Agri-inputs & biocontrol
Biofertilizers and biopesticides
An umbrella category unified by acting through a living organism rather than by any common biology: target specificity, viable count as the specification, shelf life, and the asymmetry in registration requirements.
“Biofertilizers and biopesticides” is not one mechanism but a class of products whose active principle is an organism or its metabolite. The mechanisms inside the class have nothing in common with each other. Cry proteins from Bacillus thuringiensis dissolve in the alkaline midgut of a lepidopteran larva, are activated by gut proteases and form pores in the epithelial membrane. Trichoderma competes for rhizosphere niche and parasitises pathogen hyphae. Azospirillum changes root architecture through phytohormones rather than through nutrition. What unites them is not biology but the consequences of selling a living population.
Specificity as both the virtue and the ceiling
A synthetic insecticide hits a conserved target — a sodium channel, an acetylcholinesterase — and is therefore broad. A biological agent works through an interaction that has to match: a Cry toxin needs a receptor of the right type, cadherin or aminopeptidase N, in the gut of a particular insect order. That is where the remarkable selectivity comes from, and equally where the narrowness comes from: one product covers part of a pest complex, not the complex. The same dependence on matching makes biologicals context-sensitive — efficacy varies with soil pH, temperature, leaf wetness and the resident community far more than a chemical equivalent does.
The specification is a viable count
A chemical product is specified by percentage of active ingredient, and that percentage does not change in a warehouse. A living product is specified by titre — colony forming units per gram or per dose — and titre declines from the day of manufacture. So the label guarantees content at manufacture under stated storage conditions, not at the moment of use; so manufacturing date and cold chain are part of the specification for this category rather than a logistics detail. Formulation development here largely reduces to extending that window: drying with protectants, spore preparations instead of vegetative cells, oil suspensions that hold water activity down.
The registration asymmetry
Data requirements are split across regulatory branches, and the split explains much of the industry’s shape. In the United States biopesticides are registered under FIFRA through a dedicated EPA division, the Biopesticides and Pollution Prevention Division, with a reduced toxicological package relative to conventional chemistry but mandatory strain characterisation and an infectivity assessment. In the EU, plant protection goes through Regulation (EC) No 1107/2009 — since 2022 under data requirements rewritten specifically for micro-organisms — while plant nutrition products go through Regulation (EU) 2019/1009, where micro-organisms form their own component material category, initially limited to four taxa and widened afterwards.
The practical consequence is that the same strain falls into different regimes depending on the claim made for it. Claim suppression of a pathogen and it is a plant protection product with the full burden; claim improved nutrient uptake and it is a biostimulant. The boundary runs through the wording of the claim rather than through the biology, and it is usually what decides what ends up on the label.