To What Extent Does Yellow Rust Infestation Affect Remotely Sensed Nitrogen Status?

Area of Science:

• Agricultural Science
• Plant Pathology
• Remote Sensing

Background:

• Crops face multiple stresses in fields, complicating stress detection.
• Existing phenotyping studies often focus on single stresses, neglecting complex field conditions.
• Wheat yellow rust can mimic or mask other stress symptoms, impacting accurate assessment.

Purpose of the Study:

• To investigate the impact of wheat yellow rust on reflectance measurements.
• To assess how yellow rust affects nitrogen status evaluation in wheat.
• To improve crop phenotyping by accounting for disease-induced spectral changes.

Main Methods:

• Utilized a multi-sensor mobile platform for RGB and multispectral imaging.
• Applied the SegVeg approach (U-NET and pixel-wise classifier) to identify disease damage.
• Analyzed reflectance data and nitrogen status in relation to disease severity and yield.

Main Results:

• Disease damage proportion effectively predicted grain yield, comparable to visual scoring.
• Wheat yellow rust altered reflectance in both damaged and healthy leaf areas by affecting nitrogen status.
• The Normalized Difference Red Edge (NDRE) index from healthy areas or damage proportion mitigated spectral interference.

Conclusions:

• Disease impact must be integrated into reflectance-based decision support tools for accurate crop monitoring.
• Phenotyping strategies need to address the challenges posed by multiple co-occurring stresses.
• Further research is required to develop robust methods for multi-stress phenotyping.