Vol. 7, Issue 3 (2019)
Biocontrol efficacy of Trichoderma isolates against tomato damping off caused by Pythium spp. and Rhizoctonia solani (Kuhn.)
Author(s): Markidahun Biam and Dipali Majumder
Abstract: Damping-off of tomato is one of the worst diseases of tomato nurseries in Meghalaya. Pathogens can kill both germinating seeds and young seedlings.Management of damping off by fungicides is not the most desirable mean to manage the disease. Integration of biocontrol agents, specially the Trichoderma spp., which can reduce doses of fungicides is considered as better management strategy against the damping off of pathogens. Considering the fact, present investigation was formulated and aimed on to evaluate bio-efficacy of Trichoderma formulation against Pythium spp. and Rhizoctonia solani Kuhn. Cause damping off in tomato. The bio priming of tomato seeds with 4 Trichoderma isolates (TR 55, TR 66, TR 122 and TR 136) showed considerable increase in germination percentage and vigour index over control, with highest germination percentage and vigour index recorded in TR 55 (75.13% and 47.99% respectively). Among the treatments (seed, soil and seed plus soil) highest reduction in incidences of pre-emergence and post emergence damping-off was obtained with the isolate, TR 55 (seed plus soil treatment) in both the pathogens i.e., Pythium spp. and R. solani Kuhn. The rhizosphere colonization of Trichoderma spp. showed that the rate of colonization increases up to 45 days after sowing and reduced at 60 days after sowing in all the treatments. Colonization was highest in TR 55 (3.73 × 106) followed by TR 122 (3.63× 106), TR 66 (3.50× 106) and TR 136 (3.37× 106). Plant height, number of leaves and flowers per plant, dry and fresh weight, root length and yield of tomato was significantly superior in Trichoderma treated plants and low in control. Viability of Trichoderma in talcum powder showed that microbial count was highest initially but a gradual decline was recorded with the increase in the storage time.
How to cite this article:
Markidahun Biam and Dipali Majumder. Biocontrol efficacy of Trichoderma isolates against tomato damping off caused by Pythium spp. and Rhizoctonia solani (Kuhn.). 2019; 7(3): 81-89.