What Is the Difference Between Rice Barnyardgrass and Barnyardgrass? A Quick Guide to Telling Them Apart

Rice barnyardgrass and barnyardgrass are both grasses in the Poaceae family, and both are common weeds in fields, marshes and ditches, and their similar appearance always makes them hard to tell apart. 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 damages rice over the long term. Barnyardgrass, meanwhile, looks extremely similar to rice. The culms are upright, the base is inclined or geniculate, and it is smooth and hairless. The leaf sheaths are loose; the lower ones are longer than the internodes, and the upper ones are shorter than the internodes; there is no ligule; the leaf blades are hairless.

2. How do you control rice barnyardgrass and barnyardgrass?

Rice barnyardgrass control:

1. Agricultural control

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

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

(3) Improve sowing quality so that a single sowing gives full emergence, using the seedlings to suppress the weeds.

2. Chemical control

(1) For the first application, during paddy land preparation, choose 50-60 ml/mu of Alozin + 15-20 g/mu of Taiyangxing, apply by splashing with water or by mixing with soil and broadcasting, then transplant rice seedlings after an interval of 3-7 days. For the second application, carry it out 15-20 days after rice transplanting, choosing 40-60 ml/mu of Alozin + 10-15 g/mu of Taiyangxing (Taiyangxing can be replaced with 10% pyrazosulfuron-ethyl), mix with soil and broadcast, with a water layer of 4-6 cm, kept for more than 5 days.

(2) For controlling rice barnyardgrass in transplanted fields in the middle and late stages, use 50 ml/mu of anilofos (Alozin, containing 300 g of active ingredient per liter) emulsifiable concentrate + 40-60 g/mu of 50% quinclorac wettable powder, applied at the 4-7 leaf stage of rice barnyardgrass (plant height 10-30 cm); drain the water 1-2 days before application, keep the spray volume at 7-10 liters/mu, and normal irrigation can be resumed 1-2 days after spraying. You can also choose 2.5% penoxsulam (Daorie) at 80-100 ml per mu, and spray with shallow water.

Barnyardgrass control:

1. Manual control

Pull out barnyardgrass while it is still young.

2. Chemical control

(1) For sealed weeding at the sprouting stage in direct-seeded fields, you can use bensulfuron-methyl · pretilachlor (with safener), pyrazosulfuron-methyl · pretilachlor (with safener), pretilachlor (with safener), etc.;

(2) For post-emergence stem and leaf herbicides in direct-seeded fields, you can use: quinclorac, quinclorac and quinclorac mixed formulations, etc., after the 2.5 leaf stage of rice, at 10-20 g of active ingredient per mu, diluted with 30-45 kg of water and sprayed evenly. When barnyardgrass occurs severely, you can use penoxsulam (Daorie) 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 mixed formulations, etc., at 10-20 g of active ingredient per mu, diluted with 30-45 kg of water and sprayed evenly. When barnyardgrass occurs severely, you can use penoxsulam (Daorie) at 30-50 ml per mu, or bispyribac-sodium at 3-4 g of active ingredient per mu, diluted with water and sprayed evenly.