If you start asking this kind of question, it’s likely, you have already a good understanding of the basics of mushroom cultivation. You got familiar with substrate, sterilization, and cultivation parameter. But now you come to the point that you are wondering if you could get more out of the money that you spent on growing mushrooms.
In this article, I will talk about four strategies you can apply to your business in order to raise the mushroom yield. You can decide to use only one of these strategies, or you could combine them to push the yield even further. Which I would recommend, especially because many of them are interdependent.
The strategies I will talk about are
- Mushroom species
- Supplement level
- Spawn rate
Let’s go right into the details and how they increase the mushroom yield.
The first strategy focuses on the mushroom species you choose to grow. Here I don’t mean that you choose between, for example between Pleurotus or Lentinula, I mean that within each of these families there are differences in performance.
Let’s look at the results of a study that was published in 2010 by Fanadzo. The author investigated two different Pleurotus species (P. ostreatus and P. sajor-caju) grown on different substrates (wheat straw, maize stover, and thatch grass).
The author found for the non-supplemented wheat straw a biological efficiency (BE) of 71% and 45.6% for P. sajor-caju and P. ostreatus respective. This means P. sajor-caju has a 56% higher BE on wheat straw that P. ostreatus.
If we look at another substrate, P. ostreatus reaches a BE of 97% while P. sajor-caju only achieved a BE of 40%. And here we are already into the next topic. If you choose a mushroom species, you have to know on which substrate you want to grow it.
While researching for this topic, I came across an important issue – the taxonomy of mushroom species. For example, Pleurotus sajor-caju was pre-1996 put into the category of Pleurotus, and since 1996 it was reclassified in the category Lentinus sajor-caju.
And here starts the problem. The reclassification was done in 1996, the paper we discussed was from 2010, but still, they used the old taxonomy. And it’s getting more complicated. Mycologists often use the name Pleurotus sajor-caju for the variety Pleurotus pulmonarius. This point was addressed by Paul Stamets in his book Growing Gourmet and Medicinal Mushroom Species (Amazon affiliate link).
This mismatch and misuse make the comparison between different mushroom species a little bit trickier.
The best advice I can give to you is that you treat each mushroom species as a separate species. Thereby you don’t fall into the trap I just described – that you think you deal with a Pleurotus species, but in reality, it’s a different species.
After you have decided which mushroom species you want to grow, you have to figure out what is the optimum substrate for this species. The better approach would be the opposite – and that’s what is usually done. You start with the substrate, which is the most abundant in your area and then choose the mushroom species accordingly.
To illustrate what I just said, let’s look at table 1. If you want to grow P. ostreatus then according to the first study I talked in the last section the best substrate would be maize stover which reached a 50% higher BE compared to wheat straw and thatch grass.
|Substrate||Pleurotus ostreatus (%)|
Table 1: Comparison of the biological efficiency of P. ostreatus grown on different substrates
But you could argue that a BE of roughly 50% isn’t that good and yes, you are right, and if you choose the right substrate you can get to a higher BE as the following results of another study are showing us.
In this research paper, the author compared the BE of five different substrates if they were used for the cultivation of P. florida. The results are shown in figure 1. Here the best result (BE 136) was achieved by using wheat straw followed by rice straw with a BE of 123, and sorghum with a BE of 117.
Figure 1: Influence of different substrates on the biological efficiency (BE) of P. florida
If you want to learn more about How Substrate Influences your Mushroom Yield this article is for you. In it, I will explain in detail which factor will impact your yield and how you can use the knowledge to increase it.
But there is more to it than just the substrate. If we read the science paper more carefully, we found that the author supplemented each substrate with wheat bran (10%). Which brings us directly to the next topic.
Every mushroom farmer uses a specific version of a supplement to get the results he expected. But very few dig deeper into this exciting subject. And I totally get it. It’s a ton of work to not only search for the articles but also analyzing them, and that’s where I come into the picture. I will do the research and analyzing for you. The only thing you have to do is to grab the information and apply it to your business.
To get into this topic, I will use the results of the first study in which the author compared two different Pleurotus species on various substrates. In his research, he used two different supplements (maize bran and cottonseed hulls) and analyzed their influence on the BE. The following figure (2) shows the BE for P. ostreatus for different substrates, which were supplemented or not.
While we see for wheat straw an increase in the BE, we see a drop in the BE for both maize stover and thatch grass.
Figure 2: Influence of different substrates and supplements on the biological efficiency of P. ostreatus
This result is different from figure 3, which gives us information about the influence of different substrates and supplements on the BE of P. sajor-caju. Here we see clearly an overall increase if the substrate were supplemented with cottonseed hulls. If instead maize bran was used the BE drops. These results indicate that P. sajor-caju prefers a different substrate composition than P. ostreatus.
Figure 3: Influence of different substrates and supplements on the biological efficiency of P. sajor-caju
Let’s go and talk about the last point – the spawn rate. Spawn rate is the amount of spawn used per kg on substrate on a dry weight basis. The following figure 4 shows a clear correlation (0.808) between the spawn rate and the yield. The highest yield was in this research achieved at a spawn rate of 6-7%.
Figure 4: Influence of the spawn rate on the fresh yield of P. ostreatus
If we combine all these findings, they clearly indicate that to get to the highest possible yield, we must combine them. We have to use the right substrate and supplement level which are appropriate for the specific mushroom species we want to grow. And then we have to add the right amount of spawn to get where we want to be.
While each mushroom farm is unique because of its location and therefore conditions it’s in, all the information I am presenting to you can just be a guideline for you. For this reason, I started a database in which I collect all substrate and supplement combination and their results. Currently, the database comprehends 70+ different substrate mixtures.
To bring you more value, I am interested in hearing from you what of the things you read on my website did you apply and what kind of results did you get.
More about the supplement level and spawn rate can be found in my article How your Inoculation Method can Impact your Mushroom Yield. In it, I will provide you a six-step approach to increase efficiency and at the same time reduce the risk of contamination.