Multi-Scale Remote Sensing for Fall Armyworm Monitoring and Early Warning Systems

Fall armyworm (FAW) is a polyphagus pest with a preference for young maize leaves that relocates to the cob during cob development and can devastate maize yields. Time series anomaly change detection and first derivative growth pattern analyses were conducted under the hypothesis that, if unimpeded and occurring during the vegetativegrowth stage, FAW presence will result in a reduction of the LAI or total green biomass (NDVI) of the crop. We have conducted observations NDVI/LAI at three different scales from continental to field scales., (i) Sentinel-2 a+b and (ii) micro-satellite Planet Scope, (iii) multispectral camera. Correlations between LAI and (i) NDVI of (i, ii, iii) were R2 0.60, 0.66 and 0.35, respectively. The NDVI time series and first derivative were then compared to the FAW damage recorded using a mobile app.