Major fungicide classes and how to select them
- Contact (Protectant) Fungicides: Form a surface barrier preventing fungal spore germination; examples include Mancozeb 75% WP, Copper Oxychloride 50% WP, and Sulphur 80% WP; best applied preventively before rain.
- Systemic (Curative) Fungicides: Penetrate foliage and move vascularly to cure established internal fungal infections; examples include Triazoles (Tebuconazole, Propiconazole) and Strobilurins (Azoxystrobin).
- Dual-Action Combination Fungicides: Synergistic premixes (like Metalaxyl + Mancozeb, or Azoxystrobin + Difenoconazole) combining external protective shielding with internal curative arrest.
- Bio-Fungicides: Beneficial microorganisms (Trichoderma viride, Pseudomonas fluorescens) that colonize roots and suppress soil pathogens naturally.
Fungicide Resistance Action Committee (FRAC) rules
Repeated application of single-site systemic fungicides from the same FRAC group leads to the rapid selection of resistant fungal strains. Farmers should rotate between differing FRAC modes of action across spray rounds, or tank-mix single-site systemic chemicals with broad-spectrum multi-site contact protectants.
Application timing, weather and sprayer hygiene
- Apply fungicides preventively when weather forecasts predict cloudy, cool, and humid conditions that favor fungal sporulation.
- Use a hollow cone nozzle on a well-maintained knapsack or power sprayer to ensure fine droplet coverage on leaf undersides.
- Observe the mandatory Pre-Harvest Interval (PHI) printed on the product packaging before harvesting produce.
Official source
Check the latest rules, benefits and forms here. KisanPe is an independent platform and is not a government website.
Directorate of Plant Protection, Quarantine & Storage (CIBRC) ↗Related on KisanPe
Common questions
What is the difference between contact and systemic fungicides?
Contact fungicides stay on the outside of plant leaves to stop spore germination, whereas systemic fungicides penetrate into plant tissues to cure internal infections.
Why is it risky to use the same systemic fungicide repeatedly?
Fungal pathogens can quickly mutate and develop chemical resistance against single-site systemic fungicides, rendering them ineffective.
Where can farmers check approved fungicide registrations for their crop?
On the official portal of the Directorate of Plant Protection, Quarantine & Storage (ppqs.gov.in) under CIBRC approved lists.
General guidance, not personal advice. For your farm, ask your local Krishi Vigyan Kendra or agriculture officer.
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