How Penoxsulam Delivers Targeted Weed Control in Modern Rice Cultivation

Introduction
Penoxsulam is a highly effective post-emergent herbicide widely used in paddy fields. It offers selective control of both broadleaf weeds and sedges, helping rice farmers reduce competition and increase yields. Its excellent crop safety, low usage rate, and environmental friendliness make it a preferred choice in integrated weed management.

Key Features & Advantages

1. Selective Herbicide for Rice

   • Safe for transplanted and direct-seeded rice.

   • Can be used on both dryland and paddy rice.

2. Wide Spectrum Weed Control

   • Controls Echinochloa spp., Cyperus difformis, Monochoria vaginalis, Scirpus spp., and Ludwigia spp.

   • Effective even at low application rates (10–40 g a.i./ha).

3. Excellent Systemic Activity

   • Rapidly absorbed and translocated within weeds.

   • Inhibits ALS enzyme, halting cell division and growth.

4. Long-Lasting Effect

   • Residual activity suppresses weed regrowth for up to 3–4 weeks.

   • Reduces the need for multiple applications.

5. Environmentally Friendly

   • Low toxicity to fish and aquatic organisms.

   • Breaks down easily in soil and water, minimizing residue buildup.

Applications

• Recommended Rate: 15–40 g a.i./ha depending on weed species

• Application Method: Ground sprayer or drone with adequate water coverage

• Compatibility: Can be tank-mixed with other herbicides like bensulfuron-methyl or cyhalofop-butyl

How It Works

Penoxsulam inhibits the acetolactate synthase (ALS) enzyme, essential for the synthesis of branched-chain amino acids (valine, leucine, isoleucine). Without these amino acids, weed cells cannot divide and grow, leading to gradual death.

Because rice metabolizes the active ingredient differently, it remains unharmed, making Penoxsulam highly selective.

Limitations & Precautions

• Avoid application to fields with ALS-resistant weed populations

• Not suitable for crop rotation with ALS-sensitive crops (e.g., legumes) within a short period

• Requires adequate soil moisture for best performance

• Use protective equipment during handling

FAQs

Q: Can Penoxsulam control grassy weeds like barnyardgrass?
A: Yes, it’s effective on early-stage barnyardgrass but may need a tank mix for larger grassy weeds.

Q: How soon can I rotate to another crop after using Penoxsulam?
A: Rotation interval is typically 3–6 months, depending on the following crop and soil conditions.

Q: Is Penoxsulam suitable for organic farming?
A: No, it’s a synthetic herbicide not approved for organic use.

Conclusion

Penoxsulam provides targeted, efficient, and environmentally responsible weed control in rice cultivation. Its low-dose effectiveness, systemic action, and residual benefits make it an indispensable tool for farmers looking to maximize rice yield while simplifying weed management.