Fungicides: Characteristics
Metal content and impurities: how buyers judge a fungicide
What this tab covers The physical and chemical properties that set its grade, price and uses, with the commercial grades and the standards that define them.Commercially, fungicides are judged by active ingredient content, impurities (ETU for mancozeb), particle size and suspensibility for powders, and stability in mixtures.
Properties that matter commercially
| Property | Value / specification | Why it matters | Source |
|---|---|---|---|
| Mancozeb metal content | Mn at least about 20%, Zn at least about 2.5% (FAO, indicative) | identity and activity | FAO specification (indicative) |
| ETU impurity | kept below about 0.5% of mancozeb (indicative) | toxicological limit | FAO specification (indicative) |
| Copper content | copper oxychloride about 57% Cu; copper hydroxide about 64% Cu (stoichiometric) | dose per hectare | stoichiometry |
| Particle size and suspensibility | WP and WG need fine, stable suspensions | coverage on leaves | CIPAC methods (indicative) |
Commercial grades
- Mancozeb technical (about 85-90%) and 75% WP
- Copper oxychloride 50% WP, copper hydroxide 77% WP
- Single-site technicals (95-98%) and SC or EC mixtures