Green Mold (Trichoderma)

Nan's Nook : Archives : Contams : Mold : Green Mold
  Subtopic Posts Updated Creator
Possibly normal Blueing?  -    
For the love of shrooms, HELP!!!  12 02/12 12:39am Tigress113
I have a moldy question  10 12/15 11:46pm kobayashi
Is this contam  3 02/12 12:37am Scotsman

By Tripster (Tripster) on Wednesday, September 12, 2001 - 07:30 pm:

Anyone know what this is and have any suggestions about what I should do?

Black Spot

By Tripster (Tripster) on Wednesday, September 12, 2001 - 07:35 pm:

Nevermind the captions btw. It doesn't look to me like mold to me at all, more like the someone burnt the substrate. Also, as you might be able to see the mycelium is trying to grow over it, so should I just leave it and see what happens or start this jar over? Thanks for your help in advance.


By Johnseemore (Johnseemore) on Wednesday, September 12, 2001 - 08:10 pm:

looks DOA buddy

By Eatyualive (Eatyualive) on Wednesday, September 12, 2001 - 08:17 pm:

throw it out. looks like trichoderma. otherwise i would say to wipe your needle with rubbing alcohol before innoculating or you should be more sterile when preparing your substrate. presterilize your mix in the oven before mixing it.

By Nan (Nanook) on Saturday, October 20, 2001 - 04:33 am:

OK, a contam that forms or erupts in a location other than your Innoculation Point, it is usually the jar sterilization that has failed. If Contams start where you shot the needle... Look at your needle & homemade syringe first.

This is another case where Dextrose can help clean up your growing. If you shoot a jar of dextrose with the Spores, incubate for 7-10 days, you will know if the inoculum is "hot" and clean before you shoot jars... Sometimes you get weak prints... Or Dirty Prints. Sure it takes an extra week, but you save enormous amounts of spores... And you can glass the jar with your eyeball and spot trouble before it shows up in all the jars... Honey is not clean enough to eyeball well, but dextrose is pretty good here.

Shroom Glossary

By Timothy Leary (Timothyleary) on Friday, January 25, 2002 - 05:03 am:


By Tigress113 (Runigun) on Monday, October 15, 2001 - 08:33 pm:

Ok, we had a battle with the green meanies, and bleached out the entire room, walls, windows, every surface. Then we bombed the room with a strong disenfectant and installed a hepa filter...we have a new batch of 24 colonized beautifully...except for the green meanie we found on the bottom of a few of them. We immediately removed them from the grow room (they did have pins on them). Our setup is a terrarium with damp verm on the bottom...humidifies wonderfully...but should we go to perlite? When we dunk we empty out the old verm, bleach the container, and put in new this our problem? We are getting really apprehensive to even go into the room and fan...but I can't think of anything we've done wrong..we got the doorknobs, ceiling, floor, wall and windows, and wash our hands before going in....hope somebody can help, because this is really pissing me off!

By Lichen (Lichen) on Monday, October 15, 2001 - 09:46 pm:

Ok, your solution is twofold.
1) you should be using Perlite rather than Vermiculite as your 'Humidifier'.
2) you need to treat the affected areas with a spritz of Lime water, very diluted. The green loves acid, and alkali kills it. Just buy some horticultural lime and mix a teaspoon of it into a Spray Bottle, and spritz the Perlite judiciously. If you are using double-end casing, you may want to soak the vermiculite under the cakes in lime water as well.

Keep up the good hygeine, and let us know if you have further problems :0)

By Snoopy (Snoopy) on Thursday, November 01, 2001 - 05:30 am:

I just picked my first shrooms and on a few of the big fat ones there appears to be a small amount of greenish looking mold, very trace amounts on the base of the shrooms. Is this okay to eat after they have been dried?

Also I notice on the cakes themselves, I notice small little patches of what appear to be darker shades, perhaps mold? Should I pick the rest of the shrooms all are about an inch or so in length and spray with h202, and then dunk for the 2nd flush or should I let the shroomz continue to grow bigger before I pick and dunk?

By Nan (Nanook) on Thursday, November 01, 2001 - 05:49 am:

Wash the shrooms under running water.

Remember cakes dehydrate and stress out during fruiting. They discolor. I would think you are seeing normal stress. Clean your cakes, dunk them, recase them. This all sounds normal with the exception of some possible contam on the shroom itself... This is very unusual and I think perhaps what you are seeing is the effects of some stress and dehydration...

