Despite sulfur, cotton-like fungus killing seeds

[jonnyq]

Hi all! I could use some advice from those wiser than me (read: everyone on this board) if you've got the time...

So, I've got four planters, each with 1:1 perlite:peat, in two soda-bottle terrariums. Each planter sits in about 1/4" to 1/2" of water.

I initially planted several seeds in each, and the majority fell victim to a cotton-like fungus. Two seeds germinated; one has trap-leaf, the other is starting to form its first trap leaf.

I then started spraying the planters twice a week with a solution of 1 tablespoon 90% sulfur powder fungicide in 400mL of purified water.

During this time, I stratified another batch of seeds and planted them three weeks ago. One has germinated, but many of the others have fallen victim to this cotton-like fungus despite my sulfur spraying...

Am I too much water, making the peat/perlite too amenable to this fungus? Is there another fungicide I should be supplementing with? Is this problem common? Should this be expected?

Cheers,
Jonathan

[ICPS-bob]

This is not a common problem if there is adequate air circulation. Your perlite/peat mix is fine.

Your setup is not entirely clear to me. Are the "soda-bottle terrariums" covers over your planters? If so, that is the problem. VFT seeds and plants do not need a cover (often referred to as chamber of death). The resulting super high humidity and lack of air circulation is an ideal environment for growing mold and fungus.

[Not a Number]

Bob brings up a good point. I take it that you are using the soda-pop bottle terrariums as germination chambers.

While humid warm conditions are ideal for germinating many types of seeds it is also ideal for growing fungus.

Your batch of peat moss probably contains spores of the fungus you are experiencing. If the fungus is unknown finding a fungicide that is effective or partially effective is a hit-or-miss affair. Sulfur based fungicides are usually the last stop.

Before sowing a new batch of seeds I would clean everything (bottles, pots, tools etc.) with hot water and a bleach solution. I would also either replace the batch of peat moss or at least sterilize your media before sowing the seeds.

Lois Ochs recommends using a 10% bleach solution to flush your medium, then flushing well several times with water. Do not sterilize your peat in the microwave as Lois says this causes the peat moss to breakdown.

Other home remedies you can try:

A thin mulch of finely chopped/milled long fiber sphagnum moss - reputed to have anti-fungal properties.

Many home gardeners mist seedling pots with a weak brew of chamomile tea which is also reputed to have anti-fungal properties.

[jonnyq]

First off, thank you so much for the advice! For a newcomer like me, it's so helpful to find a supportive community like this! That being said, please forgive my many questions...

So, yes, indeed, this was (up until I read your posts) a soda-bottle terrarium at my job... The basic setup was:

...with a gooseneck desk lamp housing a daylight CFT bulb on a timer, on from midnight to 10:00AM each night. (I figured that the overlight fluorescent lights during working hours give it a little extra light boost...)

At this point, I don't have any more seeds, so I'll probably hold off for a while and see if I can keep the three that have germinated alive long enough to reach their first dormancy in winter, 2009... But thanks for the advice on helping to sterilize my remaining peat/perlite; Just in case I'll need it, I'll sterilize my remaining medium this week...

As to the existing fungus in the planters, I take it there's not much left I can do? Removing the soda-bottles should provide a less hospital environment for the fungi, which, with the sulfur, may help?

As to the fungus spores in the medium, is it likely that they will pose a danger to the seedlings? (i.e. Am I fighting a lost cause with this round?)

And lastly, the 1/4" to 1/2" pool of purified water that I have the planters routinely sitting in... not recommended?



And forgive my self-indulgence, but with these three seedlings, I feel like a proud first-time parent:

[rwatkins]

I agree with removing the bottles, however you need to do so gradually... like over a period of a week or so. Seedlings are not as forgiving as mature plants, and the sudden loss of humidity may kill them due to moisture loss.

[jonnyq]

Removing the bottle definitely helped... I kept the bottles tilted open on at a 45-degree angle for the past four days and totally removed them today, so now they're in the open air... The seedlings are all still alive and healthy after a weekend of half-open air (heh), and fungus has only killed one additional seed, while five additional seeds have actually survived to sprout! (Last week, the ratio was reversed...)

(Now, to keep them alive...)

Thanks again for the help! I'll try not too screw up too much more...

[plantlife]

glad to hear of your victory over the fungus