Welcome. If you are coming directly from my article Things to know before starting a mushroom farm and want to learn more about substrates, supplementation, and sterilization than go ahead.
If you are coming directly to this site and you do not have read the article, I highly recommend reading it first. The article gives you a brief overview of every aspect of growing. He will set the foundation for everything you will learn in the following paragraphs.
But if you prefer to read this article first no problem at all.
Let’s dive into it.
Table of Contents
Understanding the different SUBSTRATE types
As you may know, mushrooms are growing on all sorts of substrates like straw, wood, or grass. But not all mushroom species will grow well on all these substrates. I experienced that while working on a mushroom farm in Canada.
The main substrate there was wood in the form of chips. But the owner of the farm had no control over what type of wood he would get. The mushrooms were growing, but with different yield. Unfortunately, the owner did not measure the yield of the various wood types in the past.
He just started to do so while I was working alongside him on the farm. After realizing the difference and switching from wood chips to wood pellets, he increased his yield by 30% to 50%. That’s a lot, just by using the right substrate as a growing medium.
Another thing to know before we dig deeper into this topic is that mushrooms are classified into three different types.
- Primary decomposer
- Secondary decomposer
- Tertiary decomposer
Primary decomposer grows on all sorts of substrates if it contains enough carbon. While secondary decomposer will only grow on substrates which is already decomposed. And finally, the tertiary decomposer will grow only on the “leftovers” from the secondary decomposer.
For your mushroom production, you should use either primary decomposer like, e.g., oyster mushrooms or shiitake or secondary decomposer like, e.g., button mushrooms.
With that said, let’s dive in by first repeat what we already learned throughout my article Things to know before starting a mushroom farm. If you read this article you can skip this section but I recommend that you use the following section as a possibility to recap.
Most of the substrates which are used for growing mushrooms are a mixture of mainly three parts.
- The main compound (e.g. wood or straw)
- Supplements (e.g. wheat bran) and
When preparing the substrate, we must have several things in mind.
- Mycelium running rate (MRR)
- Numbers of days to initiation (NDTP)
- Numbers of days to harvest (NDTH)
- Biological & Economical Yield (BY & EY)
- Biological Efficiency (BE)
- Average length of stripe (ALS)
- Average thickness of pileus (ATP)
Let’s talk about each of them.
The mycelium running rate (MRR) is defined by the distance (l) the mycelium grows within a certain amount of time (n).
The number of days to initiation (NDTP) is the time from stimulation to primordia initiation.
The number of days to harvest (NDTH) is the time from primordial initiation to harvesting the mushrooms.
The biological yield (BY) is defined as the yield per block without removing the lower hard and dirty portion.
While the economic yield (EY) is defined as the yield per block after removing the lower hard and dirty portion.
The biological efficiency (BE) is defined as the total biological weight in gram (TBW) in relation to the total weight of the substrate in gram used (TWS).
Now, after we have all these definitions in place, we can understand the differences between the different substrates better. Let’s have a quick look into typical types of substrates like straw and wood.
Substrate | Wood
The types of wood are divided into softwood (Fig. 1) and hardwood (Fig. 2). Examples for softwood are hemlocks, cedars or douglas firs. Whereas oak, elm, chestnut or beech are classified as a hardwood.
This classification stems from the physical structure and makeup of the wood. Softwood contains more lignin and lower hemicellulose than hardwood.
Figure 1: Cellular structure of a hardwood (yellow poplar).
Figure 2: Cellular structure of a softwood (white pine).
Whereas softwood comes from gymnosperm trees which usually have needles and cones, hardwood comes from angiosperm trees that are not monocots. The density of wood has nothing to do with this classification. Although hardwood has typically a higher density than softwood. The color of different wood types is shown in figure 3.
Figure 3: Different types of wood.
Is a class of complex organic polymers that form important structural materials in the support tissues of vascular plants and some algae. Lignins are particularly important in the formation of cell walls, especially in wood and bark […].
Is an organic compound with the formula (C6H10O5)n, a polysaccharide consisting of a linear chain of several hundred to many thousands of [..] units.
Cellulose is an important structural component of the primary cell wall of green plants […].
