Impact of Alleyway and In-row Planted Groundcovers in Midwestern Vineyard

In many Midwestern vineyards a one meter weed-free strip is maintained directly beneath the vines to reduce vine-weed competition. Conventionally, this strip has been conserved with repeated applications of herbicide, mainly glyphosate. The necessity for this weed-free strip to reduce vine-weed competition has been well documented in more arid climates. However, in areas with higher soil fertility and adequate rainfall grapevines can become overly vigorous and competition with a groundcover (GC) has been shown to be a useful tool to alleviate excess growth. Moreover, stand establishment and early vine growth have not been well documented when planting GC immediately following the vine planting. The main objective of this project was to assess the severity of competition for water between ‘Edelweiss’ grapevines and neighboring permanent GC treatments. In year one (2014), the vineyard and GCs were established, where the GCs were planted immediately after the vines. Generally, GC treatments had lower Midday Leaf Water Potential (Ψmd) than the herbicide sprayed control, however, none of the treatments exhibited even slight water stress between 2015 and 2017. Vine-GC competition was most apparent in the three years of pruning weights, where the most native grass GC treatment had an average of 158% lower weights than the control. Results suggest that planting specific groundcovers in both the alleyways and in-row areas of the vineyard during the first year of establishment can be overly detrimental to vine growth and causes reduced yields but other groundcovers can be a useful alternative to chemical weed control.