about 3 years ago

Can anyone identify this disease of the oil palm?

Dear Sirs/Madam
My name is Thuan, I come from vietnamese.
I have some pictures of the oil palm sick. I want to know what it is. please show me know the cause and how to prevent this disease
Please help me. Thank you very much ( I am not good at english, lol)

Periods of a disease (images)

I provide you with some images of the leaves sick.

This is the oil palm plantation one year. This disease appeared one month ago. It's the rain season

This disease is concentrated into a region or scattered in the oil palm planttation.

I have used the original fungicide carbazide and hexaconazole produced in Vietnam but not effective

Vietnamses
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3 answers

Barbara J. Ritchie almost 3 years ago

The symptoms do not look like ‘freckle’ that is caused by the fungus Cercospora elaeidis and is found mostly in nurseries, this disease occurs mainly during the middle and at the end of the dry season. The fungus is present in Central America and in West African oil palm growing countries and has been recorded in Tanzania but is not found in SE Asia including Viet Nam.

There are other fungi that can cause leaf spots similar to those in your pictures. These have been known to cause considerable problems in oil palm nurseries, examples are -Helminthosporium, Bipolaris, Curvularia, Drechslera, these fungi tend to cause lesions that have a halo around them that can be very pale or become yellow-orange in colour. The taxonomy of these fungi has changed considerably over the years and so searching the literature for the palm diseases they cause can be confusing and frustrating sometimes. Poor nutrients in nursery polybags; growing in peat soils; uneven watering; bags too close together creating a microclimate suitable for the fungi to spread easily can contribute to the spread of these nursery diseases. Polybags should be big enough for the palm to grow from a germinated seed to a plant between 9-12 months old when they will be ready for transplanting into the field. Planting into a small bag and then replanting into a bigger bag gives more opportunity to damage the young palms and damaged plants are more susceptible to these nursery diseases.

Most of these diseases do not respond well to fungicide application and to be perfectly honest spraying is often a waste of time and money. Chemicals should be a last resort and then only if you are sure they will be effective.

I suggest sanitation and hygiene as a way to control this problem. Make the rows wider for the polybags still in the nursery so that the fronds do not touch the fronds of another young palm. Do not spray water over the fronds, only water straight into the polybags. When was the last time the nursery palms had fertiliser? They may need an extra dose of fertiliser but be careful not to give them too much as you do not want the nursery palms to produce too many new fronds too quickly. Badly infected nursery palms must be removed and destroyed, either bury or burn them, do not leave them at the edge of the nursery field as they will be a source of infection.

Sometimes young palms suffer from transplanting shock and what may have been a few small insignificant lesions in the nursery can become a problem for newly planted out palms. These palms should recover given time, however if there are a lot of dying or dead fronds these should be removed. Oil palm is a resilient plant and with a bit of extra care and attention they should recover.

Where in Viet Nam are you based? I would be most interested in knowing as some years ago I worked with NIPP in Ha Noi and SOFRI in My Tho as well as teaching courses at universities in Ha Noi and Can Tho.

I hope this reply goes someway to help solve your problem, please ask if you have further questions.

David Hughes about 3 years ago

Hi Thuan
I have spoken on the phone with a disease expert at CABI in the UK (Barbara Ritchie). She will do some research on this and provide an answer in the coming day or two. There are a few possible identifications for the disease which I know based on published knowledge. But they have not been recorded in Vietnam, so we need more details.

Can you also provide images of the underside of the leaves please. Ultimately, the precise diagnosis relies on a morphological examination of the spores (if this turns out to be a fungus as I suspect it is). Are there any diagnostic labs that exist nearby?

How widespread is this problem? Are you a nursery for Oil Palm.

Do you have access to fungicides? Which ones?

Providing all these answers will be helpful as we find a solution for you.

thanks

david

Thuan_attapeu almost 3 years ago

Hi Barbara
Thank you very much for your help!
This is the oil palm plantation one year. The disease appeared a month ago. It's the first of the rain season. I suspect that it's a fungus but I'm not sure or could be a nutrient deficiency. There is an expert come from Maylaysians to visit the oil palm plantation here ,According to he it is just a symptom of deficiency of fertilizer.He ensure that only need to add fertilizer and after one month the oil palm will back to normal green and these spots caused by fungus will not effect the oil palm tree. I hope it's true
If I have further question, I will contact you again.I'm looking forward your help

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