The cellulose content of […] wood is 40-50% […].
Is a polysaccharide related to cellulose that comprises about 20% of the biomass of most plants. […]
Hemicellulose is branched […]. Examples can be seen in table 1.
Table 1: Types of polysaccharide (in %) in hardwood and softwood.
When it comes to growing mushrooms for the most part hardwood is the better choice although softwood contains more lignin than hardwood (Table 2). Why is this the case? Glad you ask.
Table 2: Chemical composition of softwoods and hardwoods, temperate-zone hardwoods (values in %).
To answer this question, we must dive deeper into the world of fungus. In doing so, we will find that there are three different types of wood-decay fungus.
- The brown rot fungi
They break down hemicellulose and cellulose that form the wood structure.
- The soft rot fungi
They break down cellulose in the wood.
- The white-rot fungi
They break down the lignin in wood.
Most of the edible mushrooms like Pleurotus (“Oyster” mushroom), Lentunila (“Shiitake”) and Agaricus (“Button” mushroom) are a white-rot fungus.
If we look at the composition of both softwood and hardwood (table 2), we recognize that hardwood tends to have less lignin. But wait! Did not you say the higher the lignin, the better? If this is true, then softwood would be the way to go and not hardwood. Where is the logic behind it?
To understand this issue, we must look at the decay process itself, especially the time it takes to decay each component. The following table 3 compares the chemical composition of different substrates to the MRR.
Table 3: Influence of the chemical composition of different substrates on the MRR [cm/day].
If we calculate the correlation between each chemical component and the MRR, we get the following results (Figure 4). Figure 4 shows a negative association for hemicellulose and cellulose and a positive correlation for lignin regarding MMR. That means, the lower the hemicellulose and cellulose content, the fast the MRR and the higher the lignin content, the higher the MRR as well.
This means we just confirmed what we already knew, but softwood contains way more resin than hardwood. This resin has anti-fungal properties.
Figure 4: Correlation between the chemical components (hemicellulose, cellulose, and lignin) and the MRR [cm/day] for Pleurotus ostreatus and Pleurotus florida.
Substrate | C:N ratio
If we look more closely at the C:N ratio, we will recognize that a nitrogen deficiency will inhibit the growth of the mycelium.
On the other hand, a low nitrogen level can stimulate the ligninolytic enzyme production, whereas a higher level of nitrogen can suppress this enzyme. Ligninolytic enzyme or lignin-modifying enzymes (LMEs) are enzymes that are produced by fungi and bacteria. These enzymes can break down lignin through oxidation.
Besides the C:N ratio (Figure 5 to 7), we have also to consider the Lignin:Cellulose ratio as well as the amount of hemicellulose, because of their influence on the MRR as I will explain later more in detail.
Figure 5: Correlation between the average C:N ration of different substrates and MRR of Pleurotus ostreatus (AS: ammonium sulfate, U: urea, AS:U 1:1).
Figure 6: Correlation between the average C:N ration of different substrates and MRR of Lentinula edodes (AS: ammonium sulfate, U: urea, AS:U 1:1).
Figure 7: Correlation between the average C:N ration of different substrates and MRR of Agaricus blazei (AS: ammonium sulfate, U: urea, AS:U 1:1).
There are three different ways to use wood as a substrate for growing mushrooms – logs, wood chips, and sawdust. The average C:N ratios for these different cultivation methods are:
Log culture ≥ 100:1
Agro-waste 50 – 100:1
Straw & agro residues 25 – 50:1
If we look at these numbers, we might conclude that log cultivation is the way to go. But the C:N ratio is not the only thing we have to consider. Before I go into this topic, let me use an analogy to describe the effect.
Think first of a solid stone wall that is getting hit over and over by a wave of water. To go through this stone wall, it will take a long time, because every time the water hits the stone wall, it will remove only a small fraction of it.
Now, let’s assume this stone wall would be porous. In this case, the water will find its way faster through the wall, because every time it hit the wall, it will have more contact areas.
