WINETECH Technical Yearbook 2020

THANK YOU TO: Agricol and Barenbrug for their donations of seed for the demos and to Christof Muller (Agricol) and Ivan Jansen van Rensburg (Barenbrug) who provided the recommendations for each site and offered technical insight at the demo sessions. The following farm owners, producers, vineyard managers and viticulturists who took part in the establishment of the demo collection in 2019: De Wetshof: De Wet Family. Wandsbeck: Philbert Lourens and PK Uys. Brugplaas: Kobus de Wet. Eureka: Arno Hugo. Klipdrift: Ruan Brink. Nuwerus: JW Pieterse and Herman Schoeman. La Motte: Hanneli Rupert-Koegelenberg and Jaco Visser. Oliphantskop: Anthonij Rupert Wines and Chris Loubser. Vlakkenheuwel: Boet and Frederik le Roux. Heldersig: Paul Myburgh and Tharien Hansen. Kanonkop: Krige Family and Ryno Maree. Cavalli: Smith Family and Craig Barnard. Klein Constantia: Z Bakala, C Harman and Carlo Prins. For more information, contact Emma Carkeek at emma@vinpro.co.za.

on the grapevine row. A bit of effort is re - quired to sow it by hand under the drippers or prior to rainfall as early as possible. Once established, however, medics can produce a dense groundcover over the grapevine row which remains intact after it has died, act- ing as a form of a mulch to protect the soil in the hot summer months and suppress weeds. Although results may vary, it may take two to three seasons for the cover to be established after which it should re-es- tablish itself each year or only require seed at a very low density. If water constraints or the likelihood of frost damage necessitate termination using a chemical treatment or mowing, it should be done after the medics has set seed. Given the increasing pressure to minimise the use of herbicides in vine- yard management programmes, the case for cultivating medics on the grapevine row is compelling enough to warrant further investigation and small on-farm trials. One of the take-home messages from the demo sessions was the importance of cor- rect execution of cover crop establishment. Factors such as the timing, seedbed prepa- ration, equipment used, seed quality and sowing rate, as well as fertilisation deserve attention for successful integration of cover crops in one’s vineyard management pro - gramme.

Mixture of oats, stooling rye, radish, tiller radish and vetch at Cavalli, Stellenbosch.

CONCLUSION The outcomes of the 2019 demos again emphasised the site-specificity of cover crop species and mixes, as well as their response to climatic conditions and soil type.

The lack of rain in the Robertson and Worcester region in 2019 created chal- lenging growing conditions, and cover crop growth was largely unsuccessful in these re- gions. One of the highlights of the demo ses- sions was the success of the medics grown

WINETECH TECHNICAL YEARBOOK 2020 136