Cyperus compactus: How to Spot and Control This Sedge in Rice
Cyperus compactus is a tall sedge weed of irrigated and rainfed lowland rice fields in the Philippines. It can live for more than one season, and it spreads by seed and by underground stems. This page shows how to spot it among your palay, how it hurts the crop, and how to control it before it spreads.
What Is Cyperus compactus?
This damo is a sedge from the Cyperaceae family. It has no common English name, and no common Filipino local name either. So this page calls it by its scientific name, Cyperus compactus. You will find 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, it drops seeds that sprout when farmers prepare the field. Second, it sends out rhizomes, which are stems that creep under the soil and push up new shoots. Because these rhizomes stay hidden, a clump you cut at the surface can grow back from below. That is why digging works better than cutting with this sedge.
| Name | Cyperus compactus |
|---|---|
| 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 compactus
Like other sedges, it has a solid stem with three sides and no nodes. Roll the stem between your fingers and you will feel its edges. The stems stand erect and can grow up to 70 cm tall. Its leaves feel spongy and grow about as long as the stem. At the top, look for a cluster of many big, round spikes made up of reddish brown spikelets.
- Erect stems that can reach 70 cm, standing tall among young rice plants.
- Soft, spongy leaves that give a little when you press them.
- Leaves that reach about the same length as the stem itself.
- A crowded top cluster of big, round spikes with reddish brown spikelets.
- A solid, three sided stem with no joints, which marks it as a sedge, not a grass.
Why It Hurts Your Palay
Like most sedges, Cyperus compactus competes with palay for light, water and fertilizer. Its tall stems can shade young rice plants, while its roots draw on the same soil nutrients your crop needs. Because it can live past one season, an old clump keeps taking resources crop after crop.
When it flowers, its seeds can mix with harvested palay and lower the quality of the seed you keep. Thick clumps also give rats and insect pests a place to hide near the rice hills. If you leave it alone, its rhizomes slowly widen each patch.
How to Control Cyperus compactus
- Dig out each clump with a hoe or bolo and lift the rhizomes too, because pieces left in the soil can sprout again.
- During land preparation, rake up rhizome pieces that come to the surface and dry them in the sun instead of leaving them in the mud.
- Remove plants before the round heads turn reddish brown, so they cannot add seed to your field.
- Clean bunds and canal edges near the paddy, since perennial clumps there can survive between crops and creep back 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 Cyperus compactus 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 compactus 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 compactus?
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 compactus
What is the common name of Cyperus compactus?
How do I control it in my rice field?
Why does it grow back after I cut it?
Get Cyperus compactus 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.
The account is free, no credit card.
