Early Detection of Fungal Diseases in Winter Wheat by Multi-optical Sensors

Abstract

Biotic factors such as pests and pathogens cause a substantial damage to wheat crops which leads to reduction in yield in a range from 10% to 50%. Application of fungicides and pesticides on one hand protects the crop but it also increases the crop production cost. Pathogens affect photosynthesis, respiration, translocation of water and nutrients of the crop and mostly the visual symptoms are detected too late to protect the crop. The objective of this study was to detect the plant fungal diseases by non-invasive sensor technologies and to determine the early outbreak of the disease. The experiment was conducted in the greenhouse where the two wheat cultivars namely; Monopol and Kalahari were infected with three fungal diseases viz. Fusarium culmorum, Septoria tritici and Blumeria graminis f.sp. tritic. Throughout the experiment four spectral sensors were used namely, Isaria, Handyspec, Multiplex and Infrared thermal camera. The results showed that as early as 2 days after inoculation (DAI), an increase in the average canopy temperature and maximum temperature difference within the canopy (MTD) was observed. Similarly, the REIP calculated from Handyspec showed significant difference between the infested and the control plants before the visual symptoms appeared. Multiplex measured chlorophyll content which is related to the photosynthesis process allowed to detect the early symptoms in contrast to the Isaria which, does not show a significant difference between control and infected plants.