Drought and heat stress induce differential physiological and agronomic trait responses in cotton

Authors: BISTA, MOHAN - Mississippi State University; ADHIKARI, BIKASH - Mississippi State University; SANKARAPILLA, LEKSHMY - Mississippi State University; PIERALISI, BRIAN - Mississippi State University; REDDY, K - Mississippi State University; Jenkins, Johnie; BHEEMANAHALLI, RAJU - Mississippi State University

Submitted to: Industrial Crops and Products
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/27/2024
Publication Date: 9/4/2024
Citation: Bista, M.K., Adhikari, B., Sankarapilla, L.V., Pieralisi, B., Reddy, K.R., Jenkins, J.N., Bheemanahalli, R. 2024. Drought and heat stress induce differential physiological and agronomic trait responses in cotton. Industrial Crops and Products. 222(2024):119540. https://doi.org/10.1016/j.indcrop.2024.119540.
DOI: https://doi.org/10.1016/j.indcrop.2024.119540

Interpretive Summary: Prolonged droughts and rising temperatures pose a significant threat to cotton yields, particularly during the crucial stages of flowering and boll development. While the individual effects of drought or heat on cotton traits are well-documented, our study sheds light on their combined interaction effect in cotton. We conducted a comprehensive study using twelve genetically diverse upland cotton cultivars in four distinct growing environments: control (CNT), drought stress (DS), heat stress (HS), and the combined drought and heat stress (DHS) during the flowering and boll development stages. Combined stress has a more pronounced negative impact on plant health and yield traits than individual stresses. For instance, leaf temperature increased by 11°C under combined stress, 9°C under heat, and 2°C under drought compared to control-grown plants. Drought stress was more influential in reducing boll numbers with or without heat. Drought stress without heat reduced oil content by 10%. The combined stress effects on most traits were not simply the sum of individual stress effects. This study highlights the importance of improving combined stress tolerance at the reproductive stage, not just drought or heat alone. This knowledge is crucial for developing more resilient cotton for hot and arid environments, thereby enhancing sustainability and productivity.

Technical Abstract: Prolonged droughts and rising temperatures pose a significant threat to cotton yields, particularly during the crucial stages of flowering and boll development. While the individual effects of drought or heat on cotton traits are well-documented, our study sheds light on their combined interaction effect in cotton. We conducted a comprehensive study using twelve genetically diverse upland cotton cultivars in four distinct growing environments: control (CNT), drought stress (DS), heat stress (HS), and the combined drought and heat stress (DHS) during the flowering and boll development stages. Our findings reveal that the combined stress has a more pronounced negative impact on plant health and yield traits than individual stresses. For instance, leaf temperature increased by 11°C under combined stress, 9°C under heat, and 2°C under drought compared to control-grown plants. Drought stress was more influential in reducing boll numbers with or without heat. Compared to the control-grown plants, a per °C increase in leaf temperature decreased cotton yield by 12% and 2% with and without drought, respectively. Further, drought stress without heat reduced oil content by 10%. All physiological and some agronomical traits showed a weaker association between control and combined stress. Moreover, the combined stress effects on most traits were not simply the sum of individual stress effects. This study highlights the importance of improving combined stress tolerance at the reproductive stage, not just drought or heat alone. This knowledge is crucial for developing more resilient cotton for hot and arid environments, thereby enhancing sustainability and productivity.