Detecting the invasive fall armyworm pest incidence in farm fields of southern India using Sentinel-2A satellite data
Mathyam Prabhakar, K.A. Gopinath, Nakka Ravi Kumar, Merugu Thirupathi, Uppu Sai Sravan, Golla Srasvan Kumar, Gutti Samba Siva, Guddad Meghalakshmi, S. Vennila
Abstract
Damage of fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith) on sorghum from the farmers’ fields of southern India was assessed using space-borne data. Comparison of the Sentinel-2A satellite data of pre and post infestation periods revealed reduction in Leaf Area Index (LAI) in the infested fields. Groundtruth data confirmed that FAW infestation reduced LAI by 49.7%, biomass by 32.5% and grain yield by 51.8%. Infestation at Panicle Initiation (PI) stage caused maximum yield loss compared to flag leaf visible and boot stages. The interaction results showed FAW infestation at different crop stages had significant effect on biomass and yield, but not on LAI. Regression analysis with spectral vegetation indices revealed LAI (R2: 0.82) and NDVI (R2: 0.80) were significantly superior in identifying FAW infestation from the satellite data. This study demonstrates feasibility of site specific pest management and prevents further spread of the invasive FAW.