Hyperspectral Remote Sensing Detection of Root-Knot Nematode Infestation in Mungbean under Various Management Strategies

In response to the pervasive threat of Meloidogyne incognita infestation in mungbean crops, this study explores the application of hyperspectral remote sensing methodology to detect and assess root-knot nematode presence, while investigating the efficacy of diverse management strategies. Spectral remote sensing was used to record the reflectance pattern of the Root-knot nematode (RKN), M. incognita infestation on mungbean plants under various management methods under glasshouse pot conditions. Leaf reflectance was measured on plant canopies of mungbean which revealed that reflectance varies with different inoculum levels of root-knot nematode. The spectral reflectance pattern was maximum at the highest inoculum level of 6000 J2/ pot with respect to the wavelength of 250–750 nm and minimum at 0 inoculum level or 100 J2/ pot corresponding to a wavelength of 800–1600 nm. In response to nematode management, mungbean plant canopy reflectance showed that at a lower wavelength of 350–750 nm, spectral reflectance were mixed and can be determined easily for low or high pattern. However, at wavelengths >800–1600 nm, the lowest and median reflectance was found with carbofuran 3G @ 1 kg a.i/ha and 2 kg a.i/ha, respectively. Similarly, high and low reflectance pattern for Trichoderma harzianum was observed at the concentration of 2 and 1% (w/w) respectively but the reflectance pattern was similar for neem seed oil at two different concentrations of 1 and 2% (v/w). The highest reflectance was observed with untreated un-inoculated control. The valuable information on the use of hyperspectral data gathered from the hand-held spectrometer and small unmanned aerial systems for large-scale mapping of the root-knot nematode infestation could be possible. Hence, the effect of M. incognita on the root system of mungbean can be non-invasively diagnosed by using hyperspectral data at the early growth stage of aerial plant canopy.