Weed Research (2002) 42, 242-248

T. Heisel, J. Schou, C. Andreasen and S. Christensen (2002)
Using laser to measure stem thickness and cut weed stems
Weed Research 42 (3), 242-248
Abstract: Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO₂ laser. Treatments were carried out on pot plants, grown in the greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not. A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses on a field scale are discussed.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Christian Andreasen, Torben Heisel

Research topic(s) for pests/diseases/weeds:
surveys/sampling/distribution
control - general

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Solanum nigrum (weed)	Beet/sugarbeet (Beta vulgaris)	Denmark