## 3 Results and Discussion
### Oblique Cut Test  
The oblique cutting structure of the clamping and cutting arrangement device for Solanaceae scion and stock seedlings was designed using two structures -- that is, the short knife and long knife. The seedling-clamping structure adopted the 4-claw structure and MHL2 pneumatic clamper as the power source, after which oblique cutting tests of the eggplant and tomato seedlings were conducted. The ear and stock seedlings were grafted by the gratter using the casing. The difference in leveling efficiency between the short-knife type and long-knife type were compared, including the grafted-seedling leveling efficiency, operating efficiency, and survival rate. The success rate, half-cut rate, and uncut rate of oblique cutting of the ear and stock seedlings using the short-knife and long-knife structures are shown in Table 3.  
The short-knife oblique cutting success rates for eggplant and tomato seedlings are 80.45% and 89.10%, respectively, while those of the long knife are 97.76% and 94.55%, respectively. The one-way ANOVA results show that the oblique-cutting success rate for eggplant seedlings using the long-knife type is considerably higher than that of the short-knife type, but there is no significant difference in the oblique-cutting success rate for tomato seedlings between the two.  
The half-cut rate of eggplant and tomato seedlings cut obliquely using the short knife are 13.46% and 6.09%, respectively, while those of the long knife are both 0.96%. The one-way ANOVA results show that there are considerable differences in the half-cut rate between the two types of obliquely cut eggplant and tomato seedlings. Among them, the half-cut rate of eggplant seedlings cut using the short knife is the highest, followed by the half-cut rate of tomato seedlings cut using the short knife, there being no significant difference between the two seedlings cut using the long knife.  
The uncut rate of the obliquely cut eggplant and tomato seedlings using the short knife are 5.77% and 4.81%, respectively, while the obliquely cut eggplant and tomato seedlings using the long knife are 1.28% and 4.17%, respectively. The one-way ANOVA results show that the uncut rate of eggplant seedlings using the short knife is significantly different than that using the long knife, but there is no significant difference between the two types of obliquely cut tomato seedlings.  
Overall, the failure of oblique cutting can be divided into two categories -- that is, half-cut and uncut failures. Although there are coordinates to locate the position of the  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline \multirow{2}{*}{**Knife Type**} & \multirow{2}{*}{**Seedlings**} & \multicolumn{3}{c}{**The Seedlings Cutting Situation (\%)**} \\ \cline{3-5}  & & **Success** & **Half** & **Fail** \\ \hline \multirow{2}{*}{Short knife} & Eggplant stock & 80.45 c & 13.46 a & 5.77 a \\  & Tomato scion & 89.10 bc & 6.09 b & 4.81 a \\ \hline \multirow{2}{*}{Long knife} & Eggplant stock & 97.76 a & 0.96 c & 1.28 b \\  & Tomato scion & 94.55 ab & 0.96 c & 4.17 ab \\ \hline \hline \end{tabular} One-way ANOVA on oblique-cutting success rate. Different letters indicate significant differences between treatments by using the least-significant difference at \(p<0.05\).  
\end{table}
Table 3: Comparison of the success, half and fail rate of the two knife and seedling types.  
obliquely cut seedlings, differences in seedling traits\(-\)such as skewed stems\(-\)can affect the clamping angle, leaving seedlings half-cut or even uncut during the oblique cutting process. The half-cutting rate using the short knife is significantly higher than that using the long knife. It is speculated that the short knife cannot cover the range of angle differences caused by skew stems\(-\)that is, the long knife is more tolerant of seedling trait differences.