# Performance Testing and Evaluation of Drum-Type Stem-Separation Device for Pepper Harvester
## 4 Conclusions  
In this study, to improve the PTR after harvest with the current pepper harvester, two types of stem-separation devices were manufactured: A three-shaft drum and a four-shaft drum. For red pepper varieties, AR Legend and Jeokyoung varieties were used as test samples, and the optimal rotation speed was selected based on factor performance tests for each drum and the conveyor rotation speed. The optimum rotational speeds were 0.9 m/s, 2.7 m/s, 1.3 m/s, and 0.5 m/s for shaft1, shaft2, shaft3, and the conveyor, respectively. To evaluate the comparative performances of the three-shaft drum and four-shaft drum stem-separation devices, the performance was tested according to each state, such as moving or non-moving status during picking operation or not, respectively. The stem-separation device developed in this study showed improved performance compared to the currently existing products. The three-shaft and four-shaft drum-type stem-separation devices used in this study resulted in 86.0% and 90.1% higher SSE than up to 82.7% of the results in previous studies. The four-shaft drum has higher SSE and lower PTR than the three-shaft drum, so the four-shaft drum was confirmed to be more suitable for stem separation. However, for the four-shaft drum, the material cost and processing cost were 23% higher than the three-shaft drum, and it is necessary for manufacturers to choose between the three-shaft drum and the four-shaft drum in consideration of performance and price. The drum-type stem-separation device developed in this study can be supplied to farms to additionally reduce labor costs after harvesting using a machine. The mechanism using the drum-type is used in various industrial applications [38; 43] and the drum type is concluded as one of the most effective stem-separation devices for pepper harvesters. To apply the stem-separation device to diverse species of peppers, it is necessary to conduct additional experiments with species other than the species tested in this study. Conceptualization, S.-Y.S. and Y.C. ; performed the experiments and analyzed the data, S.-Y.S. and D.-C.K. ; methodology, M.-H.K. ; writing--original draft preparation, S.-Y.S. and Y.C. ; project administration, Y.C. ; writing--review and editing, Y.C., D.-C.K. and M.-H.K. All authors have read and agreed to the published version of the manuscript. This work was supported by the Korea Institute of Planning and Evaluation for Technology in Food, Agriculture and Forestry (IPET) through the Agriculture, Food and Rural Affairs Convergence Technologies Program for Educating Creative Global Leader Program, funded by the Ministry \begin{table}
\begin{tabular}{c c c c c c c} \hline
**Item** & **Source** & **DF** & **Anova SS** & **Mean Square** & **F Value** & **Pr ¿ F** \\ \hline \multirow{4}{*}{SSE 1} & Shaft & 1 & 99.4200 & 5.0700 & 0.2800 & 0.6140 \\  & Variety & 1 & 38.8800 & 38.8800 & 2.1500 & 0.1803 \\  & Shaft*variety & 1 & 55.4700 & 55.4700 & 3.0700 & 0.1176 \\  & Error & 8 & 144.3400 & 18.0425 & & \\ \(\square\) & Total & 11 & 243.7600 & \(\square\) & \(\square\) & \(\square\) \\ \hline \multirow{4}{*}{PTR 2} & Shaft & 1 & 99.1875 & 99.1875 & 8.06 & 0.0219 \\  & Variety & 1 & 33.6675 & 33.6675 & 2.74 & 0.1367 \\  & Shaft*variety & 1 & 52.5008 & 52.5008 & 4.27 & 0.0728 \\  & Error & 8 & 98.4666 & 12.3083 & & \\ \(\square\) & Total & 11 & 283.8225 & \(\square\) & \(\square\) & \(\square\) \\ \hline \multirow{4}{*}{DR 3} & Shaft & 1 & 148.4033 & 148.4033 & 87.17 & 0.0001 \\  & Variety & 1 & 0.1633 & 0.1633 & 0.1 & 0.7647 \\ \cline{1-1}  & Shaft*variety & 1 & 0.03 & 0.03 & 0.02 & 0.8977 \\ \cline{1-1}  & Error & 8 & 13.62 & 1.7025 & & \\ \cline{1-1}  & Total & 11 & 162.2166 & \(\square\) & \(\square\) & \(\square\) \\ \hline \end{tabular} 1  
\end{table} 
Table 6: Statistical results of field test based on shafts of drum type and variety of pepper.