Issue link: http://winesandvines.uberflip.com/i/670981
May 2016 WINES&VINES 87 WINE EAST GRAPEGROWING 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 Gentle around the vine. Call OESCO, Inc. for an estimate or a catalog 800-634-5557 Fischer mowers are gentle around the vine. The GL series has sensor controlled hydraulic swing arms that retract when the sensor touches the vine. This makes it ideal for mowing grass safely near or around vines. Quality. Tradition. Innovation. www.oescoinc.com 8 Ashfi eld Road / Rt. 116, Conway, MA 01341 as proposed by Sabbatini and Howell (2010). This practice minimizes the use of wood with buds whose potential yield has been reduced by early defoliation the previous season. There can also be some compensation in cluster weight reduction by an increase in berry weight. Trace bloom leaf removal in the six- year trial with Chardonnay re- sulted in an average increase in berry weight of about 6%. Researchers were confident that potential negative year- after side effects could be man- aged, and similar trials with trace bloom leaf removal were conducted in commercial vine- yards in southern Pennsylvania in 2010 and 2011 on Pinot Noir, P i n o t G r i s a n d C h a r d o n n a y. These trials showed similar re- s u l t s — r e d u c t i o n s i n c l u s t e r compactness and rot. However, the rot reductions in commer- cial vineyards were generally smaller, an effect attributed to: 1) the fact that all treatments received full season Botrytis fungicide programs (rather than the abbreviated program in the s i x - y e a r C h a r d o n n a y t r i a l above), and 2) that rot devel- oped in some vineyards as a result of bird damage. Next steps Leaf removal in these studies has utilized hand labor. With the high cost and growing scarcity of labor, mechanization of trace bloom leaf removal is an impor- tant next step to improve cost effectiveness and adoptability of this practice (see photo on page 88). To date, the examination of air pulse leaf-removal technology using machines from Collard and BlueLine has met with some en- couraging results: Researchers are observing many of the same beneficial effects as with trace bloom leaf removal by hand, though to a lesser degree. We are hoping further research will im- prove that outcome. Air pulse leaf removal efficiency has ranged from 32% to 60% and was most efficient on vertical shoot position and four-arm-kniffen trel- lis systems, as opposed to more three-dimensional systems like high-wire no-tie (a very common, low-cost trellis system for hybrid grapes in Pennsylvania). Fortu- nately, the pulse air technology does not appear to damage inflo- rescences when applied just before bloom, and future assessments of return bloom will determine the potential for year-after effects of mechanized trace bloom leaf re- moval on bud development. Early leaf removal and yield Growers interested in applying pre-bloom/trace bloom leaf re- moval in their vineyards need to consider a number of factors be- fore doing so. Trace bloom leaf removal intentionally reduces the number of berries per cluster (by an average of about 20% in our six-year study with Chardonnay) and can therefore reduce yield to some extent. The potential for negative effects on yield (Poni et Chardonnay with fruit-zone leaf removal performed at trace bloom (left) is com- pared with Chardonnay with leaf removal performed after fruit set. Note that the number of berries and typical compact architecture of clusters are conserved when leaf removal is performed after fruit set.