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94 WINES&VINES November 2017 WINEMAKING WINE EAST 168 hours of incubation. Acervuli (small asexual fruiting bodies resembling a cushion or blister consisting of a mat of branching filaments that is produced on a host by some fungi) were only observed forming on grape berries after seven to 10 days of moist incubation. Characteristic five- celled conidia with apical and basal appendages were present in both cirrhi and acervuli. In-vitro culture Conidia from some samples were aseptically transferred within a laminar flow hood to full strength potato dextrose agar (PDA) in Petri plates to obtain pure cultures for species iden- tification. Sealed Petri plates were placed under fluorescent lighting that provided a 12-hour photoperiod at 21° to 24° C. After 10 days, a 5-mm mycelium plug was transferred to Petri plates containing PDA and autoclaved carnation leaves or PDA, and the Petri plates were placed under the conditions described above. The num- ber of days until acervuli formed was noted. The colonies of Pestalotiopsis on PDA were whitish with crenated edges and aerial mycelium. Acervuli formed after 20 days on PDA, whereas acervuli formed within 10 days when autoclaved carnation leaves were added to the PDA. Two species of Pestalotiopsis have been identi- fied from sequence data of the internal transcribed spacer (ITS)-rDNA, which was compared to Gen- Bank sequences. Both Pestalotiopsis sydowiana and Pestalotiopsis microspore were identified. Fungicide evaluation Both Volenberg and Morton had realized early in their investigations into the symptoms of what turned out to be Pestalotiopsis that grow- ers had changed their spray programs before their vines exhibited the new signs of fungal disease. Morton knew in 2014 that the grower had stopped using Pristine, a commonly used strobilurin-boscalid product, earlier in the sea- son because he didn't think they needed "stro- bies" in their spray program. When Volenberg first saw rot on clusters after considerable rainfall in 2015, he reviewed the grower's spray program and suggested he in- 251 Gambee Road, Geneva, NY 14456 Phone: 315-759-2118 Toll free: 888-234-6752 Fax: 315-789-1848 Email: cjennings@vancemetal.com Website: www.vancemetal.com Quality Rugged 12 gauge, Custom & Stock Stainless Tanks Catwalk Systems • Pump Over Carts • Custom Hoppers, Chutes & Bins PROUDLY MADE IN THE USA Acervuli found on a Merlot berry after moist incubation. LUCIE MORTON