Climate Change & Weed Management: Small Grains

How to use the tables:

Check if the table has data for a weed species you’re trying to manage (e.g. Wild Buckwheat)

You can then see how the performance of the herbicide against the weed will change under different climate conditions.

  • A red “-“ means the herbicide will be less effective as the climate factor increases
  • A green “+” means the herbicide will be more effective as the climate factor increases
  • A blue “=” means there will be no change in efficacy
  • A white “ND” means there was no research data for that interaction

Herbicide Efficacy in Small Grains

Herbicide 
(Trade name) 
Herbicide group numberPhotosynthetic pathwayCommon name 
(Scientific name)
CO2TemperatureReference number
2-4, D4C3Wild buckwheat 
(Polygonum convolvulus)
+ND2
Bromoxynil 
(Maestro®)
6C4Kochia 
(Kochia scoparia)
=ND2
Dicamba 
(Clarity®)
4C4Kochia 
(Kochia scoparia)
ND1
Pinoxaden 
(Axial XL®)
1C3Purple false brome 
(Brachypodium hybridum)
ND+3

Management Recommendations

Credit to Vipan Kumar, Associate Professor at Cornell School of Integrative Plant Science Soil and Crop Sciences Section, and Bryan Brown, Senior Extension Associate at NYS Integrated Pest Management, for reviewing the following recommendations:

  • Diversifying your weed control options is beneficial to off-set herbicide resistance and the potential of decreasing herbicide efficacy with climate change. Instituting cultural and/or mechanical practices, such as cover crops, competitive crop rotation, improve agronomic practices (seed spacing, timing, etc.) will help the crop out compete the weed population. 
  • Other considerations include mechanical tools such as, strategic tillage, seed destructor technology, chaff lining, electric weeders, etc. Using precision, spot sprayers, or spray drones can reduce overall application amounts of herbicides.

The efficacy of herbicides is expected to either decreaseincrease, or maintain effectiveness depending on the specific chemistryspecies, and climate factor(s) involved. This web page focuses on problematic weeds in small grain cropping systems and provides data sourced from the current scientific literature to help build an understanding of how these future shifts might affect weed management. Please note that only a small group of weed species have been studied, so there are many common weeds with no available information on changing herbicide efficacy. However, given the currently available literature, we conclude that photosynthetic pathway, herbicide resistance, and herbicide chemistries will have the most impact on efficacy and management.  

See our other web pages and fact sheets in this series for information on photosynthetic pathways, herbicide resistance effects, and climate change impacts for additional commodity areas. Growers should refer to the current Cornell Pest Management Guidelines for information on pesticides labeled for use in New York State. Contact an area extension specialist for current information on best practices in weed management and herbicide rotation.

 

Credits

This content was authored by Caroline Marschner, Sharon Bachman, Isabella Colucci, John Pirrung, Sophie Westbrook, and Toni DiTommaso. We would also like to express our gratitude again to Vipan Kumar and Bryan Brown for their invaluable support and expert input on this project and these fact sheets.

Disclaimers

Read the pesticide label prior to use. The label is the law.  The information contained on this page is not a substitute for a pesticide label. Trade names used herein are for convenience only; no endorsement of products is intended, nor is criticism of unnamed products implied.

This work was supported by a joint research and extension program funded by the Cornell University Agricultural Experiment Station (Hatch funds) and Cornell Cooperative Extension (Smith Lever funds) received from the National Institutes for Food and Agriculture (NIFA,) U.S. Department of Agriculture. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

References