Water Delivery To Casings

 by Nan

The Nook : Archives : Casings

1) Read Stamets and Chilton - The Casing Layer

"The enlargement of a pinhead into a fully mature mushroom is strongly influenced by the available water, without which a mushroom remains small and stunted. With the casing layer functioning as a water reservoir, mushrooms can reach full size. This is particularly important for heavy flushes when mushrooms are competing for water reserves."

2) Get a pump type garden sprayer


When you case your bed... You need to spray it down with water. Not a misting, you need to really soak it.

Now if you are doing this right and you are using a trigger type spray mister , you will be seeing your doctor on (or about) your third casing for treatment of carpal tunnel syndrome in your index finger... Get my drift?

Day 1) - When you case your bed, you need to get your pump sprayer out, fill it with distilled or purified Water and soak down the casing until it is saturated.  Your tray should be equipped with drain holes in case you get it too wet, but the idea here is to soak down to the point it will not hold any more water without dripping off excess. A soaking like this will take anywhere from 30 seconds to a couple of minutes spraying time depending.

Day 2) - You will find your casing has dried considerably as water was absorbed into the substrate over the previous 24 hours. Repeat the soaking as you did on Day 1

Day 3) - Casing should be pretty damp on Day 3. Repeat the soaking as you did on Days 1 & 2. The casing should take less water each day before becoming saturated.

Day 4) - Your casing should still be wet after Day 3, in which case you have worked enough water into the casing to support a nice flush. If by chance the casing is only damp on Day 4, soak it again. The casing needs enough water delivered by Day 3 or Day 4 to remain with a very damp/wet surface for 24 hours after the previous soaking.  When this condition is obtained you can cut off bulk water delivery with the pump pressure sprayer.

Once you have the water worked into the casing you can then mist with a trigger type sprayer* with the idea that you spray lightly every day, only enough to replace water lost to evaporation until pins form. This will not injure your trigger finger on a hand mister. However you must beware: Casings contain a living BREATHING organism. It generates heat (increased evaporation), exchanges gases (increases evaporation), and transpires water (more water loss). Casings lose far more to evaporation than people realize, and as the casing develops mycelia replaces available water with mycelia tissue... And they need more. So mist heavy with the trigger sprayer pre-flush, sometimes it's necessary to bring out the pressure sprayer for a another soaking.  The idea is that once pinning starts all the required water should be in the bed, and misting the walls of the chamber to increase humidity is all the water support you should need to complete the flush. * See: Misting

If you are not doing this, or something similar, you are not getting enough water into your casings to support the largest fruit and healthiest flushes. Note that some water rich substrates (straw, well moistened compost) will not require such large volumes of water.  This tek is key with cased grain or cased PF cake. - Nan

ExamplesDone Correctly   :   Done Incorrectly

Casings : Casing Overview : Misting/Moisture Control : Archives Main : The Nook

Posted by: Mycota Dec 14 02, 05:34 PM GMT
How to Manage the Watering of a Mushroom Crop
Paul J. Wuest

Mushroom quality and speed of production are affected by casing depth, moisture, and watering. The initial moisture content of casing, as well as how and when water is applied, affects the number of pins that form and the size and quality of the mushroom. Water and watering are frequently THE FACTORS that separate excellent growers from average growers, and (as might be implied), can seem confusing if the overall goals of watering are not fully understood or implemented. Before getting into the watering, a few statements about the casing layer are in order.

Normally a depth (measured after initial water has been applied) of 1 to 1.25 inches of casing is adequate for most mushroom crops. There are growers and farms where casing depth will be as much as 1.75 to 2 inches, but such depth is usually found only where peat moss is the casing medium. There is nothing inherently wrong with a deep casing layer, but with good management there is no need to use so much casing. Further, the deeper the casing the longer the interval between casing and picking. More could be said about casing, but this general guideline is adequate to bring on satisfactory crops.

Note: Most Cubie growers case with depths of 1/2  to 1-1/2 inches... With the average being 3/4 to about an inch deep - Nan

Watering the casing is an art, in that growers must i) judge when to water, ii) decide how much water is needed, and iii) know how to apply the water. The following comments are suggested as factors to be considered about watering, rather than an all-inclusive watering schedule.

How to Apply Water
Before discussing when to apply water, it is important to mention how water should be applied and the work habits of the person applying water. A roseface (water-break) spray head is needed to water mushroom casing. It is desirable that the roseface produce a very fine stream of water in a rather long high arc for the initial waterings; the potential for sealing the casing by the force of the water is thus minimized. A roseface with 750 to 1000 holes 0.01 inch in diameter is quite acceptable for the task
How a person applies water depends on initial training and level of supervision.

