OPTICAL RECOGNITION OF SCAB-DAMAGED WHEAT

Authors: Delwiche, Stephen - Steve; Pearson, Thomas

Submitted to: American Association of Cereal Chemists Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 9/19/2004
Publication Date: 9/19/2004
Citation: Delwiche, S.R., Pearson, T.C. 2004. Optical recognition of scab-damaged wheat. AACC Annual Meeting Abstracts. Available: http://www.aaccnet.org/meetings/2004/abstracts/a04ma47.htm.

Interpretive Summary:

Technical Abstract: Fusarium head blight (FHB), also known as scab, is a fungal disease that occurs in small grains. Scab results in depressed yields and can also adversely affect grain quality. Because of the potential for production of deoxynivalenol (DON), FHB is also a food safety concern. A study was conducted which examined the potential of NIR reflectance for detection of scab-damaged wheat kernels. More than 5,000 kernels from commercial releases and breeders lines of hard red spring wheat, equally divided between infected and healthy categories, were examined by single kernel reflectance (1000-1700 nm). Using statistical classification techniques, such as linear discriminant analysis and non-parametric (k-nearest-neighbor) classification, an upper level for accuracy of NIR-based classification schemes at approximately 97% was established. An exhaustive search of the most suitable wavelength pairs for the spectral difference, log(1/R at wavelength 1) minus log(1/R at wavelength 2), revealed that the low-wavelength region of a broad carbohydrate absorption band (centered around 1200 nm) was very effective at discriminating between healthy and scab-damaged kernels, with approximate accuracies of 95%. Such accuracies were deemed sufficient for development of the technology for a two-wavelength high-speed commercial sorter. Ongoing research is aimed at demonstrating the reduction in DON concentration that is achieved by two-wavelength sorting.