Vol. 8, Issue 12 (2019)

Author(s):
Rajendra Kumar Bais, Ved Ratan, Sumit Kumar, Ashutosh Tiwari and Somesh

Abstract:
The present experiment was conducted to test the efficacy of bio-control agents, plant extracts and fungicides in vitro against Alternaria solani causing early blight of tomato. The efficacy of two fungal and one bacterial antagonist (T. harzianum, T. viride and P. fluroresenes) were evaluated through dual culture technique. Six plant extracts viz., Azadirachta indica (Neem), Zingiber officinale (Ginger), Allium sativum (Garlic), Eucalyptus spp (Eucalyptus), Dhatura stramonium (Datura) and Ociumum sanctum (Tulsi) at five concentrations i.e. 1%, 2%, 3%, 4%, and 5%. and six combination of systemic and non-systemic fungicides viz., Mancozeb, Roko, Carbendazim, Companion, Blitox 50 and Sanchar also at five concentrations i.e. 50ppm, 100ppm, 250ppm, 500ppm and 1000ppm were evaluated through poison food technique. All bio-control agents, highest inhibition of radial growth of test fungus was recorded in P. fluorescens showed maximum inhibition (56.03%) followed by Trichoderma harzianum (51.58 %), while minimum mycelium growth inhibition was observed in Trichoderma viride (47.78%). Among different plant extracts used, Allium sativum (Garlic) was significantly inhibit the mycelial growth of pathogen in all concentrations followed by Azadirachta indica (Neem). Among combination of systemic and non-systemic fungicides at different concentrations, the significant maximum growth inhibition was recorded in Metalaxyl + Mancozeb (Sanchar) at 100, 250, 500 and 1000 ppm concentration which inhibited the fungal growth as 100 per cent respectively, followed by Mancozeb and Carbendazim + Mancozeb was most effective in this study.