Sheela, Paul TRoshna, SKAU2017-08-052017-08-052013http://krishikosh.egranth.ac.in/handle/1/5810027604Spent mushroom substrate (SMS) is the composted organic material, left after the harvest of a crop of mushroom. SMS is high in organic matter and rich in plant nutrients. Several studies revealed that SMS can be effectively used for management of crop diseases. Hence an attempt has been made on the use of spent oyster mushroom substrate against nursery diseases of black pepper. Under these circumstances, a study was conducted to evaluate the potential of SMS of oyster mushroom substrate as potting mixture for the management of nursery diseases of black pepper. The main constraint in the production of quality pepper cuttings is the incidence of diseases especially that caused by Phytophthora capsici. In addition the occurrence of anthracnose by Colletotrichum gloeosporioides, leaf rot and blight by Rhizoctonia solani and basal stem rot by Sclerotium rolfsii were also causing damage to the cuttings. The above fungal pathogens were isolated from diseased specimen following standard procedure and their pure cultures were maintained. The popular oyster mushrooms P. florida and P. sajor-caju were used for the production of SMS and were cultivated in two different substrates viz., paddy straw and saw dust. Microorganisms present in the SMS were enumerated at different stages of growth of mushroom on the substrates as well as from weathered SMS. From among the microbes enumerated four isolates each of fungi and bacteria were used for further studies. In vitro evaluation on the antagonistic efficiency of these isolated organisms against P. capsici revealed that all the four fungal isolates (FA-1, FA-2, FA-3 and FA-4) and the two bacterial isolates (BA-1 and BA-4) were found antagonistic to the foot rot pathogen. Among these FA-4 and BA-4 gave the maximum inhibition of 80.4 and 75.6 per cent respectively. The compatibility of the antagonists was studied and two antagonists viz., FA-4 and BA-1 were used for the preparation of consortium. The antagonists viz., FA-4, BA-1 and BA-4 were also evaluated against the other pathogens C. gloeosporioides, R. solani and S. rolfsii by dual culture technique. The bacterial isolates, BA-1 and BA-4 were effective against C. gloeosporioides whereas only BA-4 was effective against R. solani and S. rolfsii. The fungal isolate FA-4 completely inhibited C. gloeosporioides whereas it gave 44 and 55 per cent inhibition respectively for R. solani and S. rolfsii. The fungal antagonist FA-4, was identified as Trichoderma hamatum by studying cultural and morphological characters. The bacterial isolates BA-1 and BA-4 were identified as Pseudomonas aeruginosa and Bacillus subtilis respectively. The potential of spent mushroom substrate in potting mixture for the management of nursery diseases of black pepper was studied under potculture conditions. The treatments were applied at the time of planting, 60 DAP and 80DAP. Among the various treatments, consortium of bio agents P. aeruginosa and T. hamatum gave less incidence and severity of Phytophthora rot with 10.7 per cent incidence and 26.45 per cent severity respectively after 100 DAP. It was followed by the treatments T. hamatum and B. subtilis from SMS. As a whole, the bio agents from SMS gave better disease control than other treatments. Among treatments with SMS as potting mixture, saw dust SMS was found good compared to paddy straw. The texture of fresh paddy straw SMS was not suitable for the proper rooting and sprouting of cuttings. In case of sprouting percentage, the treatment with 50% saw dust SMS of P. sajor-caju as potting mixture gave maximum germination followed by consortium of bio agents from SMS. The height of cuttings and number of leaves were maximum in treatments with consortium of T. hamatum and P. aeruginosa followed by the treatments with individual application of T. hamatum and B. subtilis. SMS is unique in its chemical composition and the presence of antagonistic microflora which helps to suppress the pathogens multiplying in the soil ecosystem. From the pot culture experiment it was clear that for the management of nursery diseases of black pepper, the best treatment was consortium of bio agents from SMS. This is not only because of its antagonistic property but also due to its plant growth promoting ability. So from the present study, it can be concluded that the use of consortium of P. aeruginosa and T. hamatum was effective for both disease management and plant growth promotion in pepper nursery.ennullThesis