Which substrate should you choose for growing oyster mushrooms?


Having the best substrate for a specific mushroom can be the difference between making or losing money.

One of the main tasks of a mushroom farmer is, therefore, regularly testing different substrates and their influence on the performance of the cultivated mushrooms in searching for the best substrate-mushroom-fit.

In today’s video, we will, therefore, explore the influence of sunflower read residue, safflower hay, bean straw, and oak sawdust on the growth and yield of Pleurotus djamor, Pleurotus citrinopileatus, and Pleurotus erygnii.

If we analyze these four substrates, we find the following carbon-to-nitrogen ratios.

[2] C:N ratio of four different substrates.

A factor that impacts the growth rate of the mycelium and, thus, how long it takes to grow mushrooms. Here, a high carbon-to-nitrogen ratio means a lower mycelium growth rate and vice versa.

Due to this fact, mushroom farmers will adjust the carbon-to-nitrogen ratio to their needs by adding, for example, wheat bran to the primary substrate. Besides, gypsum and or limestone are added to the mix. The limestone to adjust the pH value. The gypsum as a source of calcium and sulfur.

In today’s research, only gypsum was added. The mixtures were then bagged and autoclaved at 121°C for 90 minutes. After the cool down, the bags were inoculated with a spawn rate of 3% and incubated at 25°C in the dark.

To initiate the fruiting, the temperature was dropped to 16 to 18°C while the humidity was maintained at 85%. During this period, light was applied for 8 hours daily.

The first parameter which was measure is the number of days to the spawn run.

[2] NDSR (number of days for spawn run) for three different mushroom species on four different substrates.

As oak sawdust has the highest carbon-to-nitrogen ratio, the mycelium takes up to 24.2 days to fully colonize the substrate. Which is roughly 20 % longer if the same mushroom species would be grown on bean straw.

If we take a closer look at the graph, we see different growth rates on the same substrate for the three mushroom species. For all four substrates, Pleurotus djamor grew the fastest while Pleurotus eryngii was the slowest.

This difference is more noticeable if we look at the second parameter, the number of days to primordia formation.

[2] NDTP (number of days to primordia formation) for three different mushroom species on four different substrates.

Here, Pleurotus eryngii need up to 20 days to form pinheads if grown on sunflower head residue. That is a 4.5-fold difference in comparison with Pleurotus djamor.

After the primordia formation, the number of days to harvest indicates how long it takes to harvest the first mushrooms.

[2] NDTH (number of days to harvest) for three different mushroom species on four different substrates.

Here, the shortest time with 3.7 days was found growing Pleurotus djamor on safflower hay. Again, Pleurotus eryngii took the longest.

If we summarize our findings concerning the growth rate, we find that using bean straw can reduce the time on average by 5.7 days compared to oak sawdust.

But time is not everything.

While cultivating a fast-growing mushroom species is crucial, nothing is gained if these species yield a low yield. Every mushroom farmer is, therefore, very eager about this parameter.

[2] Yield for three different mushroom species on four different substrates.

If we compare first the four substrates, we notice that oak sawdust yielded on average 203 g. Whereas sunflower head residue on average only 146 g. A difference of 57 g or almost 39 %.

The highest yield, with 210 g, could be found on safflower hay. On the other hand, if we compare the three mushroom species, we find that Pleurotus djamor yields on average 208 g. Closely followed by Pleurotus eryngii with 199 g. While Pleurotus citrinopileatus yielded in only 170 g, which is 18 % lower than Pleurotus djamor.

But these numbers come with a caveat.

While Pleurotus djamor reaches this yield throughout 3 flushes, Pleurotus citrinopileatus over only 2 flushes and Pleurotus eryngii between 1 and 2 flushes.

[3] NOFL (number of flushes) for three different mushroom species on four different substrates.

Only if you combine these two factors, the duration of the whole cropping cycle and the yield, you know what the best substrate-mushroom-fit is.

Talk to you in the following video.


[1] 📝Funda Atila, Evaluation of Suitability of Various Agro-Wastes for Productivity of Pleurotus djamor, Pleurotus citrinopileatus and Pleurotus eryngii Mushrooms, Journal of Experimental Agriculture International, ISSN: 2457-0591, ISSN: 2231-0606 (Past),Vol.: 17, Issue.: 5, DOI : 10.9734/JEAI/2017/36346, https://creativecommons.org/licenses/by/4.0/

[2] Own figures based on [1]