The same is true when it comes to the decaying process of wood by our mycelium. We can compare the wood log to the stone wall. Because of his compact form, there are not many areas to attack the log. The mycelium growth, therefore, is slowly. If we use instead of wood chips (like the porous stone wall), the mycelium has way more areas to attack and therefore grow faster.
With that said, the more surface, the more contact points for the mycelium to attack, the faster its growth!
To illustrate the impact of the particle size on the yield and BE, let’s look at a study that was done in 2001. In this study, the author ordered wood chips from different commercial hardwood sawmills. The requirement was that the wood chips should be between 4-0.21mm.
After analyzing the particle size, the author found the following distribution (Figure 8). As clearly visible, the variation between the four sawmills and therefore, the provided particle sizes are large. Even though all the commercial sawmills used the SIEVE standard.
Figure 8: Particle size distribution of wood chips from four different commercial hardwood sawmills.
The wood chips (Northern red oak) were then prepared for the inoculation with Lentinula edodes and the yield, as well as the BE, was measured (table 4, Figure 9, and Figure 10).
Impact of particle size on the BE and yield of Lentinula edodes.
Table 4: Yield (g/log), percentage BE and means for three crops of L. edodes grown on various wood chip sizes.
While for the first two crops, the yield and BE were similar, they dropped at the 3rd crop. If we look at each particle cluster, we see a higher yield and BE for 0.85-1.7mm particles. If the particle size is smaller than 0.85mm, the yield and BE dropped significantly. Above 1.7mm and below 4.0mm the drop is smaller.
Figure 9: Influence of the wood-chip particle size on BE.
Figure 10: Influence of the wood-chip particle size on yield.
First, it seems that there is an optimum particle size regarding biological efficiency (BE). According to this study, everything between < 4.0 mm and > 0.85 mm would lead to a high BE. Or to make it clearer, everything below 0.85 mm will reduce the BE.
Second, if this is true, then the particle size distribution is sup-optimal (Figure 8) because on average, 53% of all particles are below 0.85 mm. Which means that our biological efficiency will be affected.
I tried to come up with an explanation for this effect. The only one I found is to compare the particle size to a food source for animals. If every 2nd food source (here 53% of all particles) is too small (in our example < 0.85 mm) the more often one animal will bump into each other one and therefore slow down until both find a bigger food source.
Now that we understand the impact of the particle size on the yield and BE, let’s compare different sawdust materials. To do so, we examine a study done in 2014. In this study, the author used sawdust from five different trees and a mixture of all five to grow Pleurotus ostreatus.
The author measured the mycelium running rate (Fig. 11), the yield, and the BE. The five trees were Fig tree (T2 Ficus carica), Rain tree (T3 Albizia saman), Mahogany tree (T4 Swietenia mahagoni), Ipil ipil tree (T5 Leucaena leucocephala) and Eucalyptus tree (T6 Eucalyptus globulus). T1 is a mixture of all five sawdust. Each substrate was supplemented with 30% wheat bran and 1% lime.
Figure 11: Effect of the wood type on the mycelium running rate (MRR).
The best results were achieved with the mahogany tree (T4) as a substrate.
Substrate | Straw
Straw, as all of you already know, is a by-product of the agriculture industry. This means you as a (future) mushroom farmer will use the waste of one industry and turn it into a profit.
There are several types of straw-like rice straw, barley straw, or wheat straw. The main difference of them is their lignin, hemicellulose, and cellulose content, which impacts their C/N ratio. In other words. These three compounds are the nitrogen and carbon source for your mushrooms.
To better understand the impact of these different types of straw, let’s look at a study that compared wheat straw, rice straw, sugarcane bagasse, maize straw, and sorghum straw (Figure 12). The study was conducted in 2016 to evaluate these substrates regarding the quality, production, and growth of Pleurotus florida.
Figure 12: Influence of different types of straw on biological efficiency.
Wheat straw has the highest yield and shortest NDTP and NDTH.
Followed by rice straw and sorghum straw.
Now in order to understand these results better, let’s compare these substrates more in detail. If we do that, it gets interesting. We talked already about the influence of hemicellulose, cellulose, and lignin on the mycelium running rate. To see this effect in action, we will first look at the chemical composition of these five substrates (Figure 13 to Figure 15).