Use the contam test. Put the shroom under running tap water and rub the spots in question. Does it wipe off? Does it smear? Does it feel slimey?

If the answer is no, you are fine. If the answer is yes, don't eat the shroom.

By Snoopy (Snoopy) on Thursday, November 01, 2001 - 01:32 pm:

okay great thanx Nan

By whoever (Livedangerous) on Monday, November 19, 2001 - 05:14 am:

i dont get it. i had no green mold in my jars before birth or for two weeks afterwards but now the cakes that have a lot of "white fuzz" seem to be turning to green fuzz. what is the likely cause of this contam so as to avoid this in the future. also, anyone ever think of pouring a little hydrogen peroxide on the mold spots in an effort to kill the contam. im sure ill get plenty of people telling me im stupid for suggesting that one but at least tell me why you think it wouldnt work.

By jim brown (Shrhobbyist) on Monday, November 19, 2001 - 05:32 am:

There's not much to do about green mole. Pitch them. Did they all get green mold?

By Lichen (Lichen) on Monday, November 19, 2001 - 05:49 am:

when cakes age they become susceptible to contams, especially the green mold, trichoderma. It starts brilliant white and turns green quickly, usually within 2 days.
I have no idea why this is happening to your cakes, unless they are old. However, since you say, if I understand properly, that they have only been out of the jar 2 weeks, that isn't it, because cakes are normally good for at least a month, maybe six weeks, before they age and weaken and succumb to trich. My cakes go three flushes, usually two months or so before they begin to die. So there's a few possibilities.
1)you have the heat up too high in the terrerium
2)there is trich present in the terrerium
3)they were weak cakes to begin with.
a few questions:
1)How long did these cakes take to 100% colonization? If it was more than a month, it could well be they were weak in the first place
2)did they fruit satisfactorily? If they didn't, it could indicate an internal problem.
3)What sort of humidification system are you using? If it's perlite, how long have you had it in there without treatment of some kind, as hydrogen peroxide? If it's another humidifier tek, it could still be the cause.
4)how often do you let the growth chamber air out(fanning)?

Let us have some more details, and maybe we can help you.

In the meantime, once your pfcakes succumb to trichoderma, they're ruined beyond help. You need to throw them away and sterilize your growth chamber.

By Nan (Nanook) on Monday, November 19, 2001 - 07:38 am:

Are you sure it's mold. Have you done the contam test???

Place a cake under running water and rub the discolored spots with your finger. If it smears it's mold. If is does not smear or feel slimey it is discolored mycelium.

By quote: (Quote) on Monday, November 19, 2001 - 01:25 pm:

peroxide is ineffective vs. green mold.

By whoever (Livedangerous) on Monday, November 19, 2001 - 06:59 pm:

i have a heater maintaining my closet(which is where the terrariums reside) at a temp of 80 degrees. my cakes took longer than expected(a month and a half although i may have been waiting for the mycellium to spread to places it simply was never going to) to colonize and this baffled me but i just figured the temp was too low as i did not add the heater to the closet till after birth. some of the cakes are fruiting rather well, but others not worth a shit. i have a perlite terrarium in which i mixed hydrogen peroxide with the water when it was added originally(a month ago maybe) and i also have two spray type terrariums with shields. i try to drain the excess water often but i do not live in a sterilized environment by any means, my dog does not help this matter. i fan about twice a day which i though was enough. side note: the cakes in my spray terrariums are fruiting much better than those in the perlite terrariums. if you need some more info let me know. thanks guys.

By Tigress113 (Runigun) on Monday, November 26, 2001 - 08:44 pm:

Ok, so we have 12 cakes we innoculated which were starting to show serious green meanie growth when we checked them. We birthed them in perlite mixed with lime (the cakes aren't touching the lime) and they show absolutely tremendous mycelial growth (literally 1/4 inch mycelial growth). My question is, if these cakes sprout shrooms, are they ok? We had a much smaller outbreak of green meanie which we "cured" with lime treatment, and those shrooms were fine...anxious to hear back as it would suck if we coudn't use them!

