There is currently no uniform global definition of plant bio-stimulant (PBS) and the criteria for its classification are different. However, the market for PBS products is growing rapidly, and registration is required for gaining market access. The need of manufacturers for a fair registration process has driven the ongoing improvements to relevant laws and regulations in various regions. Recently, the European Union (EU) and the United States (US) have made corresponding adjustments to their PBS regulations, which will subsequently affect their registration application processes.
Definition of PBS
PBS is any substance or microorganism used on plants to enhance nutritional efficiency, abiotic stress tolerance and crop quality traits, regardless of nutritional content. There are many types of PBS products, from a single compound, such as betaine, to a bioactive mixture extracted from a natural raw material, such as seaweed extract.
In the absence of a clear definition in current regulations, PBS is often defined by method of exclusion, so it is neither a pesticide nor a fertilizer or a plant growth regulator (PGR). However, this method often leads to confusion because it is hard to distinguish between PBS and PGR, as these two types of products have partial overlapping.
New EU PBS regulations
The EU does not have a uniform definition of organic fertilizers and PBSs, nor does it have unified regulations. Each member state has its own regulations.
On 25th June this year, the EU published Regulation (EC) No. 2019/1009 related to fertilizers, which includes PBSs. This new regulation expands the definition of “fertilizer” and unifies the management of fertilizers throughout EU member states. This regulation will replace existing Regulation (EC) No. 2003/2003.
The new regulation has the following main features:
- It expands the concept of fertilizers, i.e. fertilizers include mineral fertilizers, organic fertilizers, soil improvers, growing mediums and PBSs. Therefore, for the first time, PBSs are clearly defined as fertilizer products in the EU.
- The regulation is part of the EU's circular economy package, which aims to encourage large scale fertilizer production using domestic organic and secondary raw materials, in line with the “Circular Economy Model” of transforming waste into nutrients for crops.
- After a product is registered, it will be granted a CE label for release in all EU member states.
- Manufactures can launch their products in national markets using national rules, without using the CE label.
The new regulation still excludes several types of products that are not applicable, such as animal by-products and animal-derived products, which are controlled by Regulation (EC) No. 1069/2009. Plant protection products are subject to a specific pesticide regulation (Regulation (EC) No. 1107/2009), other than fertilizers subject to the new regulation.
The EU also revised its pesticide regulation when its new fertilizer regulation was published. The definition of PGR was amended to "influencing the life processes of plants, such as their growth, without being a nutrient or PBS," meaning that a product defined as a nutritional ingredient or a PBS needs to be registered according to the requirements of the fertilizer regulation. Otherwise, a product that affects plant growth is a PGR and shall come under the pesticide regulation.
However, many biological products not only improve nutrient absorption rate, stimulate plant growth and enhance root structure development, they can also act like pesticides in terms of pest control. If a product combines these two functions and is mainly used as a pesticide, it should be registered under the pesticide regulation. However, if the pesticidal effects of a product are not significant, there is no need to indicate these effects in the label and its ability to control pests should not be advertised. The product can, therefore, be registered as a PBS.
Under the new regulation, clearer standards related to fertilizer product management and market access approval will become available, and registration fees may increase for producers. The existing European fertilizer regulation (Regulation (EC) No. 2003/2003) focuses on inorganic fertilizers and mineral fertilizers, and EU member states have different requirements for plant stimulants. Some states have very high requirements related to biopesticides while others have very low requirements. Only MSDS are required to be registration.
The new regulation, which is currently in the transitional stage, will be implemented fully and formally from 16th July, 2022, with some of its articles taking effect from July this year, but its guidance documents and supporting rules have not yet been confirmed. Before 16th July, 2020, all relevant supporting guidance documents will be released. Due to the current unavailability of these guidance documents, the implementation of the new regulation, including data requirements, registration management rules, organizational management rules and standards for responsible organizations, are still uncertain. Many details need to be explained over the next few months, especially those related to data requirements and registration methods. The upcoming guidance documents will make the regulatory system clearer and more complete, to unify the registration procedures of relevant products in the EU.
Regulation in the US
The USDA defines a PBS as " a substance or micro-organism that, when applied to seeds, plants or the rhizosphere, stimulates natural processes to enhance or benefit nutrient uptake, nutrient efficiency, tolerance to abiotic stress, or crop quality and yield."
The US EPA also defines a PBS as a “naturally-occurring substance or microbe that is used either by itself or in combination with other naturally-occurring substances or microbes for the purpose of stimulating natural processes in plants or in the soil, in order to, among other things, improve nutrient and/or water use efficiency by plants, help plants tolerate abiotic stress, or improve the physical, chemical, and/or biological characteristics of the soil as a medium for plant growth."
The EPA intends to distinguish PBSs from PGRs using this concept. A PBS is defined by method of exclusion as a substance or microorganism that does not conform to the definition of a PGR under the FIFRA Act. In the US, fertilizers are regulated by the USDA while pesticides, including PGRs under the FIFRA Act, are regulated by the EPA. Algae extract is considered a PGR and is regulated under the FIFRA Act by the EPA. The registration requirements for algae extract are similar to those for pesticides. The EPA’s definition of a PBS is based on the product's mechanism of action, which is still a topic of discussion.
Summary
In the new European fertilizer regulation, PBSs are classified as fertilizers, except those that are also pesticides while PGRs are classified as pesticides. In the US, PBSs are expected to be classified as separate from fertilizers, but this issue is still in discussion.
Although PBS development technology has achieved progress and many products have been released in the market and recorded good effects, there is still room for improvement in terms of regulation. The concept of PBS needs to be further clarified and the product registration process still needs to be further standardized, to ensure that products can be registered through reasonable channels. The guidance documents to be issued by the EU are expected to help in the creation of universal labels in the region, allowing relevant products to enter the market in a fair manner.