Figure 13: Hemicellulose content of different types of straw.
Figure 14: Cellulose content of different types of straw.
Figure 15: Lignin content of different types of straw.
But more interesting to us is the question about the correlation between these three components and the MRR. Here (Figure 16) we see, that the higher the hemicellulose content, the longer it takes for the mycelium to grow, which means a slower MRR.
Figure 16: Correlation between the three compounds (hemicellulose, cellulose, and lignin) and the MRR.
To illustrate this relationship, I put both correlations next to each other (Figure 17). The left figure shows the MRR measured in cm per day, and it shows that the higher the amount of hemicellulose, the slower the MRR. The right figure shows the MRR measured in days and shows the higher the amount of hemicellulose the longer it takes, which makes sense because the MRR in cm per day is smaller.
Figure 17: Correlation between hemicellulose and MRR with MRR [cm/day] (TOP), MRR [days] (Bottom).
Now let’s look at the MRR for all five types of substrate (Figure 18). The MRR for wheat straw is the fastest of all five types of substrate (25 days). This makes sense because the amount of hemicellulose is the lowest of all five, and this positively influences the MRR.
While cellulose and lignin are one of the highest, they correlate both in a positive way, which means wheat straw should have the shortest MRR (measured in days) of all the five substrates. Which is the case.
Let’s look at another substrate sugarcane bagasse with the slowest MRR. The amount of hemicellulose is one of the highest, which is bad when it comes to MRR. The cellulose and lignin content is also one of the highest, which is suitable for a short MRR, but it seems that these two components do not affect the MRR that much. Or to describe it differently. It appears that the main driver for MRR is hemicellulose.
Figure 18: MRR for five different types of substrate.
For the NDTP (Figure 19 and Figure 20), we get the same result. Wheat straw has the shortest NDTP with only 27 days and sugarcane bagasse one of the highest (40 days). The correlation of hemicellulose, cellulose, and lignin supports this behavior.
Figure 19: NDTP (days) for five different types of substrate.
Figure 20: Correlation between the three compounds (hemicellulose, cellulose, and lignin) and NDTP.
The same is true for the NDTH (Figure 21 and Figure 22). Wheat straw growth the fastest (30 days) and sugarcane bagasse (40 days) almost the slowest.
Figure 21: NDTH (days) for five different types of substrate.
Figure 22: correlation between the three compounds (hemicellulose, cellulose, and lignin) and NDTH.
But what about the yield and BE? Here we get quite interesting results (Figure 23 to Figure 24). While the MRR measured in days was short for wheat straw and long for the sugarcane bagasse, the yield for wheat straw is the highest (1360 g) and for sugarcane bagasse is the lowest (756 g).
This is exactly what we want. A short growing period and high yield.
Figure 23: Yield (g) for five different types of substrate.
The correlation between the three compounds hemicellulose, cellulose and lignin and the yield point in the same direction (Figure 24).
Figure 24: Correlation between the three compounds (hemicellulose, cellulose, and lignin) and yield.
The same is true for the BE (Figure 25 and Figure 26).
Figure 25: BE (%) for five different types of substrate.
Figure 26: Correlation between the three compounds (hemicellulose, cellulose, and lignin) and BE.
To summarize our finding let’s make a side by side comparison (table 5).
Table 5: Impact of hemicellulose, cellulose, and lignin on the growth, yield and BE.
The findings in table 5 are making total sense because if we go back to the types of fungus we are growing – here white-rot fungus – they break down lignin. Which means they prefer lignin over the other two. For cellulose, the finding concerning the MRR is more apparent than for the yield, which means for the MRR, the correlation is as shown, for the yield it is neutral.
In the end, you want a substrate low in hemicellulose and high in lignin, and in the middle range for cellulose.
To summarize our finding, let’s make a side by side comparison of the three different cultivation methods (table 6)
|Log Cultivation||Wood Chips||Sawdust|
Good yield & BE
High yield & BE
Low yield & BE
Needs a lot of space
|can be labor-intensive||can be labor-intensive|
Table 6: Comparison between log, wood chips, and sawdust cultivation.
