*Corresponding author Introduction
Climate change has become a central challenge for global agriculture in the 21st century. Increasing temperatures, altered rainfall patterns, and more frequent extreme weather events are already affecting crop yields and plant health (Janni et al., 2024). Rice, a staple for more than half of the global population, is extremely vulnerable to changes in climate. Changes in climate not only affect rice growth and yields directly but also influence the pests and diseases that attack rice crops. Fungal diseases of rice are particularly climate-sensitive, as their life cycles and infection rates depend on environmental factors such as temperature, humidity, and rainfall. These diseases have historically led to significant reductions in crop yields, with fungal pathogens estimated to reduce global rice production by around 14% annually (Agrios, 2005). As the climate warms and weather patterns become more erratic, there is growing concern that the incidence and distribution of rice fungal diseases will be altered significantly.
Several major rice fungal diseases pose significant threats to rice production. Rice blast, caused by the fungus Magnaporthe oryzae (anamorph Pyricularia grisea), is one of the most destructive rice diseases worldwide and can lead to total crop failure under conducive conditions (Asibi et al., 2019). Sheath blight, caused by Rhizoctonia solani, is another devastating disease, particularly in intensive rice systems, known for thriving in warm, humid environments (Singh et al., 2016). Brown spot fungus Cochliobolus miyabeanus (anamorph Bipolaris oryzae) historically caused the Bengal famine of 1943 and continues to affect rice grain quality and yield (Padmanabhan, 1973; Sunder et al., 2014). Bakanae disease, caused by Fusarium fujikuroi, primarily affects seedlings, leading to abnormal elongation, weakening of plants, and sometimes plant death, with significant yield losses in severe cases (Shin et al., 2023). False smut (Ustilaginoidea virens) has been increasingly observed in many rice-growing regions, possibly due to changing climate conditions and agronomic practices, affecting grain quality and reducing yields (Arumugam Gopalakrishnan et al., 2024). The impact of these diseases is influenced by climate variability. Long periods of rain or high humidity can trigger epidemics, while drought stress or unusually high temperatures can either exacerbate certain diseases or suppress others.
In recent years, many countries have reported changes in rice disease patterns that are consistent with climate trends. Diseases once considered “secondary” are emerging as primary threats under new environmental conditions. For example, brown spot is resurging in Philippines and India during erratic weather (Macasero et al., 2024; Pannu et al., 2005), and rice false smut, long minor, has become a frequent cause of crop losses in many Asian countries (Khanal et al., 2023; Li et al., 2024). Meanwhile, persistent threats like rice blast and sheath blight continue to pose challenges as weather becomes more variable. Below, we provide an in-depth look at how climate change is impacting each of these major rice diseases, followed by the implications for rice agriculture and strategies to adapt to these emerging challenges (Table 1).
Table 1.
Comparison of major rice fungal diseases and their interactions with climate factors, impacts, and controls
| Pathogen (disease) | Optimal infection temperature | Optimal relative humidity | Climate change impact | Control strategies |
|---|---|---|---|---|
| M. oryzae (rice blast) | ~25-28 o C optimal for infection and sporulation (Bevitori et al., 2014) | High humidity (≥93%) required; prolonged leaf wetness favors epidemics (Bevitori et al., 2014) | Warming climates can expand blast to higher latitudes/altitudes (more outbreaks in cooler regions) (Luo et al., 1995). | Grow blast-resistant rice varieties; adjust planting time and fertilization to avoid peak disease conditions; maintain good field sanitation and monitoring. Use fungicides (e.g., tricyclazole) preventively in high-risk periods. Breeding new resistant cultivars and implementing early warning systems are key adaptation strategies under a changing climate (Bevitori et al., 2014). |
| Extremely high night temperatures (>20 o C) can suppress infection, so in some already hot tropical areas further warming may reduce blast severity (Bevitori et al., 2014). | ||||
| Overall, climate change is expected to increase blast frequency in many areas (more favorable dew periods and warmer nights) and potentially expand its range. | ||||
