Bioefficacy of fungicides, plant extracts and essential oils against Exserohilum turcicum (Pass.) Leonard and Suggs causing Northern leaf blight of maize

Abstract

Eight fungicides, ten botanicals and ten essential oils were taken for their in vitro evaluation against Exserohilum turcicum (Pass.) Leonard and Suggs incited of Northern Leaf Blight of Maize. Among all the tested fungicides (Azoxystrobin 23%, Thiophenate methyl 75%, Propiconazole 25%, Tebuconazole 25.9%, Captan 50%, Zineb 75%, Cymoxanil 8%+Mancozeb 64% and Zineb 68%+Hexaconazole 4%), propiconazole 25% showed maximum inhibition of mycelial growth (92.22%) under in vitro conditions at 5ppm concentration. Among all the tested botanicals Heena (Lawsonia inermis) was found to be most effective in inhibiting mycelial growth (71.11%) at 10% concentration. Lemon tulsi oil was found best in inhibiting mycelial growth (71.30%) of Exserohilum turcicum, among all the tested essential oils at 50ppm concentration. Fungicides, plant extracts and essential oils showing good results under in vitro conditions were tested under glasshouse conditions. Foliar spray of Propiconazole 25%EC@0.1% showed reduced disease incidence (23.33%) compared to control (46.33%). Application of 5% of Heena extracts reduced the disease incidence (26.67%). Plants when sprayed with Lemon tulsi oil showed reduced disease incidence (24.17%). The study reveals that not only the fungicides but also the natural plant extracts can greatly contribute to reduce the incidence of disease because of the antifungal compounds present in plants.