Chinese Sprangletop in Rice: How to Spot It and Control It
Chinese sprangletop is a slender, tufted grass weed of irrigated and rainfed lowland rice fields in the Philippines. Its thin, sometimes reddish leaves hide well among young palay. This page shows how to spot it, how much harm it does to your crop and how to control it before it sets seed.
What Is Chinese Sprangletop?
Chinese sprangletop (Leptochloa chinensis) belongs to the grass family. Local names include kuring kuring, marapagay, maroy paroy, salay maya and palay maya. You will find it in both irrigated and rainfed lowland rice fields. It grows in slim, upright tufts that can reach 120 cm, so it can easily keep pace with the rice around it.
Most plants live for only one season, so it usually behaves as an annual. Still, some plants live on and act like perennials. It spreads mainly by seed, and each plant makes a great many. Pieces of stem can also take root. So a cut stem left lying on wet soil may start a new plant.
| Name | Chinese sprangletop |
|---|---|
| Scientific name | Leptochloa chinensis |
| Family | Poaceae (Graminae) |
| Weed group | Grasses (see the three groups) |
| Local names | Kuring kuring, marapagay, maroy paroy, salay maya, palay maya |
| Life cycle | Annual, sometimes perennial |
| Spreads by | Primarily seeds but can also propagate culm cuttings |
| Where it grows | Irrigated and rainfed lowland rice fields |
How to Identify Chinese Sprangletop
Like other grasses, it has round, hollow stems with clear joints, or nodes. Look for slender, upright tufts up to 120 cm tall. The leaves are long, flat and thin, almost papery, and some turn reddish or purplish. Later, a narrow panicle appears, shaped like an egg in outline, with many thin branches that carry small spikelets. Next to the heavy heads of barnyard grass, this seed head looks light and airy.
- Slender, upright tufts stand up to 120 cm tall between the rice hills.
- Leaves are flat, thin and papery, and some show a red or purple tint.
- A narrow, open panicle with many fine branches holds tiny spikelets.
- Pulled stems left lying on wet soil can root again and start new tufts.
- Look alike tip: its thin, airy seed head differs from the dense, drooping head of barnyard grass.
Why It Hurts Your Palay
Chinese sprangletop is a C4 weed, so it grows fast in strong sun and heat. While it grows, it takes water, light and fertilizer from your rice. Each plant can also make 27,000 seeds. So a few plants left to ripen can load your soil with seed for the next crop.
When it competes at 16 plants per square meter, it can cut rice yield by as much as 48 percent. Besides that, it hosts other rice pests, such as the green leafhopper and the zigzag leafhopper. These insects can stay alive on the weed between crops. Then they move into your new palay as soon as you plant it.
How to Control Chinese Sprangletop
- Carry pulled plants out of the paddy instead of leaving them on wet soil, since stem pieces can root again.
- Hand weed early, before the thin panicles open. Each plant can shed thousands of seeds, so good timing matters more than extra effort.
- Keep a steady layer of water in the field once the rice can take it. Its seeds sprout best on moist soil without standing water.
- Check between the hills for reddish or purplish tufts, because its thin leaves blend in with young rice.
What to Do at Each Age of Your Rice
- 0 to 5 days: keep the soil saturated. Use a pre emergence herbicide only if the field had many weeds last season.
- 6 to 10 days: hand weed in transplanted rice. In direct seeded rice, this is the window for an early post emergence spray.
- 11 to 20 days: keep water in the field, weed by hand or with a rotary weeder, and let Azolla and the Altica beetle help. Spray only if those fail.
- 21 to 30 days: top up the water and keep weeding. Spray only if weeding fails.
- 31 to 40 days (transplanted rice): hand weed. A spray this late is only a rescue.
- After any post emergence spray, bring the water back within 1 to 3 days at 3 to 5 cm and hold it for 4 to 5 days. Keep young rice above it.
Active Ingredients That Work on Grasses
If water and weeding cannot hold Chinese sprangletop down, choose an active ingredient that works on grasses at the age of your rice. Each active ingredient in it is in a herbicide registered in the Philippines for rice. Shop by the ingredient on the label, never by the brand. If your field also has other kinds of weeds, the weed control helper in anee.io finds the ingredients that cover all of them.
