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w w w. v w m m e d i a . c o m J u l y - A u g 2 014 | V I N E YA R D & W I N E RY M A N A G E M E N T 4 1 ing those that are interior to the canopy, leaving the exterior leaves as protection from direct sun expo- sure. This work should be done as early after berry set as possible in order to allow the grapes time to acclimatize. This work should be postponed, however, if a heat wave is forecasted to occur soon after the work will be completed. In extreme situations, or where vine vigor is not adequate to pro- vide natural shading, shade cloth can be installed. It can reduce ambi- ent temperature in the canopy as well as solar radiation onto the clus- ters. Shade cloth comes, gener- ally, white, green and black, and in shade factor percentages; the high- er the percentage, the more sun is blocked. Green cloth blends well with the vines for aesthetic purpos- es, but growers may experiment with other colors for more or less reflectivity. Cloth should be made from lightweight, UV-resistant fab- ric and not unravel when cut. Installing the cloth in strips that cover the fruiting area, rather than over the entire vine, limits the shaded area to the fruit zone and is preferable to cloth that covers entire vines which can unnecessar- ily reduce vine productivity through l o w e r e d p h o t o s y n t h e t i c r a t e s , delay vine development and restrict air flow to the vegetative canopy. Strips are more cost effective, since they utilize less material, and they can be tied to the drip wire and left in the field rather than removed each year, saving labor and elimi- nating storage needs. As a last resort, in vineyards with abundant water supply, sprin- klers and misters can be employed during peak temperatures to cre- ate a cooling effect in the vine- yard. When temperatures exceed 100°F, sprinklers can be used for evaporative cooling. Traditional impact sprinklers, which provide total vineyard coverage, use copi- ous amounts of water, so targeted sprinklers and misters have been used more recently to provide cool- ing with reduced water use. When using sprinklers, water use can be minimized by monitoring the tem- perature in the fruiting area, and turning sprinklers off and on as needed, as the cooling effect will continue as long as water contin- ues to evaporate off the vine. Heat damage can cause sig- nificant quality issues and yield losses in the vineyard. A combined approach using proper vineyard design, irrigation, canopy manage- ment and other tools is advised to mitigate the impacts of extreme heat in the vineyard. Remi Cohen is the vice president of operations for Cliff Lede Vine- yards in Napa Valley. Her primary areas of expertise include viticulture, sustainable vineyard management, winemaking, grower and winery relations, and strategic business development. She also writes a wine industry blog, which can be found at blog.vinestowine.com. Comments? Please e-mail us at feedback@vwmmedia.com. Clusters should have exposure to dappled sunlight. Photo: Thinkstock/ danchooalex Don't Get Caught in the Dark T - P o s t s • H w y S t a k e s • R e b a r • E n d P o s t s • W i r e · Night Harvest · Night Spray · Chemical Mixing Areas · Diesel fill stations · Parking Areas · Portable Restrooms · Many many More uses Easily set up and maneuvered by one person – Goes up in seconds - Standard 120 Volts The Luminite Light Tower Use for Night Compliance Protection Vineyard Industry Products See the VIDEO at www.vinbiz.com Call for more info. 800-544-2210 SOIL & CELLAR REMI COHEN