Pathogenicity of Phaeoacremonium Aleophilum Associated with Grapevine Decline in Kurdistan Region-Iraq

Abstract

The disease severity of Phaeoacremonium.  aleophilum on the symptomatic leaves of  Taefi (cv.) ranged between 0.27-0.32 after two and four months of inoculation with significant difference from  Rashmew (cv.) Pathogenicity test was performed on two cultivars, Taefi and Rashmew, under the greenhouse conditions. One year-old rooted grape cuttings were inoculated with P. aleophilum  by two methods, injecting the spore suspension into the green shoots, and artificial inoculation of wounded shoots with mycelial mat. Symptoms appeared as brownish to black discoloration in a longitudinal section of all plant shoots. The highest canker length (20.67 mm) was produced after four months of wounding on Taefi shoots with significant difference from control treatment. Inoculation by wounding shoots was more effective than injecting shoots. P. aleophilum caused significant reduction in fresh and dry weight of green shoots compared with non- inoculated treatment. Under field condition, two methods of inoculation were adopted, wounding the green shoots, and drilling a hole into the grapevine arms followed by inoculation with mycelial mat. The highest canker length (17.50 mm) was obtained after 5 months on wounded shoots of Rashmew (cv.) with a significant difference from  Taefi (cv.).This pathogen has been reported for the first time in Iraq.