Some successful growers train watering personnel to move the rose-face constantly, from left to right and right to left, perhaps three passes per 4 feet of bed, watering one-half the width of the surface. Once a person has developed a movement pattern, a cadence of "l,"2,"3" can be followed for applying water. Experience suggests that use of a cadence during watering is a technique whereby a manager can direct how much water should be applied. This means that during the count of "1," water is directed from left to right starting at the center of the bed. Between the counts of "1" and "2," the rose is moved from the right to the left a bit closer to the sideboard, and between "2" and "3" the final swipe is made, even closer to the sideboard and in the opposite direction. Directing the water from the center to the sideboard means that the person watering must move the spray head in or out to assure that the water is aimed at the target area.

Sealed Casing and Scratching
Casing will seal if the water falling on it falls with too much force or if too much water is applied at one time, or a combination of the two occurs. The person doing the watering must invert the roseface so that it points up and away from the casing, rather than pointing directly at the casing surface. This procedure dissipates the energy behind the water by forcing the water through an arc-like trajectory before the water falls gently onto the casing. The most common failures during watering are i) the roseface is not moved quickly enough over the casing surface, ii) the movement is not rhythmic and uniform, and iii) there is too much overlapping of the watered area. Once casing is sealed (becomes nonporous), mushroom production will be drastically reduced or delayed;

neither is desirable.

Some growers find it necessary to scratch the casing surface following initial applications of water because the casing is sealed. Sealing is common when peat is used, especially when the peat is applied by a belt-fed casing machine. Scratching is recommended by some growers; others avoid the practice. A rule of thumb when scratching the casing is to restrict scratching to the depth where spawn has not grown. Scratching casing that contains spawn damages the mycelium, and this restricts the size of the developing mushrooms and may cause mushrooms to form under the casing. Scratching works for some farmers and not for others, so scratching is not a practice recommended for all mushroom operations.

When to Water
Initial water is applied immediately after casing, or at least during the first or second day after casing, and additional applications of water are continued - as frequently as the structure of the casing permits - for a few days until the casing contains as much water as it can hold. This volume of water is referred to as the water-holding capacity. I

t is essential that the casing receive all the water it can hold at this time, for the casing must always be moist from bottom to top, that is, from its surface to where it contacts the compost. As the spawn enters the casing, it will absorb water. The spawn grows from the compost up through the casing, so the casing initially dries more rapidly closer to the compost than elsewhere. If casing is allowed to dry a good bit, it will lose its ability to absorb water. When this occurs, it will no longer act as a water reservoir, mushrooms borne upon it will be soft and pithy, and yields will be reduced. When too much water is in the casing, spawn growth slows or stops -with resultant production delays or spawn death.

A radical way to apply initial water to peat casing is to flood the casing. In a day or so after the water is absorbed, scratch the peat to break up the crust and restore texture to the casing; this method is used immediately after casing and not during cropping. It is suggested that this method of watering be tried and evaluated in a small area before using it throughout an entire growing room.

After initial waterings, it may be necessary to water lightly, mist, or fog until pins appear. Where such a light amount of water is to be applied, the cadence during watering should be increased from "1"— "2"—"3" to perhaps "1"-"2"-"3" or even "1,""2,"3," but the movement pattern of the rose-face does not change. These numbers and dashes are used to give an idea of the speed at which the arm of the watering person moves. Precisely when to water and how much water to apply when bringing on first break is something that has to be learned - and it's usually
different for each cultivar.

Watering Different Cultivars
White mushrooms are capable of withstanding heavy waterings when the pins are about the size of a pencil eraser (approx 0.25 inch) in diameter. Watering a cream cultivar at the same rate will destroy most of the pins. Cream mushrooms must have pins that are at least twice that size (about 0.5 inch) before large quantities of water can be applied. The rough-white mushroom is closer to cream than to white cultivars in terms of tolerance to watering. It is possible to apply too much water too early with either the cream or the rough-white cultivar and thereby destroy the pins.

How to Apply Enough Water
When the first water of the day is applied at a fast cadence, a second heavier watering can be applied without as much chance of sealing the casing. Delay is essential when applying more than one watering per day, for the casing absorbs the first water and binds it, and thus becomes physically conditioned to accept more water; binding of water usually requires 3 to 5 hours. Once the initial buttons develop and thereafter during cropping, a roseface that provides a-coarser water stream (1000 to 1300 holes of 0.02 inch diameter) can be used. The mushrooms and buttons break part of the force of the water and the extensive rhizomorph formation holds the casing, so sealing is much less likely to occur, even with a coarser roseface.

