Classification by selectivity and movement
- Selective herbicides: Control specific weed types (e.g. broadleaf weeds or grassy weeds) without harming the main cultivated crop (for example, 2,4-D in wheat or Pendimethalin in pulses).
- Non-selective herbicides: Destroy all green plant tissue upon contact (for example, Glyphosate or Glufosinate-ammonium), used primarily for non-crop clearing, bund clearing, or targeted zero-tillage burn-down.
- Systemic vs contact herbicides: Systemic herbicides translocate through the plant vascular system to kill root systems, while contact herbicides destroy only the foliage directly wetted by the spray.
Application timing: PPI, Pre-emergence and Post-emergence
Pre-Plant Incorporated (PPI) herbicides are mechanically mixed into the soil prior to seeding. Pre-emergence herbicides are applied to moist soil after sowing but before crop or weed emergence, creating a chemical barrier that stops emerging weed seedlings. Post-emergence herbicides are sprayed onto actively growing weeds when the main crop is already established.
Nozzle selection, calibration and spray safety
- Always use flat-fan or flood-jet nozzles for uniform droplet deposition on soil or weed foliage; avoid hollow-cone nozzles which create drift-prone fine mist.
- Apply when soil has adequate moisture (vapsa condition) for active chemical absorption.
- Wear protective boots, gloves, and aprons; triple-rinse spray tanks thoroughly before using the equipment for other crops.
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 pre-emergence and post-emergence herbicides?
Pre-emergence herbicides are applied to the soil before weed seedlings sprout, while post-emergence herbicides are sprayed directly onto actively growing weed foliage.
Why is nozzle choice critical when spraying herbicides?
Flat-fan nozzles produce uniform, coarse droplets that minimize wind drift and provide complete soil or weed surface coverage.
Where can farmers check approved herbicide recommendations for specific crops?
On the official portal of the Directorate of Plant Protection, Quarantine & Storage (ppqs.gov.in) under the CIBRC approved herbicide list.
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.