| R. solani (sheath blight) | ~26-29 o C optimal for mycelial growth (up to 34 o C) (Biswas et al., 2011; Nandi et al., 2023) | High humidity (≥90%); requires very high moisture, e.g., water-saturated canopy (Hashiba, 1984) | Higher temperatures and humidity under climate change are likely to increase sheath blight incidence and severity. Warmer nights and extended growing seasons can enhance disease spread, potentially allowing it to thrive in new regions that were previously too cool (Ganesh and Roka, 2024). | Integrated management is essential: use rice varieties with moderate resistance (no fully resistant varieties yet), and avoid practices that create dense, humid canopies (e.g., excessive seeding rate or nitrogen fertilizer) (Uppala and Zhou, 2018). Rotate crops to break the disease cycle and remove weed hosts. Apply fungicides as needed at early disease onset (e.g., at tillering or booting) and monitor fields closely during warm, humid periods (Ganesh and Roka, 2024). |
| C. miyabeanus (brown spot) | ~25-32 o C (disease thrives in warm conditions) (Barnwal et al., 2013; Dallagnol et al., 2011) | High humidity (≥90%) with dew or light rains over several days is optimal (Choudhury et al., 2019) | Likely to become more problematic with climate change. Warmer temperatures and drought stress can predispose rice to brown spot, especially in nutrient-poor or rainfed systems (Macasero et al., 2024). In regions with reduced inputs or more frequent dry spells, brown spot frequency and severity may increase (Wickramasinghe et al., 2023). | Strengthen overall crop health to reduce susceptibility: ensure adequate nutrition (correct N, P, K levels) to avoid predisposing nutrient deficiencies (Carvalho et al., 2010; Singh et al., 2005). Use disease-resistant varieties if available. |
| Remove and destroy infected crop residues after harvest to limit pathogen carryover (Barnwal et al., 2013). In high-risk situations, apply fungicides (e.g., propicon-azole or strobilurins) at critical growth stages (tillering and booting) for protection (Nargave et al.,2023). | ||||
| F. fujikuroi (bakanae disease) | ~28-34 o C (Chan et al., 2004) | Needs humid, warm weather at flowering for seed infection (Singh et al., 2019) | Climate warming and elevated CO₂ strongly favor bakanae (Matić et al., 2021). Projected climate scenarios show increased bakanae incidence and spread, especially in newly warm regions (Shin et al., 2023). More frequent heavy rainfall during flowering can increase seed infection for next season. | Rely on rigorous seed treatment: treat or soak seed with fungicides (e.g., ipconazole, fludioxonil, metalaxyl-M, and azoxystrobin) or hot water (55-57 o C) to kill seed-borne spores (Chen et al., 2023; Eğerci et al., 2022; Zhang et al., 2024). Use certified disease-free seed lots. Rogue out infected seedlings early to curb spread. Develop and plant bakanae-tolerant varieties where available. Adjust planting time to avoid exceptionally hot sowing periods. Ensure good field sanitation (destroy infected residues and alternative weed hosts) to lower inoculum (Bashyal et al., 2023). |
| U. virens (false smut) | Mycelia can grow between 15-37 o C with maximum growth at 28 o C (Sathiyaseelan et al., 2025) | High humidity (≥80%) around flowering; thrives in very humid, cloudy conditions (Baite et al., 2021) | This emerging disease is exacerbated by changing climate patterns (Sharma et al., 2024). Warm, humid conditions during rice flowering have led to more frequent and widespread false smut outbreaks in recent years (Anbazhagan et al., 2024; Masurkar et al., 2023). Climate change (including warmer nights and altered rainfall timing) has expanded the geographic range of false smut and increased its incidence, making it a growing threat in many rice-growing regions (Jonathan and Mahendranathan, 2024). | Use clean, disease-free seed to prevent introduction (the fungus can carry on seed). Avoid late planting and excessive nitrogen fertilizer, as these create conditions (late-season flowering, lush canopy) that favor false smut (Chaudhari et al., 2019). Apply protective fungicide sprays at the booting and flowering stages to reduce infection of panicles (Sharma et al., 2024). Developing and planting false smut-resistant rice varieties and adjusting planting dates to avoid high-risk weather during flowering, are longer-term strategies to manage this disease under climate change (Baite et al., 2021, 2022; Sharma et al., 2023; Wang et al., 2019). |
The Impact of Climate Change on Rice Fungal Diseases
Rice blast.
