Question

Choose a post-emergence herbicide which is used for controlling weeds in the rice crop.

• A. Pendimethalin
• B. Atrazine
• C. Bispyribac sodium
• D. Pyroxasulfone

Hint:

Remember: Pendimethalin = pre-emergence, Bispyribac sodium = post-emergence for rice.

Answer 1

The Correct Option is C

Step 1: Understanding herbicide classification.
Herbicides are broadly classified into pre-emergence and post-emergence herbicides.
Pre-emergence herbicides are applied before weed seeds germinate, whereas post-emergence herbicides are applied after weed emergence.
Step 2: Herbicides in rice crop.
- In rice, weed control is very important during the early stages to reduce crop-weed competition.
- Post-emergence herbicides are widely used because they target weeds after they have already emerged, ensuring effective control.
Step 3: Analysis of options.
- (A) Pendimethalin: This is a pre-emergence herbicide, not a post-emergence one.
- (B) Atrazine: Used mainly in maize as a pre-emergence herbicide, not suitable for rice.
- (C) Bispyribac sodium: This is a selective post-emergence herbicide, highly effective for controlling grasses, sedges, and broad-leaved weeds in transplanted rice.
- (D) Pyroxasulfone: Mostly used as a pre-emergence herbicide in other crops, not as a post-emergence in rice.
Step 4: Conclusion.
Hence, the correct post-emergence herbicide used for controlling weeds in rice crop is Bispyribac sodium.