Recent study documents damage to rice crops by three fall-applied residual herbicides

Recent study documents damage to rice crops by three fall-applied residual herbicides
Fall-applied residual herbicides are a commonly used control for glyphosate-resistant Italian ryegrass -- one of the most troublesome weeds in Mid-South row crops. But research published in the journal Weed Technology shows rice growers need to be cautious. Some residual herbicides can have a negative impact on rice crop performance. Credit: Weed Technology vol 32 issue 5

Fall-applied residual herbicides are a commonly used control for glyphosate-resistant Italian ryegrass—one of the most troublesome weeds in Mid-South row crops. But research published in the journal Weed Technology shows rice growers need to be cautious. Some residual herbicides can have a negative impact on rice crop performance.

The warning follows field studies conducted in Stoneville, Mississippi, where rice is frequently planted in rotation with soybean, grain sorghum, and cotton. Researchers made fall applications of clomazone, pyroxasulfone, S-metolachlor, and trifluralin to determine their impact on subsequent rice growth and yields.

Each herbicide was applied at both the suggested use rate and at two times the suggested use rate to see whether their persistence in the soil would negatively influence rice planted during the following growing season.

Fourteen days after rice crop emergence, scientists found that pyroxasulfone, S-metolachlor, and trifluralin had produced greater injury to plants than clomazone, regardless of the application rate. The same was true for rice seedling density, height, and maturity.

"Among the in our study, only clomazone should be used as a fall-applied residual herbicide to target glyphosate-resistant Italian ryegrass prior to seeding ," says Jason Bond of Mississippi State University.


Explore further

Researchers confirm glyphosate resistance in junglerice

More information: Benjamin H. Lawrence et al, Effect of Fall-Applied Residual Herbicides on Rice Growth and Yield, Weed Technology (2018). DOI: 10.1017/wet.2018.41
Citation: Recent study documents damage to rice crops by three fall-applied residual herbicides (2018, November 15) retrieved 21 July 2019 from https://phys.org/news/2018-11-documents-rice-crops-fall-applied-residual.html
This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.
6 shares

Feedback to editors

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more