TITLE:
Comparing Canopy Hyperspectral Reflectance Properties of Palmer amaranth to Okra and Super-Okra Leaf Cotton
AUTHORS:
Reginald S. Fletcher, Rickie B. Turley
KEYWORDS:
Amaranthus palmeri, Discrimination, Gossypium hirsutum, Remote Sensing Technology
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.9 No.13,
December
25,
2018
ABSTRACT: Palmer amaranth (Amaranthus
palmeri S. Wats.)
is a major weed problem of cotton (Gossypium hirsutum L.) production systems in
the southern United States. Hyperspectral remote sensing has shown promise as a
tool for crop weed discrimination, and there is a growing interest in using
this technology for identifying weeds in cotton production systems. Information
is lacking on differentiating Palmer amaranth from cotton with an okra
leaf structure based on canopy hyperspectral reflectance properties. Two
greenhouse studies were conducted to compare canopy hyperspectral reflectance
profiles of Palmer amaranth to canopy hyperspectral
reflectance profiles of okra and super-okra leaf cotton and to identify optimal
regions of the electromagnetic spectrum for their discrimination. Ground-based
hyperspectral measurements of the plant canopies were obtained with a
spectroradiometer (400 - 2350 nm range). Analysis of variance (ANOVA, p ≤
0.05), Dunnett’s test (p ≤ 0.05),
and difference and sensitivity measurements were tabulated to determine the
optimal wavebands for Palmer amaranth and cotton
discrimination. Results were inconsistent for Palmer
amaranth and okra leaf cotton separation. Optimal wavebands for distinguishing Palmer amaranth from super-okra leaf
cotton were observed in the shortwave infrared region (2000 nm and 2180 nm) of
the optical spectrum. Ground-based and airborne sensors can be tuned into the
shortwave infrared bands identified in this study, facilitating application of
remote sensing technology for Palmer amaranth discrimination from super-okra
leaf cotton and implementation of the technology as a decision support tool in
cotton weed management programs.