Watering During the Crop
The speed at which a crop grows, i.e., the time interval between breaks, becomes a decisive factor in deciding when to water and how much water to apply. The speed of the crop is affected by compost and air temperatures. If a break is coming on quickly, water must be applied quickly and early, perhaps as early as the last two picking days of the previous break. When a break develops slowly, then it may be desirable to apply the water more slowly and over a longer period. Under no circumstances should a casing be allowed to dry out completely. If the casing becomes dry, the only way to re-moisten it is by very light repetitive waterings. If casing with an active spawn growth dries out, the mycelium seems to surround the soil or peat particles in a way that prevents water adsorption. The casing has the appearance of harboring a grey mold, but actually it is spawn.

Mushrooms growing on dry casing tend to show water-stress symptoms. They are light and pithy (spongy) and the veils tend to be stretched. The cap bottoms appear to be perpendicular to stem since the cap is not fully rounded. Mushrooms harvested from casing too dry during one stage of their development will have a good bit of casing attached to them; this is especially true of first-break mushrooms.

How much water should be added after first break? A quasi-analytical rule may be used to determine this. Mushrooms are about 90 percent water, so a pound of harvested mushrooms per square foot of bed means that 0.9 lb of water has been removed from that same square foot. If an additional pound is expected on second break, then 0.9 lb of water has to be replaced, plus a bit more for evaporation. This quantity is needed only for second break, since subsequent breaks normally are not as heavy. A gallon of water weighs just a bit more than 8 pounds; the Imperial gallon will weigh close to 10 pounds. After calculating the total pounds of mushrooms harvested (lb/ft2 times the total harvested area - in square feet), you can calculate the volume of replacement water by taking nine-tenths of this figure and dividing it by 8 (US gal) or by 10 if you're using Imperial gallons.

Water, Temperature, and Cropping
A scenario of what a grower will see and what should be done as a crop is developing will bring a number of factors together to make a total picture.
The compost has been cased for 8 to 10 days and the air temperature has cooled to 60F; compost temperature is in the lower 70s. Fresh air going into the room causes the room air to smell fresh, the mycelium is knitting together, and pins are starting to form. If the casing tends to dry, a quick "1,"2,"3" watering cadence is needed to prevent its becoming overdry; fogging the casing surface every second day is an alternative, and floors and walls should be soaked routinely to minimize drying. A few days later, when the pins of a white cultivar are about the size of a pencil eraser, the first in a series of first-break waterings begins. Morning and afternoon waterings are applied in the "1"-"2"-"3" cadence.

If a cream cultivar is being grown, water is not applied at this time; a delay of about 2 days will give the pins time to grow to twice the size of a pea. After the initial first-break watering, water will have to be applied two, three, or as many times as needed so the casing remains at its moisture-holding capacity while the pins of the first-break mushrooms develop into buttons. Ifa heavy break is developing, additional water may be applied from the button stage up to the onset of harvesting.

Watering should be avoided during the harvest period; quality usually suffers. Second-break pins form before first-break mushrooms are harvested. Water needs to be applied towards the end of first break since the harvested mushrooms absorb much of the water in the casing. If compost or air temperatures cause the crop to break on a short interval - 4 or 5 days - quite a bit of water must be added before the end of the first-break harvest. Too much water applied to a cream or an off-white cultivar at this time will cause a great number of dead pins, depressed yields in third break, and practically no production at all during fourth break.

Once second break pins have matured into small buttons, heavier applications of water can commence. These should be continued until the casing again reaches a good moisture level. Repeated waterings during a single day are far better for the crop than single waterings on successive days. At the same time, too much water applied at one time or too much water applied over a 24-hr period can result in dead or dying pins, especially with off-white and cream cultivars.

Many growers notice the abundance of dead pins after second break and erroneously think it to be a symptom of a virus condition, rather than of water damage. Less water is needed with each successive break, and the casing must be" moist, but not wet. This requirement can usually be met by watering fourth and subsequent breaks no more frequently than twice weekly, preferably waiting until buttons have developed.

Overwatering can result in the death of pins and small mushrooms, and underwatering or poorly timed waterings produce soft, poor-quality mushrooms. Most growers learn through experience how to water, which roseface to use, and the frequency of water applications as the crop matures. The guidelines presented here cannot substitute for a keen sense of observation and experience with how different cultivars respond to different watering patterns. When a watering pattern is changed, a wise grower will record the changes, along with information about how the mushrooms look before and after the water was applied. Such a reference can be useful in making decisions about future crops.


