Hydrolea zeylanica: How to Spot and Control It in Rice Fields
Hydrolea zeylanica is a creeping broadleaf weed with blue purple flowers. Farmers call it kangkong kangkungan or lupo lupo. It grows in irrigated and rainfed lowland rice fields in the Philippines, and it spreads fast under flooding. This page shows you how to spot it and how much harvest it can take. It also shows how to control it before it takes over.
What Is Hydrolea zeylanica?
Hydrolea zeylanica is a creeping herb that likes wet ground. In English it is called Ceylon hydrolea. Farmers know it as kangkong kangkungan, garampingat or lupo lupo. Its hollow stems crawl along the soil while the tips turn upward. It is a broadleaf weed, not a grass or sedge, and it belongs to the Hydrophyllaceae family.
You will find it in irrigated and rainfed lowland rice fields. Most plants live on from season to season, though some last only one season. It spreads in two ways. First, its creeping stems act as runners and set down new plants. Next, it also makes seeds. Even cut pieces of stem can grow into new plants. So weeding that leaves broken stems in the mud can spread it further.
| Name | Hydrolea zeylanica |
|---|---|
| English name | Ceylon hydrolea |
| Family | Hydrophyllaceae |
| Weed group | Broadleaves (see the three groups) |
| Local names | Kangkong kangkungan, garampingat, lupo lupo |
| Life cycle | Perennial, occasionally annual |
| Spreads by | Runners and seeds |
| Where it grows | Irrigated and rainfed lowland rice fields |
How to Identify Hydrolea zeylanica
Look for hollow stems creeping flat on the mud, with the tips curving upward. The leaves are lance shaped to oval, pointed at both the base and the tip, with smooth edges. Some plants have smooth leaves, while others have fine hairs. Like other broadleaf weeds, the leaves have netted veins, unlike grasses and sedges. When it flowers, look for bright blue purple petals near the stem tips.
- Hollow stems lying flat on the mud, with the growing tips turning upward.
- Lance shaped to oval leaves, pointed at both ends, with smooth edges.
- Leaves that are either smooth or covered with fine hairs, from plant to plant.
- Blue purple flowers near the stem tips, easy to see against green rice.
- New plants springing up where broken stem pieces were left in flooded mud.
Why It Hurts Your Palay
This weed takes hold fast. Even a cut piece of stem can sprout into a new plant, so it fills a field quickly, most of all when the paddy is flooded. In fact, the standing water that holds back many other weeds does not stop this one.
If you leave it alone, it can take a big share of your harvest. In transplanted rice, it can cut grain yield by as much as 52 percent. In wet direct seeded rice, the loss can reach 6 percent. Those numbers come from fields where the weed was not controlled. So early action protects the most palay, especially in transplanted fields where the loss runs highest.
How to Control Hydrolea zeylanica
- When you hand weed, pull out the whole plant and carry every stem piece out of the paddy. Cut pieces left in the mud can grow again.
- Do not just chop it into the mud with a rotary weeder. Broken stems can spread the weed instead of killing it.
- Start weeding early in transplanted fields, where the yield loss can be highest. Do not wait for the blue flowers to show.
- Check the bunds and canal edges, since creeping stems there can crawl back into the field.
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 Hydrolea zeylanica 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 Hydrolea zeylanica 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 Hydrolea zeylanica?
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 Hydrolea zeylanica
What is Hydrolea zeylanica called in the Philippines?
How do I control kangkong kangkungan in my rice field?
Why does it spread after I weed it?
Get Hydrolea zeylanica out of your field
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