| Rice age (days after planting) | Transplanted rice (lipat tanim) | Direct seeded rice (sabog tanim) |
|---|---|---|
| 0 to 5 days | Butachlor, Pretilachlor, Oxadiazon, Butachlor plus 2,4 D IBE, Pendimethalin, Pyrazosulfuron ethyl plus pretilachlor, Clomazone, Penoxsulam plus butachlor, Tefuryltrione plus triafamone, Tetflupyrolimet, Thiobencarb plus 2,4 D IBE | Butachlor, Pretilachlor, Oxadiazon, Pretilachlor plus butachlor, Butachlor plus 2,4 D IBE, Pendimethalin, Pyrazosulfuron ethyl plus pretilachlor, Butachlor with safener, Clomazone, Tetflupyrolimet |
| 6 to 10 days | Butachlor plus propanil, Cyhalofop butyl plus bispyribac sodium, Bispyribac sodium, Penoxsulam plus cyhalofop butyl, Pendimethalin, Cyhalofop butyl plus propanil, Propyrisulfuron, Clomazone plus propanil, Thiobencarb plus propanil, Flucetosulfuron, Cyhalofop butyl plus florpyrauxifen benzyl | Butachlor plus propanil, Cyhalofop butyl plus bispyribac sodium, Bispyribac sodium, Cyhalofop butyl, Metamifop, Pyribenzoxim plus cyhalofop butyl, Penoxsulam plus cyhalofop butyl, Cyhalofop butyl plus propanil, Pyrazosulfuron ethyl plus pretilachlor, Pendimethalin, Propyrisulfuron, Clomazone plus propanil, Thiobencarb plus propanil, Pretilachlor plus pyribenzoxim, Penoxsulam, Flucetosulfuron, Cyhalofop butyl plus florpyrauxifen benzyl |
| 11 to 20 days | Cyhalofop butyl plus bispyribac sodium, Bispyribac sodium, Pyribenzoxim plus cyhalofop butyl, Penoxsulam plus cyhalofop butyl, Metamifop plus bispyribac sodium, Cyhalofop butyl plus ethoxysulfuron, Propyrisulfuron, Fenoxaprop P ethyl plus ethoxysulfuron, Flucetosulfuron, Florpyrauxifen benzyl, Cyhalofop butyl plus florpyrauxifen benzyl, Profoxydim | Cyhalofop butyl plus bispyribac sodium, Bispyribac sodium, Cyhalofop butyl, Metamifop, Pyribenzoxim plus cyhalofop butyl, Penoxsulam plus cyhalofop butyl, Metamifop plus bispyribac sodium, Pyribenzoxim, Cyhalofop butyl plus ethoxysulfuron, Propyrisulfuron, Fenoxaprop P ethyl plus ethoxysulfuron, Flucetosulfuron, Florpyrauxifen benzyl, Cyhalofop butyl plus florpyrauxifen benzyl, Profoxydim |
| 21 to 30 days | Metamifop plus bispyribac sodium, Fenoxaprop P ethyl plus ethoxysulfuron | Cyhalofop butyl plus bispyribac sodium, Metamifop, Pyribenzoxim plus cyhalofop butyl, Metamifop plus bispyribac sodium, Pyribenzoxim |
| 31 to 40 days | No herbicide listed at this age. Hand weed and keep the water up. | Not listed for direct seeded rice |
Spray Safely
Use only herbicides registered with the Fertilizer and Pesticide Authority, and follow the label on the pack: the rate, the timing, the water and the protective clothing. Switch herbicide groups between seasons so the weeds do not learn to survive them. Our guide to herbicides for rice explains the groups.
Keep Chinese Sprangletop Out Next Season
- Plant clean, certified seed. Weed seeds mixed into the punla are the easiest way in.
- Keep the seedbed, the canals and the bunds free of weeds, so seed does not wash or blow into the paddy.
- Plow and harrow well, and rake out the runners, roots or pieces you turn up. A small piece left in wet soil can grow a new plant.
- Pull escapes before the seed heads open, and clean the thresher and harvester before they enter the field.
- Keep the field clean after harvest and through the fallow, so fewer seeds build up in the soil for next season.
These steps work for every grass weed in the paddy, not only this one. The weed management guide puts them in order for a whole season.
Not Sure It Is Chinese Sprangletop?
Take a clear photo of the leaf, the stem and the flower or seed head, then ask Anee, the smart farm technician in anee.io, in Tagalog or English. Anee tells you which weed it most likely is, its group, and what to do at the age of your rice. You can also put the weeding days on your cropping calendar, so the team knows when to go in.
anee.io keeps your weeding, spraying and water on one calendar, and Anee answers when a plant looks wrong.
- Weeding days on the season calendar
- Photos and notes for every lot
- Anee, the smart farm technician, in Tagalog or English
Questions Farmers Ask About Chinese Sprangletop
What do farmers call Chinese sprangletop in the Philippines?
How do I control sprangletop in my palay?
Does sprangletop spread rice pests?
Get Chinese Sprangletop out of your field
With Libre + Anee, read the whole guide: how to tell it from your crop, and what to do and spray at every age of your crop.
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