Substrate | JUNCAO
In 1983, Prof. Lin Zhanxi invented for the first time a new method for growing mushrooms – the JUNCAO technology. When it comes to JUNCAO, we have first to distinguish three different definitions:
- JUNCAO: herbaceous plants that can be used as the substrate for edible and medicinal fungi cultivation.
- JUNCAO Technology: integrated techniques that use JUNCAO to cultivate edible and medicinal fungi, as well as produce mycoprotein forage and fertilizer.
- JUNCAO Industry: industry formed by the utilization of JUNCAO Technology and other interrelated techniques.
Up to now (2013), these definitions are well known in over 85 countries and 11 languages.
The idea of JUNCAO or to be more exact, the overall benefits for Biological Conversion of JUNCAO are shown in figure 27. This figure shows the underlying logic of JUNCAO. The goal with JUNCAO is not only to use grass as a substrate but to have an integrated system where everything contributes to the overall health not only of the people but also of the environment.
Figure 27: Overall Benefits for Biological Conversion of JUNCAO.
Over time many mushrooms species were tested if they could be cultivated with JUNCAO. Here is a short list with some of them
- Pleurotus spp.
- Lentinula edodes
- Flammulina velutipes
- Hypsizigus marmoreus
- Agaricus bisporus & blazei Murill
- Pholiota nameko
- Agrocybe aegerita & cylindracea
- Hericium erinaceus
- Ganoderma lucidum & sinense
- Grifola frondosus & albicans Imaz
- Tremella fuciformis, aurantialba & cinnabarina
Figure 28 gives a detail inside into the cultivation of Lentinula edodes with JUNCAO.
Figure 28: Production Techniques of Lentinula edodes Cultivation with JUNCAO.
Up to now, [..] 42 JUNCAO species have been sieved that are suitable to be utilized as the substrate for fungi cultivation (Table 7).
Table 7: Chemical composition of some JUNCAO Species.
If we compare theses number (table 7) with what we already know about the influence of hemicellulose, cellulose, and lignin on MRR and yield we clearly see that many JUNCAO species meet our requirements, which were low hemicellulose, high lignin, and medium cellulose content.
How SUPPLEMENTATION influences your Yield
Now let’s look at the impact and reasons for supplementing. We will do this by looking at five different scientific papers. Don’t worry, I don’t get too nerdy.
Supplementing of WHEAT STRAW
The first one looked at the effect of various agro-residues on growing periods, yield and biological efficiency of Pleurotus eryngii (Fig. 29).
Figure 29: Effect of various agro-residues on mycelium growing (days) – W: Wheat straw, C: Cornstalk, M: Millet straw, S: Soybean straw, B: Bean straw, P: Cotton stalk, RB: Rice bran.
If we draw a line (Figure 29: yellow) from wheat straw (Figure xx: green arrow) as a reference, we can more easily see the effect of the other agro-residues on the mycelium growing. As the orange arrows in figure 29, indicating the mycelium growing took longer if the wheat straw was supplemented with rice bran. Only the combination of wheat straw and bean straw as well as wheat straw plus bean straw plus rice bran showed a faster mycelium growth.
The same goes for the impact on the primordium initiation (Fig. 30). All other agro-residues showed a longer time frame in comparison with wheat straw.
Figure 30: Effect of various agro-residues on primordium initiation (days) – W: Wheat straw, C: Cornstalk, M: Millet straw, S: Soybean straw, B: Bean straw, P: Cotton stalk, RB: Rice bran.
If we compare the length of the harvesting period of wheat straw (Figure 31: green arrow) with the other agro-residues, we see clearly that the harvesting periods of the others take longer.
Figure 31: Effect of various agro-residues on the harvesting periods (days) – W: Wheat straw, C: Cornstalk, M: Millet straw, S: Soybean straw, B: Bean straw, P: Cotton stalk, RB: Rice bran.
But when we compare the yield, we see quite the opposite (Fig 32). Wheat straw shows the lowest yield of all agro-residues. The same goes for the biological efficiency (Figure 33).
Figure 32: Effect of various agro-residues on the yield (g/100g) – W: Wheat straw, C: Cornstalk, M: Millet straw, S: Soybean straw, B: Bean straw, P: Cotton stalk, RB: Rice bran.
