Water Clover: How to Spot and Control It in Rice Fields
Water clover is a small aquatic fern with four part leaves that farmers call Paang itik or kaya kayapuan. It grows in irrigated and rainfed lowland rice fields across the Philippines. This page shows you how to spot it, why it hurts your palay so much, and how to control it.
What Is Water Clover?
This plant is not a true clover. It is a fern from the family Marsileaceae, and its scientific name is Marsilea minuta. In English it also goes by dwarf water clover. Farmers call it Paang itik or kaya kayapuan. Even as a fern, it is grouped with the broadleaf weeds of rice.
You will find it in irrigated and rainfed lowland rice fields, in standing water or wet mud. As a perennial, it lives on from season to season. It makes no flowers and no seeds. Instead, it spreads through its creeping stems, called rhizomes, and through spores. The spores form inside small, hard cases near the base of the leaf stalks.
| Name | Water clover |
|---|---|
| Scientific name | Marsilea minuta |
| Family | Marsileaceae |
| Weed group | Broadleaves (see the three groups) |
| Local names | Paang itik, kaya kayapuan |
| Life cycle | Perennial |
| Spreads by | Vegetative parts and spores |
| Where it grows | Irrigated and rainfed lowland rice fields |
How to Identify Water Clover
Look for leaves that look like a four leaf clover, floating on the water or standing just above it. Each leaf has a long, thin stalk topped by four triangle shaped leaflets. The plant creeps by long, slender, branched rhizomes in the mud. It counts as a broadleaf weed, with flat, wide leaflets unlike the narrow blades of grasses and sedges. Down where each leaf stalk starts, you may find small spore cases and short hairs.
- Leaves with four triangle shaped leaflets, like a four leaf clover, on long stalks.
- Long, slender, branched rhizomes creeping through the mud and linking many plants.
- Small, hard spore cases and short hairs near the base of the leaf stalks.
- Dense green patches spreading across the water surface between rice hills.
- No flowers at all, since this weed is a fern that spreads by spores.
Why It Hurts Your Palay
Water clover is persistent and very competitive with rice. Its creeping rhizomes spread through the mud and send up leaf after leaf, so it soon fills the gaps between rice hills. It takes nutrients, space and light that your palay needs.
If you leave it uncontrolled, it can cut your rice yield by 70 percent. That is why you should not ignore even a small patch. Because it is a perennial that spreads from rhizome pieces and spores, it comes back after weak weeding. A field with this fern needs steady attention every season.
How to Control Water Clover
- Rake out the rhizomes during land preparation and carry them to dry ground, because any piece left in the mud can grow again.
- Remove every piece of creeping rhizome when you hand weed, since broken bits left behind start new plants.
- Clean tools, rakes and the wheels of machines before moving to the next paddy, so rhizome pieces do not spread.
- Dry the pulled plants fully on high ground in the sun, instead of throwing them into canals that feed other fields.
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 Broadleaves
If water and weeding cannot hold water clover down, choose an active ingredient that works on broadleaves 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 | 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 | Pretilachlor, Oxadiazon, Pretilachlor plus butachlor, Butachlor plus 2,4 D IBE, Pendimethalin, 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, Pendimethalin, Cyhalofop butyl plus propanil, 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, 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, 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 Water Clover 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 they flower and set seed, and carry them out of the paddy instead of leaving them on the bund.
- 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 broadleaf weed in the paddy, not only this one. The weed management guide puts them in order for a whole season.
Not Sure It Is Water Clover?
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 Water Clover
What is water clover called in Tagalog?
How do I get rid of it in my rice field?
Why does it keep coming back even after weeding?
Get Water Clover 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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