Technical Yearbook 2024

White clovers effectively established during March – pictured at the beginning of May.

A significant number of seed curls after medics naturally terminated will provide high re-seeding capacity – pictured in December.

Medics successfully trampled in a bush vine vineyard – pictured in November.

Clovers naturally terminating and successfully competing with summer weeds – pictured in October.

Broadleaf under-vine living mulches

Medics

Pinto peanut

White clover

Vetch

Strawberry clover Subterranean clover - * Taken from Barenbrug Cover Crop Guide.

Desmodium

(Halotydeus destructor) and Lucerne flea (Sminthurus viridis) and would require control when in high population to ensure effective crop establishment. • Vine berms with residues of pre-emergent herbicides after recent application should rather be planted the following year to avoid unfavourable germination conditions. • Leguminous species such as medics, clovers and vetches fix nitrogen in the soil. A legume crop can add up to 100 kg of nitrogen per hectare of cover crop if rhizobacteria is effective. The decision to inoculate seed with N-fixing bacteria, as well as the choice of leguminous crop, should take the vigour of the vineyard into account. • Seasonal variation, at its peak during autumn months, may prohibit the effective establishment of a single species, in this case, a multi-species approach may pay dividends. • Actively growing cover crops can compete with vines for nutrients and water. Generally, it is best to wait until the vineyard is mature before establishing permanent under vine cover. • Tall growing cover crops that tend to creep into the vines, such as vetch, should be avoided or flattened especially in areas prone to frost, as high-growing cover crops would increase frost risk.

White clovers provide significant competition in a young Syrah vineyard on high-potential soil.

• Under-vine cover has a considerable effect on soil temperature (decrease) and, therefore, on grapevine phenology. The choice of cover should take the desired phenological cycle into account. Final remarks The use of living mulches in vineyards is another exciting innovation at a grassroots level, where South African producers are not only adapting to changing client needs (requiring reduced chemical inputs) but also playing a pivotal role in bringing regenerative farming practices to fruition. Nonetheless, under-vine living mulches should be applied intelligently, taking the entire vineyard management system into account, and tailoring the practices to the site-specific situation. It may well not be viable/applicable in every situation. Challenges with cover crop establishment, appear to be confined to management system limitations and should easily be overcome once the practice gains ground over time.  Reference https://www.wineland.co.za/under-vine-living-mulches/

For more information, contact Etienne Terblanche at etienne@vinpro.co.za.

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TECHNICAL YEARBOOK 2024