Biochemical multi-site mode of action and bactericidal efficacy
Copper compounds function as broad-spectrum protectants, forming a toxic chemical barrier over foliage before pathogens establish infection.
- Releases cupric ions (Cu2+) on leaf surfaces upon wetting, which denature fungal and bacterial proteins and inactivate cellular enzymes.
- Multi-site contact activity (FRAC Group M01): Destroys pathogen cell membranes, preventing fungal spore germination.
- True bactericidal property: Highly effective against phytopathogenic bacteria causing leaf blights, cankers, and bacterial spots.
- Low risk of resistance development due to non-specific chemical disruption of multiple metabolic enzyme pathways.
Target crops and major plant diseases controlled
Copper fungicides are registered across extensive horticultural, plantation, and field crop commodities in India.
- Paddy (Rice): Prevention of bacterial leaf blight (Xanthomonas oryzae pv. oryzae) and false smut.
- Potato and Tomato: Prevention of early blight, late blight, and bacterial canker.
- Citrus: Control of citrus canker and twig die-back during post-pruning and monsoon flushes.
- Grapes and Cardamom: Control of downy mildew and capsule rot (azhukal disease).
- Pomegranate: Suppression of bacterial blight (oily spot disease) affecting leaves and developing fruits.
Application guidelines, phytotoxicity, and mixing precautions
Apply copper fungicides as a preventative protective barrier prior to disease outbreaks or immediately following rainy spells. Avoid spraying during extreme midday heat or combining with acidic agrochemicals, which can liberate excessive free copper and cause leaf bronzing or fruit russeting. Applicators should wear protective eye goggles, gloves, and protective clothing.
Official source
Check the latest rules, benefits and forms here. KisanPe is an independent platform and is not a government website.
Central Insecticides Board and Registration Committee ↗Related on KisanPe
Common questions
How do copper fungicides control both fungal and bacterial diseases?
Cupric ions released on moist leaf surfaces denature microbial proteins and enzyme systems, destroying fungal spore walls and bacterial cells alike.
What is the difference between Copper Oxychloride and Bordeaux mixture?
Copper Oxychloride is a pre-manufactured wettable powder (50% WP) that mixes directly with water, whereas Bordeaux mixture is prepared by reacting copper sulphate with slaked lime.
Why should copper fungicides not be sprayed during hot sunny weather?
High temperatures and acidic water can trigger rapid release of copper ions, causing chemical phytotoxicity, leaf scorching, and fruit russeting.
General guidance, not personal advice. For your farm, ask your local Krishi Vigyan Kendra or agriculture officer.
More Crop Protection & Pesticides guides
Ask Sakhi AI in your language, check live mandi prices or plan a loan with KisanPe tools.