Chrysanthemum is one of the commercially important flower crop with great potential both as loose and cut flowers in Karnataka state. In the present study, prevalence and incidence of leaf blight disease was studied in six major growing districts of South Karnataka during 2012 - 2013. The pathogen associated with leaf blight disease was isolated and identified as Alternaria alternata. The study revealed that, the disease was distributed in Southern districts of Karnataka wherever Chrysanthemum is grown. The varieties Chandini and Karnel were more susceptible to blight showing highest disease incidence (100%) and severity (100%) recorded from Mandya and Mysore regions. The lowest disease incidence, severity and PDI of 18.40%, 38.68% and 24.89% were recorded on Rajawhite variety in Bangalore region. During 2013, the highest disease incidence, severity and PDI with 100%, 98.47%, and 45.71% were recorded in Mysore district on Chandini variety. In vitro evaluation of four fungicides on Alternaria alternata revealed that Carbendazim+Mancozeb was most effective with 95.65% inhibition followed by Carbendazim, Mancozeb and Metalaxyl+Mancozeb with 68.26%, 91.30% and 91.30% inhibition of the mycelium at 2.0% concentration.DOI: http://dx.doi.org/10.3126/ijls.v9i3.12465 International Journal of Life Sciences 9 (3): 2015; 38-45
Alternaria alternata causes leaf blight of rosy periwinkle (Catharanthus roseus) in Iraq
