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Archive for the ‘physical control’ Category

Weed zapping

Do electrocution treatments have a place in weed control?

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Researchers used a tractor attachment called The Weed Zapper™ to electrocute eight types of weeds common in soybean crops, including herbicide-resistant waterhemp. (Stock photo via Ivan Radic, Flickr/Creative Commons)

COLUMBIA, Mo. — Researchers from the University of Missouri recently conducted two field studies to explore the effectiveness of electricity in weed control. They used a tractor attachment called The Weed Zapper™ to electrocute eight types of weeds common in soybean crops, including herbicide-resistant waterhemp.

The first study showed that control was more effective in the later stages of weed growth and was most closely related to plant height and the moisture in the plant at the time of electrocution. Once the weeds had set seed, the treatments reduced viability by 54 to 80 percent across the weed species evaluated. A second study showed electrocution reduced late-season, herbicide-resistant waterhemp plants by 51 to 97 percent.

At some stages of growth, the soybean crops exhibited yield losses of 11 to 26 percent following electrocution treatments – though researchers say those results likely represent a worse-case scenario. In late-season treatments, for example, the clear height differential between waterhemp and the soybean canopy means the electrocution device can treat the weed without sustained contact with the crop.

The net takeaway: When used as part of an integrated control program, electrocution can eliminate many late-season, herbicide-resistant weed escapes in soybean crops and reduce the number and viability of weed seeds that return to the soil seedbank.

Want to know more? Read the article “The Impact of Electrocution Treatments on Weed Control and Weed Seed Viability in Soybean featured in the latest edition of the journal Weed Technology.

–Cambridge University Press
via EurekAlert!

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Using electricity to remove persistent weeds

by Cambridge University Press

Weed zapping
The Weed Zapper. Credit: the weed zapper.com

Researchers from the University of Missouri recently conducted two field studies to explore the effectiveness of electricity in weed control. They used a tractor attachment called The Weed Zapper to electrocute eight types of weeds common in soybean crops, including herbicide-resistant waterhemp.

The first study showed that control was more effective in the later stages of weed growth and was most closely related to plant height and the moisture in the plant at the time of electrocution. Once the weeds had set seed, the treatments reduced viability by 54 to 80 percent across the weed species evaluated. A second study showed electrocution reduced late-season, herbicide-resistant waterhemp plants by 51 to 97 percent.

At some stages of growth, the soybean crops exhibited yield losses of 11 to 26 percent following electrocution treatments—though researchers say those results likely represent a worse-case scenario. In late-season treatments, for example, the clear height differential between waterhemp and the soybean canopy means the electrocution device can treat the weed without sustained contact with the crop.

The net takeaway: When used as part of an integrated control program, electrocution can eliminate many late-season, herbicide-resistant weed escapes in soybean crops and reduce the number and viability of weed seeds that return to the soil seedbank.

The research was published in Weed Technology.


Explore further

Examining the impact of herbicide-resistant crops on weed management


More information: Haylee Schreier et al, The Impact of Electrocution Treatments on Weed Control and Weed Seed Viability in Soybean, Weed Technology (2022). DOI: 10.1017/wet.2022.56

Provided by Cambridge University Press 

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FEBRUARY 21, 2022

Would micro-ecology be damaged by a plastic film that kills a harmful soil insect?

by Higher Education Press

Would micro ecology be damaged by a plastic film after thoroughly kill Bradysia cellarum?
Credit: Youjun Zhang

Chinese chive (Allium tuberosum) is a perennial herbaceous vegetable with medicinal qualities. Unfortunately, Chinese chive crops are severely damaged by the soil insect Bradysia cellarum. B. cellarum are mainly found in the surface soil to a depth of 5 cm. Department of Plant Protection, Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences Investigator Youjun Zhang and his team showed that thermal treatment of B. cellarum adults, eggs, larvae, and pupae at 40 °C for 3 hours produced mortalities of 100%, 100%, 100% and 81%, respectively, and the fecundity of B. cellarum significantly decreased with increasing temperature and exposure time, completely inhibiting egg-laying at 37°C for 2 hours. These data suggested that B. cellarum is quite sensitive to elevated temperatures. As long as soil temperature to a depth of 5 cm is increased and remains over 40°C for 4 hours, the mortality rate of B. cellarum will be 100%. Therefore, the team has been studying how to improve soil temperature without destroying the ecological environment.

Youjun Zhang and his team had believed that applying a light blue anti-dropping film of 0.10 or 0.12 mm thickness would be enough to kill B. cellarum under a sufficient intensity of sunlight (e.g., between late April and mid-September in Beijing, China). The method was called soil solarization. However, it was not known whether soil solarization affects soil microbial diversity. If soil solarization can kill B. cellarum and also avoid affecting Chinese chive growth and the soil microbial ecological balance, it will be an environmentally friendly control technology.

In this study, Youjun Zhang and his team show that on the first day after soil solarization, 100% control of B. cellarum was achieved. Growth of Chinese chive was lower in solarized plots than in control plots over the first 10 days after treatment, but 20 days after treatment, plants in the solarized plot had recovered and leaf height and yields were equivalent among the treatments. Moreover, the soil microbial community diversity in the treatment group decreased initially before gradually recovering. In addition, the abundance of beneficial microorganisms in the genus Bacillus and in the phyla Proteobacteria, Chloroflexi and Firmicutes increased significantly.

Soil solarization is a promising strategy to control B. cellarum. It is simple to implement, pesticide-free and non-destructive to soil microbial diversity, and it may also promote the abundance of beneficial microorganisms. Soil solarization is practical and worth promoting as a new method of control of B. cellarum infestations in Chinese chive-growing regions.


Explore further

Scientists map geographic patterns of soil microbe communities in Hexi Corridor deserts


More information: Effect of Solarization to Kill Bradysia Cellarum on Chinese Chive Growth and Soil Microbial Diversity, Frontiers of Agricultural Science and Engineering (2021). DOI: 10.15302/J-FASE-2021402

Provided by Higher Education Press

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