Ludwigia hyssopifolia: How to Spot and Control It in Rice Fields
Ludwigia hyssopifolia is an upright, yellow flowered broadleaf weed that farmers call Kahoy kahoy, malapako or tina tina. It grows in both irrigated and rainfed lowland rice fields in the Philippines. This page shows you how to spot it, how much harm it can do, and how to control it before it spreads.
What Is Ludwigia hyssopifolia?
In English, Ludwigia hyssopifolia is called seedbox. It belongs to the evening primrose family, Onagraceae. In the bukid, farmers know it as Kahoy kahoy, malapako or tina tina. These names also cover other Ludwigia weeds, so you need to check the plant closely. Being a broadleaf weed, it is not a grass or a sedge.
You will find it in both irrigated and rainfed lowland rice fields. Some plants live as annuals and die after one season, while others keep going as perennials. It spreads by seed and also by propagules, which are plant parts that can grow into new plants. Its slender, reddish pods hold the seeds that refill the soil for the next cropping.
| Name | Ludwigia hyssopifolia |
|---|---|
| English name | Seedbox |
| Family | Onagraceae |
| Weed group | Broadleaves (see the three groups) |
| Local names | Kahoy kahoy, malapako, tina tina |
| Life cycle | Annual or perennial |
| Spreads by | Seeds and propagules |
| Where it grows | Irrigated and rainfed lowland rice fields |
How to Identify Ludwigia hyssopifolia
Look for an upright, branched plant up to 60 cm tall. Its stems have ridged sides, run from green to reddish, and harden into wood near the base. Its leaves are narrow and lance shaped. Like other broadleaf weeds, the leaves have netted veins, unlike grasses and sedges. The yellow flowers have four diamond shaped petals and eight stamens, more than the number of sepals. After flowering, it forms slender, four angled, reddish seed pods.
- Upright, branched plants up to 60 cm tall standing among the young palay.
- Angled stems, green to reddish, that feel woody and hard near the base.
- Narrow, lance shaped leaves growing along the stems and branches.
- Yellow flowers with four diamond shaped petals and eight stamens inside.
- Slender, reddish seed pods with four angles forming after the flowers.
- Look alike tip: Ludwigia octovalvis has much bigger yellow flowers, while Ludwigia perennis has as many stamens as sepals.
Why It Hurts Your Palay
Ludwigia hyssopifolia is a C3 weed of rice, the same as the rice plant itself. It invades many kinds of rice culture, and it grows on both clay loam and clay soils. That means it can show up on many kinds of rice farms.
When it is left to compete fully, the losses are heavy. At a ratio of 4 to 1, weed to rice, rice yield can drop by 64 percent. At a ratio of 8 to 1, the loss can reach 81 percent. Those numbers show why early weeding pays off. Each plant left standing also drops seeds that keep the problem alive for the next season.
Nature gives you a helper here. A small leaf beetle called Altica, from the chrysomelid family, attacks this weed. Both the larvae and the adult beetles eat its leaves hungrily. So if you see small beetles chewing holes in kahoy kahoy leaves, leave them alone. Avoid spraying insecticide where they feed, because that kills your helper too.
How to Control Ludwigia hyssopifolia
- Pull young plants before the woody base forms, because older plants with hard, woody stems are tough to uproot by hand.
- Remove plants before the reddish seed pods ripen, and carry them out of the paddy so the seeds do not drop on the mud.
- Leave the Altica leaf beetles alone when you see them chewing kahoy kahoy leaves, since they weaken the weed for free.
- Since it can live on as a perennial, check bunds and field edges after harvest and remove any old plants still growing there.
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 Ludwigia hyssopifolia 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 Ludwigia hyssopifolia 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 Ludwigia hyssopifolia?
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 Ludwigia hyssopifolia
What is Ludwigia hyssopifolia called in Tagalog?
How do I control this weed in my rice field?
How much yield can this weed take from my rice?
Get Ludwigia hyssopifolia out of your field
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