Rice blast, caused by M. oryzae, is one of the most destructive rice diseases worldwide. It historically causes 10-30% yield loss annually under favorable conditions and can even decimate entire fields in severe epidemics (Ashkani et al., 2015; Musiime et al., 2005; Sakulkoo et al., 2018; Wilson and Talbot, 2009). Climate change is impacting rice blast in multiple ways. Warmer temperatures can enhance the infection process of pathogen by compromising the resistance mechanisms of rice. Experimental studies have shown that elevated temperature can reduce the defense response in rice, leading to more rapid pathogen colonization of tissues (Onaga et al., 2016). In practice, abnormally warm nights and extended dew periods have been associated with increased rice blast severity in the cool subtrophic regions (Japan and northern China) (Luo et al., 1998). Elevated atmospheric CO₂ is another factor. A free-air CO₂ enrichment study in Japan found that rice grown under higher CO₂ became more susceptible to blast infection (Kobayashi et al., 2006). These findings suggest that as climate change leads to higher temperatures and CO₂ levels, the inherent resistance of rice to blast may be weakened, potentially allowing more frequent or severe infections.
Observational evidence over the past decades supports these experimental insights. In South Korea, for example, unpredictable climate variability has coincided with irregular but severe blast outbreaks (Fig. 1). Field monitoring from 1999 to 2008 noted that unusual weather patterns in certain years led to severe panicle blast epidemics (Lee et al., 2010). More recently, 2020 saw a nationwide rice blast outbreak in Korea following an unusually prolonged monsoon and cooler summer, conditions which were highly conducive to the disease (Chung et al., 2022; Song et al., 2022). This illustrates how shifts in rainfall timing and temperature can trigger unexpected blast epidemics. Looking ahead, a modeling study projects that climate change will continue to influence blast occurrence in complex ways (Lee et al., 2022b). In warmer temperate areas, rising temperatures could eventually exceed the optimum range for rice blast development, potentially reducing its prevalence in the very long term. For instance, projections for the Korean Peninsula under high-emission scenarios suggest blast risk might increase until the mid-21st century in northern regions, then decline by 2100 as summers become too hot and dry for the pathogen. Despite these possible late-century reductions in some areas, rice blast is expected to remain a severe threat in most rice-growing regions (Yang et al., 2023). Greater climate variability, including erratic rainfall or unusual cold spells, can create periods of high risk even when average conditions become less favorable. Therefore, continuous monitoring and adaptive management are essential to managing rice blast under changing climate conditions.
Fig. 1.
Rice damage caused by the pathogens Magnaporthe oryzae, Rhizoctonia solani, and Cochliobolus miyabeanus in Korea from 2016 to 2024. The columns display the rice damage caused by each fungus from June to September between 2016 and 2024, while the rows represent temperature (o C), relative humidity (RH, %), and rainfall (mm). The damage data were obtained from reports on the 16th of each month via the National Crop Pest Management System (https://ncpms.rda.go.kr/), with different regions of Korea indicated by color codes. Meteo-rological data were sourced from the Automated Synoptic Observing System of Chungbuk on the Open MET Data Portal of Korea Meteo-rological Administration (https://data.kma.go.kr/). For temperature, the red line represents the average maximum temperature, the blue line represents the average minimum temperature, and the black line represents the average temperature. The gray shade indicates the optimal range of temperature and RH for each fungus.
Sheath blight.
Sheath blight, caused by R solani, is another major rice disease whose incidence and severity are influenced by climatic conditions. R. solani is a soil-borne fungus that infects rice sheaths and leaves, thriving in warm, humid environments. Climate warming and elevated CO₂ levels tend to create conditions favorable to sheath blight, mainly by promoting denser crop canopies and higher night-time temperatures (Shen et al., 2023). Experiments simulating future climate conditions have demonstrated a clear increase in sheath blight severity. In a free-air climate change experiment, rice grown under elevated CO₂ and increased temperature caused significantly more sheath blight damage compared to ambient conditions (Kobayashi et al., 2006). The combined effect of higher CO₂ and temperature led to larger lesion sizes and greater diseased area, ultimately causing measurable yield losses. These findings support the idea that warmer conditions, particularly warm nights, along with abundant canopy growth driven by CO₂ fertilization, create a microclimate beneath the rice canopy that favors R. solani. In essence, denser growth retains humidity and heat near the plant base, making fungal infection more likely.
