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96 WINES&VINES November 2017 The association of Alternaria with clusters displaying symptoms of red rachises suggests that more research needs to be done that fo- cuses on why these saprophytic and opportunistic pathogens are not being controlled with current pest- management programs. Morton notes that once specific fungi are identified as potential pathogenic agents in the field, the next step is to do controlled experiments to verify their pathogenicity. Based on observations made in Maryland in September 2017, Morton reports that Cabernet Sau- vignon remains the variety with by far the most susceptibility to cluster stem wilt. The Maryland grower was not able to stop this from occurring again with appli- cations of pre-bud break lime sul- fur and a pre-bloom spray of Pristine. In view of this, Morton believes that more attention should be paid to the black-dot pycnidia present on the vine phloem/bark tissues. They are enclosed sacks of fruiting bodies that lie just beneath the epidermis and may be impervious to fungi- cides. She is hopeful that green- house tests both in her laboratory in Charlottesville and at Virginia Tech will help shed light on what turns "Pesta" and Alternaria from benign to pathogenic. Volenberg's projects involving Pestalotiopsis include: 1. Determining the environ- mental conditions that are conducive to Pestalotiopsis infection. 2. Identifying fungicides that provide control of Pestalo- tiopsis. 3. Identifying Pestalotiopsis species involved in grape- vine infections. Morton's projects involving Pestalotiopsis include: 1. Evaluating new test results on buds and another year of red-stemmed cluster stem wilt. 2. Working with plant patholo- gists at Virginia Tech to study a potential link be- tween Pestalotiopsis and bud necrosis. 3. Looking at the possibility of mite involvement with spreading the fungus. WINEMAKING WINE EAST - B E C O PA D - Y E A S T & E N Z Y M E S - C R U S H PA D E Q U I P M E N T - S T E R I L E F I LT R AT I O N - W I N E R Y H O S E - O A K A LT E R N AT I V E S EASTERN WINE LABS Serving the Analytical needs of East Coast Wineries WWW.EASTERNWINELABS.COM Ph 609-859-4302 Cell 609-668-2854 chemist@easternwinelabs.com AOAC Member Basic Hoe comes with a Hillup and a Takeaway Blade. Additional attachments include .3 Tooth Cultivator, Undercutter Blade, Rotary head, " NEW " Rolling Cultivator and "Vine Auger". The Green Hoe Company, Inc. 6645 West Main Road, Portland, NY 14769 PHONE (716) 792-9433 FAX (716) 792-9434 WWW.GREENHOECOMPANY.COM GREEN GRAPE HOE The references for this article are available online at winesandvines.com/features. Alternaria on Vidal Blanc with wilt issues in Pennsylvania. JOYCE RIGBY