Armstrong Research and Demonstration Farm
Leaf removal practices are common in many viticulture regions, leading to improved fruit quality. However, little research has been done on the benefits and challenges of leaf removal on cold-climate grape cultivars grown in the Upper Midwest that have high acidity. Potential benefits of leaf removal include increased canopy air circulation and sunlight exposure, decreased cluster disease, and improved flavor, pH, and titratable acidity (TA). Potential leaf removal challenges include fruit sunburn, fewer photosynthesizing leaves around clusters, production of fruit offflavors, and increased production cost due to labor-intensive leaf removal. The objective of this study was to determine if leaf removal around grape clusters is beneficial to improve fruit quality (soluble solids, pH, and TA) of grape cultivars grown in Iowa.
Iowa State University
Portz, Dennis N.; Riesselman, Leah B.; Seeley, Crystal; Beamer, Paul; and Nonnecke, Gail R., "Effects of Leaf Removal on Fruit Quality of Wine Grapes Grown in Iowa" (2012). Iowa State Research Farm Progress Reports. 140.