Weeds are a problem for farmers ,because they take water and nutrients so the rice plants get less. Therefore, it is important to know how to handle weed properly.
Not like rice, many weeds die underwater. The weeds seeds are found in the soil and spread with wind and rinse water. Some weed seeds are mixed with rice seeds. During the first six weeks, weed seeds are the most harmful.
Controlling weeds
Ploughing kills weeds and burns weed seeds, so that they can‘t germinate. If the field is flooded for two weeks most of the weed dies. Therefore you should plough and flood two times before sowing.
Keep irrigation canals and field edges clean from weeds and take rice seeds that are free of weeds. With using quality seeds you get stronger plants and can handle weeds better. Sorts that are better to tiller in a early stage, are able to suppress weeds better.
If you transplant two week old seedlings, you give rice an advantage towards weeds. If you don‘t have the time to transplant, you can start planting pre-germinated seeds. Put the rice seeds in water and remove the ones which float. Make sure to use healthy rice that is free from weeds. Let it sit overnight until the next morning. Then let it germinate for two days.
More weed grows when there is to much space between the rice plants. Lowland rice can be planted 15 to 20 cm apart from each other. Weeding is more easy when the rice plants are in lines.
When you plant directly, you should weed after three weeks for the first time. Two to three weeks later, you can weed for a second time. With transplanted rice you need to only weed one time when the plants start to tiller. At tillering stage is the best time to add nitrogen. Herbicides can also be used but not all are suitable to control weeds. The field should be clean so you don‘t have to fertilize the weeds.