Figure 33: Effect of various agro-residues on the biological efficiency (%) – W: Wheat straw, C: Cornstalk, M: Millet straw, S: Soybean straw, B: Bean straw, P: Cotton stalk, RB: Rice bran.
To get a better feeling about the effect of various agro-residues, I put all the data in one big table (Table 9). The winners of this study were wheat straw plus millet straw with 10% rice bran and wheat straw plus pea straw with 20% rice bran. Both show short periods and high yield.
Table 9: Overview of the effects of various agro-residues on mycelium growing, harvesting periods, yield, and biological efficiency (%) – W: Wheat straw, C: Cornstalk, M: Millet straw, S: Soybean straw, B: Bean straw, P: Cotton stalk, RB: Rice bran.
Supplementing of Corn Cobs
This paper analyzed the influence of different nitrogen-rich supplements during the cultivation of Pleurotus florida on corn cob substrate. The test series contain 24 different mixtures plus one reference (corn cob).
The first Figure 34 shows the influence of different nitrogen-rich supplements on the growth rate. Unfortunately, we do not have a reference (Figure xx: green arrow) for this study.
Figure 34: Influence of different nitrogen-rich supplements during cultivation of Pleurotus florida on corn cob substrate on the growth rates – CC: Corn cobs, U: Urea, AS: Ammonium sulphate, GF: Gram flour, SM: Soybean meal, MC: Mustard cake, GNC: Groundnut cake, CSC: Cottonseed cake, M: Molasses.
The next figure 35 shows the influence on the spawn run. Here the author used a reference (Figure 35: green arrow), so we can better understand the impact. 21 out of 24 mixtures had a faster spawn run in comparison with the reference (Figure 35: green arrow). The other three were almost similar.
Figure 35: Influence of different nitrogen-rich supplements during cultivation of Pleurotus florida on corn cob substrate on the spawn run – CC: Corn cobs, U: Urea, AS: Ammonium sulphate, GF: Gram flour, SM: Soybean meal, MC: Mustard cake, GNC: Groundnut cake, CSC: Cottonseed cake, M: Molasses.
Next up is the influence on the primordia initiation. Again 21 out of 24 mixtures had a faster response compared to the reference (Figure 36: green arrow). Two of them, both groundnut cake (GNC), seems to harm the growth rate if used at a higher supplement rate.
Figure 36: Influence of different nitrogen-rich supplements during cultivation of Pleurotus florida on corn cob substrate on the primordia initiation – CC: Corn cobs, U: Urea, AS: Ammonium sulphate, GF: Gram flour, SM: Soybean meal, MC: Mustard cake, GNC: Groundnut cake, CSC: Cottonseed cake, M: Molasses.
The fourth Figure 37 shows the influence on the yield. Here 21 out of 24 mixture showed a higher yield than the reference. Up to 9 out of 24 mixture showed a 33% increase in yield compared to the reference (Figure 37: green arrow). Only one (GNC 5%) had a lower yield.
Figure 37: Influence of different nitrogen-rich supplements during cultivation of Pleurotus florida on corn cob substrate on the fruitbody yield – CC: Corn cobs, U: Urea, AS: Ammonium sulphate, GF: Gram flour, SM: Soybean meal, MC: Mustard cake, GNC: Groundnut cake, CSC: Cottonseed cake, M: Molasses.
Finally, we put all these findings in one big table and rated them accordingly (Table 10). The study showed that supplementing at a low rate (max. 2-3%) has a positive impact not only on the growth rate but also on the yield.
Table 10: Overview of the influence of different nitrogen-rich supplements during cultivation of Pleurotus florida on corn cob substrate – CC: Corn cobs, U: Urea, AS: Ammonium sulphate, GF: Gram flour, SM: Soybean meal, MC: Mustard cake, GNC: Groundnut cake, CSC: Cottonseed cake, M: Molasses.
What is the Optimum Supplementation Level for my Substrate?
The third study looked at the performance of Pleurotus ostreatus mushroom grown on maize stalk residues supplemented with various levels of maize flour and wheat bran.