Posted by: psilli me May 28 03, 10:36 PM GMT
OK, my FOAFOAF has been reserching and thinks that some of her problems are related to low humidity levels (small fruits, split caps, exessive aborts, drying of casing, ect.) Perlite has been used in the past, with misting 3-4 times daily. That produced the results state above. She made a "pickle jar" humidfier from the archives but it isn't doing much either. The container is a 35gallon Sterilite with a 1inch hole on each side near the bottom to allow for some gass exchange.

Fanning has been done by hand 3-4 times daily as well.

She is pretty sure (as am I) that the problem is low humidity, she has used a cheap hygrometer to measure and it reads a consistant 85%Rh with the "pickle jar" thing running.

Does anyone have any tips or proven tech for getting the Rh up to 95%?

Posted by: Nanook May 28 03, 11:56 PM GMT
^ ^ ^

Posted by: robinhood May 29 03, 12:14 AM GMT
Nan, since you're on a roll today spreading the casing tek love, I'm gonna ask another question. This casing tek you posted above doesn't say anything about covering the casing. Are you just spraying it and letting it evaporate to the open air? What about contams? What about CO2 buildup? Obviously it works for you, but is everyone else wasting their time?


Posted by: Nanook May 29 03, 12:19 AM GMT
I assume that people who are fruiting casings are aware they belong in controlled environmentswink.gif

The problem I see: everybody is too dry in the substrate layer of their casings.

Posted by: robinhood May 29 03, 12:28 AM GMT
nono.gif Assuming makes an ASS out of U and ME.......well ok, maybe just ME! laugh.gif Well thanks for all the advice. Unfortunately my foaf told me he already birthed his WBS casings, so there won't be any misting upon misting upon misting. However, rumor has it that he spawned some of that WBS substrate into quarts of popcorn, which are already looking happy after 24 hours....maybe he can try it with those? wink.gif

Posted by: highroller May 29 03, 12:30 AM GMT
Fair assumption Nan.

If one is spraying casings the humidity should be high enough to have them in the "open" air. I don't know, upper 80%-mid 90%?
What concerns, robin(Rh... hehe), do you have about CO2 or contams other than the norm?
He's giving you the straight poo as far as I'm concerned. Works for me.

Posted by: Nanook May 29 03, 12:38 AM GMT
If one is spraying casings the humidity should be high enough to have them in the "open" air. I don't know, upper 80%-mid 90%?

Exactly, simply drop them into a bin and snap a cover on them, fan as required. In a closed container with a growing casing at proper fruiting temps the casing transpires moisture, it will condense on the walls. You need to mist the casing to replace that lost water, even after you have them fully hydrated.

Posted by: robinhood May 29 03, 12:38 AM GMT
Well highroller, it just seems to me that when you add a casing layer and cover it, the casing doesn't absorb the moisture and "dry out" (as the tek describes) to be sprayed again the next day. On the contrary, the moisture condenses on the saran wrap or foil. That's why I thought he meant spraying it and leaving it open without a cover.

Posted by: robinhood May 29 03, 12:41 AM GMT
Ah......see he was already typing it! Man you're quicker than the average human......or ARE you human? think.gif ohmy.gif ph34r.gif alien2.gif

Posted by: Nanook May 29 03, 12:48 AM GMT
No, the water is absorbed by the substrate under the casing. The casing acts as a wick to feed the liquid into the mycelial mass. It takes 24 hours for the mycelia to wick up the first soaking, and it takes 2 soakings total to hydrate the substrate, then one more good watering to top off the casing itself (which is depleted by giving water to the substrate).

Then you have daily evap losses, these can usually be dealt with using a hand mister, humidifier tek, whatever... But misting or humidifiers are no substitute for watering the casing down, and misting alone may not replace water transpired by the casing if the humidity is too low (many times...); another soaking from the pressure sprayer sometimes needs to be applied just as pinning starts to keep things wet enough. They have to have water to give fruit drool.gif wub.gif


Posted by: psilli me May 29 03, 09:39 PM GMT
So correct me if I'm not understanding this...

a well moistened casing layer is more important than an exact Rh in the chamber. meaning that even under the 85% Rh healthy fruits should be produced from a well watered casing layer. is this correct?

