Grapevines affected by Phaeomoniella chlamydospora and other Phaeoacremonium species show symptoms of poor early growth and reduced vine vigor. Vines later become stunted. Declining vines show decreased trunk caliper size, have shortened internodes, reduced amount of foliage, and smaller leaf size Foliar symptoms develop that can include interveinal chlorosis and marginal necrosis and wilting, which may ultimately result in premature defoliation.Hot water treatments were applied to eradicate Phaeoacremonium aleophilum and Phaeomoniella chlamydospora from dormant grapevine wood.
In this research the effects of hot water and chemical treatments were evaluated in control of main decline pathogens of grapevine. In this experiment, plots consisted of 4 groups with each treatment replicated three times and arranged in a Randomized Block Design.Four groups of 10 cuttings were treated for each temperature and time, and four additional groups of 10 untreated cuttings were prepared as controls. At the end of the growing season, cutting sprouting and shoot weight were evaluated.Cuttings were hot-water treated at 50°C ,55°C and also soaking plant material in Carboxin –thiram (0.2 gr/l) and tap water for three periods: 30, 45 and 60 min.Cuttings first inoculated with Pa. chlamydospora and Phaeoacremonium aleophilum and then subjected to a hot water treatment were planted for six to eight weeks. Vascular discoloration was scored followed by isolation from the cuttings onto potato dextrose agar amended with 0.1 g l-1 tetracycline (PDA-tet). Isolations confirmed the presence of the pathogens in the inoculated, hot-water treated cuttings as well as in the inoculated, untreated control cuttings.
This finding, leads to the conclusion that hot water treatments are effective in eliminating vine decline pathogens from dormant wood. Results demonstrated that a thirty-minute hot water treat grapevine planting material using protocols with temperatures of up to 50°C are able to eliminate these pathogens from dormant wood cuttings.Effects of temperature and water potential on fungal response in culture were investigated to find effective control strategies for nurseries