A new study is shedding light on how to make cotton more climate-resilient through improved water use efficiency.
- A research team at Clemson University in the US has discovered that certain root traits in upland cotton can significantly enhance WUE (water use efficiency).
- They found that root weight and length, surface area and volume of very fine roots (less than 0.25 mm in diameter) are key to improving water use efficiency.
THE SIGNIFICANCE: Cotton is an essential crop for the United States economy, but traditional breeding practices have unintentionally left modern cotton varieties vulnerable to climate change stresses.
- WUE is a critical trait for crop resilience in the face of climate change. It measures the amount of biomass or economic yield produced per unit of water used, often summarised as “crop per drop.”
- Upland cotton is a relatively drought tolerant plant and can grow in a variety of climates. Current varieties were developed based on above-ground traits such as harvest index, boll number, boll weight, seed weight and fibre quality.
THE STUDY: Enhancing the cotton root system can help increase a plant’s ability to acquire water and nutrients and maintain productivity under most conditions.
- This study tested genotypes from the major cotton-growing regions in the US—Western, Southwestern, Midsouth and Eastern.
- Cotton varieties Deltapine 14, Station Miller and Southland M1 performed best in the study.
- Hardpans, compacted soil zones that neither roots nor water can penetrate, pose a significant problem affecting plant growth leading to yield losses of up to 50% and making plants more susceptible to drought stress.
- Future studies will verify these results with more genotypes under field conditions and evaluate lint yield in relation to root traits and WUE, as well as verify the results under different soil and water conditions.
THE RESEARCH: The Clemson University team was led by Sruthi Narayanan, associate professor of crop ecophysiology. Om Prakash Ghimire, doctoral student, was the lead author for the paper about the project.
- Other researchers from Clemson were Walker Spivey, Michael Jones and William C Bridges.
- Vasu Kuraparthy from North Carolina State University also participated in the study as did Todd Campbell and Joe Thomas, researchers with the United States Department of Agriculture Agricultural Research Service.
- This research was funded by the United States Department of Agriculture (USDA) Agricultural Research Service and Cotton Incorporated.
ONGOING WORK: Clemson University scientists are involved in several cotton research projects, including:
- Using molecular tools and unique plant germplasm to understand and improve the genetics underlying oil content in upland cotton.
- Developing improved breeding tools, namely DNA markers, germplasm, and enhanced management practices to help boost US cotton production.
- Tweaking cotton genes to develop higher-yielding, better-quality cotton.
- Determining how to breed for more sustainable cotton varieties in Earth’s ever-changing environment.
WHAT THEY SAID:
These traits will be valuable in developing the next generation of water-use-efficient Upland cotton varieties. A major limitation to yield is root exploration failing to keep up with boll growth. This imbalance between root and shoot activity affects the ability of the plant to fill bolls.
— Sruthi Narayanan
Associate Professor (Crop Ecophysiology)
Clemson University
Cotton genotypes that can maintain water-use-efficiency even when root growth is limited by soil hardpans can be good selections for the southeastern United States.
— Om Prakash Ghimire (Lead Author)
Doctoral student
Clemson University
