Heat Stress Impact on Cotton Growth and Yield

Cotton is inherently susceptible to elevated temperatures, particularly during reproductive stages, when episodes of heat stress can disrupt physiological processes and markedly reduce lint yield and fibre quality. High temperatures impair pollen viability and anther dehiscence, triggering boll abscission and a diminished boll set. Photosynthetic efficiency declines under heat stress due to damage to photosystem II, reduced chlorophyll content and impaired stomatal regulation, leading to lower carbohydrate supply for developing bolls. Concurrently, heat stress provokes an overproduction of reactive oxygen species, which, if unchecked, cause lipid peroxidation, membrane destabilisation and cell death. Plants deploy a suite of defence mechanisms, including induction of antioxidant enzymes and synthesis of heat shock proteins, to mitigate oxidative damage and maintain protein stability. Nutrient status and hormonal signalling also modulate heat tolerance by influencing water relations, osmotic adjustment and gene expression. From the molecular to the agronomic scale, research has elucidated key traits—such as enhanced antioxidant capacity, sustained stomatal conductance and stable boll weight—that underpin resilience. Globally, rising temperatures threaten cotton production in major growing regions, necessitating integrative strategies that combine physiological insight, breeding for thermo-stable genotypes and targeted agronomic interventions to secure fibre supply under a warming climate.

Research from Nature Portfolio

Recent studies have demonstrated that exogenous application of growth regulators can substantially protect cotton during episodes of elevated temperature. Foliar sprays of signalling molecules such as hydrogen peroxide and salicylic acid bolster antioxidant enzyme activities, preserve chlorophyll content and sustain photosynthetic rate, leading to improved boll weight and fibre quality under short-term heat regimes. In parallel, targeted foliar nutrition with elements such as zinc, potassium and boron has been shown to enhance leaf water potential, stomatal conductance and enzymatic antioxidants, thereby reducing membrane damage and supporting boll development when plants face supra-optimal temperatures. These interventions collectively maintain key physiological functions during reproductive phases and offer practical approaches to ameliorate heat-induced yield losses.

Heat Stress Impact on Cotton Growth and Yield publication trend

The graph below shows the total number of articles in heat stress impact on cotton growth and yield across all publications each year (not limited to Nature Index journals).

Technical terms

Reactive oxygen species (ROS): Highly reactive molecules produced under stress that can damage cellular components if not scavenged.

Antioxidant enzymes: Proteins such as superoxide dismutase and catalase that detoxify reactive oxygen species and protect cells from oxidative stress.

Boll: The pod-like fruit of the cotton plant that contains seeds and fibres; its number and weight directly influence yield.

Heat shock proteins: Molecular chaperones induced by high temperature that stabilise other proteins and prevent aggregation.

Relative water content (RWC): A measure of plant water status, calculated as the ratio of actual tissue water to maximal water-holding capacity.

Stomatal conductance: The rate at which CO₂ enters and water vapour exits the leaf through stomata, reflecting gas-exchange capacity.

References

1. Response and Tolerance Mechanism of Cotton Gossypium hirsutum L. to Elevated Temperature Stress: A Review. Frontiers in Plant Science (2016).
2. Exogenously applied growth regulators protect the cotton crop from heat-induced injury by modulating plant defense mechanism. Scientific Reports (2018).
3. Role of mineral nutrition in alleviation of heat stress in cotton plants grown in glasshouse and field conditions. Scientific Reports (2019).
4. Unraveling Heat Tolerance in Upland Cotton (Gossypium hirsutum L.) Using Univariate and Multivariate Analysis. Frontiers in Plant Science (2022).
5. Heat Stress in Cotton: A Review on Predicted and Unpredicted Growth-Yield Anomalies and Mitigating Breeding Strategies. Agronomy (2021).
6. Exploiting Agronomic and Biochemical Traits to Develop Heat Resilient Cotton Cultivars under Climate Change Scenarios. Agronomy (2021).