physan 20

I just bought some more and since joining Daves , I have found somany things I was doing wrong --
How do you use for damping off ?

Tony, I just read the label for physan 20-it doesn't treat "damping off", and this product is not being encouraged to apply to plants. It says apply "to hard non-porous surfaces". In other words, its a product you would use to clean your greenhouse or the products you use to grow. Bleach is a lot cheaper to disinfect surfaces.
Damping off is a common term used to describe one of two fungus...pythium (root rot) or rhizoctonia (stem rot). They are two totally different fungus, and the fungicide that you would use on one would not help with the other. The chemicals used for either fungus are pretty expensive (rhizoc is easier and cheaper to get rid of. Daconil, I think is sold in stores and you apply to the foliage and then keep dry, ) If you are not a commercial grower, then it would be cheaper by far to throw the seedling container with the damping off away then to invest $ 100 or more in the chemical needed to treat it. As well, because seedlings are so tender, and pythium moves so fast in a single container of dirt , by the time you treated it, ( takes at least a week to see results) the seedlings would almost all be dead. Better to keep the soil on the dryer side once the seeds germinate. Hope that answers your question.

I also have had problems with damp off on seedlings. Seems to be the most problem when the plants are too damp. They say to bottom water but with a tiny seedling thats hard. I have had good results watering the seedlings with hydrogen peroxide, 2 T to a quart. It seems to really help. I also was using lots of peat in my seedling mix, I quit using that and am using coco fiber and it seems to have helped with lots of bugs and problems I was getting with the peat.
Rebeccanne

I found web site
http://www.physan.com/
1/2 way down page .

Seeds and Seedlings - Damping Off
Treat seeds and seedlings by soaking in a solution of 1 1/2 teaspoons of PHYSAN 20 concentrate in 1 gallon of water for 5 minutes. Fill the flask containing the seed or seedlings with enough PHYSAN 20 solution to completely cover the seeds/seedlings. Drain the PHYSAN 20 solution off the seeds/seedlings before planting. Use a fresh solution of PHYSAN 20 for each flask.

Seedlings - Damping Off (ornamental plants only)
Make a solution of 1 1/2 teaspoons of PHYSAN 20 concentrate in 1 gallon of water. Soak seedlings in PHYSAN 20 for 5 minutes. Use a soak container large enough to completely immerse one flask of seedlings at a time. Change the solution daily or more often if solution becomes visibly dirty.
If a garden soil is used for planting seedlings, completely saturate the soil in PHYSAN 20. Place the soil in a pot or tray and add enough PHYSAN 20 solution to completely cover the soil. Let the solution drain through the soil or pour off excess.

USE: 1 1/2 teaspoons of PHYSAN 20 concentrate in 1 gallon of water.

PHYSAN 20 solution is effective in stopping the spread of damping off when sprayed on seedlings. Spray seedlings so that all surfaces are thoroughly wet.

USE: 2 tablespoons of PHYSAN 20 concentrate in 3 gallons of water of 2 tsp. PHYSAN 20 concentrate in 1 gallon of water.

With the risk of setting of a lot of flares here, I would like to put my spin on it...

If you sterilize your equipment in water with some bleach and flush well afterwards, and then use soilless mixes, damping off should be less of a problem. Just make sure the temperature of the mixture is in the range preferred by the seeds.

E.g. if recommended germination range is 70-78F, then target 74. If you keep temperatures 65F or 85F you have a lot bigger chance of damping off.

Physan and other self proclaimed miracles are not a substitute for proper preparation and control of the process. E.g. even with physan, damping off will occur if you do not sanitize your setup first and stress the young seedlings with temperatures which are too different from their optimum.

If your seedlings are attacked by damping off nevertheless, then Physan would not have helped. My statement here - or argument if you like - is that damping off would not have occurred if you followed above whether or not you use Physan.

I was asked by a lady in a local gardening club to help review her setup due to lots of problems with lights and she also used some kind of "mental support" product to convince herself that damping off was less with the product than before. What we were able to find out, however, was that by dosing the seedlings every week with this she kept the growing mix damp which actually helped the seedlings survived. She changed to pure water but continued to dose them frequently and she had close to 90% germination with no damping off.

I mention this because I honestly believe that using Physan is not going to guarantee good result, and similarily, not using Physan is not going to mean damping off. Damping off is simply a description we give to seeds which die before they germinate (or latest shortly after they germinate). Damping off can be caused by disease which can be eliminated through proper temperature and moisture control (plus sanitizing the equipment upfront) or it can be caused by sudden drafts, cold soil, lack of water, etc.

