Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Weed Control without Chemicals

15.03.2012
Weed zapping with lasers! A research project in Hannover uses laser technology to kill weeds in an early growth stage. This environmental-friendy method offers news possibilities for weed control for agriculture and garden centers.

The laser beam can be used to selectively fight weeds in an early growth stage. This is the result of a current research project between the Laser Zentrum Hannover (LZH) and the Biosystems and Horticultural Engineering (BGT) faculty of the Leibniz Universität Hannover.


Exact positioning of the laser beam (shown here in red) on weed model plants in a laboratory setting

More and more, environmentally safe methods are being used to rid fields used for agricultural and horticultural of unwanted plants, or weeds. Chemical pesticides can be used selectively and are suitable for use where conventional, thermal methods such as flaming are either not exact enough, or are too energy consuming. However, drift and overdosing often lead to harmful herbicide residues in the top soil layers, or in surface water. By using an exact, selective laser beam, the growth of weeds can be impaired by destroying the sensitive growth centers of the plants, their so-called meristems. Current laboratory results show that a minimum dose of around 35 Joules is necessary to kill seedlings, and this laser energy can be exactly and effectively adapted to the plant species and growth stage.

Researchers from the LZH Department of Materials and Processes, Safety Technology Group are using a CO2 laser in the infrared range with a wavelength of 10.6 µm in their current investigations. The laser radiation has a direct thermal effect on the plants. By using a galvanometer scanner with a flexible mirror system, the laser beam can be moved quickly from plant to plant, and can be focused with high precision on the near-surface meristems. Under laboratory conditions, an accuracy of

A stereo camera system is used to recognize the plants and optimize the position of the laser beam. After using a complex processing method, scientists of the BGT have compared camera images based on threshold level filtering and edge detection, with Active Shape Models of the plants. The position of the leaves can be used to determine exactly where the meristem position is, and once these coordinates are found, a signal is sent to the laser to “hit the target”.

Scientists at the LZH have been able to determine exactly how much energy is needed to achieve an optimal effect on the target, making this method especially efficient. At the moment, different irradiation times in different weed concentrations are being tested concerning economic viability. Current knowledge shows that the best results for large areas can be provided by using autonomous field robots working in a stop-and-go mode.

The project „Investigations on the Effect of the Laser Beam on young Plants for Weed Control using Image Processing“ is subsidized by the German Research Foundation (DFG).

Contact:
Laser Zentrum Hannover e.V.
Michael Botts
Hollerithallee 8
D-30419 Hannover, Germany
Tel.: +49 511 2788-151
Fax: +49 511 2788-100
E-Mail: m.botts@lzh.de
The Laser Zentrum Hannover e.V. (LZH) carries out research and development in the field of laser technology and is supported by the Ministry of Economic Affairs, Labour and Transport of the State of Lower Saxony (Niedersächsisches Ministerium für Wirtschaft, Arbeit und Verkehr).

Michael Botts | Laser Zentrum Hannover e.V.
Further information:
http://www.lzh.de

More articles from Life Sciences:

nachricht Chip-based optical sensor detects cancer biomarker in urine
05.12.2019 | The Optical Society

nachricht Scientist identify new marker for insecticide resistance in malaria mosquitoes
05.12.2019 | Liverpool School of Tropical Medicine

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: The coldest reaction

With ultracold chemistry, researchers get a first look at exactly what happens during a chemical reaction

The coldest chemical reaction in the known universe took place in what appears to be a chaotic mess of lasers. The appearance deceives: Deep within that...

Im Focus: How do scars form? Fascia function as a repository of mobile scar tissue

Abnormal scarring is a serious threat resulting in non-healing chronic wounds or fibrosis. Scars form when fibroblasts, a type of cell of connective tissue, reach wounded skin and deposit plugs of extracellular matrix. Until today, the question about the exact anatomical origin of these fibroblasts has not been answered. In order to find potential ways of influencing the scarring process, the team of Dr. Yuval Rinkevich, Group Leader for Regenerative Biology at the Institute of Lung Biology and Disease at Helmholtz Zentrum München, aimed to finally find an answer. As it was already known that all scars derive from a fibroblast lineage expressing the Engrailed-1 gene - a lineage not only present in skin, but also in fascia - the researchers intentionally tried to understand whether or not fascia might be the origin of fibroblasts.

Fibroblasts kit - ready to heal wounds

Im Focus: McMaster researcher warns plastic pollution in Great Lakes growing concern to ecosystem

Research from a leading international expert on the health of the Great Lakes suggests that the growing intensity and scale of pollution from plastics poses serious risks to human health and will continue to have profound consequences on the ecosystem.

In an article published this month in the Journal of Waste Resources and Recycling, Gail Krantzberg, a professor in the Booth School of Engineering Practice...

Im Focus: Machine learning microscope adapts lighting to improve diagnosis

Prototype microscope teaches itself the best illumination settings for diagnosing malaria

Engineers at Duke University have developed a microscope that adapts its lighting angles, colors and patterns while teaching itself the optimal...

Im Focus: Small particles, big effects: How graphene nanoparticles improve the resolution of microscopes

Conventional light microscopes cannot distinguish structures when they are separated by a distance smaller than, roughly, the wavelength of light. Superresolution microscopy, developed since the 1980s, lifts this limitation, using fluorescent moieties. Scientists at the Max Planck Institute for Polymer Research have now discovered that graphene nano-molecules can be used to improve this microscopy technique. These graphene nano-molecules offer a number of substantial advantages over the materials previously used, making superresolution microscopy even more versatile.

Microscopy is an important investigation method, in physics, biology, medicine, and many other sciences. However, it has one disadvantage: its resolution is...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

The Future of Work

03.12.2019 | Event News

First International Conference on Agrophotovoltaics in August 2020

15.11.2019 | Event News

Laser Symposium on Electromobility in Aachen: trends for the mobility revolution

15.11.2019 | Event News

 
Latest News

Detailed insight into stressed cells

05.12.2019 | Life Sciences

State of 'hibernation' keeps haematopoietic stem cells young - Niches in the bone marrow protect from ageing

05.12.2019 | Life Sciences

First field measurements of laughing gas isotopes

05.12.2019 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>