Exactly two years ago, I wrote
an article¹ about the regulation of
biostimulants and the challenge of
classifying microorganisms based
on their function.

Dr. José Carvalho

Now might be a good time to re-
flect on the thousands of hours the
regulatory community has spent on
this discussion and the results so far.

How much time have regulators and stakeholders invested
in trying to categorize microorganisms based on function i.e. if
they fall under a pesticide claim or a biostimulant claim? It is
like trying to fit a square peg into two round holes. Why is functional classification proving so difficult? And how many more
hours are we willing to spend going in circles?

Here are my takeaways from conversations with growers
in my role as a crop advisor. Talking to end users provides a
much-needed reality check.

“The microorganism does not care what you call it”, said
an academic researcher at a meeting last year. The fact is that
all microorganisms, if able to colonize and/or interact with
the plant, will deliver a biostimulant function. Products con-
taining B. thuringiensis, Metarhizium, Beauveria bassiana are
great biostimulants according to their users and can be well
supported by evidence. Claiming that a microorganism will
not have a biostimulant effect is difficult to prove, and even
harder to demonstrate that a negative event will not occur. Of
course, some of these products could also be used to control
pests and diseases – just that they cannot claim such an effect
on the market.

From a biological stance, differentiation based on function
will be challenging, if not impossible, for the majority of microorganisms known today. There will be a few exceptions—
well-known microorganisms that primarily influence nutrient
availability and participate in the nutrient cycle while having

minimal impact on the plant’s immunity or disease response.

If we ask academics or even PhD students researching microorganisms in agriculture, they will not understand the ongoing efforts to define such an artificial border. And does it matter what their function is?

From a consumer safety, environmental and non-target organisms’ perspective, there should be no difference in the protection goals based on different functional label claims. Thus,
the only difference regarding the label claims is the product’s
liability to deliver on claims A, B and C, and how these claims
are supported by data from an efficacy standpoint. For example, Bacillus velezensis when applied to the soil will have a
biostimulant effect on the plant, stimulate plant defense, and
protect the plant from fungal diseases. Different claims will result in different labels—even though the product applied is the
same, used by the same farmer and ultimately consumed by
the same end user. The distinction lies in the intended use, not
necessarily in the product itself.

The challenge we face today is a cumbersome regulatory
system—one that attempts to apply a chemical-based framework to microorganisms used as pesticides, while simultaneously keeping biostimulants outside of that system in an effort to preserve innovation. This policy makes no sense and
the hours spent on quick fixes and workarounds will not solve
the main issue: the microorganism cannot understand which
name you are putting on it. Brazil got ahead of the rest of the
world to solve this in a pragmatic way, by setting the same
standards for safety assessments, and consequently stopping
an endless discussion that cannot be resolved scientifically.
Meanwhile, the rest of the world tries to make it work – by having an artificial separation based on different principles unrelated to biology – and continues generating confusion at the
grower level, with the same microorganisms being sold with conflicting messages in the same market.

In the real world, when a microorganism is applied to a
crop the risks are the same, irrespective of label claims and
which name the regulatory system decides to call it. Yet, today, this is not reflected in regulatory practices because microorganisms used as biocontrol/pesticides are much safer than
biostimulants due to the scrutiny by regulators, controls, secondary regulations, record keeping and enforcement actions.
Then, it is more puzzling why should microorganisms used as
biocontrol be recorded on the farm books – applications, dose,
supplier of the product, quantities reported annually, etc. –
whereas biostimulants are not. As a consumer, this is difficult
to understand: food safety agencies impose strict scrutiny and
record-keeping requirements on microorganisms labeled for
‘control,’ yet allow those labeled as biostimulants—without
undergoing the same level of evaluation—to enter the same
market without any traceability requirements. It is difficult to
justify such contradiction, both from a regulatory science as
well as consumer protection point of view.

Well, we cannot change it because of competitiveness and
innovation. Nevertheless, we cannot keep our heads in the
sand and pretend we are learning to snorkel. We need to talk
about it. What is the best way to close this regulatory gap in
the long term, to prevent more confusion at the grower level?
We could start by aligning safety requirements – and by this, I
mean looking at the biocontrol side and seeing which requirements really need to be answered with data – and reviewing
the procedures in place to authorize both types of product
claims. At the end of the day, it is just a claim on efficacy which
is different, the safety concerns should be the same; including
crop safety, consumer protection, grower exposure and environmental safety.

One day we will get there, and the faster we start addressing the issue, instead of using more quick fixes, the faster growers will broadly adopt biological solutions.

Why are growers confused? The ones I talked to do not look
for label claims distinction, they are all microorganisms. Crop
advisers are clear about the claims’ differences but also recognize that the important point for them is “to do” the job. If there is confidence in recommending a product, they will do
it. So how does the grower decide between a Bacillus subtilis biostimulant and a Bacillus subtilis fungicide? What is the
difference between these bottles’ content that justifies such a
different claim? And why does one bottle need to be on the
farm records while the other does not when both are applied
to the crop? This point of record-keeping remains very confusing to me. Understandably, in a world where the food value
chain (particularly supermarkets) sets the rules on what can
be used, having off-record applications seems extremely useful to me. Considering that growers in Europe need to report to
supermarkets which pesticides they apply, where and when,
and have imposed restrictions on numbers, the use of a biostimulant product becomes advantageous.

Now, the million-dollar question: why would you not place
your microorganism in the market as a biostimulant product?
Well, there seems to be no good reason. And probably that is a
reason for so many products being made available and the increasing skepticism of growers towards products that deliver
multiple functions.

The practical question, or the billion-dollar one: how do
we resolve it? By recognizing the science behind microorganisms and how biology works. Other approaches will always
lead to streets with low illumination and reduced clarity,
which is fundamental in functioning regulatory systems. I recognize the need for short-term solutions to address the current market challenges and prevent farmers from losing trust
in microbial products—especially after using mixtures that
failed to deliver on their claims. But we also need long-term
action to ensure our regulatory systems are effective, fair and
grounded in science.

There is no convincing scientific argument, from a safety
viewpoint, to differentiate a microorganism based on a bioprotection or biostimulant claim written on a bottle. Yes, in
jurisdictions where efficacy is assessed by agencies, then a
separate efficacy assessment might be justifiable.

The sooner we begin this conversation, the sooner we
can find a solution that supports innovation, ensures safety,
and protects crops, consumers, and the environment. Being stuck on this topic for another two years seems counterproductive
for the whole industry and the adoption of biologicals by growers.