I am sure not everyone agrees, but Physan is no more than snake oil IMHO. You might as well add 1/4 tsp of red food coloring to the water and bottle it as a "scarlet seed protection system"

Ok, I will now craw back under my rock

-- Kenneth

lol Kenneth, I don't think there are flare ups going on....are there? I couldn't agree more...sterlize your setup before growing and back off the water when they germinate-gradually but definitely. Once my seeds germinate, if the soil is wet, I don't water them that day, unless there is still sds germinating, and then just a splash-enough to get the seeds wet. Good air circulation is good too. The best thing to keep in mind is that the dryer your soil is, the better roots you get. Water displaces oxygen, and roots need oxygen to grow. You would be very shocked to see how dry I let the soil get when the seedlings are growing. If there is any doubt about the fungus that cause "damping off" are, everyone should google it and go for the university websites. Plant pathologists will tell you that its the two I named above. Its real important to know what fungus you have so you can treat it appropriately-otherwise its a hit or miss game.

The reason I got the physan was after the plants reached about 3 to 4 inches high [ in jiffy pellets and rock wool ] I transplanted / put in plastic costco cups and put supersoil around them . 3 or 4 days later they start falling over with damping .
I mixed up H202 and poured over supersoil potting mix the day before .
I was misting every day [H202 mixture = 1/2 cup H202 [ 3 % I buy at $1 store ] , 1 gallon distilled water ] and the jiffy pellets or rock wool are / were in a tray with a clear plastic dome and a heating pad under . After they reached 3 inches they were hitting top of dome .
I continued to mist them with H202 after moving to cups . The cups do have holes in the bottom , but no heat . They are in a cold frame [ greenhouse no heat ] 2 tube lights above about 4 inches from dome and about 18 to 24 inches above cups .
The plants dieing are Brugs , Datura , Hibiscus , and tomatoes .

If I understand you correctly, you kept the plastic dome on the plants all day in sun up until they were 3" high? And misting these plants as well? Were you watering the jiffy pellets at the same time as misting? Without seeing the operation, I would say that you should have removed the dome top after they germinated and you could see the first leaves. Wasn't it like a sauna in there? And hot? If you were only misting then was the pellets drying out? Looking for stress factors here like the plants drying out,or too wet and too hot. I would guess that if the plants died from a fungus, then they got it before you transplanted, because it would take 5 days or so before the plant started to exhibit the signs of the fungus. And if i understood yr operation correctly, then you had an environment perfect for generating a fungus. Excess moisture and heat. I would also be concerned about the amt of H202 that you were exposing these small plants to as well. Depending on how long you were misting ( to runoff, or longer) and then drenching the soil before transplanting, they may have developed a toxcity to the H202. Not sure about that but a guess. How cold is your cold frame at night, and how hot does it get during a sunny day? Do you ventilate ?

ah-ha!
I think I know what went wrong. You are not having a damping off problem. You are having a transplant problem.


Daming off is death of plants prior to - or immediately after - germinating. It is not death of the plants 3-4 " high.
I suspect your plants died from transplanting chock instead. No amount of hydroperoxide or physan could have helped them with that.

The reason hydroperoxide is sometimes used is to kill unwanted pathogens although - as I have tried to argue - it is more of a percieved benefit than a real benefit (if they were dying from damping off, e.g. seeds not germinating, then they would have died with or without physan and that other meassures can actually be more effective).

A few pointers which may help in future:
- once seedlings germinate, uncover the seedlings immediately (do this gradually over a few days but do not keep them covered until 3-4" tall)

- when you water seedlings, do not mist. This is only done on very small seeds (begonia, carrot) where the surface of the soil must be very consistently moist due to the very small surface sown seeds. Once the seedlings germinate (sprout) you need to water properly.

- proper watering means soaking the entire root ball so it is wet and then let it drain.

E.g. if you use jiffy pellets or rockwool then this material must be soaked and then allowed to drain (empty saucer, etc). Do not mist the outside of the pellet/rockwool. The plant roots will die from lack of water because the inside of this material will be dry but appear wet on the outside. Instead water with a watering can in the saucer and let the material soak up water. Then empty the saucer and let the material drain. This is the only way to water properly.

- Do not mist seedlings. This cause more chance of fungal disease. Keep the leaves dry, but make sure rootball is moist. watering is done through the roots, not through the leaves.

- when you transplant, make sure you transplant into moist soil. Preferably do not use "supersoil" or other soil with fertilizer added. Young transplants will not be able to cope with this. Use regular potting soil and/or more soilless mixes until plants are bigger.

