Rice Flatsedge: How to Spot and Control Payong Payong in Palay
Rice flatsedge, or Cyperus iria, is an annual sedge weed of irrigated and rainfed lowland rice fields in the Philippines. Farmers call it payong payong, siraw siraw or taga taga. It comes up soon after you transplant or seed your palay. This page shows how to spot it early and how to control it before it sets seed.
What Is Rice Flatsedge?
This damo is a sedge from the Cyperaceae family, and its scientific name is Cyperus iria. Filipino farmers know it as payong payong, siraw siraw or taga taga. You will find rice flatsedge in both irrigated and rainfed lowland rice fields.
It is an annual, so each plant lives for one season only. It spreads by seed alone, but it makes plenty of them. Its seedlings also come up quickly once the rice goes in. Because it starts so early, it competes with young rice right from the beginning. That is why early weeding matters most with this sedge. Watch your field closely in the first weeks after transplanting or direct seeding, and pull it before it flowers.
| Name | Rice flatsedge |
|---|---|
| Scientific name | Cyperus iria |
| Family | Cyperaceae |
| Weed group | Sedges (see the three groups) |
| Local names | Payong payong, siraw siraw, taga taga |
| Life cycle | Annual |
| Spreads by | Seeds |
| Where it grows | Irrigated and rainfed lowland rice fields |
How to Identify Rice Flatsedge
Like all sedges, it has a solid, triangular stem with no nodes, while rice has a round, hollow stem with joints. The stems feel smooth. Its leaves are long and narrow, tapering to a point. At the top, it carries an umbrella shaped flower head with many erect spikelets that spread outward. The spikelets range from yellow to yellowish brown, which gives the heads a golden look.
- Smooth, three sided stems with no joints, easy to tell from rice stems.
- Long, narrow leaves that taper to a fine point at the tip.
- An umbrella shaped flower head with many erect spikelets spreading outward.
- Yellow to yellowish brown spikelets that give the head a golden color.
- Seedlings appearing between rice hills soon after transplanting or direct seeding.
- Smallflower umbrella sedge shares the name payong payong, but its heads form tight, round balls instead.
Why It Hurts Your Palay
Rice flatsedge is a C4 weed. It takes hold fast once the rice is planted, transplanted or direct seeded alike, and a single plant can shed 3,000 seeds. When nobody controls it, it can reduce rice yield by as much as 40 percent.
This weed also does harm beyond competition. It can act as an alternate host for other rice pests, such as green leafhoppers. It can also host Pyricularia oryzae, Rhizoctonia solani and Sarocladium oryzae. These fungi cause rice blast, sheath blight and sheath rot, in that order. So a weedy field keeps these pests and diseases close to your palay.
How to Control Rice Flatsedge
- Start weeding early, in the first weeks after transplanting or direct seeding, because this sedge establishes soon after the rice goes in.
- Pull plants before the yellow spikelets ripen, since it spreads only by seed and one plant can produce 3,000 seeds.
- Keep bunds and canals free of it, because it can host green leafhoppers and the fungi behind blast, sheath blight and sheath rot.
- Level the field and keep water evenly over the soil, so seedlings have fewer bare, dry spots to come up in.
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 Sedges
If water and weeding cannot hold rice flatsedge down, choose an active ingredient that works on sedges 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, Pyrazosulfuron ethyl plus pretilachlor, Imazosulfuron, Penoxsulam plus butachlor, Tefuryltrione plus triafamone, Thiobencarb plus 2,4 D IBE | Butachlor, Pretilachlor, Oxadiazon, Pretilachlor plus butachlor, Butachlor plus 2,4 D IBE, Pyrazosulfuron ethyl plus pretilachlor, Butachlor with safener |
| 6 to 10 days | Butachlor plus propanil, Cyhalofop butyl plus bispyribac sodium, Bispyribac sodium, Penoxsulam plus cyhalofop butyl, Imazosulfuron, Propyrisulfuron, Clomazone plus propanil, Thiobencarb plus propanil, Flucetosulfuron, Cyhalofop butyl plus florpyrauxifen benzyl | Butachlor plus propanil, Cyhalofop butyl plus bispyribac sodium, Bispyribac sodium, Pyribenzoxim plus cyhalofop butyl, Penoxsulam plus cyhalofop butyl, Pyrazosulfuron ethyl plus pretilachlor, 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, Bentazone, Cyhalofop butyl plus ethoxysulfuron, Propyrisulfuron, Fenoxaprop P ethyl plus ethoxysulfuron, Flucetosulfuron, Carfentrazone ethyl, Florpyrauxifen benzyl, Cyhalofop butyl plus florpyrauxifen benzyl | Cyhalofop butyl plus bispyribac sodium, Bispyribac sodium, Pyribenzoxim plus cyhalofop butyl, Penoxsulam plus cyhalofop butyl, Metamifop plus bispyribac sodium, Bentazone, Pyribenzoxim, Cyhalofop butyl plus ethoxysulfuron, Propyrisulfuron, Fenoxaprop P ethyl plus ethoxysulfuron, Flucetosulfuron, Carfentrazone ethyl, Florpyrauxifen benzyl, Cyhalofop butyl plus florpyrauxifen benzyl |
| 21 to 30 days | 2,4 D amine, 2,4 D IBE, MCPA, Metamifop plus bispyribac sodium, Bentazone, Metsulfuron methyl plus chlorimuron ethyl, Fenoxaprop P ethyl plus ethoxysulfuron, Carfentrazone ethyl | 2,4 D amine, 2,4 D IBE, Cyhalofop butyl plus bispyribac sodium, Pyribenzoxim plus cyhalofop butyl, MCPA, Metamifop plus bispyribac sodium, Bentazone, Metsulfuron methyl plus chlorimuron ethyl, Pyribenzoxim, Carfentrazone ethyl |
| 31 to 40 days | Metsulfuron methyl plus chlorimuron ethyl | 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 Rice Flatsedge 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.
- Prepare the land well: flood, plow, let the weed seeds sprout, then kill them when you harrow. Level the field so water covers it evenly.
- Pull escapes before their flower clusters turn brown, since one clump drops a great deal of tiny seed.
- 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 sedge weed in the paddy, not only this one. The weed management guide puts them in order for a whole season.
Not Sure It Is Rice Flatsedge?
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 Rice Flatsedge
What do farmers call rice flatsedge in Tagalog?
How do I control it in my rice field?
Can this weed spread rice diseases?
Get Rice Flatsedge out of your field
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