Plant nutrient and disease management control by bioformulation of Spent Mushroom Substrate (SMS) and Trichoderma asperellum -
Plant nutrient and disease management control by bioformulation of Spent Mushroom Substrate (SMS) and Trichoderma asperellum
Paddy straw (PS) based silica (Si) rich Spent Mushroom Substrate (SMS) of Pleurotus ostreatus for Plant Nutrient and Disease Management in wilt (caused by F. oxysporum f. sp. lycopersici) susceptible tomato plant. Raw PS and SMS generated by P. ostreatus cultivated on PS only, and PS amended with 5% soybean cake (SC) were bio-fortified with Trichoderma asperellum (TA). SMS (PS+ 5% SC) was found supporting the growth of T. asperellum to an extent of 12.37 × 1013 conidia/g substrate. Bioformulations were developed employing Press Mud (PM) and Talcum Powder (TP) as carrier materials. SMS promoted the growth of biocontrol agent Trichoderma asperellum. Potential use of formulation in plant nutrient and wilt management in tomato.
Solid state fermentation (SSF)
SMS (PS, PS+ 5% SC) and raw PS were used as substrates for the SSF study. Samples were ground sieved to mesh size of 345 μm with sieve number 45.100 g sample from each substrate was moistened (75% humidity) and transferred to a 1 L conical flask, and autoclaved (15 psi) for 30 min at 121 ◦C. All the flasks were inoculated with the spore suspension of T. asperellum having conidia count of 108 spores/ml and incubated at 28±2 ◦C for ten days. Fungal growth (spores/g substrate) was recorded on the 10th day using a hemocytometer, and the fermented substrates were used further to develop bioformulations.
Development and shelf life estimation of PM and TP based bioformulations
Substrates raw PS and SMS (PS, PS+ 5% SC) were used for developing the PM and TP based bioformulations. The substrates were fully colonized with T. asperellum by the SSF process and air dried under laminar flow. Different bioformulations were developed using carrier materials (PM and TP), mixed in 1:2 ratio with each air-dried T. asperellum colonized substrate and 1% w/w of Carboxymethyl Cellulose (CMC) used as an adjuvant. The developed bioformulations were further air-dried under aseptic conditions, maintaining the moisture level to 8% and stored in sterile polypropylene bags at 4 ◦C. A shelf life study for the bioformulations was performed by spread plate method for six months, with 30-day time interval.
Seeds were grown separately in nursery trays after surface sterilization and raised under environmental conditions. After 21 days, a healthy seedling was transferred per pot having small holes at the bottom with 4 kg of soil along with of 50 gm bioformulation/kg of soil. Spore suspension of F. oxysporum was added in pots to all treatments except the control. The pots were placed in a randomized block, with three replicates per treatment.
Development of bioformulations and shelf life study
The microbial viability of T. asperellum for the developed bioformulations was evaluated for 6 months at 28 ± 2 ◦C. T1 provided the highest initial spore count (12.37*1013 cfu/g bioformulation) for T. asperellum, retaining the viability of 2.37*108 cfu/bioformualtion after 6 months at 4 ◦C. Viability studies of bioformulations depicted the trend in the order T1>T2>T3>T4>T5>T6. Simultaneously, a gradual loss in spore count was noticed with an increase in time duration for all the bioformulations. Remarkably the shelf life results in the present study supported the fact that PM-based bioformulations were comparatively more proficient than TP-based bioformulations.
Germination percentage of tomato seeds, Disease Severity Index (DSI), nutritional and nutraceutical properties of tomato plant, effect of different treatments on carbohydrates, TSP, and TSS content and effect of different treatments on nutraceutical parameters were analyzed to kmow the importence of bioformulation of Spent Mushroom Substrate (SMS) and Trichoderma asperellum.
The presence of Si in plants is documented to decrease the potency of several crop diseases, especially in plants affected due to wilting; as Si may accrue in plant cell walls and stimulate the phenylpropanoid pathway along with instigation of defense enzymes such as ammonia-lyase, β-1,3-glucanase, chitinase, peroxidase, phenylalanine, polyphenol oxidase, etc.
This further validates the current findings, postulating that the increase in antioxidant activity and plant growth parameters observed could be attributed to high Si content in SMS, thereby attesting the obtained results in the experiments conducted
Adhering to this concern, a unified approach adopted in the current work delivers a holistic solution to suitably manage the agriculture waste (PS) and SMS of P. ostreatus by developing an effective bioformulation with biofertilizer and biopesticidal potentials. In this context, the study endeavored to produce T. asperellum based bioformulations using substrates (raw PS, SMS (PS), and SMS (PS+ 5% SC)), employing PM and TP as carrier materials. In microcosm investigation, comparing the efficacy of different developed bioformulations with pesticide (carbendazim) and control, TF-I (SMS (PS+ 5% SC) SiTAPM) dramatically enhanced the qualitative and quantitative attributes of tomato crops with a very effective biocontrol capability against Fusarium wilting. The presence of considerable amount of Si in SMS and adoption of PM over TP offered the best results pertaining to plant health and disease management. The suggested approach can assist farmers in producing nutritious mushrooms as well as utilize SMS for the development of biopesticides and biofertilizers, thereby helping in the circular economy.
However, the novel bioformulation still has a lot to offer in terms of better yield, rapid multiplication, colonization, and extended shelf life of T. asperellum, along with advancements in texture, storage, and packaging. Improvements in T. asperellum strain by molecular approaches would help in developing more proficient bioformulation. The use of different cost-effective carrier materials can also be explored to economize the product. Moreover, a field-level study involving farmers is desirable before the commercialization of the product.
Reference:
Singh, G., Tiwari, A., Gupta, A., Kumar, A., Hariprasad, P. and Sharma, S., 2021. Bioformulation development via valorizing silica-rich spent mushroom substrate with Trichoderma asperellum for plant nutrient and disease management. Journal of Environmental Management, 297, p.113278.