- pre-moisten the potting soil/soilless mix and firm it carefully around the existing root ball in the larger pot. Then water thoroughly until the completely soaked and then let drain. You can temporarily (for 1 day) cover the seedlings with a plastic container to keep humidity high (good when transplanting) but do not keep them covered. Also watch temperatures under the cover (must not be too high. Keep flourescent light bulbs atleast 24" away when covered).

- do not fertilize immediately after transplanting. give the plants a few days to settle in before you start this.

If you follow above, you should have a lot less problems.

Thank you , have recieved several emails so far . the rockwool seems to hold water longer and more of it than the jiffy pellets . I'll stop misting . picture of what I found this morning .
Itook out of 6 pack for picture

Tony,

Just out of curiosity, what medium is that plant growing (dying) in? It looks rather non-porous and the plant could be drowning for lack of oxygen. Or perhaps root rot (pythium) has taken out what little root system it had. I agree with Kenneth that Physan is not a good idea. Several decades ago I used a commercial mercury compound (called PanoDrench) to fight damping off. I was much more unenlightened then.

Today I use much brighter overdriven T8 cool white fluorescents, I pull the clear covers as soon as the seedlings emerge, and I use a small fan to provide a gentle artificial breeze. The fan dries the surface of the growing medium, which also deters damping off. The "exercise" in the wind also makes the seedlings much sturdier.

I use Premier Pro-Mix BX and I add extra Perlite as my sterile growing medium. It is much more "open" than the medium in your picture. I wouldn't use Jiffy anything. Tried it. Didn't like it. Despite Jiffy's claims, when I set the Jiffy pots in the garden the plant roots did a very poor job of growing through the walls of the Jiffy pots.

I now use pots made from the bottoms of 2-liter soft drink bottles. That gives me much more root volume, the roots grow very fast and become rootbound even in the large pot, which holds the big root ball together nicely. By "kneeding" the flexible plastic pot a little, the root ball loosens and drops out into my hand intact. Since the wall of that root "pot" is made of roots, they enter the surrounding garden soil very quickly. I am now experimenting with some 3-liter soft drink bottles for even more root volume.

MM

What I can't figure out is why everyone covers up the seeds that they are trying to germinate. I propagate hundreds of flats of plants and never cover the seedling trays. They are in a greenhouse so I guess it is more humid in there than in a house. I only have problems with plants dampening/rotting when they are kept to wet.

j_vino
How often do you water ? Do seed trays allow water to drain away or do they sit in water ? [ holes in bottom of trays ]
I thought the seeds would stay warmer and the condensation helped keep them moist .
Does that make sence ?

j_vino, I was wondering the same thing. I just put the seed on top as well and mist and cover-I use black plastic if it requires dark (like zinnias) and clear plastic for light. I am in a greenhouse too, but I find that if I cover I only have to mist once a day. I get great germination. The key is to remove the plastic when they germinate, and cut back on water some. I think some people are leaving the plastic on too long.

Tony seed flats definitely have holes in the bottom. The reason its better not to cover is because seeds need light to germinate and when you cover them with dirt, you are cutting off the light. They still germinate-just takes longer and isn't neccesary. Larger seeds take longer to germinate and they are aided by putting in dirt-the dirt does help in this case to keep the seed moist.

I was covering with clear plastic domes and some seeds were in jiffy 7 pellets and some in rockwool .
Other than pushing down , I didn't cover seeds with dirt or peat .
Over the years , I have tried all kinds of things .
I quess this year it was either /or - misting - covering with clear plastic domes .
Seeds can up , then dampening off on some . Or when I transplanted
dampening off on some .
Can the watering can [ plastic ] cause dampening off ? I fill a 25 gallon tub with city water and use the watering can to fill my misting bottles and water plants with . I don't rinse or clean it other than setting in sun and letting it dry after using .
The physan 20 worked out to 1/4 ounce to a gallon of water [ I used a turkey baster - it is marked in 1/4 ouces and milli-liters .
I am glad I joined this site .
Thanks to everyone who has responded

The flats do have holes in the bottom and they are not allowed to sit in water. They are grown on expanded metal benches with bottom heat. I water the seedlings once a day in the am unless it is very hot then then I will also water after lunch. I grow both covered and uncovered seeds with good success and the typical dapening off / mold problems don't exist when they are not covered.

how do you water ? I have been misting in the morning and using turkey baster to add water for bottom watering when there is little condensasion on clear plastic domes .

I water overhead using a dramm lemon head breaker (pl750 I think). It has a soft water flow and it is a very even pattern. The pl1000 (redhead) is nice too.