The first interesting discovery is the impact of supplementation on the number of contaminated bags (Table 11). As expected, we see some contaminated bags, but unfortunately, the author provided no reference (no supplementation), and the sample size is way too small (only four bags per supplement level). For me, there is no real correlation visible between supplementation or supplement level and contamination. In my opinion, this study must be redone.
Table 11: The effect of wheat bran and maize flour supplements on the number of contaminated bags on the maize stalk base substrate.
More interestingly is the effect of the different supplement levels on the mycelium growth rate (Figure 38) or as we so far call it mycelium running rate. While there is no apparent difference between maize flour and wheat bran visible, we can see clearly that the higher the supplementation level, the slower the mycelium growth. The correlation is with -0.88 (MF) and -0.82 (WB) very strong.
Figure 38: Average mycelial growth rate of Pleurotus ostreatus per supplement level.
In the same token goes the impact of the different supplement levels on the NDTP (Figure 39). The higher the supplement level, the longer it takes to colonize the bags fully.
Figure 39: Average days to full colonization of maize stalk substrate supplemented with different levels of maize flour (MF) and wheat bran (WB).
Next is the impact of the different wheat bran supplement levels on the time required for pinhead formation (Figure 40). While we see a difference for the first flush with a maximum on the 8% level. The periods for the other two flushes are very close only for the 20% level (2nd flush) and 18% level (3rd flush). Flush three takes, in general, some days longer than flush two.
Figure 40: Effect of wheat bran (WB) supplementation levels on the time required for pinhead formation between flushes.
The impact on the time needed for pinhead formation is for the 1st flush supplementing with maize flour more stable (Figure 41) than for the supplementation with wheat bran (Figure 40). When supplementing with 14% or higher, the periods are getting longer.
Figure 41: Effect of maize flour (MF) supplementation levels on the time required for pinhead formation between flushes.
Now let’s have a look at the impact of different supplementation levels on biological efficiency (Figure 42). While for wheat bran (WB), there is no clear trend visible (correlation -0.02), we can spot a small trend for maize flour (correlation +0.49). Which means the higher the supplementation, the higher the biological efficiency.
Figure 42: Average biological efficiency (BE) of Pleurotus ostreatus on maize stalk substrate supplemented with different levels of maize flour (MF) and wheat bran (WB).
And finally, the overview of all described parameters (table 12). The best results with maize flour (MF) were achieved at a supplement level of 8% both for speed (38 days) and biological efficiency (136).
While for wheat bran (WB) we get a range (supplement level of 2% to 12%) in which the best results are in.
I assume that the drop in the biological efficiency at the 8% level is the result of an outlier and therefore the effect of the small sample size (only two out of four bags could be used).
Table 12: Overview on the average effects of maize flour (MF) and wheat bran (WB) supplementation on the NDTP, MGR, BE and yield (MSY) of Pleurotus ostreatus grown on maize substrate.
Optimizing the Yield with Supplementation
In this paper, the author evaluated various substrates and supplements for the biological efficiency of Pleurotus sajor-caju and Pleurotus ostreatus. The author used three different substrates – wheat straw, maize stover, and thatch grass and two different supplements – maize bran, and cottonseed hull.
Table 13 gives us an inside in some chemical constitutions of the substrate. The exciting part for me is the C:N ratio, because so far we look more into the three compounds hemicellulose, cellulose, and lignin but we did not compare really their C:N ratios with each other.
Here Maize stover shows with 87.5 the highest and maize bran with 23.5 the lowest value.
Table 13: Some chemical constituents of substrates and supplements used in the study.
Figure 42 gives the impact of the different substrates and supplements on the biological efficiency of Pleurotus ostreatus. The grey column in this figure is this time our reference. As we can clearly see wheat straw supplemented with maize bran or cottonseed hull has a higher BE. Whereas maize stover and thatch grass could not be improved by supplementing with these two supplements.
Figure 42: Interaction among supplements and substrates on BE of Pleurotus ostreatus.
But if we compare our findings with the biological efficiency of Pleurotus sajor-caju, we see a big impact when supplemented with cottonseed hull both for wheat straw and maize stover (Figure 43).
