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United States Department of Agriculture

Agricultural Research Service

Title: Comparison of Preemergence and Postemergence Weed Control Systems in Newly Established Pecan

Authors
item Faircloth, Wilson
item Patterson, Michael - AUBURN UNIVERISTY
item Foshee, Wheeler - AUBURN UNIVERSITY
item Nesbitt, Monte - AUBURN UNIVERSITY
item Goff, William - AUBURN UNIVERSITY

Submitted to: Weed Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 30, 2007
Publication Date: October 1, 2007
Citation: Faircloth, W.H., Patterson, M.G., Foshee, W.G., Nesbitt, M.L., Goff, W. 2007. COMPARISON OF PREEMERGENCE AND POSTEMERGENCE WEED CONTROL SYSTEMS IN NEWLY ESTABLISHED PECAN. Weed Technology. v.21 p 972-976.

Interpretive Summary: For Valencia peanuts, pod brightness is a useful characteristic in the grading process, at the buying points. Presently, trained personnel (inspectors) make visual observation of each peanut pod, from samples drawn from bigger lots, and determine the percentage of discolored pods present in the samples. From these determinations they grade the entire lots and the grade can have an affect on the price at which the Valencia peanuts are sold. The visual method, though seem to be reliable, is not accurate due to the human element involved. An instrument may be more methodic and objective and the design and operation of an optical system for this purpose is described here. A narrow beam of white light was collimated on to the surface of a peanut pod at four consecutive positions on the circumference separated by 90' from each other. Diffuse reflectance from the peanut surface is measured at each position, using a silicon detector with UV enhanced response. The average of these four values was found to be a good indicator of the pod brightness and was used to detect the discolored peanuts. Results from the measurements done with this instrument showed a high degree of correlation with the visual evaluations earlier made by trained inspectors.

Technical Abstract: . For Valencia peanuts, pod brightness is a useful characteristic in the grading process, at the buying points. Presently, trained personnel (inspectors) make visual observation of each peanut pod, from samples drawn from bigger lots, and determine the percentage of discolored pods present in the samples. From these determinations they grade the entire lots and the grade can have an affect on the price at which the Valencia peanuts are sold. The visual method, though seem to be reliable, is not accurate due to the human element involved. An instrument may be more methodic and objective and the design and operation of an optical system for this purpose is described here. A narrow beam of white light was collimated on to the surface of a peanut pod at four consecutive positions on the circumference separated by 90' from each other. Diffuse reflectance from the peanut surface is measured at each position, using a silicon detector with UV enhanced response. The average of these four values was found to be a good indicator of the pod brightness and was used to detect the discolored peanuts. Results from the measurements done with this instrument showed a high degree of correlation (r 2 =0.98) with the visual evaluations earlier made by trained inspectors.

Last Modified: 11/28/2014
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