Evaluation of the best time for spawning of Pleurotus eryngii mushroom to standardize the cultivation technology in Rajasthan, India

Akansha Deora (  akanshadeora22@gmail.com ) Maharana Pratap University of Agriculture and Technology Dr. S.S. Sharma Maharana Pratap University of Agriculture and Technology Abhitej Singh Shekhawat Maharana Pratap University of Agriculture and Technology Suresh Kumar Maharana Pratap University of Agriculture and Technology Poonam Kumari Maharana Pratap University of Agriculture and Technology Kalpana Yadav Maharana Pratap University of Agriculture and Technology Vinita Dahima Maharana Pratap University of Agriculture and Technology Poonam Yadav Maharana Pratap University of Agriculture and Technology


Background
The word "Mushroom" has been used in different forms at different times and in different nations.
Commonly, mushroom refers to all macrofungi which possess stalks and caps or all the large and eshy fungi [1]. They are rich in protein, dietary bre, vitamins and minerals [2][3][4]. In India, due to suitable weather conditions and abundance of cheaper agro residues like straw, leaves and stalks of different eld crops, mushroom cultivation has been adopted by progressive farmers, which not only bene tted them with an additional source of income but they are also recycling the farm products.
Since water resources are not satisfactory in Rajasthan and agriculture is mostly rainfed that is why mushroom cultivation has great potential in Rajasthan as this industry is labour intensive & requires less water and land as compared to commercial farming. Currently in Rajasthan, the subtropical and tropical varieties of mushroom like oyster and milky mushroom are rising and gaining popularity. Button mushroom is also being grown but due to unavailability of temperate climate throughout the year, it is being grown during very limited period of the year i.e. winter season only [5].
Oyster mushroom is classi ed under Phylum -Basidiomycota and belongs to Family -Pleurotaceae. Pleurotus eryngii (DC.ex FR.) Quel. is the largest species in the Oyster mushroom genus, Pleurotus, which also contains P. ostreatus, P. sajor-caju and P. orida. It has a thick, white and meaty stem or stalk called stipe, a large tan cap called pileus and gills are present underside of the pileus. P. eryngii is also called as Kabul Dhingri and King Oyster Mushroom [6,7]. Unlike other mushrooms species, this genus shows much diversity in their adoption to the varying agro climatic conditions [8]. Different species of Pleurotus can be grown all around the year at various temperature ranges. In subtropical climatic conditions, some species of Pleurotus are suitable like P. citirinopileatus, P. sajor-caju, P. orida and P. salmoneo stramineus (Pink oyster) that commonly require comparatively low temperatures making them suitable to cultivate during September to March months of the year in the state. The suitability of P. eryngii is found to be in winter months of the year. However, not much work had been done to standardize its cultivation technology in existing weather conditions; the study is aimed to evaluate the optimum parameters for getting higher biological e ciency.

Results
Data in the Table 1 indicates that, among the different months tested for the e cacy of P. eryngii production, the mycelial run was observed to be the fastest in the month of December (19 days) and January (19.4 days). Months of November and February gave same results (22.4 days) and the same trend was followed for the pinhead initiation time. This trend ( Fig. 1) exhibited due the fact that the temperature started declining slowly with the onset of November and reached minimum range at the end of November and continued to be in the same minimum range till mid January and further, started  (Table 2). November gave signi cantly higher BE% (72.1%) than January (65.5%) and February (56.8%). The uctuation in this trend ( Fig. 2) in case of BE% is because of the higher temperature after mid January and lower temperature after mid November when the fruiting bodies of January and November months started developing, respectively. Average fruit body weight and fruit body measurements were highest in the months of January (93.5g) and February (93.1g) as shown in Table 3, shown by mushroom were accordingly perfect.  SEm ± : Standard error of the mean. CD(p = 0.05) : Critical difference, where p = level of significance. All the observations are average of five replications.

