Efficacy of grain spawn and Lime/Gypsum ratio | Oyster Mushroom

Choosing the right amount of lime and gypsum as well as the optimal ratio between them is crucial as the values will influencing the mycelial growth rate. In today’s video I’ll, therefore, talk about a research paper in which the authors compare different treatments with lime and gypsum as well as several types of grain with each other.


Grains of wheat, sorghum, pearl millet, barley, rye, and maize were cleaned and soaked in water 24 hours. After the excess water was removed, calcium carbonate known as lime and calcium sulfate known as gypsum was added at different ratios. The grains were then filled in bottles and autoclaved at 15 psi for 1 hour. After the cooldown, the bottles were inoculated with oyster mushroom cultures and incubated at 27°C (81°F).

The first plot shows the mycelial growth for the different types of grain over all 18 samples. As the following plot shows, the highest mycelial growth can be found on black gram and millet.

When adding lime and gypsum, we see that treatment three leads to the highest growth rate. Here, lime and gypsum are added in a 1 to 1 ratio.

This means the highest mycelial growth rate can be achieved using black gram supplemented with lime and gypsum in a 1 to 1 ratio.

Talk to you in the next video.

You are still here, then let me give you some more insides into the data. But before, let me introduce you to the following graph.

This kind of representation of the data is called the box and whisker plot. The dot on the left side indicates the minimum value of all the given data. The dot on the right the maximum value of them. Q1 is called the first quartile and represents the first 25% of the data. Q3 stands for the third quartile representing 75% of the data. The median gives us the value of the 50% of all the data. Meaning each sector represents 25% of the data.

With that in mind, let us look at the data from today’s research paper. The plot represents the data taken from the maize experiment. The lowest and highest values are the minima and the maxima of the growth rates. Here, 1.8 and 3.3.

The bottom of the box indicates the value of the first 25%, while the top of the box the last 25% of the data, representing 75% of all data. The values are 2.0 and 2.7.

The line represents the median, meaning 50% of the data while the cross the average. Which are 2.4 and 2.3.

The size of the box gives us an understanding of how close the data are. The difference between the lowest and the highest value the range of the data. Here, 1.5.

One additional thing. The average is not part of the original box and whisker plot. But adding this value gives you a better idea of the distribution of the data. Meaning if the values lean more toward higher or toward lower values.

With that in mind, we can now understand the data of today’s research paper better. If we look at the first four boxes containing the data from maize, rye, jao, and wheat, we see that the mycelial growth rates are closer to each other, while for black gram or millet, we see a broader range of values. The minimum value for the black gram is lower than that of maize and rye. But the median is higher than the two, indicating a better choice.

Remember when I said that treatment three leads to the highest growth rate? If we look at all the other four treatments, we see similar behavior. The values are more spread in comparison to treatment three.

With that said, thanks for watching and talking to you in the next video.


Rukhsana A, Abida A, Rehmatullah Q, Zahid A, Kishwar N S. Efficacy of Grain Spawn and Lime/Gypsum Ratio on Mycelial Growth of Oyster Mushroom. Adv Biotech & Micro. 2019; 13(5): 555871. DOI: 10.19080/AIBM.2019.13.555871