Effect of Operation Variables of Potato Digger with Double Chain Conveyors on Crop Handling and Machine Performance

Abstract— The experiments were conducted at Al- Gimma Agricultural Scheme  in the Tragma area- Shendi locality, River Nile State during April – 2017,  to study the effect of some operational factors related to harvesting machine such as tractor forward speed (4.4, 5.6 and 6.7km/hr, harvesting depth (16, 18 and 21cm) and the conveyer inclination (15° and 20°) on some of potato crop handling such as lifting potatoes, cut of potatoes, Bruised and Total bruised (Damage) index potato and some of machine performance such as travel reduction (wheel slippage), effective field capacity and fuel consumption. The results showed that, there were significant influences of forward speed, harvesting depth and conveyer inclination on tubers lifting, cut of potatoes while the effect of different forward speed showed no significant effect on potatoes damage, further no significant on the percentage of scuffed damage tubers, peeler damage tubers, severe damage tubers, total damage index as effecting by conveyer inclination. As the digging depth of digger increased from 16 to 18, the lifting potatoes increased from 93.42 to 94.42%, while decreased from 94.42% to 87.72% when the digging depth decreased from 21cm to 18cm. Significant and consistent increase in tubers lifting percentage was recorded due to increase in conveyer inclination. Less percentage of scuffed, peeler, severe damage tubers and total damage index of 0.2%, 0.0%, 1.6% and 21.9, respectively were recorded at speed of 6.7km/hr, while the highest percentage of scuffed, peeler and severe damage tubers of 2.1%, 0.3% and 2.7% respectively were recorded at Speed of 4.3km/hr.

Statistical analysis (P<0.05) showed that increasing the forward speed, increased effective field capacity and fuel consumption significantly while there was no significance effect on wheel slippage. Furthermore, increasing the digging depth increased the wheel slippage and fuel consumption significantly where the effective field capacity significantly decreased. The conveyer inclination showed no significant effect on machine performance.