Discussion
Pleurotus mushroom is gaining popularity among the growers due to its simple cultivation technology of growing on wheat or paddy straw over other agro residues. Its cultivation helps in recycling of agrowastes as well as lls the protein gap prevalent among majority of the country. According to this worldwide survey, various types of wastes have been found to be useful for Oyster Mushroom growing in particular months. Around 20°C and 20±1°C, respectively are most appropriate temperatures for cultivating Pleurotus eryngii [9,5]. A minimum temperature of (13.4-24.2°C) proved to be the best for growing oyster mushroom [10]. Winter season was found to be promising for obtaining maximum yields and B.E.s of different strains of Pleurotus species [11]. This con rms our ndings that the mycelial run and pin head initiation in our case was fastest in the month of December Cultures were multiplied on malt extract agar and maintained in test tubes. We prepared six combinations from these three cultures through mycelial anastomosis. Out of them, one strain was found to be the most suitable under sub-tropical climate, which we later named as "Pratap King Oyster-1" (P.K.O-1) and this strain has been used in our experiment.
Preparation of master culture. The study complies with local and national regulations. For the collection of seeds or plants, all relevant permissions or licenses have been obtained. Healthy wheat grains were soaked in water overnight and were boiled up to semi cooked conditions in the next morning. Excess water was drained off and seeds were left for surface drying. These seeds were then mixed with 1% CaCO 3 and were lled in milk glass bottles or polypropylene bags which we later sterilized at 20 lbs psi pressure (126.5 o C) for 2 hrs. After cooling, each bag was inoculated aseptically with two mycelial agar bits of P.K.O.-1 culture in Laminar Air Flow and incubated at 20±1 o C in incubator for 20-25 days till the grains were fully impregnated with the mycelium of inoculated mushroom culture [6] (Fig. 5).
Preparation of substrate. The experiment was laid out by using straw of wheat crop, since; it is easily available and cheap. Straw was chopped into 3-5 cm pieces and chemically treated by soaking in mixture of Bavistin (8g), Formalin (300ml) and Nuvan (30ml) with water in drum of 200 litre capacity and kept overnight. On the next day, after decanting excess water, it was used for spawning purpose [12] (Fig. 6).
Spawning. The experiment was performed for the four winter months viz. November, December, January and February. For layer spawning, substrate lled in bag was pressed to a depth of 2-3 inches and broadcasted with spawn above it. Similarly, 2nd and 3rd layers of entire substrate were put simultaneously and after spawning, some amount of substrate is put over it, and then the bags tied up with rubber bands (Fig. 7). Thus, ve bags in each month were spawned and they were maintained under optimum conditions of mushroom growth. The date of spawning was also kept same in every month.
Thus, four treatments with ve replications of each were placed using Completely Randomized Design to reach the conclusion so that a consolidated recommendation can be made as to how the King Oyster can be grown with maximum BE.
Crop management and harvesting. After 20-22 days of spawning, when spawn run gets completed and bags turns white in colour due to white mycelial run, the polythene covers were teared off. Pin heads came out after 2 to 3 days of removing the polycovers which later developed into mature fruit bodies [13].
At this stage, mushrooms were plucked off by twisting in clockwise direction at the substrate level, counted and weighed separately for each replication at every harvest (Fig. 8). Yield was recorded and the Biological e ciency was also calculated.
Biological e ciency. The Biological e ciency was also calculated by following the given formula [1].

Statistical analysis. Statistical Analysis Software (SAS software) developed by Indian Statistical
Research Institute (ISRI), New Delhi was used for performing statistical analyses of data. The critical differences among treatment groups were determined using the ANOVA test at level of signi cance (p= 0.05). All the experiments were carried out in ve replications in Completely Randomized Design (CRD).
The data analysis for this paper was generated using SAS software. Copyright Average number of days taken in spawn run completion and pin head initiation in different months.

Figure 2
Page 9/12 BE% obtained from different months.  Number of fruiting bodies and average weight of Pleurotus eryngii in different months.

Figure 5
Photographs of steps for spawn preparation of Pleurotus eryngii from culture.

Figure 6
Photographs of steps for substrate preparation. Photographs of steps for substrate inoculation or spawning.

Figure 8
Photographs of different growth stages of Pleurotus eryngii from spawn run to harvesting.