Extreme weather is becoming the new normal: why anticipating water stress matters more than ever

A heatwave that reflects a lasting trend

Over the past few weeks, large parts of Europe have been hit by successive heatwaves, with temperatures surpassing 40°C in several countries. Although it is still too early to quantify their impact on this season’s harvest, one thing is already evident: extreme heat is no longer an exceptional event. It is becoming a defining feature of agricultural landscape.

Early field observations nevertheless call for caution. The effects of a heatwave cannot be assessed while it is occurring. Crop response depends on several interacting factors, including the duration of the stress, soil moisture reserves, nighttime temperatures, rainfall following the event and, above all, the crop’s growth stage. A complete assessment will only be possible once harvest is finished.

Beyond their potential impact on yield, these successive heatwaves reinforce a broader reality: the increasing frequency of extreme weather events is becoming a fundamental agronomic parameter that growers must now integrate into their crop management decisions.

Every field responds differently

When crops face extreme heat, limited rainfall or prolonged dry conditions, there is often a temptation to estimate yield losses using a single figure. In reality, crop response is far more complex.

Two neighbouring fields exposed to the same weather conditions can perform very differently. Soil depth, water-holding capacity, crop genetics and agronomic practices all influence a crop’s ability to cope with water stress. Current field observations already reveal striking contrasts, sometimes within the very same field.

Corn provides a particularly good example. Across many regions, crops are entering flowering, one of the most critical stages for determining final yield. Water stress during this period can disrupt pollination, reduce kernel set and significantly affect yield potential.

Although this example focuses on corn, the same principle applies across many broad-acre crops. A crop’s ability to withstand periods of extreme heat depends not only on its environment but also on when stress occurs during its development.

Visible symptoms appear only after water stress has already begun

When crop leaves begin to roll under extreme heat, the plant is not just starting to experience water stress. By that stage, it has already activated a series of natural defense mechanisms.

To conserve water, the plant progressively closes its stomata, reducing transpiration. While this response helps preserve available water, it also limits carbon dioxide uptake and slows photosynthesis. If these conditions persist, plant growth declines, biomass accumulation is reduced and yield potential may already be compromised-well before any visible symptoms appear.

In the field, these physiological changes gradually become visible through a range of warning signs: leaf rolling during the hottest hours of the day, poor overnight recovery, slower vegetative growth and, under prolonged stress, the progressive drying of lower leaves.

In other words, visible symptoms do not mark the onset of water stress-they reveal that the plant has already been under stress for some time. This changes the way growers need to approach climate risk management.

Anticipating rather than reacting: a new approach to crop resilience

For decades, heatwaves and drought were largely seen as exceptional events that required action only after damage had become visible. As these events become more frequent and more severe, agriculture is shifting towards a different approach: preparing crops before stressful conditions occur.

This preventive strategy relies on a combination of complementary agronomic practices, including improving soil health, selecting appropriate genetics, optimizing irrigation where available, adopting sound crop management practices and integrating innovations that support the plant’s natural physiological responses.

At Elicit Plant, this approach is enabled by EliTerra® technology. Rather than responding once stress has occurred, EliTerra® prepares the plant in advance by triggering a physiological signal before critical conditions arise. This allows the plant to adjust its metabolism, optimize water use and improve its ability to cope when water becomes limiting.

The objective is not to replace proven agronomic practices, but to enhance their effectiveness as part of a broader strategy focused on anticipation and resilience.

Early observations from several trial networks this season already support this approach. Despite particularly challenging conditions, crops prepared ahead of the heatwaves appear to have maintained greater biomass and better preserved their development potential. As with any agronomic assessment, these observations will naturally need to be confirmed at harvest.

Preparing agriculture for a changing climate

The full impact of this latest heatwave will only become clear once harvest is complete. One conclusion, however, is already undeniable: episodes of extreme heat and water scarcity are becoming more frequent, occurring earlier in the season and lasting longer. Together, they are fundamentally reshaping the conditions under which crops are grown across Europe.

As climate variability continues to intensify, agriculture will need to draw on every available lever: improved agronomic practices, more efficient water management, advances in plant genetics, decision-support tools and innovative biosolutions.

More than an evolution in farming practices, the industry is undergoing a fundamental shift in mindset. The challenge is no longer simply to respond to water stress once it occurs, but to anticipate it-helping crops maintain their productivity and resilience in an increasingly unpredictable climate.