|Shuey, Chad - UNIVERSITY OF MARYLAND|
|Liang, Shunlin - UNIVERSITY OF MARYLAND|
|McMurtrey Iii, James|
Submitted to: American Society of Agronomy Meetings
Publication Type: Abstract Only
Publication Acceptance Date: August 2, 2001
Publication Date: October 22, 2001
Technical Abstract: Temporal changes in the spectral characteristics of weeds is important for application of remote sensing to identification for weed management. We investigated leaf and canopy reflectance characteristics for common weed species with an objective to understand the temporal and age-size effects on weed spectral characteristics. The leaf and canopy reflectance measurements were made for weeds that were 57, 73 and 99 days old, obtained by staggered planting, using a spectroradiometer in the 350- 2500nm range. The results indicated that leaf spectral characteristics did not show significant differences between the different growth stages for foxtail, jimson weed, pigweed and lambsquarters. The canopy reflectance characteristics were similar in all the age classes for each weed. This suggests that there would be little difference in spectral characteristics of mature weeds after canopy closure. However seedling weeds before canopy closure may differ in spectral properties but would need to be discriminated from soil, shadow and crop before application to weed management would be possible.