Study on the Cultivation of Oyster Mushrooms in the Idle Space of Flower Greenhouse Sheds
1 Materials and Methods
1.1 Experimental Materials
1.1.1 Test Materials
The oyster mushroom cultivar "Zaoqiu 615" was provided by the Tianda Edible Fungi Research Institute of Jiangdu City, Jiangsu Province.
1.1.2 Cultivation Facilities
The flower greenhouse shed used for the experiment was a glass-steel frame composite structure. In winter, the shed was heated by radiators and insulated with plastic film. Ventilation holes were arranged around the perimeter, and a fan and a wet curtain were installed on the north and south sides respectively. The internal environmental temperature of the shed was 23-29°C, and the relative humidity was 80%-85%
. The cultivar grown on the seedling beds was arrowroot (Maranta arundinacea), and the space beneath the seedling beds was left vacant year-round.
1.1.3 Bti Pesticide
Bacillus thuringiensis subsp. israelensis (abbreviated as Bti) was provided by Researcher Song Jindi of the Vegetable Research Institute, Jiangsu Academy of Agricultural Sciences.
1.2 Experimental Methods
1.2.1 Experimental Design
The basic composition of the treatments was 48% cottonseed hulls, 48% corncobs, and 4% quicklime. The specific design is shown in Table 1. Treatments 1 and 2 had 8 replicates, while CK and treatments 3-7 had 3 replicates, with 25 mushroom bags per replicate. The experiment was arranged in a randomized complete block design, with a 0.2 m spacing zone between replicates.
1.2.2 Experimental Methods
On October 29, 2014, the substrate was mixed; on November 2, it was bagged and inoculated. The mushroom bags were polypropylene bags measuring 18 cm × 40 cm, and after filling, the dry weight was approximately 1.3 kg. After inoculation, the bags were placed in a culture room for mycelial colonization (Figure 1). During the colonization period, the room temperature was maintained at 25-28°C, and the humidity was around 70%. After about 30 d of colonization, once the mycelium had fully covered the bags, they were transferred beneath the seedling beds in the shed for fruiting. Before transfer, lime powder was spread on the ground, and then the bags were evenly stacked on pre-laid plastic boards, with a total of 3 layers. To promote the emergence of mushroom buds,
slits about 1 cm deep and about 3 cm in diameter were cut on both sides of the bags. During the fruiting period, a sprayer was used to humidify daily, keeping the humidity inside the shed at 80%-90%, and sticky insect traps were used to kill insects. The area was frequently ventilated during cultivation to avoid excessively high carbon dioxide concentrations in the shed. To control the damage from gall midge larvae, on the 10th day of fruiting, 5 g/L Bti pesticide was applied to the bags of treatment 1, while CK and treatments 3-7 were treated with different concentrations of Bti pesticide, as detailed in 1.2.1. The application method was pin-hole injection.
1.2.3 Detection Methods
An electronic scale was used to weigh the oyster mushroom yield, with an accuracy of 0.01 kg.
2 Results and Analysis
2.1 Oyster Mushroom Yield Under Different Cultivation Modes
As shown in Table 2 and Figure 2, under the cultivation conditions of the flower greenhouse shed, both the raw-material cultivation mode and the sterilized-substrate cultivation mode achieved a certain yield, but the two cultivation modes differed considerably in fruiting time and fruiting body traits. This was shown by the fact that the fruiting time distribution of the fruiting bodies in the sterilized-substrate cultivation mode was relatively even, with the fruiting amount declining over time; whereas the raw-material cultivation mode had obvious peak fruiting periods, namely the 25th day and the 55th day of fruiting, with an obvious trough period between the two flushes. The conversion rate of the raw-material cultivation mode was higher than that of the sterilized-substrate cultivation mode, but the moisture content of the fruiting bodies was also higher. Because the cultivation environment temperature and light intensity were higher than usual conditions, the moisture content of the fruiting bodies under both cultivation modes was noticeably low, especially under the sterilized-substrate cultivation mode, resulting in a low fruiting body conversion rate during the experimental period. Among them, the fruiting body conversion rates of the raw-material cultivation mode and the sterilized-substrate cultivation mode were 87.5% and 71.9%, respectively, which is similar to the research results of Niu Yurong et al. The high-temperature environment also triggered a certain degree of insect pest damage. In the early stage of raw-material cultivation, varying degrees of gall midge damage appeared inside the bags. In daily production, gall midge is a common disease, but because winter temperatures are relatively low, it generally does not cause serious damage and is relatively easy to control. However, the temperature in this experimental environment was relatively high, causing a more severe outbreak of insect pests, especially in the bags of raw-material cultivation, where gall midge larval damage appeared about one week after entering the shed. Therefore, Bti pesticide was used to control gall midge larvae and achieved a good control effect.
2.2 Economic Benefits of Oyster Mushroom Cultivation Under Different Cultivation Modes
As shown in Table 3, the raw material cost, transportation cost, and labor cost of the two cultivation modes were the same; the difference was that sterilized-substrate cultivation required sterilization. Under the raw-material cultivation mode, the oyster mushrooms had a high moisture content, low output rate, and were more susceptible to gall midge larval damage, so their marketability was not as good as that of sterilized-substrate cultivation, and therefore the market price was lower. Calculated according to local market prices, the economic benefit of raw-material cultivation was 1.100 yuan/kg, and the economic benefit of sterilized-substrate cultivation was 1.614 yuan/kg. In addition, the concentrated fruiting method of raw-material cultivation placed high demands on storage and preservation, and when market conditions were poor, it would severely reduce economic benefits; whereas sterilized-substrate cultivation fruited more dispersedly and was less susceptible to short-term market fluctuations. Therefore, in actual production, the sterilized-substrate cultivation mode can be given priority. If calculated on the basis of placing 8,000 mushroom bags per 667 sq m, the raw-material and sterilized-substrate cultivation modes could bring economic benefits of 11,400 yuan/667 sq m and 16,800 yuan/667 sq m, respectively.
2.3 Effect of Bti Pesticide on Controlling Gall Midge Larvae
As shown in Table 4, under the application of different concentrations of Bti pesticide, the fruiting body yields of different treatments showed obvious differences. This was shown by the fact that pest damage was effectively controlled in the treatments with high-concentration application, and the yield was significantly different from CK and noticeably higher than that of the treatments with low-concentration application. The difference between treatments 3 and 4 was not significant, and the difference among treatments 5, 6, and 7 was not significant. Therefore, an application concentration of 5 g/L was the most appropriate application concentration. In addition, in the use of ordinary cultivation methods at the experimental base, the method of low concentration applied multiple times also achieved a relatively good effect.
3 Conclusion
Cultivating oyster mushrooms in the idle space of flower greenhouse sheds can not only effectively utilize the suitable environment inside the greenhouse shed, achieving rapid fruiting, a short growth period, and a shortened production cycle for oyster mushrooms, but can also make use of the idle space in flower sheds, bringing more economic benefits to flower-producing farmers and enterprises. This experiment compared two oyster mushroom production modes and found that the sterilized-substrate cultivation mode had dispersed fruiting time and fewer occurrences of insect pests, making it a suitable cultivation mode. However, limited by the environmental conditions inside the shed, the moisture content of the fruiting bodies produced under the sterilized-substrate cultivation mode was relatively low, affecting yield and marketability. This point is worth improving in further research, such as by adopting shade nets and adding localized cooling and humidifying devices.