Future of cotton in a warming climate

Pakistan is among the 10 largest cotton-producing countries in the world. There was a time when Pakistan ranked as the fourth-largest cotton producer globally; however, due to a decline in production in recent years, it has now slipped to around seventh position. Within this broader context, one significant and unique reality is that Pakistan, particularly South Punjab, is the only major cotton-producing region in the world where cotton is cultivated under comparatively extremely high temperatures.

South Punjab, especially Multan, Bahawalpur, and Dera Ghazi Khan, are key cotton-producing areas. During the cotton season (May to July), temperatures typically range between 35°C and 42°C, while during severe heatwaves they can rise to between 45°C and 50°C. The primary reasons include dry weather, low humidity, intense sunlight, and high solar radiation, all of which further intensify heat stress on the crop. At times, even nighttime temperatures fail to provide the required cooling, thereby increasing overall crop stress.

In recent days, South Punjab has experienced extremely severe heat conditions. Daytime temperatures have reached up to 48°C, while nighttime temperatures have been recorded at 31°C. When nighttime temperatures exceed 28°C, shedding of cotton flowers and squares begins. At present, the effects of these extreme weather conditions on the cotton crop are already becoming visible.

Similarly, cotton-growing areas of Sindh—particularly Sukkur, Khairpur, Nawabshah, Sanghar, Mirpurkhas, and the Hyderabad division—also represent important agricultural zones for cotton cultivation. During the cotton season, temperatures in these regions generally range between 36°C and 43°C, while in some cases during severe heatwaves they may approach or even exceed 45°C. The relatively dry and hot climate, low rainfall, and prolonged summers significantly impact cotton production, making heat stress a major agricultural challenge here as well.

For cotton cultivation, a temperature range of 25°C to 32°C is considered optimal. Within this range, the cotton plant remains healthy, pollen functions effectively, and fruit development proceeds efficiently, resulting in maximum yield. As temperatures exceed 32°C, negative effects begin to emerge. At 34°C, pollen development starts to decline; at 37°C, pollen germination is significantly affected; at 43°C, the process becomes severely weakened; and at 47°C, pollen activity almost completely stops, disrupting boll formation and causing a sharp decline in yield.

Excessive heat leads to shedding of cotton flowers and bolls. Bolls open prematurely, and overall plant growth is severely affected. Heat stress also disrupts pollen development and germination, weakening boll formation and resulting in significant yield losses. In addition, high temperatures increase whitefly infestations and negatively affect seed germination. Severe environmental stress further deteriorates the quality of both lint and seed. Fiber quality declines in terms of strength, length, and uniformity, creating serious challenges for the textile industry in obtaining quality raw cotton.

When temperatures in Pakistan sometimes rise to 48°C–50°C, the impact on cotton becomes extremely damaging, adversely affecting both yield and quality.

In contrast, other major cotton-producing countries experience relatively different and more moderate climatic conditions. In the Cotton Belt of the United States, particularly Texas, temperatures generally range between 25°C and 35°C, although they may occasionally reach 38°C to 42°C. However, due to better humidity levels, rainfall patterns, and overall climatic balance, the impact of heat is distributed differently. In Brazil, cotton is mostly grown in a moderate and humid climate, where temperatures typically remain between 24°C and 35°C, and periods of extreme heat are relatively limited. Similarly, in China’s Xinjiang region, daytime temperatures during cotton cultivation range from 25°C to 35°C, while cooler nights help reduce overall climatic stress.

In Egypt, cotton is cultivated in a relatively warm but moderately balanced climate, where summer temperatures generally range between 30°C and 40°C, and may occasionally be slightly higher in certain areas. However, overall heat stress conditions are less severe and more balanced compared to Pakistan’s extreme heatwave conditions. In addition, Egypt’s agricultural system, particularly its irrigation and management practices, also helps mitigate the impact of climatic stress on the crop to some extent.

In this comparative perspective, it becomes evident that Pakistan, especially South Punjab and Sindh, lies among the regions where temperature intensity and heat stress are comparatively more severe. This is why, according to some experts, several imported cotton varieties used in Pakistan—typically developed for environments of around 38°C to 40°C—are unable to maintain their full performance under temperatures exceeding 45°C and extreme heatwaves, thereby increasing risks to both yield and quality.

For addressing cotton production challenges and farmers’ financial constraints, two fundamental pathways emerge: increasing per-acre productivity and reducing production costs. Experiences from different countries show that success does not lie in focusing on a single aspect but in addressing both simultaneously. In Turkiye’s case, where yields of approximately 5500 kg per hectare (137 maunds) are being achieved, the focus has now shifted toward cost reduction and efficient resource utilization. Even under severe water scarcity, cotton cultivation has been made possible with just two irrigations, resulting in a slight yield reduction (around 9.5%) but a 13% reduction in costs—demonstrating that effective strategy and stakeholder dialogue can produce workable solutions even under climatic and resource constraints.

Similarly, in hot regions like Egypt and Pakistan, where temperatures reach up to 45°C, it must be acknowledged that this does not mean abandoning cotton cultivation, but rather developing varieties and agricultural strategies capable of performing relatively better under extreme heat. Although complete tolerance at around 45°C is not currently possible and yield reduction at this level is inevitable, progress can still be made. In Pakistan, regions such as Potohar, including Attock and surrounding areas, are being identified as suitable for quality seed production due to lower pest pressure and more favorable environmental conditions. In these areas, high-density planting—around 60,000 plants per acre instead of the traditional 15,000 to 30,000—combined with improved management practices can help address production challenges more effectively.

However, beyond all these practical considerations, the most fundamental point remains that strengthening cotton breeding programs is essential. The relatively integrated public-sector research system seen from the 1980s to 2012 has weakened due to resource constraints, leadership gaps, and administrative and political interference, while the private sector remains largely focused on short-term business models. In this context, modern technologies such as biotechnology and molecular approaches must be balanced with conventional field breeding, genetic improvement, multi-environment testing, and seed strengthening processes. At least 40 to 50 percent of research and development resources should be directed toward field-based breeding and seed development. Overall, these experiences collectively suggest that the solution to the cotton crisis lies not only in technology or financial support, but in the intelligent use of resources, regional agricultural strategies, institutional strengthening, and above all, a shift in priorities and thinking—so that both farmer productivity and production costs can be brought onto a balanced and sustainable path.