## 3 Results
### Correlations of Reflectance and Vegetation Indices with Soybean Yield  
The Pearson correlation (r) between REFs with SY was the strongest for NDRE (r = 0.75) and weakest for REF in the red wavelength range (R, r = \(-\)0.0046) (Figure 5b,c and Table 3). A stronger correlation with the SY was observed for 6 VIs (r = 0.36-0.75) and 18 VIs showed \begin{table}
\begin{tabular}{l c c c} \hline \hline
**Parameter** & **Juvenile Nematode (r)** & **Female Nematode (r)** & **FNEMS+JNEMS (r)** \\ \hline July 7 vigor & 0.33 & 0.39 & 0.41 \\ July 21 vigor & 0.01 & 0.07 & 0.04 \\ Vigor recovery & \(-\)0.29 & 0.28 & \(-\)0.33 \\ Yield & \(-\)0.30 & \(-\)0.40 & \(-\)0.39 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Correlations of juvenile and female nematodes with crop vigor and soybean yield. Figure 4: Presentation of contrasting differences in (**a**) 7 July vigor; (**b**) 21 July vigor; (**c**) yield; (**d**) vigor recovery; (**e**) soybean cyst nematode population; and (**f**) aerial imagery-derived normalized difference red edge index for resistant and susceptible soybean varieties under different fungicide treatments (A to I). moderate-to-weaker correlations (0.15-0.26). Among the VIs, NDRE (r = 0.75) had the highest and GDVI (0.36) had the lowest correlation with SY. \begin{table}
\begin{tabular}{l c c c c} \hline \hline
**Vegetation Index/Reflectance Feature** & **Yield (r)** & \
\begin{tabular}{c} **Juvenile** \\ **Nematode (r)** \\ \end{tabular} &
\begin{tabular}{c} **Female** \\ **Nematode (r)** \\ \end{tabular} & **FNEMS+JNEMS (r)** \\ \hline Blue & \(-\)0.62 \({}^{\star}\) & 0.50 \({}^{\star\star}\) & 0.50 \({}^{\star\star}\) & 0.58 \({}^{\star\star}\) \\ Green & \(-\)0.39 & 0.14 & 0.19 & 0.18 \\ Red & \(-\)4.64 \(\times\) 10\({}^{-3}\) & 0.09 & 0.02 & 0.08 \\ Red Edge & \(-\)0.08 & \(-\)0.09 & \(-\)0.04 & \(-\)0.08 \\ Near Infrared & 0.15 & \(-\)0.21 & \(-\)0.20 & \(-\)0.24 \\ Normalized Difference Vegetation Index (NDVI) & 0.26 & \(-\)0.42 & \(-\)0.32 & \(-\)0.45 \({}^{\star\star}\) \\ Infrared Percentage Vegetation Index (IPVI) & 0.26 & \(-\)0.42 & \(-\)0.32 & \(-\)0.45 \({}^{\star\star}\) \\ Green Normal Difference Vegetation & 0.73 \({}^{\star}\) & \(-\)0.48 & \(-\)0.53 \({}^{\star\star}\) & \(-\)0.58 \({}^{\star\star}\) \\ Index (GNDVI) & 0.18 & \(-\)0.32 & \(-\)0.26 & \(-\)0.35 \\ Green Difference Vegetation Index (GDVI) & 0.36 & \(-\)0.34 & \(-\)0.34 & \(-\)0.40 \\ Enhanced Vegetation Index (EVI) & 0.21 & \(-\)0.34 & \(-\)0.28 & \(-\)0.37 \\ Leaf Area Index (LAI) & 0.21 & \(-\)0.34 & \(-\)0.28 & \(-\)0.37 \\ Non-Linear Index (NLI) & 0.20 & \(-\)0.34 & \(-\)0.27 & \(-\)0.37 \\ Modified Non-Linear Index (MNLI) & 0.15 & \(-\)0.36 & \(-\)0.25 & \(-\)0.38 \\ Soil Adjusted Vegetation Index (SAVI) & 0.21 & \(-\)0.36 & \(-\)0.29 & \(-\)0.39 \\ Optimized Soil Adjusted Vegetation Index (OSAVI) & 0.24 & \(-\)0.39 & \(-\)0.31 & \(-\)0.43 \({}^{\star\star}\) \\ Green Soil Adjusted Vegetation Index (GSAVI) & 0.48 & \(-\)0.40 & \(-\)0.41 \({}^{\star}\) & \(-\)0.47 \({}^{\star\star}\) \\ Green Optimized Soil Adjusted Vegetation & 0.59 & \(-\)0.45 \({}^{\star\star}\) & \(-\)0.48 \({}^{\star}\) & \(-\)0.54 \({}^{\star\star}\) \\ Index (GOSAVI) & 0.19 & \(-\)0.34 & \(-\)0.27 & \(-\)0.37 \\ Normalized Difference Red edge Index (NDRE) & 0.75 \({}^{\star}\) & \(-\)0.40 & \(-\)0.49 \({}^{\star}\) & \(-\)0.50 \({}^{\star\star}\) \\ Green Ratio Vegetation Index (GRVI) & 0.74 \({}^{\star}\) & \(-\)0.48 \({}^{\star\star}\) & \(-\)0.53 \({}^{\star}\) & \(-\)0.58 \({}^{\star\star}\) \\ Green Chlorophyll Index (GCI) & 0.74 \({}^{\star}\) & \(-\)0.48 \({}^{\star\star}\) & \(-\)0.53 \({}^{\star}\) & \(-\)0.58 \({}^{\star\star}\) \\ Green Leaf Index (GLI) & \(-\)0.31 & \(-\)0.13 & 0.04 & \(-\)0.08 \\ Simple Ratio (SR) & 0.17 & \(-\)0.37 & \(-\)0.27 & \(-\)0.39 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Correlations of reflectance and vegetation indices with nematode populations and soybean yield.