Confusion is growing among farmers as Sustainable Agriculture Incentives (SFI) regulations blur the line between banned silica pesticides and allowed silicone biostimulants.
The government-backed scheme, part of the post-Brexit Environmental Land Management (ELM) programme, rewards growers who commit to sustainable practices for three years, but many are unsure where silicon fits in as certain chemical treatments are strictly prohibited.
Although silica pesticides are specifically prohibited under the SFI regulations, some producers incorrectly assume that silicone biostimulants fall under the same restrictions. Not so, says Mike Stoker, an agronomist at Orion Future Technologies.
“Silica is a common substitute for chemical pesticides. However, silica is not allowed under the SFI system,” Stoker said. “The use of silicon biostimulants, which make silicon available to plants and have the potential to reduce abiotic stresses such as drought, salinity, and heavy metal toxicity, remains viable.”
Stoker explained that the confusion stems from similar names, even though the products operate in fundamentally different ways. Silica insecticides are designed to kill pests, whereas silicone biostimulants help plants access silicon through monosilicic acid, increasing resilience rather than acting as an insecticide.
He added that silicon biostimulants also help crops absorb silicon as well as other essential nutrients. “Enabling plants to absorb more silicon strengthens plant cell walls and promotes root growth, which can lead to increased yields,” he said.
“The plant can also absorb other nutrients such as boron, calcium, and iron, which can also help improve resilience to common stresses.”
Stoker warned that SFI-compliant land is likely to be under greater stress than usual as a dry summer and mild autumn bring pest threats.
“With aphids and CSFB being a threat this fall, using silicone products can thicken the plant’s cell walls and increase the density of hairs on the leaves to protect against stinging pests,” he said.
“In some areas the ground is still very dry, so using silicone helps plants root deeper and faster, helping them find moisture.”
Mr Stoker called on policymakers to improve the wording of the SFI guidance to prevent further misunderstandings. “There is confusion regarding the use of silica pesticides and silicone biostimulants,” he concluded.
“Although silica should not be used in SFI, it is possible to use silicone biostimulants as a biological method to fortify plants against environmental pressures.”
As SFI continues to evolve, clearer communication around product categories could help farmers avoid costly mistakes and make the most of the system’s sustainability goals.