Field observations also suggest that sheath blight may worsen with climate change, particularly in areas that are becoming warmer and wetter (Savary et al., 2001; Wu et al., 2014). Farmers and researchers in parts of Asia have reported higher sheath blight pressure in years with unusually high humidity and temperature (Sharma et al., 2009; Willocquet et al., 2000; Yang et al., 2024). Conversely, extremely hot and dry conditions can limit sheath blight, as the pathogen requires moisture. The net effect of climate change on sheath blight will depend on the balance of these factors. In monsoonal climates like Korea and Japan, a trend towards milder nights and increased humidity during the growing season has the potential to extend the window of sheath blight infection. Modeling studies using climate scenario data for Korea have indeed predicted increased risk of sheath blight epidemics if summers remain sufficiently wet (Kim et al., 2015; Kim and Cho, 2016). On the other hand, improved agronomic practices, such as breeding for partial resistance and better spacing of plants, can mitigate some climate impacts. However, the experimental evidence warns that if future rice fields encounter higher CO₂ and temperature levels, sheath blight may become more severe and require more proactive management.
Brown spot.
Brown spot of rice, caused by C. miyabeanus, is a re-emerging disease that has historically been associated with crop failure under adverse environmental conditions. Notably, an epidemic of brown spot, exacerbated by drought and poor crop nutrition, contributed to the Bengal famine of 1943, resulting in massive hunger and mortality (Padmanabhan, 1973). This tragic example underscores how climatic stress like severe drought can dramatically increase brown spot severity and impact food security. Brown spot tends to be the most severe in rice grown under suboptimal conditions. It often flares in rainfed or upland rice systems, especially where water or nutrients are limited (Sunder et al., 2014). Under climate change, increased frequency of droughts and high-temperature heatwaves in some regions can predispose rice plants to brown spot infection (Barnwal et al., 2013). Water-stressed plants have reduced vigor and compromised defenses, making them more susceptible to C. miyabeanus (Dariush et al., 2020). Indeed, these studies have noted that brown spots are of particular significance under drought conditions or in direct-seeded, low-input fields where rice experiences moisture stress.
There is evidence that brown spot incidence is rising in certain areas as climate patterns shift. For example, surveys in the Philippines have found brown spot becoming more prevalent and economically important in recent years (Macasero et al., 2024). Drought condition can accelerate the life cycle of brown spot pathogen to some extent, but the disease's occurrence is often kept in check by good crop management and adequate irrigation (Barnwal et al., 2013). Climate change threatens to upset this balance by increasing the likelihood of the stress conditions that brown spot exploits. Prolonged dry spells or erratic rainfall distribution, which results in periodic drought followed by sudden wetness, can favor brown spot. Drought weakens the plant, and subsequent humidity allows the pathogen to sporulate on stressed tissue. In well-irrigated or cooler environments, brown spot tends to remain a minor issue. Therefore, climate change impacts on this disease are expected to be region-specific. Areas that experience increased drought frequency or higher average temperatures without corresponding improvements in crop nutrition and water management may see more frequent brown spot outbreaks. On the other hand, regions with sufficient irrigation or rainfall might not see a large surge in this disease despite warming, as long as rice plants are not physiologically stressed. Overall, brown spot illustrates how climate-change effects on plant health are often indirect. Water availability and host stress play a dominant role in the dynamics of this disease (Sunder et al., 2014).
Bakanae disease.
