Why Bispyribac-Sodium is a Key Herbicide for Effective Rice Weed Management

Introduction

Bispyribac-sodium is a post-emergence, selective herbicide widely used in rice cultivation to control a broad spectrum of weeds, including annual grasses, sedges, and broadleaf weeds. Its high efficacy, low use rate, and crop safety make it a vital tool for improving rice yields.

Product Information

• Name: Bispyribac-sodium

• Chemical Name: Sodium 2,6-bis[(4,6-dimethoxypyrimidin-2-yl)oxy]benzoate

• CAS Number: 125401-92-5

• Appearance: White to light brown crystalline powder

• Formulations: SC (Suspension Concentrate), OD (Oil Dispersion)

• Use Rate: Very low (10–30 g a.i./ha)

Key Features

• Selective herbicide: Safe for transplanted and direct-seeded rice

• ⚡ Post-emergence control: Effective against established weeds

• Systemic action: Translocated within weeds for complete kill

• Wide weed spectrum: Controls grasses, sedges, and broadleaf weeds

• Low application rate: Reduces cost and chemical load on fields

Applications

Bispyribac-sodium inhibits acetolactate synthase (ALS), an enzyme vital for amino acid synthesis in weeds. This disrupts weed growth and leads to gradual plant death while leaving rice unharmed.

Advantages

• Strong control of multiple weed species in flooded rice fields

• Works at low doses, minimizing environmental impact

• Reduces competition and improves rice yield potential

• Flexible use in transplanted and direct-seeded rice systems

Limitations

• Limited activity on weeds beyond 5-leaf stage

• Risk of ALS-resistant weeds if used repeatedly

• Requires precise water management in rice paddies for best results

FAQs

Q: Can bispyribac-sodium be mixed with other herbicides?
A: Yes, it is commonly tank-mixed with pre-emergence herbicides to enhance control and manage resistance.

Q: How soon after application can rice be irrigated?
A: Light irrigation may be applied 24–48 hours after spraying to optimize absorption.

Q: Is it effective against perennial weeds?
A: It is mainly effective on annual weeds; additional control measures are needed for perennials.

Conclusion

Bispyribac-sodium is an essential herbicide for rice farmers, providing post-emergence control of key weeds with excellent crop safety. When used as part of an integrated weed management program, it helps maintain cleaner fields and maximize rice productivity.