By Lichen (Lichen) on Monday, November 26, 2001 - 09:15 pm:

If there is no visible contamination on the fruiting cakes, they're fine. I doubt the cake would fruit hardly at all if it's riddled with trich. If in doubt, cut the cake straight in half and see what the inside looks like, because lots of times a cake can look good on the outside but be rotten and contammed inside (if there is contamination competing with the mycelium. This is why it's a fallacy to say that cakes can 'overcome' a contam in the jar--it just doesn't work)

By quote: (Quote) on Monday, November 26, 2001 - 10:49 pm:

personally, i'd pass on anything from a contam'd cake.
it's just not worth the risks.

By ggg (Ggg) on Monday, November 26, 2001 - 11:47 pm:


By Mr. Tambourine Man (Tambourine_Man) on Tuesday, November 27, 2001 - 12:01 am:

I'm confused. So Quote, if a cake produced great flushes of shrooms and when it was tossed at the end of its life it was discovered to have contams inside of it you wouldn't eat the shrooms that it produced?

By quote: (Quote) on Tuesday, November 27, 2001 - 12:05 am:

a cake full of contams would not give great flushes,
so that's not a problem.
and no, i would not eat anything from a contam'd cake,
i'm not that desperate,
and i have plenty more.

By Nan (Nanook) on Wednesday, November 21, 2001 - 01:10 am:

Green mold is evil stuff. Use lots of lime in the casings where Trich has been a problem. Trich seems to crop up here when the pH of the casing "sours" or drops. Stamets & Chilton report:

5. pH: The pH of the casing must be within certain limits for strong mycelial growth. An overly acidic or alkaline casing mixture depressed mycelial growth and supports competitors. Agaricus brunnescens prefers a casing with pH values between 7.0-7.5. Even though the casing has a pH of 7.5 when first applied, it gradually falls to a pH of nearly 6.0 by the end of cropping due to acids secreted by the mushroom mycelium. Buffering the casing with limestone flour is an effective means to counter this gradual acidification. The optimum pH range varies according to the species. (See the growing parameters for each species in Chapter XI.)


The he reports for P. Cubensis:

After fully run, cover with the standard casing whose preparation is described in Chapter VIII. Layer to a depth of 1-2 inches. The casing should be balanced to an initial pH of 6.8-7.2.


I am finding this to be sour with enriched casings, and Trich is not controlled. It is true that bringing the casing pH up inhibits the mycelium growth into the casing... But it sure keeps the Trich at bay.

I am even considering sweetening pure Verm casings with some Lime... Trich is a real problem with carpeting in many areas, especially beds & trays set closest to the floor. Dust mites, flies, dust, skin particles, hairs... This is the source. Once you get a good dose of Trich spores spread about it can be difficult to control... So I started increasing the pH of my casings used on my beds.

Trich is the first contam to attack orange peels.

The Trich gets really nasty on enriched casings... I think it is because the pH drops faster in the presence of Nitrogen (Bat Guano, Worm Castings, sea weed... whatever), and there is food there for Trich to chow... And unless you are antiseptic, it will chow early rather than late. Hydrogen Peroxide is completely useless against Trich Your best bet is to cull contamed cultures and beds early before the contam goes into it's green sporulation stage. Trich will erupt on pure verm casings too, but the contam does much better on a soured enriched casing

If you accidentally inoculate your grow room with Trich while moving contamed cultures you are pretty well set back in the contam department. Growing contams to "see what happens" is not cool, they are sporulating and setting you up for a big contam fall. Contams are hazardous. Don't nurse contamed cakes. Pitch contams ruthlessly. The best bet is to keep contams nipped in the bud and never let them get a foothold, because once they do

Strong Sanitizer is required to kill Trich spores and I let the sanitizer solution sit and dry after wiping/spraying to ensure it has a chance to work. Moving trays and bins higher up off the floor helps. Carpets & pets can make things a nightmare. Don't let pets in grow areas, tape down some drop cloths over carpeting... Clean room tactics.

An ion or ozone generator may be something to look at where Trich is a problem.

Now I am curious for some second and third flush reports on pure Coco casings...

