Bio-efficacy of certain botanicals against colony growth and spore germination of Exserohilum hawaiiensis a causal agent of leaf blight of wheat.
Patil V. S., Srikant Kulkarni
Author Affiliation: Department of Plant Pathology, University of Agricultural Sciences, Dharwad - 580 005, India.
Karnataka Journal of Agricultural Sciences 15 : 391-396
Abstract : Among the extracts of 35 plants evaluated in vitro against Exserohilum hawaiiensis, Eucalyptus globus inhibited the maximum mean spore germination (88.48%), followed by Lantana camara (87.54%) and Flacourtia ramontchii (85.43). A significant increase in spore germination inhibition was observed with increasing extract concentration. At 5% concentration, the maximum inhibition was observed in Lantana camara (78.27%), Eucalyptus globus (76.52%), F. ramontchii (75.41%), Memecylon edule (72.00%) and Leucas stelligera (68.28%). At 10% concentration, the maximum inhibition was observed in Eucalyptus globus (89.92%), Lantana camara (89.26%), F. ramontchii (86.99%), Memecylon edule (80.14%) and Colebrookea oppositifolia (73.37%). At 20% concentration, the maximum inhibition was observed in Eucalyptus globus (99.02%), Lantana camara (95.10%), F. ramontchii (93.90%), Leucas stelligera (91.28%) and Elaeagnus latifolia (90.80%). Crude extracts (20%), Eucalyptus globus, Lantana camara, F. ramontchii, Leucas stelligera and Elaeagnus latifolia were effective in inhibiting conidial germination. The crude extracts of Acacia concinna, Allium sativum, Colebrookea oppositifolia, Eucalyptus globus, Elaeagnus latifolia, F. ramontchii, Lantana camara, Leucas stelligera, Ligustrum neilgherrense, Memecylon edule and Mangifera indica exhibited excellent spore germination inhibition. Considering the inhibition of colony growth, Memecylon edule exhibited 100% inhibition, followed by Eucalyptus globus oil at 0.5% concentration. Acacia concinna, F. ramontchii, Eucalyptus globus (leaf extract), Mangifera indica at 20% concentration inhibited colony growth of Exserohilum hawaiiensis. Azadirachta indica, Bougainvillea glabra, Clerodendron inerme [Clerodendrum inerme], Elaeagnus latifolia, Lannea coromandelica, Lantana camara were effective in reducing spore germination, but were ineffective in reducing colony growth of Exserohilum hawaiiensis.