Author
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Fitzgerald, Glenn |
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Submitted to: Agronomy Abstracts
Publication Type: Abstract Only Publication Acceptance Date: 8/30/2001 Publication Date: N/A Citation: N/A Interpretive Summary: Technical Abstract: The strawberry spider mite (Tetranychus turkestani) is a serious pest in California cotton and causes reddish discoloration on leaf surfaces that may be detectable through remote sensing. Once mite populations reach a critical threshold, the entire field is typically sprayed with pesticide. If outbreak locations can be identified, it might be possible to control them with site-specific pesticide applications. To determine whether detection is possible, AVIRIS imagery was collected over USDA-ARS cotton research fields at Shafter, California, in 1999. Additionally, spectral signatures were recorded using a liquid crystal tunable filter camera system mounted on a high-clearance field vehicle. Cotton plants in the field were imaged and spectra collected from 450- 1050 nm for various scene components such as mite damaged areas on leaves, healthy leaves, shadow, and soil background. These signatures were used in a linear spectral unmixing procedure to unmix the AVIRIS data, producing abundance maps for each scene component. The procedure successfully distinguished between a field that had been kept mite-free and an adjacent field where mites were allowed to infest the cotton crop. Areas of relatively greater mite damage (abundance) within the mite-infested field were also identified. |