By SYDYSTYK (Addict) on Friday, October 19, 2001 - 08:40 am:

watch out i made a spore syringe from a print that was made in a wide mouth witha index card at the bottom i was sterilizing with h2o2 which i thought to do the job i then innoc 60 jars with contamed spores, they colonized with mold fairly quick yet the mold looked like mycelium, so i was like 12 day colonization, bad ass, then i noticed at the top of the jar the colon was turning pretty pretty colors, then at a closer look i could not locate any rhizo in any of the 60, i then put some of these spores in a honey tek sure enough mold grew fuzzy 2" on top----the lesson i learned---- the honey tek is useful for more than mycelium production, it would have saved me making,waiting on, and cleaning 60 jars -----if you have any doubt about a home made syringe save yourself a lot of work and a lot of foul language, test your spores in the honet tek, ive lost hundreds of jars over the course of my farming-75% of which were preventable-newbys need to be careful and not cut any corners, if i would have failed my first time i might not be here still(by the way, i made a ton of jars one day knowing i was buying a large PC the next day, 26 hours later in 90 degree(yes in july it was 90 in my room) heat i came back to my grow room, to a putrid smell that lasted days, and lost many jars)

By Nan (Nanook) on Friday, October 19, 2001 - 10:11 am:

Just be careful with Contams. Don't breath them.

By Dreamer (Dreamer) on Saturday, October 20, 2001 - 04:12 am:

is the contaminant in the syringes???

or in the cakes???

just wondering!!!

half of the cakes seem ok...the other half has a few patches of the color I mentionned previously

take care,Dreamer

Posted by: rooster Jun 20 03, 10:51 AM GMT


Pennsylvania State University, University Park, PA, USA

Background and objectives
Since 1993, Trichoderma green mould has reached epidemic proportions in the mushroom industry in North America. Trichoderma green mould colonizes mushroom compost, competes with Agaricus bisporus mycelium for space and nutrients, and results in large areas of the growing beds that do not produce mushroom fruiting bodies. The epidemiology of this fungal disease is poorly understood and controversial. At first, the impression was that the occurrence of this disease appeared randomly. Earlier research has reported that factors in compost preparation were related to the growth and development of Trichoderma harzianum [1]. Initial observations made at farms in Pennsylvania also suggested that composting (phase I and/or phase II) procedures were often associated with disease development [2]. This research project seeks to evaluate and quantify some predisposing cultural factors for disease occurrence and to learn why severity of disease varies among farms. A goal of this research is to establish a wider base of information regarding compost nutrition, crop management and sanitation correlated with the growth and development of Trichoderma green mould. Preliminary tests were conducted on some predisposing factors identified by the survey.

Materials and methods
Trained technical service personnel experienced in mushroom cultivation were used to develop and conduct a diagnostic survey at mushroom farms. Specific cultural factors in a crop were monitored at individual commercial farms in Pennsylvania as crops progressed from phase I through to harvesting. Cultural factors were quantified and subjectively rated to describe growing characteristics and procedures at critical times in the process. Severity was based on the percentage of growing bed affected, percentage of the room infested and disease onset in relation to the stage of the crop. Standard Mushroom Research Center (MRC) substrate preparation, spawning, casing and mushroom-growing procedures were followed. After spawning the compost was inoculated with 2.0 ml of a trich spore suspension containing 1x107 spores per ml.

Results and conclusions
Preliminary results of the diagnostic survey indicate that dense, wet, overly mature phase I substrate, problem phase II, spawn infestation and increased fly infestations are the most common contributing factors related to increased incidence of Trichoderma green mould disease. One possible common thread between the compost-related problems is a lack of oxygen during phase I or phase II composting. Experiments have been tested for monitoring oxygen during phases I and II, to investigate the effect of low oxygen on disease development. Tests were conducted to determine the effect of different spawn and spawn-carrying materials on the growth and incidence of Trichoderma green mould. Initial results suggested that fully colonized spawn run compost, used as the source of spawn, and non-grain spawn, resulted in less incidence and severity of Trichoderma growth when compared to grain spawn. Excess compost moisture was found to be a predisposing factor to an increase in severity and incidence of Trichoderma green mould. In other experiments it was determined that Trichoderma spores did not germinate at spore concentrations less than 1x102. This result is of importance to mushroom growers and researchers, in that it suggests that disease development may not occur or may be slower to develop on farms with lower spore loads. It was also shown that spores did not germinate on the surface of the casing using spore inoculum carried in a liquid, either water or nutrient broth. This lack of germination, even with high spore concentrations, is not understood and merits further investigation. This result may suggest that secondary infection after casing is not part of the disease cycle and that fungicides applied after casing have minimal influence in preventing the spread of Trichoderma green mould within a crop.

1. Grogan HM, Gaze RH, 1995. Mushroom Science XIV, 653-660.
2. Romaine CPD, Royse J, Wuest PJ, Beyer DM, 1997. Mushroom News 45, 20-28.

Shroom Glossary