This experiment clearly defines the effect of adding supplements to the casing with or without commercial compost supplement; either made purely from high protein or with combined protein/lipid source.

High protein supplement in the compost alone increases yield by 13.8% (4.6kg/m2) over control, whilst lipid/protein blend is slightly higher at 15.2% (5.1kg/m2). Adding casing supplement increases yield by 15.4-29.2%; highest response being when there is a protein/lipid blend or protein in the compost. Mushroom piece weights are substantially higher when casing supplement is combined with compost supplement (1.5g to 2.6g higher) when compared to compost supplement on its own. A definite synergy is observed here. Mushroom quality was always better when there are casing and compost products together.

Introduction

The use of supplementation in the compost is well established in the mushroom industry since the early 1970’s. Most have been based on the use of high protein supplements (Carroll & Schisler) using formaldehyde to denature it and giving it delay release characteristics. Later Parker (1991) developed a variant on this using natural carboxylic acid salts to coat the feed particles which gave similar delay release mechanism. The coating process also permitted the use of a mix of nutritional components more suited to the mushrooms requirements including lipids (fats). The company Nutrigain manufactures these lipid/protein products under commercial brands Natural Gold and Organic Gold.

Parker later went on to research further the nutritional requirements of the mushroom crop and within this scope also investigated the casing layer. It has always been understood that the nutrition source can only be in the compost and in fact the casing layer must be totally inert for pinning to occur (Flegg). The work on casing additives has been carried out previously over some 10 years and is highlighted in this paper, that supplementation of the casing with the right type of product represents a key way forward for mushroom growers to reach consistent yields of 40kg/m2+ of high quality mushrooms.

Of important note is the piece weight of mushrooms. With increasing labour costs all over the world, it is pointless increasing yield if the grower cannot increase the individual weight of each mushroom and therefore tackle reducing the largest variable cost in growing.

Material and Methods

Phase 3 compost: Tunneltech Ltd. Casing McDon Peat. Spawn Triple X.

Compost was removed from blocks and mixed together to homogenise. Compost was measured out two 7kg lots for each test and put into a plastic growing tub with appropriate treatment as below with replicate. Protein supplement was Champfood (1.4%), lipid protein was Organic Gold (1.4%) and casing supplement Mycroliquid (220ml/m2). The compost is lightly pressed and casing added to a depth of 50mm.

Casing is watered with 2L/m2 water and plastic bag applied to prevent moisture loss and build up CO2 during the case run. Temperature in compost is controlled to 24-25C during this period. After 5 days the plastic is 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.

Results and Discussion

There are 2 tables of results; one with and one without casing supplement. The tables are then laid out as follows; the left hand column are by flush and flush totals. Along the top is compost treatments; nothing, high protein soya (1.4%) and lipid protein supplement (1.4%). Numbers in black are yield (untrimmed), red are average weight of each mushroom in grams and green is % increase in yield on control ie nothing in compost and nothing in the casing.

No 1.4% 1.4%

supplement   Protein Lipid/

in Compost Protein

Yield % Piece Yield  % Piece Yield  % Piece

Weight Weight Weight

1st 1235 14.3 1375 11.3 13.4 1465 18.6 17.9

2nd 922 9.7 1025 11.1 1110 11.7

1st & 2nd 2157 2400 11.2 2575 19.3

3rd 425 8.4 540 10.8 400 15.7

Total 2582 2940 13.8 2975 15.2

Kg/m2 33 37.6 38.1

Table 1: Yield results with nothing in casing

Yields are increased by the addition of any type of compost supplement. In 2 flushes the range was 11.2 – 19.3% over control. In 3 flushes the range was between 13.8 and 15.2% over control. Individual piece weight of all flushes was higher with lipid/protein supplement.

No 1.4% 1.4%

supplement   Protein Lipid/

in Compost Protein

Yield % Piece Yield  % Piece Yield  % Piece

Weight Weight Weight

1st 1430 15.8 12.6 1685 36.4 15.8 1655 34.0 15.5

2nd 1187 13.0 1070 16.3 1307 12.9

1st & 2nd 2617 21.3 2755 27.7 2962 37.5

3rd 362 11.3 455 17.2 375 13.1

Total 2980 15.4 3210 24.3 3337 29.2

Kg/m2 38.1 41.1 42.7

Table 2: Yield results with casing supplement added

Yields are increased very significantly by the addition of any type of casing supplement whether there is protein, lipid protein or nothing in the compost. In 2 flushes the range was 21.3 – 37.5% over control. In 3 flushes the range was between 15.4 and 29.2% over control. In both 2 and 3 flush scenarios the yield was highest when casing supplement combined with lipid/protein compost supplement. Individual piece weight was highest when combined with protein supplement.

This experiment clearly shows the strong positive effect of adding supplements to the casing with or without commercial compost supplement; either made purely from high protein and with combined protein/lipid source.

Mushroom piece weights are substantially higher when casing supplement is combined with compost supplement when compared to compost supplement on its own. A definite synergy is observed here. Mushroom quality is always better when there are casing and compost products together. Table 3 shows the average increase in piece weight across all three flushes. Supplementing the casing has a strong effect on increasing piece weight and therefore picking rates whether compost supplement is present or not. The biggest response is when lipid/protein or protein supplement is also present.

No supplement   1.4% 1.4%

in Compost Protein Lipid/Protein

Piece  % Piece  % Piece  %

Weight   Weight Weight

No Casing

Supplement 10.8 12.1 12.0 15.1 40.0

Casing Supplement 12.3 13.9 16.4 52.2 13.8 27.8

Table 3: Percentage increases in piece weight with supplements

Further works needs to be done with combinations of liquid supplement feeder on compost surface together with compost and casing to establish whether the same synergy is demonstrated.

References

Carroll AD, Schisler LC (1976) Delayed release nutrient supplement for mushroom culture. Appl Environ Microbiol 31:499–503

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

Flegg, PB (1955). Casing layer additives. MGA Journal p134-139.