Merremia emarginata: How to Spot and Control It in Rice Fields
Merremia emarginata is a creeping, twining broadleaf weed from the morning glory family that farmers call Kupit kupit. It grows in rainfed lowland rice fields in the Philippines. This page shows you how to spot it by its kidney shaped leaves and yellow flowers, and how to control it before its runners take over.
What Is Merremia emarginata?
In English, Merremia emarginata is called kidney leaf morning glory. It belongs to the morning glory family, Convolvulaceae, the same family as kangkong and kamote. Farmers know it as Kupit kupit. Since it is a broadleaf weed, it is not a grass or a sedge.
You will see it in rainfed lowland rice fields. As an annual, each plant lives through one season. It spreads through its vegetative parts, mainly its stems. The thin, reddish stems creep over the ground and send down roots at each node. So any stem piece with a node that touches moist soil can root and grow into a new plant. That is why one plant can soon turn into a patch.
| Name | Merremia emarginata |
|---|---|
| English name | Kidney leaf morning glory |
| Family | Convolvulaceae |
| Weed group | Broadleaves (see the three groups) |
| Local names | Kupit kupit |
| Life cycle | Annual |
| Spreads by | Vegetative parts |
| Where it grows | Rainfed lowland rice fields |
How to Identify Merremia emarginata
Look for thin, reddish stems that twine and creep over the soil, rooting at the nodes. The leaves are kidney to heart shaped and often wider than they are long, with irregular teeth on the edges. As a broadleaf weed, it has wide leaves with netted veins, unlike grasses and sedges. The flowers are yellow. Under each flower, the rounded sepals carry a few to many soft, white hairs. The whole plant feels lightly hairy to almost smooth.
- Thin, reddish stems that twine and creep across the soil between rice hills.
- Roots growing down from the nodes wherever the stem touches moist ground.
- Kidney to heart shaped leaves, often wider than long, with uneven teeth on the edges.
- Yellow flowers with rounded sepals carrying a few to many soft, white hairs.
- Lightly hairy to almost smooth stems and leaves when you run your fingers over them.
Why It Hurts Your Palay
Merremia emarginata spreads by creeping over the ground, so it can cover open spaces between rice hills. Its leaves shade the soil and the base of young palay. The roots at each node also draw water and fertilizer from the same soil as the rice. In rainfed fields, where water can run short, that competition hurts more.
Because it twines, its stems can wrap around rice plants and make hand weeding slow. Weeding that breaks the runners can also spread it, since each rooted piece grows on. Weeds like this give shelter to pests too. So a small patch left alone can turn into a thick mat within the season.
How to Control Merremia emarginata
- Pull out each runner whole, following it back to every rooted node, because stem pieces left on moist soil can grow again.
- Do not chop the stems into pieces during weeding, since each piece with a node can root and start a new plant.
- Carry pulled runners out of the paddy and dry them on high ground, instead of leaving them on wet bunds where they can root again.
- Unwind the stems gently from rice plants instead of yanking them, so you do not pull up or damage the palay.
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 Merremia emarginata 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 Merremia emarginata 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 Merremia emarginata?
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 Merremia emarginata
What is Merremia emarginata called in Tagalog?
How do I control this weed in my rice field?
Why does it spread so fast after weeding?
Get Merremia emarginata 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.
