## 3 Results  
### Plant Volatile Emissions Caused by ZJA and DJA Applications  
_R. confertus_ exposed to either ZJA or DJA responded with the intense emission of GLVs. Following ZJA application, (Z)-3-hexenal (Z-3-HAL), (Z)-3-hexenol (Z-3-HOL), (Z)-3-hexenyl acetate (Z-3-HAC), Z-ocimene (Z-OCI), linalool (LIN), benzyl acetate (BAC), methyl salicate (MAT), \(\beta\)-carophylene (\(\beta\)-CAR), and \(\beta\)-farnesene (\(\beta\)-FAR) emissions were identified. In addition to these, following DJA application other volatile compounds were also observed to be released; namely, (E)-2-hexenal ((E)-2-HAL) and (E)-2-hexenol ((E)-2-HOL). The correlation results for ZJA and DJA stimulants are presented in Tables 1 and 2, respectively. All pairs of GLVs display positive correlation coefficients. The compounds and their amounts for reach treatment are given in the Supplementary Files (Table S1).  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**VOCs** & **Z-3-HAL** & **Z-3-HOL** & **Z-3-HAC** & **Z-OCI** & **LIN** & **BAC** & **MAT** & \(\beta\)-CAR & \(\beta\)-FAR** \\ \hline Z-3-HAL & & & & & & & & & \\ Z-3-HOL & 0.87 * & & & & & & & & \\ Z-3-HAC & 0.87 & 0.87 & & & & & & & \\ Z-OCI & 0.76 & 0.77 & 0.79 & & & & & & \\ LIN & 0.70 & 0.79 & 0.80 & 0.90 & & & & & \\ BAC & 0.65 & 0.71 & 0.66 & 0.80 & 0.78 & & & & \\ MAT & 0.78 & 0.77 & 0.82 & 0.88 & 0.87 & 0.85 & & & \\ B-CAR & 0.79 & 0.80 & 0.82 & 0.91 & 0.90 & 0.87 & 0.92 & & \\ B-FAR & 0.72 & 0.73 & 0.76 & 0.88 & 0.82 & 0.85 & 0.89 & 0.88 & \\ \hline \hline \end{tabular}
\end{table}
Table 1: Correlation coefficients between particular pairs of GLVs emitted from _R. confertus_ after ZJA application.  
\begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline
**VOCs** & **Z-3-HAL** & **E-2-HAL** & **Z-3-HOL** & **E-2-HOL** & **Z-3-HAC** & **Z-OCI** & **LIN** & **BAC** & **MAT** & \(\beta\)-CAR & \(\beta\)-FAR** \\ \hline Z-3-HAL & & & & & & & & & & \\ E-2-HAL & 0.93 * & & & & & & & & & \\ Z-3-HOL & 0.89 & 0.90 & & & & & & & & \\ Z-2-HDL & 0.92 & 0.92 & 0.92 & & & & & & & \\ Z-3-HAC & 0.95 & 0.93 & 0.88 & 0.90 & & & & & & \\ Z-OCI & 0.79 & 0.79 & 0.84 & 0.79 & 0.77 & & & & & \\ LIN & 0.80 & 0.77 & 0.78 & 0.78 & 0.77 & 0.91 & & & & \\ BAC & 0.72 & 0.73 & 0.73 & 0.74 & 0.72 & 0.87 & 0.86 & & \\ MAT & 0.83 & 0.81 & 0.83 & 0.81 & 0.80 & 0.85 & 0.85 & 0.91 & & \\ B-CAR & 0.84 & 0.84 & 0.84 & 0.82 & 0.89 & 0.86 & 0.89 & 0.90 & \\ B-FAR & 0.74 & 0.76 & 0.79 & 0.77 & 0.73 & 0.88 & 0.86 & 0.88 & 0.86 & 0.94 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Correlation coefficients between particular pairs of GLVs emitted from _R. confertus_ after DJA application.  
For both chemical stimulants, the highest levels of particular GLV emissions were observed in the 72 h measurements following a dose of 1000 ng min\({}^{-1}\). Nevertheless, the canonical correlation results (see Figure 1) show that the simultaneous influence of time and dose has a similar effect on the plant GLVs emission. An interesting observation was that a low dose of the stimulants (i.e., 10 ng min\({}^{-1}\)) did not differentiate the GLV emission in time. On the other hand, the application of higher doses (i.e., 100 and 1000 ng min\({}^{-1}\)) gave aligned results within the same time intervals.  
Figure 1: Results of a canonical correlation analysis of two parameters (time of GLV collection and stimulant doses) on VOCs emission levels, where (**A**) refers to ZJA and (**B**) refers to DJA application.