COVER CROPS in South African Vineyards

COVER CROPS IN SOUTH AFRICAN VINEYARDS

The cover-crop trials focussed mainly on annuals, but a small number of perennials was also evaluated. Perennial cover crops are not recommended for two main reasons. One is that the perennial cover crops cannot outcompete weeds such as field bindweed and couch grass, which gradually infiltrate and eventually displace the cover crop. The other is that perennial cover crops compete with the grapevines, especially for water, during the grapevine- growing season, thereby reducing grape yields. Annual rye grass was also assessed in these trials. Based on the results, and the experience of the author, rye grass is a problem weed and should never be allowed to establish, let alone used as a cover crop.The author personally observed that rye grass had a negative impact on the performance of vineyards. Once it establishes, rye grass is difficult to control, as it readily evolves resistance to chemical weedkillers. Reference list Fourie JC, Louw PJE and Agenbag G. 2001. Effect of seeding date on the performance of grasses and broadleaf species evaluated for cover crop management in two wine grape regions of South Africa. South African Journal of Plant and Soil , 18(3), 118–127. Fourie JC, Louw PJE and Calitz FJ. 2006. Effect of seeding date on the performance of grasses and broadleaf species evaluated for cover crop management in the Breede River valley wine grape region of South Africa. South African Journal of Enology and Viticulture, 27(1), 8–14.

LUCINDA HEYNS

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