In scenarios characterized by intense El Niño events – often classified as “Super El Niño” – there is a significant increase in the probability of atypical weather conditions occurring, including excess precipitation in certain regions, irregular water distribution in others, increased canopy moisture, and operational restrictions.
These conditions do not determine, but substantially increase the likelihood that agricultural production systems will face greater sanitary pressure, especially in crops such as soybeans, corn, and wheat. The potential impact tends not to be limited to direct climate stress, but rather to the interaction between climate, pathogens, and operational capacity, creating an environment conducive to the occurrence of epidemics.
According to the Food and Agriculture Organization of the United Nations (FAO), El Niño events alter precipitation and temperature patterns on a global scale, with significant effects on agricultural production and food security. In Brazil, for example, the 2023/2024 harvest showed a significant reduction associated with adverse weather conditions, illustrating how such events can affect productive performance – albeit with significant regional variability.
El Niño events do not manifest themselves homogeneously. On the contrary, they tend to amplify regional contrasts, which requires differentiated management approaches.
In southern Brazil, there is a higher probability of frequent and heavy rainfall, which favors diseases dependent on leaf wetness and high relative humidity, in addition to increasing the risk of operational limitations. Under these conditions, the pressure from diseases such as Asian rust, white mold, leaf spots and Fusarium head blight tends to intensify.
In the Cerrado and Central-West regions, the most likely scenario involves irregular rainfall, dry spells, and high temperatures, with distinct impacts: lower initial pressure from diseases dependent on continuous moisture, but greater physiological stress on plants, uneven crop distribution, and instability in operational windows. If rainfall resumes during critical phases, the system could rapidly transition to a condition of greater sanitary vulnerability.
In Matopiba (an agricultural frontier comprising areas of Maranhão, Tocantins, Piauí, and Bahia), the risk tends to be associated with water variability, affecting the establishment and efficiency of control measures.
In the Southeast region, mixed scenarios predominate, with behavior dependent on altitude, topography, and local rainfall patterns. Under these conditions, the pressure from diseases such as Asian soybean rust, white mold, and leaf spots can intensify in a more regionalized manner.
In soybean cultivation, the sanitary risk in years with a strong El Niño influence is associated with a combination of high rainfall frequency; early canopy closure; operational restrictions for application; and pod opening under intense water conditions.
Under these conditions, the likelihood of diseases such as Asian soybean rust, septoria leaf spot, cercospora leaf spot, target spot, and white mold increases.
It is important to highlight that this is not inevitable, but rather a scenario in which control efficiency tends to be more sensitive to operational timing and environmental conditions. Reduced residual fungicide efficiency and application delays become more significant factors in the outcome. Regarding fungicide efficiency, problems related to absorption and metabolic rate cannot be disregarded. Together, these factors can compromise their residual effect. Thus, favorable weather conditions combine with inefficient chemical management. For this reason, under El Niño conditions, disease damage reaches significant proportions.
In the Cerrado region, the dynamics tend to be more dependent on rainfall distribution throughout the cycle. Stress situations followed by a return of moisture can result in rapid transitions to environments favorable to the disease, especially in unevenly distributed crops.
In intensive operating systems, any delay of even a week can be significant. Crops with this climate profile are particularly at risk.
For corn, the increased risk is related to the convergence of moisture, temperature, inoculum pressure, and ear husk coverage.
Foliar diseases and stalk and ear rots tend to be more likely to occur under these conditions, potentially impacting photosynthetic area, grain filling, and final quality. Mycotoxin accumulation is a crucial factor in El Niño situations, and can significantly compromise the quality of the grains produced.
In the soybean-corn system, especially in the Cerrado region, delays in soybean planting can shift corn planting to less favorable windows, increasing exposure to stress and disease at the end of the cycle, as well as impacting final productivity.
Wheat exhibits high sensitivity to humidity and temperature conditions during its reproductive phases. In El Niño scenarios, there is an increased probability of Fusarium head blight, especially when there is rain during flowering and grain filling.
In addition to productivity, industrial quality can be significantly affected, with the risk of mycotoxin contamination – a critical factor in marketing.
One of the main indirect effects of events like Super El Niño is the reduction in operational capacity.
Frequent rainfall can limit access to crops, the timing of application, the efficiency of re-applications, harvesting, and post-harvest handling.
Thus, even technically well-structured programs can have their effectiveness compromised. The loss of operational efficiency becomes one of the main determinants of the outcome.
Given this scenario, management tends to shift from a static logic to an adaptive and risk-based approach. In the South, there is a greater focus on anticipation and preventive protection. In the Cerrado, there is a need for flexibility and dynamic adjustments. In Matopiba, there is integration between water and sanitary risks. In the Southeast, management is guided by microclimates.
It is important to highlight that these strategies are not exclusive to El Niño years. On the contrary, they represent good practices that tend to generate returns even in more stable climate scenarios.
Super El Niño events should be interpreted as amplifiers of variability and risk, not as guarantees of specific climatic or health behavior.
Adopting strategies tailored to this scenario should be seen as a way to reduce risk and increase the resilience of the production system. Even in situations where the event does not manifest with the expected intensity, the adjustments made tend to improve operational efficiency, increase crop protection, and reduce structural vulnerabilities.
In short, logic ceases to be reactive and becomes probabilistic and strategic, where decisions are made not based on the certainty of the event, but on the relationship between risk, potential impact, and mitigation capacity.
By Ricardo Silveiro Balardin, DigiFarmz
* Article published in Cultivar Grandes Culturas Magazine No. 321
Receive the latest agriculture news by email
Receive the latest agriculture news by email
With the mission of replacing the acclaimed BH series, the new Valtra M5 tractors bring concepts such as versatility and simplicity from the old series, but add a great deal of technology and features to further expand the range of customers and markets.
The new Valtra M5 Series, which includes the M165, M185, and M205 models, maintains the concept of a heavy-duty multi-purpose tractor, focusing on power, traction, transmission, and hydraulic system designed to support large implements during long periods of work
