameters measured included threshing efficiency, grain cleaning efficiency, grain breakage percentage, grain loss in straw, straw chopping efficiency, and fuel consumption. Moisture content was determined by the oven-dry method (130°C for 19 hours).

Methodology Flowchart

                        graph TD;
A[Fabricate Wheat Thresher] --> B[Field Testing];
B --> C[Vary Wheat Varieties V1, V2, V3];
C --> D[Vary Crop Moisture Content M1, M2, M3];
D --> E[Vary Feeding Rate FR1, FR2, FR3];
E --> F[Measure Dependent Parameters];
F --> G[Analyze Performance Metrics];
G --> H[Determine Optimal Operating Parameters];                    

Discussion

The study confirms that optimal threshing performance (high efficiency, low breakage/loss) is achieved under specific conditions, particularly around the mid-harvesting moisture content (16.6%). The brittle nature of grain at lower moisture content (late harvest) increased breakage, while very high moisture (early harvest) reduced overall efficiency. Higher feeding rates generally increased threshing and cleaning efficiencies but also increased fuel consumption. Faisalabad-2008 (V2) showed superior resistance to grain breakage compared to the other varieties tested.

Key Findings

- The wheat thresher achieved the highest mean threshing efficiency (98.83%) and grain cleaning efficiency (98.93%) for wheat variety Faisalabad-2008 (V2) at a crop moisture content of 16.6% (mid harvesting stage) and a feeding rate of 52 kg/min (FR3).
- The least grain breakage percentage (0.75%) and minimum grain loss in straw (0.16%) were observed at a feeding rate of 47 kg/min (FR2) and mid harvesting stage (16.6% moisture).
- Straw chopping was most accurate and uniform (2.28 cm) at 16.6% moisture content (mid harvesting stage), while it was non-uniform (1.93 cm) at the late harvesting stage.
- Maximum fuel consumption (6.71 L/h) and energy utilization (76.57 kWh) were recorded for wheat variety Lasani-2008 (V3) at the maximum feeding rate (FR3, 52 kg/min).
- Crop moisture content and feeding rate significantly affected threshing efficiency, cleaning efficiency, and grain damage.

Conclusion

The performance of the locally developed wheat thresher is maximized for Faisalabad-2008 (V2) when operated at a mid-harvesting moisture content of 16.6% and a feeding rate of 52 kg/min for maximum efficiency, or 47 kg/min for minimum grain loss and breakage. These findings provide recommendations for optimizing the thresher's operation within conservation agriculture systems.

Fact Check

1. The maximum mean threshing efficiency achieved was 98.83%. (Confirmed in Abstract and Conclusion)
2. The least grain breakage percentage found was 0.75%. (Confirmed in Abstract)
3. The maximum fuel consumption recorded was 6.71 L/h for variety Lasani-2008 (V3) at FR3 (52 kg/min). (Confirmed in Abstract and Table 5)

Mind Map