Material Insights · Understanding the Material World

Copper and Fungicides

Copper salts such as copper oxychloride, copper hydroxide and Bordeaux mixture are among the oldest fungicides and remain a mainstay of organic and wet-climate farming. The tie matters far more to fungicides than to copper, and in Europe regulation, not the metal price, now sets how much copper farmers can use.

Copper (commodity) and Fungicides (chemical): 3 relationships.

How they are linked

1. Active ingredient

Physical flow · Asymmetric · Copper to copper fungicides

The copper ion is the active agent in copper fungicides: it is dissolved or precipitated as copper sulphate, oxychloride, hydroxide or oxide, which stick to leaves and kill fungal spores on contact.

  • about 25% copper metal in copper sulphate
  • 50% copper in a standard copper oxychloride wettable powder, India

Bordeaux mixture is made by mixing copper sulphate and hydrated lime in water, typically 1 kg of each in 100 litres for a 1% spray. Because the deposit resists washing off, copper sprays are favoured in high-rainfall areas. For the fungicide maker copper is the main input, but for the copper market this outlet is minor next to wire, building and machinery uses.

Sources: Copper Development Association; Bureau of Indian Standards

2. Price link: active metal

Cost and price · Weak · Both ways

Copper fungicide makers pay a metal-linked price for their copper, but the broad pesticide price proxy used here is dominated by synthetic chemistry, so the measured link is close to nil.

  • -0.04 monthly change correlation
  • -0.28 12-month change correlation
  • 0.15 fitted elasticity

The weak and slightly negative figures say more about the proxy than about copper fungicides: copper products are a small part of a US pesticide price series. Copper price swings show up in the margins of copper fungicide makers rather than in that index.

Sources: Material Insights (World Bank, FRED, IMF data)

3. EU cap on copper use

Policy · Strong · EU rules limit copper applied to crops

The EU renewed copper compounds as candidates for substitution because copper accumulates in soil and is persistent and toxic to soil and water life, and it capped the dose per hectare.

  • 28 kg per hectare maximum copper over 7 years, about 4 kg a year on average
  • 30 June 2029 date to which the EU approval was extended by Regulation 2025/1489

Regulation 2018/1981 covers copper hydroxide, copper oxychloride, copper oxide, Bordeaux mixture and tribasic copper sulphate, and the cap applies to organic and conventional farms alike. Organic vineyards depend most on it, because copper is one of few effective organic treatments for downy mildew. A 2025 French Senate question cited about 165,000 hectares of certified organic vines in France and an Anses estimate that a 2 kg per hectare yearly limit would cut yields by 25 to 34%.

Sources: European Union (legislation.gov.uk copy); Sénat, France

For investors

Key learnings

  1. Copper fungicides are a niche for copper but copper is the core cost of the product, so the exposure runs one way: fungicide makers feel copper prices, copper miners barely notice fungicide demand.
  2. In Europe, use is capped by regulation at 28 kg of copper per hectare over 7 years, about 4 kg a year, so renewal decisions set the ceiling on European sales.
  3. Wet seasons and downy mildew pressure in vineyards and potatoes lift demand for copper sprays, especially from organic growers with few alternatives.

What to track

  • LME copper cash price: Higher copper raises input costs for copper oxychloride and hydroxide makers (Daily · LME)
  • EU decision on renewal of copper compounds: Tighter dose limits or non-renewal would cut European volumes; a renewal on current terms keeps them stable (As published · EFSA, EUR-Lex)
  • National product authorisations for copper fungicides: Withdrawn authorisations shrink the range of products growers can buy (As published · national regulators such as Anses)

For policymakers

Key learnings

  1. Copper is both a crop-protection tool and a persistent soil pollutant, so its use is regulated by dose over years rather than banned outright.
  2. Organic farming relies on copper more than conventional farming, so tight copper limits can conflict with targets to expand organic area.
  3. India sets quality standards for copper oxychloride formulations through BIS, and the EU experience shows the value of tracking cumulative copper loading in soils of intensively sprayed crops.

What to track

  • Cumulative copper applied per hectare in vineyards and orchards: Rising loads point to soil accumulation and future restrictions (Annual · national farm surveys, EU reporting)
  • Status of EU copper compounds approval: Shows whether a regulatory tightening is coming (As published · EUR-Lex)
  • Research funding for copper alternatives: Progress on substitutes eases the trade-off between soil protection and organic yields (Annual · agriculture ministries)

India

In India copper oxychloride is sold mainly as a 50% copper wettable powder, governed by BIS standard IS 1507, which is under its third revision in 2024.

Sources

  1. Price correlation, Material Insights, Material Insights (World Bank, FRED, IMF data)
  2. Commission Implementing Regulation (EU) 2018/1981 renewing the approval of copper compounds, European Union (legislation.gov.uk copy) (2018)
  3. Question on copper in organic viticulture and ministry answer (question 06307), Sénat, France (2025)
  4. Uses of copper compounds: copper sulphate's role in agriculture, Copper Development Association
  5. Copper oxychloride water dispersible powder concentrate: specification (draft IS 1507, third revision), Bureau of Indian Standards (2024)