Posted by: Nanook May 29 03, 09:46 PM GMT
Up to the point you have pins... If the casing is wet... The mycelia will never know what the humidity of the air is... It's covered with a wet blanket at 100% RH

Once pins start forming you need to pay attention to humidity of the air the mycelia is sticking up into... Stamets says 85-92% RH for cased beds... This is when you mist

Posted by: psilli me May 29 03, 09:51 PM GMT

That must have been her problem then, I think my friend was afraid to get the casing to wet. I've been informed that she has taken the steps advised in Nan's link and I will be posting the results in a few days hopefully.


Posted by: eleutheromania May 31 03, 11:08 PM GMT
Hi all. smile.gif

I was just reading through the archives and I found this Straw Tek. Now I've also read the informative page written by nan that runs you through how to saturate the crap out of your casings without getting carpel tunnel syndrome, and what good it does for your casings. I was just wondering if this rule applies to all casings?
I plan to dream about using this straw tek.

In my dream I'll case with a peat based soil mix with a pinch of lime to buffer. I just wanted to know if I was on the right track. Oh and yeah I've never grown cakes before, but In a re-occuring dream I'm currently having I have 4 colonising, 2 GC and 2 GT. So I'm going to dream of using one cake in this straw tek and maybe grow one of each strain in the old fashioned pf way, and maybe use one to try out lazy mofo's bag tek, because it looks rockin'. biggrin.gif

Oh and does anyone have any suggestions about which strain I should dream of using for which of these methods?

Jah bless you one and all. wub.gif

Edit: To add more non incriminating 'dream' headings and such.

Posted by: Nanook May 31 03, 11:25 PM GMT
I was just wondering if this rule applies to all casings?

Good question. You don't need to go so wet with straw because this substrate gets wet pasteurized and is ready to spawn with plenty of moisture already in it. I dry case straw at the the time of spawning, then give it a heavy misting after 72 hours.

When I spawn straw I spawn a whole tub and pack it down. Case it with dry 50/50 and snap a cover on it. The dry casing absorbs all the drippage during the 72 hour spawn run, then you can start to get it moist... Not wet.

Posted by: shroomie May 31 03, 11:38 PM GMT
yeah nan i use potting soil and i saturated like you said and i drained off excees water but pin formation seems so much slower than when i only kept it moist, won't the soil turn to mud and make it difficult for the pins to push through? it's been a week today last crop i grew i had already harvested about 90% in the same time it's taken the last batch to even pin. you tell me, should i cut back on saturarating the soil? what would be a better casing? cocc coir or vermiculite. one last question, if you go to shroom wizard's homepage he says that using this method will produce an equal amount of shrooms to the dry brf used, so i used a 2 lb bag and i know for sure i won't get 2lbs of shrooms even wet, thats seems hard to believe, may he be lying? he says using his tek you harvest more shrooms than any other technique he tried which he said was all the teks and "this way produces the more fuit than any other technique" could this be true?you tell me nan biggrin.gif

Posted by: Nanook May 31 03, 11:48 PM GMT
You got the casing good and wet, you can stop soaking it down already. Mycelia grows just fine into wet casings...

As to the rest of your questions... You already know I have found some problems in that tek, I am not it's biggest fan. I would contact the author wink.gif

Posted by: eleutheromania May 31 03, 11:58 PM GMT
Ok then, thanks for the advice nan. smile.gif

Do you find that 50/50 (verm and coco coir, no?) is better or atleast easier than peat based soil+lime? Because it sure would be easier, for me atleast, to obtain the materials for a 50/50 casing, since I already have the verm, and a few shops around my place are selling bricks of "coir peat" for $1.50 AUD.

Posted by: Nanook Jun 01 03, 12:08 AM GMT
They both work fine... Given the choice in that circumstance I let my pocketbook decide smile.gif

Posted by: Mycota Feb 02 03, 08:20 PM GMT
Mushrooms are about 90 percent water, so a pound of harvested mushrooms per square foot of bed means that 0.9 lb of water has been removed from that same square foot.

If an additional pound is expected on second break, then 0.9 lb of water has to be replaced, plus a bit more for evaporation.

This quantity is needed only for second break, since subsequent breaks normally are not as heavy.

A gallon of water weighs just a bit more than 8 pounds; the Imperial gallon will weigh close to 10 pounds.

After calculating the total pounds of mushrooms harvested (lb/ft2 times the total harvested area - in square feet).

You can calculate the volume of replacement water by taking nine-tenths of this figure and dividing it by 8 (US gal) or by 10 if you're using Imperial gallons.

Mycota (6T) wink.gif