Cost effective solution against insects in long-term grain storage by natural diatomaceous earth

Diatomaceous earth, a naturally occurring sand, is a go-to remedy for household and garden infestations. It’s also a key element in an EU move to eliminate phosphine-based practices in the grain supply chain.

According to the Food and Agriculture Organization of the United Nations, between 20 % and 40 % of global crop production is lost to pests. This figure is expected to rise in future, due to climate change and increased freight transport practices. One method of preventing crop loss is through synthetic insecticides. While these are useful, the accumulation of some of the insecticides in the environment can harm wildlife and human health.

Focusing on grain storage, the EU-funded PestiSi project offers an innovative solution: PestiSi, a highly effective insecticide named for the project. “It is safe and natural and can be applied during long-term grain storage,” highlights László Berta, project coordinator and CEO of Pentele Mg. Zrt., a company that oversees agricultural projects. PestiSi can replace phosphines and other toxic chemicals used when storing grain, and can therefore support the EU to meet its Farm to Fork targets, for reducing the use and risk of chemical pesticides.

A closer look

The active ingredient in PestiSi is diatomaceous earth, silica made up of fossilised remains of phytoplankton.

“Insects breathe through a capillary system: air enters the spiracles and moves through the tracheal system,” notes Berta. Their spiracles are protected by small hairs that stop normal dust from entering the body. “However, the needle-like crystals of diatomaceous earth can enter these holes (spiracles) and kill the insects,” explains Berta.

Concerning the safety of diatomaceous earth, he stresses: “As this works through mechanical means rather than chemical, it is completely harmless to humans and other vertebrates.” By contrast, conventional treatments using phosphines are highly toxic and hazardous.

PestiSi kills pests in 2 weeks, while a single treatment can last for a year, ensuring that the grain does not deteriorate. Extracting the insecticide from grain is easy. But since the amount needed for treatment is under the thresholds of the European Code on Inorganic Dust Residues, it does not need to be removed.

Going to market

The project finalised product development and validated it at industrial scale. It also developed a commercialisation strategy and managed distribution channels. “All our goals were successfully achieved during the project,” confirms Berta. As for the key result, Berta notes: “In the project, we found that we could successfully move from the proof-of-concept level to product level, by carrying out tests not only at the laboratory scale but also at industrial scale.”

These tests were led and monitored by certified inspection and verification companies including SGS and MertControl, which confirmed how highly effective the product is.

“We also developed an industrial-sized mixing system that can efficiently treat large volumes of grain with PestiSi and provide the crucial homogenous distribution of the product in the grain,” adds Berta. Once the system was finalised, a patent application was submitted, in January 2021. Additionally, the project set up a group of interested parties including potential first-time buyers.

“In the market, there is an upward trend towards natural insecticides and for the reduction of chemicals including phosphines. Diatomaceous earth-based products are probably the best alternatives to current chemical, highly toxic insecticides. We will now work to reach the widest possible range of users,” Berta concludes.