Active Ingredient and GABA Receptor Mode of Action
Fipronil belongs to the phenylpyrazole chemical class (IRAC Group 2B), functioning as a GABA-gated chloride channel blocker.
It disrupts normal central nervous system inhibition, resulting in continuous hyperexcitation, convulsions, and mortality in targeted insect pests.
- Active Molecule: Fipronil 0.6% GR (Granules) formulated on high-density inert micro-carriers
- GABA Blockade: Blocks chloride ion flow through nerve cell membranes, paralyzing insect neuromusculature
- Root Uptake & Acropetal Translocation: Absorbed through plant roots and translocated acropetally to protect newly emerging tillers
- PGR / Greening Effect: Stimulates root elongation and enhances nitrogen assimilation, resulting in visible crop greening and enhanced tillering
Target Crops and Soil-Foliar Pest Complexes
Regent Ultra is registered for transplanted paddy and sugarcane facing severe borer complexes early in the cropping cycle.
In rice, it eliminates yellow stem borer larvae and gall midge before tillers suffer 'dead heart' or 'white ear' damage.
- Paddy (Rice): Yellow stem borer (Scirpophaga incertulas), leaf folder, whorl maggot, and gall midge
- Sugarcane: Early shoot borer (Chilo infuscatellus), root borer, and subterranean termites
- Vegetables & Nurseries: Soil root grubs and early sucking pests attacking tender seedlings
Application Guidelines and Field Management
In paddy, broadcast Regent Ultra granules evenly across standing water (2 to 3 cm depth) within 15 to 25 days after transplanting.
In sugarcane, apply granules along planting furrows over setts at sowing or during early intercultural earthing up.
- Application Rate: Apply at 4 kg per acre uniformly across the field using a mechanical granule broadcaster or hand broadcasting with gloves
- Water Maintenance: Maintain standing water for 4 to 5 days after application in paddy fields to facilitate root absorption
- Operator Safety: Always wear protective rubber gloves; never handle chemical granules barehanded
Official source
Check the latest rules, benefits and forms here. KisanPe is an independent platform and is not a government website.
Central Insecticides Board & Registration Committee ↗Related on KisanPe
Common questions
What is the technical ingredient in Bayer Regent Ultra?
Regent Ultra contains fipronil 0.6% GR in a high-density granular formulation.
What is the 'greening effect' associated with fipronil?
Fipronil stimulates root development and enhances physiological nitrogen uptake, leading to visibly greener plants and increased tillering.
When should Regent Ultra be applied in paddy?
Apply within 15 to 25 days after transplanting when the field has shallow standing water.
General guidance, not personal advice. For your farm, ask your local Krishi Vigyan Kendra or agriculture officer.
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