Impact of Spent Mushroom Substrate on Glomus mosseae Establishment in Wheat (Triticum aestivum) and Pearl Millet (Pennisetum glaucum)

Abstract

The application of spent mushroom substrate (SMS) in soil increases yields and improves quality of agriculture produce. Glomus mosseae is a predominant species of arbascular mycorrhizae (AM) fungus in soils and it help the plant in many ways. The substrate from the production process of cultivated mushrooms is a material with a high lignocellulosic content and rich in organic matter, which, when incorporated into the soil, changes its chemical attributes. Thus, this substrate can be used in the preparation of organic compounds, the manufacture of biofertilizers and chemical soil conditioner in semi-arid regions. Thus, the research tried to evaluate the presence of the substrates at different concentrations in the growth, development and establishment of G. mosseae fungi at 45 and 60 days after sowing to help the productivity of wheat and pearl millet for three consecutive years from 2018-19 to 2020-21under screenhouse conditions. One year old button mushroom SMS was mixed in sterile sandy loam soil at 10, 20, 30% (w/w basis) and pure culture of G. mossea was applied at 450-500 sporocarp/kg of soil and then filled with earthen pots of 30 cm diameter. Twenty seeds of wheat cv. WH 1105 were sown in each pot during the third week of November every year and maintained. Similarly, twenty seeds of pearl millet cv. HHB 67 (I) was sown in each pot in first week of July every year and maintained. The plants raised in soil without SMS but inoculated with G. mosseae served as control. The treatments were replicated ten times and the experiments were laid out as per RCBD design. The observations on mycorrhizal colonization (%) and sporocarps numbers per 100g soil were taken at 45 and 60 days after sowing (DAS) in wheat and pearl millet. In wheat cv. WH 1105, the root colonization (%) and sporocarp numbers/100 g soil of G. mosseae were higher when SMS at 30% was applied in soil and lowest in control.  These increased further in all treatments at 60 DAS as compared to 45 DAS stage during three years of experimentation. The root colonization at 60 DAS was significantly high at 24.9, 34.8 and 27.9 % when SMS applied in soil at 30% and it was lowest at 20.2, 30.1, 23.1% in control during 2018-19, 2019-20 and 2020-21, respectively. The sporocarp numbers at 60 DAS were also found to be high at 255, 195 and 325 sporocarps/100 g soil when 30% of SMS was applied in soil and lowest at 210, 172, 265 sporocarps/100 g soil in control during 2018-19, 2019-20 and 2020-21, respectively. In pearl millet hybrid HHB-67 (Improved), the root colonization and sporocarp numbers/100 g soil of G. mosseae were higher when SMS at 20% was applied in soil and lowest in control.  These increased further in all treatments at 60 DAS as compared to 45 DAS stage during three years. The root colonization at 60 DAS was significantly higher in 34.0, 35.3 and 34.7% when SMS was applied at 20% and it was lowest at 34.3, 33.2, 31.1% in control during 2018-19, 2019-20 and 2020-21, respectively.  The sporocarp numbers at 60 DAS were also found to be high at 229, 250 and 174 /100 g soil when SMS at 20% was applied and it was lowest at 219, 205, 150 sporocarps/100 g soil in control during 2018-19, 2019-20 and 2020-21, respectively.