Grass Cover Crops in Oregon Vineyards 1988

Perennial grass cover crops are frequently grown between the vines in non-irrigated Oregon vineyards.\ud The primary reasons for using cover crops are erosion control and to allow machinery access in wet\ud weather. Grass cover crops may also have an effect on vine performance. These effects, however, are\ud not always clear. In addition, management options are available which can moderate or intensify the\ud effect of a cover crop on the vines.\ud At OSU, a research project was initiated to determine the effects of grass cover crops on grape vines.\ud Our major concern was the degree of competition between the grass and the vines. In a vineyard with a\ud sparse canopy and very poor growth, little or no competition is desired. However, in a vigorous vineyard\ud with excessive vine growth, maximum competition could be desirable. The degree of competition is\ud affected by several management options, such as choice of grass species and variety, width of the grass\ud strip, and the year the grass strip is established.\ud To better understand the relationships between grass and grapevine growth, our research concentrated on\ud three areas: 1) vineyard establishment, 2) grass vs. no grass in mature vineyards, and 3) water use of\ud different grass species