Bakanae disease, caused by F. fujikuroi, is a seed-borne fungus that causes abnormal elongation, weakness, and often death of infected rice seedlings. This disease is strongly influenced by environmental conditions during seedling growth. Warmer temperatures typically accelerate F. fujikuroi growth and spore production, increasing the risk of Bakanae outbreaks (Matic et al., 2017). Climate change, particularly rising temperatures, has been associated with greater Bakanae incidence in some rice-growing areas (Bashyal et al., 2023; Husna et al., 2024; Shin et al., 2023). A controlled environmental study provides insight into how future climate conditions might affect Bakanae. Matić et al. (2021) grew rice under different temperature regimes, which roughly corresponded to cool, moderate, and high temperature scenarios, and observed a dramatic increase in disease at higher temperatures. At a low temperature regime (day/night ~22/18 o C), the bakanae disease index was about 46%, whereas under a high temperature regime (~30/26 o C), the disease index jumped to 68-96%. This indicates that F. fujikuroi infections become much more aggressive as temperatures approach 30 o C, which is within the optimal range for the fungus. Elevated CO2 (up to 850 ppm) alone had a smaller effect on Bakanae, but in combination with high temperature it slightly enhanced fungal growth and modulated rice defense responses. Overall, the study concluded that both singly and together, higher temperature and CO2 levels expected under climate change favor Bakanae development.
In field settings, bakanae disease is more problematic in warmer climates, particularly during seasons or in regions where rice seedlings grow in high-temperature conditions (Ji et al., 2024). Farmers in parts of South Asia have reported increased Bakanae incidence during unusually hot early-season periods when seedlings are raised (Gupta et al., 2015; Singh et al., 2022). Climate change could exacerbate this issue by causing more frequent early-season heatwaves or generally raising average temperatures during the planting window. Additionally, changes in agricultural practices, such as adopting dry seedbed methods or reducing fungicidal seed treatments under climate pressures, could influence Bakanae prevalence (An et al., 2023). Notably, Bakanae is unique among the diseases reviewed here because it is seed-transmitted, meaning that management practice like using clean or treated seed play a major role in its occurrence. Even if climate conditions become highly favorable for Bakanae, the disease can be controlled with rigorous seed sanitation and the use of resistant varieties. However, regions with inadequate seed hygiene might experience Bakanae as a more regular threat in a warmer climate. Research consistently indicates that higher temperatures sharply increase Bakanae risk, so global warming without adaptive measures would likely broaden the geographic and temporal window in which Bakanae outbreaks occur.
False smut.
False smut of rice, caused by U. virens, has gained notoriety in recent decades as an “emerging” disease, partly due to changes in climate and cropping practices (Khanal et al., 2023). This pathogen infects rice panicles around the flowering stage, converting grains into smut balls of spores. Unlike blast or brown spot, false smut does not typically devastate yields, but it can reduce grain quality and produce mycotoxins, posing food safety concerns (Zhou et al., 2024). Climatic factors, especially humidity and temperature during the rice booting to heading period, are critical for false smut outbreaks. Research has found that U. virens infection is most severe under conditions of high relative humidity (>90%) and moderately warm temperatures (around 25-30 o C) during the flowering stage (Chen et al., 1994; Hegde et al., 2000). These conditions allow the fungal spores to germinate and infect the developing grains. Climate change can influence false smut by altering the frequency of such conducive conditions. For example, if a region experiences more humid nights or a shift towards a milder temperature range during heading, false smut risk may increase.
A field study in China comparing traditional rice monoculture to a rice-crayfish co-culture, which involves deeper water and creates a more humid microclimate, demonstrated the impact of humidity and temperature on false smut (Dou et al., 2023; Jiehui et al., 2022). In the rice-crayfish system, the microclimate around the panicles had consistently higher humidity and slightly lower daytime temperatures. The result was a significantly higher false smut incidence compared to standard fields. Even rice varieties that were resistant under normal conditions became susceptible when grown in the more humid, moderate temperature environment. Controlled experiments from that study showed U. virens spore germination rates were much higher under the high-humidity regime, confirming that moist conditions at flowering greatly exacerbate the disease. These findings imply that if climate change leads to wetter conditions during rice flowering, for instance, heavier rains or persistent humidity in late summer, without extreme heat, false smut could become more prevalent. Indeed, many rice-growing areas have reported increasing false smut problems in recent years, which researchers attribute to shifting climate patterns alongside the expansion of high-yielding but susceptible hybrid rice (Nessa, 2017; Sharma et al., 2024). However, extremely high temperatures (beyond 35 o C) can inhibit false smut development, so the disease may be less severe in areas facing scorching heat during flowering. Overall, a warming climate that also raises humidity, through more frequent rains or irrigation changes, is generally expected to heighten false smut risk, whereas a shift to hot, dry conditions might limit it.
