Silicon: A Powerful Ally Against Heat Stress in Crops

Heat stress is a major threat to global agriculture, reducing crop yields and costing farmers billions of dollars in lost productivity each year. When temperatures rise beyond a plant’s optimal range, critical physiological processes begin to break down, leading to reduced photosynthesis, impaired nutrient uptake, dehydration, and, in severe cases, irreversible cellular damage. There are few crops that don’t see impact when temperatures soar: wheat experiences pollen sterility at high temperatures, and tomatoes develop blossom drop. In berries, growers often see sunburn or sunscald, but also reduced sugar content and premature ripening of fruit. Likewise, in citrus, heat stress can compromise fruit size and rind quality, and in almonds, oil content is often reduced, kernels can be aborted, and nut size is smaller. Given the increasing frequency and severity of heat waves, growers need tools that help crops withstand extreme conditions and recover from damage. One such tool is the often-overlooked nutrient, silicon.

Nutrients as Multi-Taskers: Learning from Human Physiology

Just as human nutrition depends on key minerals like calcium and magnesium to maintain health via thousands of processes and organs in our body, plants rely on essential nutrients to regulate a multitude of growth and stress responses. 

Calcium, for example, strengthens bones—our foundational framework—while also playing critical roles in nerve function and muscle contraction. Similarly, silicon fortifies plants by reinforcing their basic structural unit: the cell wall. But its benefits extend far beyond mere structural support. Silicon is a multitasking nutrient: enhancing water management, boosting antioxidant activity, improving photosynthesis, and even facilitating recovery from heat-induced damage.

How Silicon Strengthens Plants Against Heat Stress

The cell wall as a fortress. Silicon is deposited in the cell walls of plants, reinforcing their structure much like calcium does for human bones. A stronger cell wall helps plants maintain turgor pressure under heat stress, reducing wilting and mechanical collapse. This structural reinforcement also enhances pest and pathogen resistance under good conditions but can be especially important when heat-stressed plants become more vulnerable to opportunistic infections.

Strong pipes, good flow. Silicon helps plants manage water more efficiently by regulating stomatal function. Stomata are tiny pores on leaves that control water loss through transpiration. Under high temperatures, plants risk losing excessive moisture, leading to dehydration. Studies have shown that silicon application can optimize stomatal closure, reducing water loss while still allowing enough gas exchange for photosynthesis.

Antioxidant defense against radicals. Heat stress leads to excessive production of a specific type of molecule: what are known as reactive oxygen species (ROS). These are problematic for plants (and humans!) because they cause oxidative damage to proteins, lipids, and DNA– visible as burn and malformed growth. Silicon enhances the plant’s antioxidant defense system by boosting the activity of enzymes like superoxide dismutase (SOD) and catalase (CAT), which neutralize harmful free radicals and prevent cellular damage.

Photosynthetic support: keeping the factory open. To grow, plants have to be able to take in carbon from the atmosphere. They do this through photosynthesis. However, high temperatures can impair chlorophyll stability and damage the photosynthetic machinery, leading to reduced energy production and slower growth. Research indicates that silicon helps protect chloroplasts (the structure where photosynthesis takes place) from heat stress, preserving chlorophyll content and ensuring continued energy generation for growth and repair.

Ensuring resources reach the plant. Heat stress can disrupt the movement of essential nutrients within plants, exacerbating deficiencies and weakening resilience. Silicon has been shown to enhance the uptake and transport of key nutrients like potassium (K), which is critical for osmotic balance and stress tolerance. This effect helps plants maintain “nutrient homeostasis” (nutrient stability and balance) even under extreme conditions.

Heat reflection: building sunscreen into leaves. Silicon deposits (known as phytoliths), in leaf tissues create a thin, reflective barrier that helps scatter excess solar radiation, reducing leaf temperature. This physical mechanism prevents overheating and reduces the risk of sunburn on leaves, stems, and fruit.

And, the good news is, even if you didn’t manage to get silicon in before the damage was done, it can still help. Beyond prevention, silicon can also assist in recovery even after heat damage has occurred. When applied post-stress, soluble silicon can accelerate cell repair, strengthen newly formed tissues, and stimulate the production of protective compounds that help plants rebuild. This ability makes silicon an invaluable tool not only for mitigating stress but also for enhancing resilience in subsequent heat events.

The Advantage of Highly Soluble Silicon Forms

While silicon is naturally present in soils, its availability to plants depends on its solubility. Traditional silicon sources, like silicate minerals, release the nutrient slowly and may not provide immediate stress relief. In contrast, highly soluble forms of silicon—such as stabilized monosilicic acid—are rapidly absorbed and distributed within plant tissues, making them ideal for real-time stress management. By using highly bioavailable silicon, growers can equip their crops with a fast-acting defense system that strengthens resilience before, during, and after heat stress events.

In summary, as heat stress becomes a more frequent challenge, growers need proactive solutions to protect their crops. Silicon, still considered only a secondary nutrient, is proving to be a critical component of plant defense, offering structural reinforcement, enhanced water retention, oxidative stress protection, and even heat reflection. With highly soluble silicon formulations, like Dune, farmers can improve crop resilience in real time, minimizing losses and ensuring sustained productivity. In an era where every degree matters, integrating silicon into nutrient management programs isn’t just an option—it’s a necessity for future-proofing agriculture.

References:

Sehla K., Sana B.S., Abdel R.M., Mehraj D.S., Bilal A.P., Baseerat A., Rizwan R., Abdel R.A. Silicon’s defensive role against biotic and abiotic stress: a review. Environmental and Experimental Botany. 2025. https://doi.org/10.1080/10426507.2025.2482090

 

Cooke J., DeGabriel J.L. and Hartley S.E. The functional ecology of plant silicon: geoscience to genes. Functional Ecology. 2016. https://doi.org/10.1111/1365-2435.12711

 

Zargar S.M, Mahajan R., Bhat J.A., Nazir M., Deshmukh R. Role of silicon in plant stress tolerance: opportunities to achieve a sustainable cropping system. Biotech. 2019. http://doi:10.1007/s13205-019-1613-z.

 

Wang M., Wang R., Mur L.A.J., Ruan J., Shen Q., Guo S. Functions of silicon in plant drought stress responses. Horticultural Resources. 2021. http://doi:10.1038/s41438-021-00681-1.