Performance of Grain Sorghum Hybrids Resistant to Acetolactate Synthase (ALS) and Acetyl Coenzyme-A Carboxylase (ACCase) Inhibitor Herbicides

Authors: WEERASOORIYA, DILOOSHI - Kansas State University; BANDARA, ANANDA - Kansas State University; Dowell, Floyd; PEIRIS, KAMARANGA - Kansas State University; Bean, Scott; PERUMAL, RAMASAMY - Kansas State University; TESSO, TESFAYE - Kansas State University

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/14/2020
Publication Date: 8/18/2020
Citation: Weerasooriya, D., Bandara, A., Dowell, F.E., Peiris, K., Bean, S.R., Perumal, R., Tesso, T. 2020. Performance of Grain Sorghum Hybrids Resistant to Acetolactate Synthase (ALS) and Acetyl Coenzyme-A Carboxylase (ACCase) Inhibitor Herbicides. Crop Science. https://doi.org/10.1002/csc2.20309.
DOI: https://doi.org/10.1002/csc2.20309

Interpretive Summary: Though second among the major feed crops grown in the U.S., sorghum (Sorghum bicolor (L.) Moench) acreage declined sharply over the past several decades. Among the many factors responsible for this includes lack of better post-emergence weed control options. Farmers opt for crops and tools that allow better management of weeds but, sorghum does not offer these options especially for post-emergence grass weeds. The discovery of sources of resistance to two classes of inhibitor herbicides in feral relatives of sorghum opened a new horizon for development of resistance based weed control option for the crop. However, depending on the background of the resistance genes, resistant genotypes express various degree of temporary interveinal chlorosis and reduced vigor during seedling stages. Also, because the resistance genes for both herbicides come from wild relatives, there is a concern about wild characteristics dragging along that can possibly undermine yield potential and grain quality in resistant hybrids. Thus, this study was aimed at generating information to pave the way for deployment of the resistance technology through evaluating the impacts of the resistance traits on agronomic adaptability, yield potential and grain and nutritional quality attributes of ALS and ACCase resistant hybrids in comparison with regular grain sorghum hybrids.

Technical Abstract: Though second among the major feed crops grown in the U.S., sorghum (Sorghum bicolor (L.) Moench) acreage declined sharply over the past several decades. Among the many factors responsible for this includes lack of better post-emergence weed control options. Farmers opt for crops and tools that allow better management of weeds but, sorghum does not offer these options especially for post-emergence grass weeds. The discovery of sources of resistance to Acetolactate synthase (ALS) and Acetyl-Coenzyme A carboxylase (ACCase) inhibitor herbicides in feral relatives of sorghum opened a new horizon for development of resistance based weed control option for the crop. The ALS trait offers resistance to a wide range of ALS herbicide chemistries while the ACCase to all fop class herbicides. However, depending on the background, ALS resistant genotypes express various degree of temporary interveinal chlorosis and reduced vigor during seedling stages. Also, because the resistance genes for both herbicides come from wild relatives, there is a concern about wild characteristics dragging along that can possibly undermine yield potential in resistant hybrids. This study is aimed at generating information to pave ways for deployment of the resistance technology through evaluating the impacts of the resistance traits on agronomic adaptability, yield potential and grain and nutritional quality attributes of ALS and ACCase resistant hybrids in comparison with regular grain sorghum hybrids.