Case Study: Rice Damage Caused by Fungal Pathogens in Korea
Since 2014, South Korea has systematically monitored rice diseases occurring from June to September through the National Crop Pest Management System (NCPMS) of the Rural Development Administration. Various rice diseases, such as rice blast, sheath blight, brown spot, false smut, and bakanae disease, have been reported nationwide. In particular, rice blast and brown spot have been monitored annually since September 2014, while sheath blight began to be systematically observed from June 2015, and false smut monitoring started relatively recently in 2021. In contrast, Bakanae has not yet been officially monitored, indicating that further investigation and management are required.
Analysis of NCPMS data from 2016 to 2024 revealed that damage caused by the rice blast fungus and sheath blight was most pronounced in August each year, whereas the highest damage rate for brown spot was recorded in September (Fig. 1). In terms of absolute damage, sheath blight caused the greatest losses and rice blast the least. However, after 2020, the damage from sheath blight showed a gradual decline, while brown spot exhibited an increasing trend.
For rice blast, the highest damage rates were observed under relatively cool and humid conditions around August. In particular, an increase in precipitation promotes the formation of a water film on the leaf surface, thereby facilitating the sporulation and spread of the pathogen. The marked increase in rice blast damage in 2020 can be interpreted because of the simultaneous occurrence of cooler-than-normal temperatures, high precipitation, and elevated relative humidity with less solar radiation (Chung et al., 2022; Song et al., 2022).
Sheath blight showed an increase in disease incidence with rising maximum average temperatures during July and August, with damage rates peaking during periods of increased temperature, relative humidity, and precipitation. Although initial damage was high, a gradual decline was observed after 2020, suggesting that despite the conducive high-temperature and humid conditions for rapid fungal germination and proliferation, the effects of climate change and control measures have been reflected.
Brown spot exhibited higher incidence within the average temperature range during July and August, with the highest damage occurring in September. The combined effects of increased temperature, relative humidity, and precipitation stimulated disease occurrence. However, a continuously increasing trend in damage was observed after 2020, warranting careful consideration in future management and control strategies (Jang et al., 2024).
Furthermore, the average temperature in South Korea provides favorable conditions for the growth of the rice blast pathogen, whereas the maximum average temperature creates an environment conducive to the development of the sheath blight and brown spot pathogens. In particular, the average temperatures in July and August are close to the optimum range preferred by the brown spot pathogen, which may explain the pronounced increase in brown spot damage thereafter.
Regionally, central regions, characterized by relatively lower temperatures, tend to experience more pronounced rice blast damage, while southern regions, with their high-temperature and humid climate, exhibit relatively higher damage rates for sheath blight and brown spot. These findings underscore the need for region-specific management strategies that consider local meteorological factors and suggest that anticipated changes in disease occurrence patterns due to climate change should prompt a reevaluation of the timing and methods of disease control.
Management Strategies Under Climate Change
Adapting rice disease management to the realities of climate change is crucial for maintaining crop yields. A core principle is integrated disease management with a climate-smart approach. No single control measure will suffice. Instead, a combination of strategies is needed to build resilience. One key strategy is breeding and deploying resistant rice varieties that can withstand both the pathogen and the abiotic stresses exacerbated by climate change. For example, breeding programs are focusing on varieties with durable blast resistance that remains effective even under high temperature stress, as well as varieties tolerant to drought to indirectly combat brown spot (Asibi et al., 2019; Paul et al., 2025). However, it is noted that varietal resistance alone can be undermined by climate stress, as heat or elevated CO₂ can impair the genetic resistance of rice to diseases (Mthiyane et al., 2024; Ofori et al., 2025; Riaz et al., 2024). This means plant breeders may need to select for resistance that expresses strongly across a range of environmental conditions and possibly pyramid multiple resistance genes to ensure effectiveness.
