my swede seeds coated with thiram germinating

Thiram: The seed coating fungicide banned in the EU

Thiram, a chemical compound called tetramethylthiuram disulfide, was used as a fungicide, primarily aimed at safeguarding crops against fungal diseases during cultivation and storage.

Its effectiveness in protecting crops, including swedes, from harmful fungal infections made it a staple in agricultural practices. However, the European Union (EU) took a decisive step in 2019 by banning the use of Thiram due to its environmental and health concerns, prompting the exploration of alternative solutions for crop protection.

What is Thiram?

Thiram belongs to the class of dithiocarbamates, which are widely employed as fungicides in agricultural settings. Its mechanism of action involves inhibiting fungal growth by disrupting key metabolic processes essential for their survival. Thiram was extensively used not only in seed coatings but also as a fungicidal treatment for crops and as an animal repellent to deter pests from damaging vegetation.

The use of Thiram in swede seed coatings

Seed treatments play a crucial role in safeguarding crop yield by protecting seeds from fungal infections during germination and early growth stages.

my swede seeds with a blue Thiram coating
Swede seeds I tested for germination with a blue Thiram coating

Thiram, with its broad-spectrum fungicidal properties, offered an effective solution for swede seed coatings, ensuring healthier seedlings and robust crop establishment. Its application helped mitigate the risk of damping-off diseases and other fungal pathogens, thereby contributing to improved crop productivity.

Swede seeds which were coated with Thiram were usually a bright red or blue colour, which helped to differentiate them from the standard “Sepiret” fertiliser coating which is normally grey. In addition to the fungicidal and pest deterrent properties of Thiram coated seeds was the added bonus was that these bright coloured seeds were easier to find in the soil when checking seed spacings along the row.

Swede seeds which have a fertiliser coating are grey in colour.

Reasons for EU ban

The decision to ban Thiram in the EU stemmed from growing concerns over its adverse effects on both the environment and human health. Thiram exhibits low-to-moderate persistence in soil and groundwater, but its breakdown products, including copper dimethyldithiocarbamate and carbon disulfide, pose environmental risks. Additionally, thiram is known to cause irritation to the eyes, skin, and respiratory tract in humans, with acute exposure potentially leading to neurotoxic effects. Furthermore, its toxicity extends to wildlife, making it a concern for ecological balance.

Exploring alternatives for swede crop protection

One alternative to Thiram for use in swede cultivation is copper-based fungicides. Copper-based compounds, such as copper hydroxide or copper sulfate, have been widely used in organic farming and are effective against a range of fungal diseases, including those affecting swedes. Copper-based fungicides work by releasing copper ions, which disrupt fungal cell membranes and inhibit their growth and reproduction. They offer a sustainable and environmentally friendly option for disease management in swede crops, with minimal risk to human health and the ecosystem.

Key points

Thiram, once a cornerstone of crop protection strategies, has faced regulatory restrictions due to its environmental and health risks, prompting the need for alternative approaches to ensure sustainable agriculture. While the ban presents challenges for swede cultivation and other crops, it also underscores the importance of transitioning towards safer and more ecologically sound farming practices. By embracing innovative solutions and holistic pest management techniques, farmers can continue to safeguard crop yields while minimising adverse impacts on the environment and human health.