Cyperus digitatus: How to Spot and Control Finger Flatsedge in Rice
Cyperus digitatus, or finger flatsedge, is a sedge weed of irrigated and rainfed lowland rice fields in the Philippines. It can live for more than one season and spreads by seed and by underground stems. This page shows how to spot its yellow, finger like flower spikes and how to control it in your palay.
What Is Cyperus digitatus?
This damo is a sedge from the Cyperaceae family. Its English name, finger flatsedge, comes from the way its flower spikes spread out like the fingers of a hand. It has no common Filipino local name. So this page uses its scientific name, Cyperus digitatus. You will see it in both irrigated and rainfed lowland rice fields.
It is usually a perennial, but some plants live for one season only. It spreads in two ways. First, its flowers make seeds that fall into the soil. Second, it grows rhizomes, which are stems that creep under the ground and send up new shoots. Because of these rhizomes, an old clump can come back in the same spot after you cut it.
| Name | Cyperus digitatus |
|---|---|
| English name | Finger flatsedge |
| Family | Cyperaceae |
| Weed group | Sedges (see the three groups) |
| Local names | None recorded |
| Life cycle | Perennial, sometimes annual |
| Spreads by | Seeds and rhizomes |
| Where it grows | Irrigated and rainfed lowland rice fields |
How to Identify Cyperus digitatus
Like other sedges, it has a solid, triangular stem with no nodes. You can feel the three edges when you roll the stem between your fingers. Its leaves are flat. At the top, it carries a compound flower head, and its spikes spread out from one point like the fingers of a hand. The spikelets are yellow, so the heads stand out against green palay leaves.
- A solid stem with three clear edges and no joints along its length.
- Flat leaves rising from the base of the plant.
- A branched flower head whose spikes fan out like fingers from one point.
- Yellow spikelets that look bright against the green rice leaves.
- New shoots coming up close to an old clump, a sign of rhizomes below.
Why It Hurts Your Palay
Like most sedges, Cyperus digitatus competes with palay for light, water and fertilizer. Because it can live for more than one season, an old clump keeps drawing on your soil crop after crop. Its rhizomes also let each patch grow wider over time, so the space left for rice keeps shrinking.
When it flowers, its seeds can end up in harvested palay and lower the quality of seed you keep. Dense clumps also give rats and insect pests a place to hide close to the rice hills. So it pays to remove it while patches are still small.
How to Control Cyperus digitatus
- Dig out each clump with its rhizomes, because pieces left in the soil can grow into new plants.
- After plowing, gather rhizome pieces that come to the surface and dry them in the sun, away from the paddy.
- Pull or cut plants before the yellow spikelets ripen, so no new seed falls into the field.
- Keep bunds and canal edges clean, since perennial clumps there can creep back into the paddy.
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 Cyperus digitatus 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 Cyperus digitatus 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 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 Cyperus digitatus?
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 Cyperus digitatus
What is the common name of Cyperus digitatus?
How do I control it in my rice field?
Why does finger flatsedge come back in the same spot?
Get Cyperus digitatus out of your field
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