Weeds are one of the major problems in rice farming, as they can cause significant yield losses if not managed properly. Direct-seeded rice is particularly vulnerable to weed infestation, as it has no transplanting phase to establish good crop canopy. Therefore, farmers need to take measures to control weeds in direct-seeded rice crops. Here’s what you need to know.
1. Identify the weeds
The first step in controlling weeds is to identify the species that are causing the problem. This information will help you select the most appropriate herbicide and timing for application. Common weeds in direct-seeded rice include barnyard grass, water grass, sedges, broadleaf weeds, and nutsedge.
2. Optimize seedbed preparation
Proper seedbed preparation is essential in controlling weeds in direct-seeded rice. The seedbed should be leveled and moist before seeding, as this will promote timely and uniform germination. Farmers should also make sure that weed seeds are buried deeply to prevent their emergence.
3. Apply pre-emergence herbicides
Pre-emergence herbicides are applied to the soil before weeds emerge to prevent their growth. The herbicide should be applied immediately after seeding and followed by a shallow irrigation to activate herbicide uptake by weeds. Some of the common pre-emergence herbicides used in direct-seeded rice include pendimethalin, pretilachlor, and butachlor.
4. Use post-emergence herbicides
Post-emergence herbicides are applied to weeds after they have emerged. They are effective in controlling weeds that have already established in the field. However, they should be used judiciously to avoid injuring the rice crop. Some of the commonly used post-emergence herbicides in direct-seeded rice include azimsulfuron, penoxsulam, and bispyribac-sodium.
5. Integrate cultural practices
Cultural practices such as row spacing, crop rotation, and water management can help control weeds in direct-seeded rice. Narrow row spacing promotes early canopy closure, which reduces weed competition. Crop rotation with non-rice crops can also reduce the buildup of weed populations. Water management through intermittent irrigation can also reduce weed growth.
In conclusion, weed management is critical in direct-seeded rice production. Identifying the weeds, optimizing seedbed preparation, applying pre-emergence and post-emergence herbicides, and integrating cultural practices are essential for successful weed control. With proper weed management, farmers can increase their rice yield and profitability.