Penoxsulam provides excellent control of sedges (Cyperus spp.), broadleaf weeds like Monochoria vaginalis, and certain grasses in both transplanted and direct-seeded rice systems. It is particularly effective against difficult-to-control weeds that have developed resistance to other herbicide groups.

As an ALS inhibitor (Group 2), Penoxsulam is absorbed by both roots and foliage, then translocated to meristematic tissues. It disrupts acetolactate synthase, preventing biosynthesis of branched-chain amino acids essential for weed growth, leading to growth cessation and eventual plant death.

While primarily designed for flooded rice, Penoxsulam can be used in dry-seeded systems with some efficacy reduction. Tank-mixing with contact herbicides like bentazone improves control in non-flooded conditions. Higher water volumes (500-600 L/ha) ensure better coverage in dry systems.

The herbicide works best at temperatures between 15-30°C. Cool conditions below 15°C slow weed metabolism and herbicide uptake, while temperatures above 35°C may increase the risk of crop injury, especially in young rice plants.

Avoid spray drift to adjacent broadleaf crops which may be sensitive. Follow the recommended pre-harvest interval (typically 60-80 days depending on formulation) to ensure residue levels comply with food safety standards. Protective equipment should be worn during mixing and application.