Journal de pathologie végétale et de microbiologie

Abstrait

Virulence Study of Phytophthora colocasiae Isolates Collected from Taro Growing Areas of Southern Ethiopia

Zerhun Tomas*, Elfinesh Shikur, Alemar Said

Phytophthora colocasiae is the most destructive fungal pathogen of taro (Colocasia esculenta), which causes taro leaf blight. Taro leaf bight symptoms differed among the same Taro cultivars grown under similar conditions. This raised the question whether Phytophthora colocasiae isolates vary in their virulence or not. To give responses for the question raised 27 taros growing farmers’ fields were surveyed during 2017 cropping season. Out of that 15 representative Phytophthora colocasiae isolates were isolated in the laboratory. Then virulence test of isolates were carried out by using detached leaf disc method. All isolates were pathogenic to taro, with significantly different (P<0.01) lesion diameter. The most virulent isolate was Sodo Zuria isolate, followed by isolates from Damot Gale and Boloso Sore with mean lesion diameters of 46 mm, 37 mm and 35 mm, respectively. On the other hand, an isolate from Hadaro and Kachabira were considered as the least virulent with a mean lesion diameter of 17 mm. virulence of the isolates was strongly associated with altitude from which sample was collected (r=0.55).