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United States Department of Agriculture

Agricultural Research Service

Title: Using Mathematica to Analyze Reflectance Spectra from Nitrogen, Potassium, and Water Stressed Plants and Pix Treated Plants

item McKinion, James
item Read, John

Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 4, 2000
Publication Date: N/A

Technical Abstract: The authors conducted research on relating stress factors in the cotton crop to reflectance observations from single leaves, from the crop canopy and correlating the results with multispectral and hyperspectral images. The images were collected from instrumentation platforms mounted on fixed wing aircraft which were flown at weekly intervals during the cotton growing season. Plants were grown in 0.15 M diameter x 1 M long PVC pots from seed. Water and nutrients were supplied via Netafim drippers under computer control from mixing tanks. Potassium, nitrogen and water stresses were induced by supplying reduced levels from the control which received 100% of water and nutrients needed for normal growth. The pots were arranged in an east-west row crop configuration under ambient conditions of sunlight and air for the 1999 growing season. Two adjacent rows of plants were subjected to each treatment level with 50% of plants on the eastern side of the row reserved for destructive sampling, and the remaining 50% plants were maintained in a complete canopy configuration. Reflectance data were collected from each treatment level and the control on a weekly basis. Both individual leaf data (six reflectance/leaf data points per treatment) and canopy data(three reflectance samples per treatment)were collected. This presentation discusses canopy reflectance data from the control and the use of Mathematica for analysis.

Last Modified: 4/19/2015
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