Figure 43: Interaction among supplements and substrates on BE of Pleurotus sajor-caju.
If we look at the percent change for the BE for Pleurotus ostreatus, we see that cottonseed hull improved the BE by 54% (Figure 43). But this change falls short in comparison with the 112% achieved only by maize stover. All other combinations showed a negative impact on the BE.
Figure 44: Percentage BE changes of Pleurotus ostreatus in different substrate/supplement combinations compared to wheat straw (WS), maize bran (MB), cottonseed hull (CSH), maize stover (MS), thatch grass (TG).
More extreme is the percent change for Pleurotus sajor-caju (Figure 45). Only the cottonseed hull both in combination with wheat bran and maize stover showed an improvement. All others are falling short. In both figures (44 and 45), the X-axis represents wheat straw BE as the basis of comparison.
Figure 45: Percentage BE changes of Pleurotus sajor-caju in different substrate/supplement combinations compared to wheat straw (WS), maize bran (MB), cottonseed hull (CSH), maize stover (MS), thatch grass (TG).
How much Spawn do I need?
Ok! Now let’s move on to the final, and fifth paper. This time we will use Pleurotus tuber-regium as the mushroom species and compare the influence of light and spawn quantity on the growth of this species. The author used cotton waste, rice straw, cocoyam peel, corn cob, groundnut shell, and three different types of sawdust as a substrate.
Let’s see what we got.
In the first table (14), we can see the impact of light on the yield in comparison with continuous darkness for different substrates. The best results for the fruitbody were achieved on cotton waste and K. ivorensis. The yield of sclerotia could be improved on cocoyam peel, M. altissima, K. ivorensis and B. angustifolia with K. ivorensis the best yield.
Table 14: Effect of light (695 lux) on sporophore and sclerotia yield in Pleurotus tuber-regium.
When it comes to the influence of the spawn quantity, we see a drop after the 10% mark (Figure 46) for all substrates (correlation is -0.800 or higher). This finding confirms what we had learned from studying paper #3.
Figure 46: Effect of the spawn quantity (%) on the spawn run (days) for Pleurotus tuber-regium on different substrates.
When it comes to the yield of the fruitbodies, we see an increase for two substrates – K. ivorensis and cotton waste (Figure 47). All other substrates showed almost no change at all. In general, the correlation (not shown) is positive for all substrates.
Figure 47: Effect of the spawn quantity (%) on the fruitbody yield (g/kg) for Pleurotus tuber-regium on different substrates.
But if we look at the yield of sclerotia, we see a tendency to lower yields with increasing spawn quantity (Figure 48). The correlation (not shown) is with the exception of cocoyam peel for all negative.
Figure 48: Effect of the spawn quantity (%) on the sclerotia yield (g/kg) for Pleurotus tuber-regium on different substrates.
Are you still with me? I hope so because only if you understand every aspect of your (future) business in detail, you are more likely to be successful in the long run.
And more importantly, the more you learn, the easier it gets. I experienced it myself. In the beginning, everything is overwhelming. There is so much to learn and understand. But the more I read, and the more I practiced, the better I got.
And what you also need to know to get better is everything about sterilization. I wrote another in-depth article about this topic with the title “How your Sterilization Method will Impact your Mushroom Yield.”
And as you know, “Yield impacts your income.”
If you want to learn more about the things which will impact your yield, then you will find my article How Do I Increase My Mushroom Yield? helpful.
Now I want to hear from you:
What fact presented in this article surprised you the most?
Which substrate mixture are you using today? And are you going to adjust your mixture after reading this article? In which way?
Let me know by leaving a quick comment.
 Note: While the data are coming from science papers. Not all science papers include all necessary information to make them 100% comparable.
 Own table based on different sources
 Note: While the data are coming from science papers. Not all science papers include all necessary information to make them 100% comparable.
 Own figure based on different sources
 Own figure based in Bhattacharjya (2014)
 Own figure
 Own table
 Own table
 S.T. Chang JUNCAO
 S.T. Chang JUNCAO
 S.T. Chang JUNCAO
 S.T. Chang JUNCAO