Figure 6. Average Ravaz Index (crop yield/pruning weight) of Cabernet Sauvignon/SO4 grown with under trellis cover crop or herbicide treated vine row, Yadkin Valley, North Carolina, 2005-2010. Columns with different letters are significantly different (P<0.05).
Herbicide showed the lowest Ravaz index.

Source: Gill Giese, Arkansas State University