Effect of using plastic on the case run with Mycrofeeder and Mycroliquid

F.H Parker and S.G Whitehall

Ballstone Farm, Quarnford, UK, 2016

This experiment clearly shows that using plastic on the casing with Mycrofeeder and Mycroliquid during case run dramatically improves the performance of the products. In Mycroliquid, the increase in yield response is 18.7% in 3 flushes (6.5kg/m2 ) more using plastic compared to not using it.In Mycrofeeder, , the increase in yield response is 13.2% in 3 flushes (4.2kg/m2 ) more using plastic compared to not using it.

This experiment was made because of continued evidence that plastic has a key role in activating the Mycrofeeder and Mycroliquid products. This became apparent because our “in house” trials were always substantially higher responses in yield and mushroom piece weight compared to commercial growers in the field.

In comparing exactly what we did compared to the commercial grower, it became evident that the major point of difference was we were using plastic on the casing layer during the case run where as they were not.

The hypothesis of why this effect is being observed is discussed later, but it is not simply to do with carbon dioxide level (CO2).

Also the timing of the plastic application is also very important and this is also discussed later.

Compost was removed from blocks and mixed together to homogenise. Compost was measured out two 7kg lots and put into a plastic growing tub with appropriate treatment as below with replicate. No compost supplement was applied. Mycrofeeder was applied at 245ml/m2 on the compost top at a dilution of 3:1 or Mycroliquid at 225ml/m2 in the casing with a dilution of 3:1 as a comparison. The compost was lightly pressed and casing added to a depth of 50mm.

Casing was watered with 2L/m2 water and either plastic with small perforations (pin holes) or paper1 was applied to compare treatments. Temperature in compost was controlled to 24-25C during this period. After 5 days the plastic or paper was removed and 2 waters of 2L/m2 are added to the casing whilst maintaining warm air temperature 22C. Airing is made on day 6.

Visual observations made throughout whole crop. Picked mushrooms are untrimmed weight. We estimate effect of this is approximately 10% inflation in yield figure compared to trimmed.

1 paper was used instead of nothing, to prevent excessive moisture loss due to large air:bed ratio in

the trial rooms. Paper will impede some of the gas exchange and moisture loss, so a normal growing

situation will probably not be as responsive as paper use!

The table are then laid out as follows; the left hand column are by flush and flush totals. Along the

top are the treatments which can be read off in top left hand side corner; product name, location of

application and treatment. Numbers in black are yield (untrimmed); those in green are % increase in

yield on controls in this case paper (not plastic).

<img src="https://www.dropbox.com/s/6ah4j8xnou63zd6/mycrofeeder1.jpg?raw=1"/>

This experiment clearly shows when using Mycrofeeder and Mycroliquid that plastic on the casing

during case run dramatically improves the performance of the products. With Mycroliquid, the

increase in yield response is 18.7% in 3 flushes (6.5kg/m2 ) more using plastic compared to not using

it. With Mycrofeeeder there is also an increase in yield response of some 13.2% in 3 flushes

(4.2kg/m2).

There is much published mushroom research about how the Agaricus mushroom produces growth

hormones to stimulate mycelium growth and other substances that help it to fight off competitors.

These are prevalent during warm temperature phases eg case running and would normally be lost

quickly to the air stream as they are produced and percolate out of the compost and casing layer. It

is hypothesised that using plastic, especially at the beginning of the case run could help to trap and

possibly enhance the levels of these substances short term.

We understand about the practicality of plastic and the concern that growers have with getting

enough water in the casing layer and the time to do it. Based on experiences in numerous

commercial farms, we know that it is possible, it just needs a change in thinking.

The effect of putting plastic on the casing stops the evaporation process and loss of water from the

casing, so firstly there is not the same need to add as much water as normal. Secondly, when we put

plastic on at the beginning of the case run for 2-3 days, the casing, compost and interface all come to

a similar temperature optimum for mycelium growth. We believe that in many commercial

situations CAC is damaged or compromised from the outset by too much water too quickly and too

soon. With plastic the opposite happens and this CAC is encouraged to ‘feed’ off the Mycro products

as is the mycelium coming in from the compost.

Interestingly, the stopping of the evaporative process also controls the compost temperatures at a

steady level and you do not ‘see’ the overheating that you might expect.

So based on adding a certain amount of water to the compost and casing on day 0, placing plastic on

for 2-3 days and then continuing to water, but to a lower level than previously as normally done, you

can arrive at the airing stage with as much water as normal, and better fed mycelium, which ultimately turns into mushroom dry weight and quality yield.

Parker, FH (1991). Method for promoting mushroom growth. Espacenet.

Parker, FH and Whitehall SG (2009) A method and composition to promote mushroom cultivation.

Espacenet.

Plastic being used practically on commercial shelf and tray farms