In vitro evaluation of fungicides against Lophodermium pinastri causing needle blight disease of blue pine in Kashmir (India)

Needle blight has appeared as threatening disease in Blue pine (Pinus wallichiana) in Kashmir Himalayan forests. The disease in Kashmir was found to be incited by Lophodermium pinastri. Various systemic and non-systemic fungicides were evaluated in vitro at various concentrations for their efficacy in inhibiting radial mycelial growth and ascospore germination of L. pinastri. The systemic fungicides were evaluated at the concentrations of 1, 10, 50, 100 and 150 ppm and non-systemic fungicides at 10, 50, 100, 500, 1000 and 2000 ppm concentration. All the fungicides at all the concentrations tested significantly reduced both mycelial growth and ascospore germination. Amongst the systemic fungicides evaluated, hexaconazole 5 EC proved superior over all other systemic fungicides in inhibiting mycelial growth and ascospore germination (76.3 and 82.2%), followed by flusilazole 40 EC (70.5 and 77.8%) and carbendazim 50 WP (69.3 and79.8%). Least inhibition in mycelial growth and ascospore germination was observed in thiophenate methyl 75 WP. Amongst the non-systemic fungicides evaluated, maximum inhibition in mycelial growth and ascospore germination was observed in chlorothalonil 75WP (70.8 and 68.4%) and mancozeb 75 WP (69.4 and 70.0%), However, least mycelial growth inhibition and ascospore germination was observed in captan 50 WP (56.5 and 60.5%) and ziram 80 WP (46.6 and 62.1%).