Improved crop management practices offer another line of defense. Adjusting sowing dates or crop calendars might help avoid peak disease periods. For instance, shifting the rice planting date so that flowering does not coincide with the most humid part of the season could reduce false smut risk (Baite et al., 2022). Similarly, altering irrigation practices, such as timing of field drainage, can modulate the field microclimate. Draining fields at the right time before heading can lower humidity and limit false smut and sheath blight, while maintaining adequate water during grain filling can reduce plant stress and decrease the incidence of brown spot (Café-Filho et al., 2019). Researchers have suggested avoiding certain practices that heighten disease risk under climate change, such as double-cropping or dense planting without breaks, which can allow pathogen carryover and create a continually humid canopy (Hossain et al., 2024; Jonathan and Mahendranathan, 2024). Instead, crop rotations or fallow periods might be used to break disease cycles. Ensuring proper nutrition, especially silicon and potassium fertilizers, known to enhance disease resistance in rice, is also important, as healthier plants better tolerate climate stress and infections (MeCarty et al., 2024). In essence, addressing factors that limit yield, such as nutrient deficiencies or water stress, is a fundamental adaptation that makes rice crops less vulnerable to both climate stress and disease.
Chemical and biological controls remain valuable tools, though they may need adaptation in timing or choice. Fun-gicide application schedules might have to be adjusted as weather patterns shift. For instance, more frequent or earlier sprays could be needed if warm, wet conditions that favor rice blast now occur sooner or more often in the season. Conversely, unexpected heavy rain can wash off fungicides, so farmers may need guidance on reapplication or on selecting systemic fungicides that are rainfast (Amoghavarsha et al., 2021). There is also ongoing research into biocontrol agents, such as beneficial microbes antagonistic to Fusarium or Rhizoctonia, that could be applied to seeds or soil to protect against diseases like Bakanae and sheath blight without adding to chemical load (Rawat et al., 2022; Yu et al., 2017). The success of these methods under field conditions needs further validation, especially in scenarios where crops experience stress due to climate change. For instance, it is necessary to determine whether biocontrol organisms can survive and remain effective when exposed to extreme heat or prolonged flooding. In any case, integrating biocontrol with moderate fungicide use and resistant varieties can reduce reliance on any single method and provide more stable disease suppression.
Perhaps the most critical need under climate change is strengthening disease monitoring and early warning systems. Because weather conditions play such a big role in rice epidemics, investing in predictive modeling and surveillance can pay off. Scientists are developing forecast models that utilize machine learning techniques and climate data to predict the risk of rice blast or sheath blight outbreaks based on weather forecasts and field conditions (Thakur et al., 2024). In South Korea, for example, a daily epidemiological model tailored to weather data is used for rice blast early warning (Lee et al., 2022a). These tools help farmers and advisory services to prepare in advance by ensuring that fungicides are readily available or by implementing preventive measures before an outbreak reaches its peaks. On a larger scale, international bodies have called for better global surveillance of plant pests and diseases in the face of climate change. The International Plant Protection Convention (https://www. ippc.int/) has proposed “Strengthening Pest Outbreak Alert and Response Systems” as part of its strategic framework, aiming to establish a global pest alert system that can track emerging disease threats (Soubeyrand et al., 2024). Such a system would gather data from multiple countries and issue warnings when, for instance, conditions are ripe for a major epidemic or when a new pathogen strain is detected moving into a region. Improved communication and farmer education are also integral to management, as farmers need to be aware that practices which were effective in the past may need adjustment as climate conditions evolve. For example, a variety that never needed spraying for brown spot in the past might start showing disease in hotter and drier years, indicating that additional intervention or a change in variety is required (Barnwal et al., 2013). Ultimately, a proactive, informed approach to disease management, one that anticipates climate-driven changes rather than simply reacting to outbreaks, is essential for protecting rice production in the coming decades.
Conclusion
In conclusion, the impact of climate change on rice fungal diseases is already observable and is likely to become more pronounced. Each of the major diseases, including rice blast, brown spot, sheath blight, bakanae disease, and false smut, has its own relationship with climatic factors, leading to varied regional outcomes. By examining long-term patterns across different areas, including Korea and other rice-growing regions, we gain insight into how warmer temperatures, changing humidity and rainfall, and rising CO₂ are reshaping disease landscapes. Proactive management, grounded in scientific research and enhanced by new technology, will be key to mitigating these effects. The challenge is significant, but with adaptation and vigilance, it is possible to protect rice crops against the twin threats of climate change and plant disease, thereby safeguarding a staple food for billions of people.
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