What makes a good biostimulant and how to spot them.

The biostimulant sector has grown rapidly in recent years, but unfortunately, so has grower confusion. There are hundreds of products now on the market and unfortunately many make vague claims and have inconsistent evidence. It’s becoming increasingly important for agronomists and growers to distinguish between science-led biostimulants and products that rely on marketing rather than measurable function.

In a new editorial on biostimulants, Unlocking the Black Box of Plant Biostimulants, du Jardin et al, highlights exactly why growers struggle to choose credible solutions: definitions vary, mechanisms are unclear and yield alone is not the only indicator of value. Crucially, the paper identifies the characteristics that separate robust, functional biostimulants from those that overpromise.

So, what really makes a good biostimulant? Our team has taken the time to translate those scientific principles into practical guidance.

It should be easy to find out what is in the biostimulant you are choosing and what its mode of action is

Manufacturers should be transparent about the active ingredient components of the biostimulant and the loading in the formulation. They should be able to explain the mode of action and how the product influences physiological processes such as:

• nutrient use efficiency
• root development
• tolerance to heat, drought or other stresses
•  rhizosphere nutrient availability
• crop quality traits

Growers should look for improvements in plant physiology, not just promises of higher yields

Increasing yield is incredibly important for growers. But relying on this alone stops growers from understanding the true value of biostimulants. Many products support really important processes which may not always translate as yield depending on growing conditions, but will still provide improved quality, reduced loss to stress and disease or other long-term benefits. These include:

• stronger root systems
• faster recovery after stress
• better nutrient transport
• higher-quality outputs (protein %, oils, sugars etc.)

The best biostimulants will have plenty of available evidence and data

Variability in field trials is normal, but reproducible results across a range of crops and environments are essential for a biostimulant to have credibility. Products should demonstrate:

• robust lab and field evidence
• multi-year trials
• consistency across soil types and seasons
• a plausible biological mechanism
• compliance with CEN/TS 17700 protocols

Look for products that support preventive stress management

Many biostimulants work best when applied before stress hits, showing a shift from reactive to preventive crop management. This is particularly true for products that:

• enhance antioxidant activity
• modulate osmotic balance
• prime stress-response genes
• strengthen root systems ahead of drought/heat

A good biostimulant should be easily integrated into crop management systems

Growers should be able to think of biostimulants as part of a plant nutrition strategy. Biostimulants work best when combined with:

• targeted fertiliser use
• appropriate timing
• soil health management

Transparency and plausibility build trust

Many products hide behind generic claims, with no explanation of how they work. A trustworthy biostimulant must:

• explicitly state the mechanism or pathway targeted
• explain why the effect makes biological sense
• provide data that links mechanisms with physiological effects and field outcomes

How do Intracrop products meet these requirements?

IntraCrop’s biostimulant portfolio easily meets the characteristics outlined by du Jardin et al for what makes a good biostimulant: clear mode of action, transparency around the active ingredient components and loading, consistent performance under stress, multi-season and multi-environment validation and measurable improvements to nutrient use efficiency, crop resilience and quality traits.

Status® is CE-marked for its ability to improve NUE, resilience to abiotic stress and quality traits. Containing 2g/L MTU® and 320g/L pidolic acid, it has unique activity on photosystem I, increasing chlorophyll and mopping up damaging oxygen free radical by increasing cyclic electron flow. Nutrino Pro® is CE-marked for tolerance to abiotic stress, containing our biostimulant technologies R100 and pidolic acid. R100 improves nutrient uptake and pidolic acid is a signalling compound directly involved with nitrogen assimilation. TFU® (products to be announced) has auxin-like root activity and cytokinin-like shoot activity increasing root and shoot growth, aiding stress tolerance and contributing to early vigour.

All three products are supported by robust, multi-season evidence. Status® has undergone over 250 trials across the UK, EU, Canada, India, South Korea, USA, Japan and more, demonstrating consistent performance under varied conditions. Nutrino Pro® shows clear, repeatable performance across trials on over 16 different crop types. TFU® is backed by extensive laboratory and field trials, with over 50 cereal trial comparisons already recorded.

Together, these products demonstrate how IntraCrop’s technologies meet du Jardin et al’s definition of good biostimulants: well-characterised, scientifically validated and proven to support crops through stress while improving nutrient use efficiency and long-term productivity.

Conclusion: what growers should look for

To summarise, a credible biostimulant should:

✔ Have a defined mode of action
✔ Improve a measurable physiological trait
✔ Show repeatable evidence
✔ Clear understanding of contents
✔ Work within a wider agronomic strategy
✔ Deliver reliable ROI
✔ Show benefits beyond yield, including resilience, quality and stability

These are exactly the foundations on which IntraCrop builds every product.