Our crop-ecophysiological research program focuses on improving productivity of agronomic crops through economically viable and environmentally sustainable agronomic practices. Climate variability necessitates the development of resilient, regionally adapted production systems and our group strives to achieve this by applying concepts from physiology, biochemistry, lipidomics, and genomics. Crop-ecophysiological responses from the rhizosphere to the global scale are studied using on-farm, greenhouse, growth chamber, laboratory, and modeling experiments. Our group's main focus is categorized under the following two themes.
Crop response and adaptation to climate change
Climate models predict continued warming and increased frequency, duration, and intensity of drought across the southeast U.S. Our research focuses on understanding crop response and adaptation to changing environmental conditions (water and temperature) in order to develop climate-resilient crop varieties. Research priorities include the identification of physiological traits and mechanisms that are associated with drought and heat tolerance, developing high throughput screening tools/traits to select for tolerant genotypes, and screening germplasm collections to identify new sources of tolerance. This research is framed at the molecular and cellular levels to understand biochemical and genetic pathways associated with stress tolerance; at the whole plant level to determine how various biochemical and physiological processes integrate to form yield under stress conditions; and at the whole field level to understand how crop plants interact with the environment. We employ lipidomic, proteomic, metabolomic, and genomic tools as well as traditional physiology tools to investigate the research questions. We study physiological processes including gas exchange and stomatal regulation, antioxidant production, lipidome and proteome changes, carbohydrate metabolism, hormonal regulation, and pollen and ovule performance to identify tolerance mechanisms or traits associated with drought and heat tolerance.
Improving field crop production through sustainable agronomic practices
Soils that are inherently low in fertility and organic matter content, and are highly prone to runoff are typical to South Carolina. Another characteristic of these soils is a hardpan that restricts root growth. More than 80% of row crops in South Carolina are produced in fields with soil compaction problems. The conventional tillage practices give little consideration to the potential runoff and erosion problems, reduce organic matter content of soils and increase the vulnerability of soils to drought stress. However, no-till field crop production is not suitable for this region because of problems with soil compaction. Our research focuses on strategies to optimize conservation tillage practices and identification of genotypes with a root system architecture that is best suited for this region. Strategies for optimization of conservation tillage include crop diversification via cover crops and new crop introductions, crop sequencing, and cultivar selection. Cover crops are evaluated for their interaction with tillage, water use efficiency, ability to reduce weed pressure, and nitrogen fertilizer requirements, while, at the same time, maintaining overall system productivity and profitability. Bioenergy crops such as switchgrass, sorghum, or miscanthus are tested as part of crop introductions to existing cropping systems. Impact of conservation tillage practices on pests and beneficial organisms is also assessed. Crop varieties with root systems that can penetrate soil hardpan, which can increase lateral root growth after sensing the hardpan, or those with deeper root systems that can extract water from deep soil profiles might perform well in the hardpan forming, drought prone soils of South Carolina. Our research aims at identification of genotypes with a root system architecture that maximizes productivity in the hardpan forming soils.
Current Projects
Improving soybean’s efficiency for heat tolerance with an integrated lipidomic and genetic approach
Funding: USDA-NIFA
Identification of molecular markers associated with root traits that improve drought performance in cotton
Funding: USDA-ARS, Cotton Incorporated
Lipid metabolic changes contributing to heat tolerance in peanut
Funding: National Peanut Board, South Carolina Peanut Board
Building partnerships for climate-smart commodities in South Carolina
Funding: USDA
Cover crop inter-seeding in organic corn production to reduce resource inputs and soil disturbance and enhance pest control and farm profitability
Funding: USDA-SARE
Stability of the high protein trait of soybeans under drought and heat stresses
Funding: United Soybean Board
A ‘non-targeted metabolomic’ approach for designing seed treatment chemicals for improving soybean germination under drought conditions.
Funding: Clemson University