What is the difference between barnyardgrass and rice barnyardgrass? A quick guide to tell them apart

Rice barnyardgrass and barnyardgrass are both grasses (Poaceae), and both are common weeds in fields, swamps and ditches, and their similar appearance always makes them hard to tell apart. Barnyardgrass, rice barnyardgrass and Leptochloa chinensis are grass weeds that occur commonly and cause serious damage in paddy fields, severely harming rice quality and yield. So what is the difference between the two? And how do you control them?

1. What is the difference between rice barnyardgrass and barnyardgrass?

Rice barnyardgrass = leaves grow vertically, leaf sheaths are blue-green, and seeds are larger; whether as seedlings, mature plants or seeds, it can mix with rice and harm rice over the long term. Barnyardgrass, by contrast, looks extremely similar to rice. The culms are upright, the base is slanting or knee-bent, and it is smooth and hairless. The leaf sheaths are loose, the lower ones longer than the internodes and the upper ones shorter than the internodes; there is no ligule; the leaf blades are hairless.

2. How do you control rice barnyardgrass and barnyardgrass?

Control of rice barnyardgrass:

(1) Remove weed seeds in combination with seed treatment, and eliminate weed seeds on the soil surface in combination with ploughing and land preparation;

(2) Carry out regular paddy-upland rotation to reduce the occurrence of weeds;

(3) Improve sowing quality so that full stands emerge in one sowing, using the crop seedlings to suppress the weeds.

Control of barnyardgrass:

(1) For direct-seeded fields, pre-emergence closed herbicides at the bud stage can include bensulfuron-methyl · pretilachlor (with safener), pyrazosulfuron-methyl · pretilachlor (with safener), pretilachlor (with safener), etc.;

(2) For direct-seeded fields, post-emergence stem-and-leaf herbicides can include: quinclorac, quinclorac and quinclorac co-formulations, etc. After the rice reaches the 2.5-leaf stage, apply 10-20 grams of active ingredient per mu, dilute with 30-45 kg of water and spray evenly. When barnyardgrass occurs severely, use penoxsulam (Daoxie) at 30-50 ml per mu, diluted with water and sprayed evenly.

(3) After rice seedling throwing or transplanting, once the seedlings have rooted, at the 1-3 leaf stage of barnyardgrass use quinclorac, quinclorac and quinclorac co-formulations, etc., applying 10-20 grams of active ingredient per mu, diluted with 30-45 kg of water and sprayed evenly. When barnyardgrass occurs severely, use penoxsulam (Daoxie) at 30-50 ml per mu or bispyribac-sodium at 3-4 grams of active ingredient per mu, diluted with water and sprayed evenly.