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The Use of Remote Sensing in Weed Control. Joshua Bushong SOIL/BAE 4213 Spring 2008. Why . Efficiency Low in areas of low populations Wasted herbicide Decrease cost with higher efficiency Population clusters Areas with low or high densities Areas with no weeds. What is Remote Sensing.
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The Use of Remote Sensing in Weed Control Joshua Bushong SOIL/BAE 4213 Spring 2008
Why • Efficiency • Low in areas of low populations • Wasted herbicide • Decrease cost with higher efficiency • Population clusters • Areas with low or high densities • Areas with no weeds
What is Remote Sensing • Remote sensing is the science and art of obtaining information about a phenomenon without being in contact with it • Can be used to discriminate between weeds, crops, soil, and structures • Collection of quantitative data that can be used to make a recommendation
Possible Uses • Fallow systems / Between Rows • Non-selective • Most practical • Lower risk • Lowest cost • In Season systems • Selective • More complex • Site Specific
Terminology • Weed • Any plant growing in the wrong place at the wrong time and in the wrong quantity, or a plant whose virtues are not yet discovered. • Hyperspectral sensing • Data collected from contiguous bands usually by one sensor. • Spectral Vegitation Indices • Ratio of reflectances from various wavelengths • Multispectral sensing • Data collected from selected bands usually by multiple sensors
Hyperspectral Imagery • Contiguous wave length imagery • Identify plant species by reflectance • Reflectance at about 780 nm • Spearmint 65 • Peppermint 60 • Green foxtail 50 • Waterhemp 35 • Pigweed: 25
Hyperspectral Imagery • Yellow Nutsedge
Hyperspectral Imagery • Pigweed
Hyperspectral Imagery • Dead Crabgrass
Multispectral Sensing • Uses selected bands • Can Identify weeds in citrus with an accuracy of about 99.07%
Multispectral Sensing Original red, green and blue image Image with weed and non-weed classifications Image with weed, citrus, tree, soil, and roof classifications Image with weed, vegetation and non-veg. classifications
Non-selective • Only needs to identify between bare soil and a plant • Reduced herbicide usage • Reduce environmental risks • Reduced costs • Fallow systems • Between rows / hooded sprayer • Row crops • Orchards
Weedseeker / Spot Spray • Cost effective • Identifies chlorophyll • Automated
Sensor-controlled Field Spraying • Real time application • Possible use in cereals • Variable Rates • Reduced herbicide usage • Crop/weed discrimination
Sensor-controlled Field Spraying • Image analysis approach • CCD cameras • Image analysis software • Discriminate between crops and weed • Color • Shape • Texture
Sensor-controlled Field Spraying • Spectral reflectance approach • Optoelectronic weed sensor
References • http://www.ntechindustries.com/concept.html • http://www.agecon.purdue.edu/topfarmer/newsletter/TFCW05_2005.pdf • http://www.blackwell-synergy.com/doi/pdf/10.1111/j.1445-6664.2006.00236.x?cookieSet=1 • Dammer, Karl-Heinz and Wartenberg, G. Sensor- based wed detection and application of variable herbicide rates in real time. Crop Protection. Vol. 26, issue 3, March 2007, p. 270-277. Weed Science in Real Time.