Crops under pressure: managing heat and radiation stress

Rising temperatures and increased solar radiation are putting crops at risk. Discover how innovative approaches and smart management practices can help protect plant health and maintain productivity.

Olive tree

Climate pressure is reshaping crop production

Climate change is no longer a distant threat to agriculture; it is a daily reality for growers worldwide. Rising global temperatures, more frequent heatwaves, and increasing solar radiation are reshaping crop production systems across temperate and Mediterranean regions. In many areas, crops are now exposed to levels of heat and light intensities that exceed their optimal physiological thresholds, leading to reduced yields, compromised quality, and higher production risks. 

As climate patterns continue to shift, farmers are increasingly seeking practical, field-proven tools to help crops cope with these stresses while maintaining productivity.

Heat and radiation stress impact core plant functions

One of the most significant consequences of climate change is the increase in thermal and radiation stress during critical crop development stages. High temperatures accelerate plant metabolism, increase transpiration, and disrupt photosynthesis. When leaf temperatures exceed 34°C, CO2 assimilation is reduced, directly affecting photosynthesis efficiency and crop productivity. 

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Figure 1. CO₂ assimilation by an intact leaf at various temperatures (Source: Cornic G. (2025), Effects of temperature on photosynthesis, Encyclopaedia of the Environment).

Crop sensitivity to increasing heat and radiation

At the same time, intense solar radiation, particularly ultraviolet and infrared wavelengths, can damage leaf tissue, cause sunburn on fruits, and impair plant water balance. These stresses are often compounded by limited water availability, making it harder for crops to cool themselves naturally. 

Several economically important crops show high sensitivity to these combined stresses:

  • Tomatoes are particularly vulnerable to heat stress during flowering and fruit set. Temperatures above optimal ranges can lead to pollen sterility, poor fruit set, and physiological disorders such as sunscald and blossom end rot.

  • Watermelon and apples are sensitive to excessive heat and radiation, which can reduce fruit size, impair sugar accumulation, and cause surface damage, directly affecting marketability.

  • Olive trees, although traditionally adapted to warm climates, are increasingly exposed to extreme heat events that reduce photosynthetic efficiency, increase oxidative stress, and negatively impact oil yield and quality, especially during fruit development and oil accumulation.

As these climatic pressures intensify, growers face a growing challenge: how to protect crops from excessive heat and radiation without interfering with normal plant functions. Traditional shading or irrigation strategies alone are often insufficient, costly, or limited by water availability. 

This has driven interest in micronized particle film technologies such as OmyaPro® Sun, designed to mitigate heat and radiation stress directly at the leaf and fruit surface.

How particle film technology helps

OmyaPro Sun offers an effective and sustainable solution to this challenge. Based on high-purity calcium carbonate, it is a finely milled particle film designed to reflect excess solar radiation while still allowing sufficient light for photosynthesis. When applied to crops, it forms a uniform, white protective layer on leaves and fruits that reduces surface temperature and limits heat stress during periods of intense radiation.

By reflecting a portion of incoming solar energy, OmyaPro Sun helps crops maintain a more favourable canopy temperature, reducing transpiration and improving water use efficiency. 

This effect is illustrated by field data from vineyards, where applications of OmyaPro Sun resulted in reduced leaf temperatures, improved plant water status, and the maintenance of a favorable photosynthetic rate under high‑radiation conditions (Fig. 2).

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Figure 2. Field measurements of grape leaf temperature, water potential, and photosynthetic rate in untreated and treated vines. Treatments: OmyaPro Sun or kaolin, 2 applications at 5% with surfactant (green berry and beginning of ripening stages). Source: Agricultural University of Athens.

Supporting climate adaptation in agriculture 

In the context of climate adaptation, this approach is particularly valuable under hot and dry conditions, where water stress and heat stress often occur simultaneously.

In crops like tomato and apples, the use of OmyaPro Sun has been shown to reduce sunburn incidence, improve fruit quality, and more uniform development under high temperature conditions. In olives, particle film applications can help protect leaves and fruits from excessive radiation, supporting stable high-quality yields in challenging seasons.

As climate change continues to redefine agricultural boundaries, solutions such as OmyaPro Sun play a crucial role in climate adaptation strategies. By reducing the impact of heat and radiation stress, OmyaPro Sun helps growers protect yield potential, improve crop resilience, and maintain quality, supporting more sustainable and profitable production systems in an increasingly unpredictable climate.

Looking for practical solutions to help crops cope with increasing heat and radiation stress? 
Our experts support growers and agronomists with application know‑how, crop‑specific guidance, and particle‑film solutions tailored to challenging climatic conditions. Click here. 

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