Assessing the potential of combined Bio control agents (Fungi and Bacteria) and AM fungi for enhancing turmeric resistance to Pythium aphanidermatum: A pot study with focus on Biometric, Disease and Enzymatic parameters

Turmeric (Curcuma longa L.) is one of the important spice crops grown in India since time immemorial and has a potential to earn foreign exchange because of its wide utilization in Ayurvedic industry. Turmeric belongs to the family Zingiberaceae. Turmeric is the third largest spice produced in the country and it accounts for about 14 % of total spices produced in India. Though it is well known for its medicinal value, its cultivation is hindered by several diseases. Among the various diseases, rhizome rot caused by Pythium sp. is a major problem in all turmeric growing areas of India. Its damage leads to 90-100% yield loss. The present studies emphasised on AM fungi (Glomus mossae) and antagonists (Trichoderma asperellum and Bacillus subtilis) against the rhizome rot of turmeric caused by P. aphanidermatum. In pot culture experiments, the combined application of T. asperellum RT (10 ml kg-1) + SA (5 ml kg-1) and B. subtilis RT (10 ml kg-1) + SA (5 ml kg-1) plus G. mosseae @ SA (20 g pot-1) –(T7) recorded the minimum Rhizome rot incidence and maximum plant growth promotion of turmeric. The same treatment showed earlier induction and increased levels of defence enzymes viz. PO, PPO, PAL and β1,3- glucanase.In field trial, the combined application of T. asperellum RT (10 ml kg-1) + SA (2. 5 lit ha-1) and B. subtilis RT (10 ml kg-1) + SA (2.5 lit ha-1) plus G. mosseae @ SA (20 kg ha-1)– (T7) reduced rhizome rot incidence to the minimum and increased the biometrics of turmeric to the maximum.