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November 2017 WINES&VINES 95 WINE EAST WINEMAKING clude Pristine. After it was applied, the affected berries dried up and dropped off. Subsequently, he confirmed the rot was caused by Pestalotiop- sis. In Volenberg's mid-June newsletter in 2016, he recommended that because Pestalotiopsis can cause fruit rots in addition to trunk and leaf problems, growers should include strobilurins such as Pristine, Abound and Flint, as well as mancozeb in their spray programs. Based on their experiences with these fungi- cides, the two researchers decided to evaluate the efficacy of mancozeb and pyraclostrobin on Pesta- lotiopsis. Solutions of mancozeb and pyraclos- trobin were added to PDA, and media was poured into Petri plates. Mancozeb and pyraclostrobin were evaluated at zero, 0.01, and 0.001 the recom- mended (mancozeb 3.36 kg/ha and Pristine 875 g/ha) field-use rate. Mycelium cores (5 mm) were placed in the center of each Petri plate. The Petri plates were evaluated for mycelium growth eight days after the mycelium transfer. The results indicated the fungicides sub- stantially inhibited the growth of Pestalotiopsis, even at low levels. The next steps Pestalotiopsis is recognized as a "weak" patho- gen, and it may require certain conditions to become a problem. Volenberg has conducted some research with Norton in a greenhouse environment that suggests the symptoms of Pestalotiopsis are transient and may succumb to summer heat. In both Missouri and Virginia, the fungus seemed to require rain to get sporu- lation. Consequently, Pestalotiopsis may not be a problem in dry climates such as California— although that remains to be seen, particularly in areas with significant fog in the fall. In early September, Morton found that Al- ternaria, another "ubiquitous" fungus, was highly associated with bunch stem necrosis and berry shrivel this season. Alternaria species also can be saprophytic or opportunistic pathogens similar to Pestalotiopsis. According to Morton and Volenberg, it appears that some grape cultivars are more susceptible to Pestalotiopsis, and their initial observations suggest the same may be true of Alternaria. Natural Corks Champagne Corks Twinline Corks Bartops VISION Synthetic Corks G-Cap® Screw Caps Sales Representatives: Chris & Liz Stamp info@lakewoodcork.com lakewoodcork.com 4024 State Route 14 Watkins Glen, NY 14891 607-535-9252 607-535-6656 Fax PIONEER INNOVATOR PARTNER Symptoms of Pestalotiopsis include early fruit drop (seen in the above left photo on Norton vines in Mis- souri) and rachis reddening and berry shrivel (pictured above right on Cabernet Sauvignon in Maryland). FRED DRESSEL LUCIE MORTON