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POSTERS: Remote Sensing and Sensor Technology

Phakopsora pachyrizi monitoring by spectral reflectance
Elias Zuchelli - Universidade de Passo Fundo. Michele Fornari- Universidade de Passo Fundo

Soybean rust (SBR) is caused by the biotrophic pathogen Phakopsora pachyrizi. SBR is a polycyclic disease where urediniospores dispersed by the wind lead to different spatiotemporal epidemics. Threshold for disease management considers SBR severity and infection timeframe. Remote sensing techniques mesure spectral response of the canopy: characterized by the wave reflectance process. This techniques can be successfully employed in disease management studies, due to the differences in the spectral responses of a healthy leaf and a diseased leaf. Based on this, the present study sought, through the FieldSpec 3 sensor, to determine the potential use of reflectance measurements to quantify the damages caused by the SBR. Plant leaves with different SBR severities (0, 0.1, 2, 3, 5%) were submitted to spectral evaluation on spectrophotometer FieldSpec 3. resulting in differences among diseased and healthy leaves (p>0.05) to spectral bands 531, 720, and 810 nm. Correlations were establish, and as severity increase plant reflectance decrease 0.018, 0.0198, 0.013 nm to respectively bands 531, 720, and 810 nm (r2= 0.76, 0.89, 0.93), respectively. Use of remote sensing is a tool able to quantify and identify SBR even with lower severity in the begin of the epidemy. This results contribute to SBR integrate disease management.