At a loss why healthy marigold start turning brown and die. Is it a fungas problem?

Too much water? Bugs in the soil? Ours die after six months or so when they are about 1.5 metres high.

Not to much water. Been letting them dry out in between. Not sure about the bugs in the soil. The roots look fine when I have pulled them out. I had what I think was Thrips at first but got on them right away. They looked good after that. There was a guy growning Marigolds on 2 Rai and doing well then he got wiped out. Looks like much the same way as what mine are doing.

There might be something in the soil. Some Peas and Beans I planted are dieing from the bottom up as well. But Peppers and Basil are fine.

That sucks after that long of growing they up and died. 1.5 meters tall.... Africian variety?

Dunno I just stole some seeds from a neighbour. 6 months is fine bu me.

Edited December 1, 201510 yr by cooked

I'm growing them in hydroponics for a tryout.

They have a fungus disease similar to your pictures on the lower leaves.

But they are not as much affected as your plants.

They're still green at the top and flowering now.

It keeps getting worse from there. Guess need to find a Fungaside to treat them. Will look tomorrow to see what I can find. Think the ones that have it that bad might as well be terminated and see if the rest can be saved.

Any good fungasides out there?

Sorry for the destructive reply, but how many pots you have of them?

It might be cheaper and more successful to grow a new batch.

Fungi is difficult to treat, there might be some spores nearby that you don't spray and the cycle begins again...

My initial reaction (or guess) was it is a Wilt and i goggled it and marigolds do get Fusarium Wilt .( I was thinking tomato wilt but very similar) If it is a wilt it usually is a hygiene problem - infected soil, seeds or water.

Usually it means getting rid of the plants and soil completely so you not spread the wilt . Usually marigolds are pretty damn tough.

Here is a link for Marigold Diseases - http://extension.psu.edu/pests/plant-diseases/all-fact-sheets/marigold-diseases

CLW ,

Yeah sorry for the destructive comment. I saw a pic of you growing one in HP. If yours is showing signs in a water based media then maybe it is a water problem or there is something floating in the air. I started with 30 plants. Down to 6 now that are still looking ok. I did start some new seedlings and they have been dieing to. Maybe with close proximity to the unheathly plants its having an effect?

Xen,

Marigolds I find are tough but easy to grow to. But I think they have met their match over here. Guess time to go chat up some locals that are growing them and see what they are doing to to keep their's alive.

If the seedlings die it might be damping-off caused by various fungi.

You can do these things:

- Use soilless media such as vermiculite or peat moss

- Heat or sun - sterilise your soil

- Treat the seeds and the soil surface with fungicide powder.

I have a half growing table of hydroponic Marigold. I will add a picture later.

Good luck!

Here is a picture of my hydroponics Marigold

And the infected plants

The disease confirmed now as mites.

The black spots are necrosis from sucking of the mites

Ah and I have been seeing the black spots on other plants too. Way to small to see or I need reading glasses. Now what to hit them with for a treatment. And will some of them recover?

Ah and I have been seeing the black spots on other plants too. Way to small to see or I need reading glasses. Now what to hit them with for a treatment. And will some of them recover?

I haven't been able to find anything specifically for treating spider mites (this would be an acaricide). I did try spraying with Bayticol which is a dog tick medicine, and had moderate success. Mites are difficult to get rid of anyway, they don't like wet leaves but in Thailand you would have to sp[[ray all day. Chaindrite cockroach spray might be worth trying.

Ah and I have been seeing the black spots on other plants too. Way to small to see or I need reading glasses. Now what to hit them with for a treatment. And will some of them recover?

You need magnifying glass or microscope to see the mites.

Unfortunately Marigold are known as trap plants for mites so with them I got these little creatures into the greenhouse and spread on other plants. [emoji53]

As already mentioned, they are difficult to treat. I searched on internet and it says that Pyrethrum or Pyrethroides might work.

Pyrethrum is, afaik, not available in Thailand.

Insecticides with Pyrethroides can be found here, just Google.

http://www.nufarm.com/Assets/23096/1/Dimethoate_label_permit_Aug_2013.pdf

Not sure if availible here but was good on red mites.

This is availible here.

Edited December 6, 201510 yr by farmerjo

Coming back to that, I used to use a product that also killed the eggs. Pyrethrum won't do that. Burn the plants I'm afraid is the only solution and even then you will have eggs hatching all over the place for years to come.

Ok thanks. Not good that it has caused further problems. I have found info that says "Malathion" works as well. Has anyone seen that here or is it under some other thai name?

I have seen the odd Pirate bug ( a natural enemy) among my plants but think need a hungry army of them to help.

I find some stuff seems hard to find here as its not stocked in alot of the stores.

lol a quick search found "Malathion" (Malanock 57) also another Mite treatment (Mite End). You can view the page here,

http://www.chiataigroup.com/Product/CropProtection/tabid/100/ctl/CategoryView/mid/426/categoryId/300/Insecticides-and-Acaricides.aspx