Winetech Technical Yearbook 2022

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0.7

Medics

Legume

The medics sown on the grapevine row successfully suppressed weeds, in particular the “kiesieblaar” (Malva parviflora L.). Cost: R640/ha

* DM = Dry Matter Production (tons/hectare). Due to late rains typical of this area, cover crops are often sown fairly late (May/June). The performance of the three mixes sown in the work rows was very good and “kiesieblaar” was scarcely found extending into the rows. The medics on the grapevine row shows excellent potential for a grapevine row cover and living mulch.

REGION: CAPE SOUTH COAST Site: Paul Cluver Wines Soil description: 15 - 20% clay with 30% gravel Vineyard irrigation: Micro Sowing date: Early May Sowing method: By hand Harvested: Late October 2021

Seeding rate (kg/ha)

DMP (t/ha)

Plot

Variety/species

Type

Observations

Barpower forage rye Haymaker grazing vetch Total mix

Cereal Legume

35 7 42

6.6 0.7 7.3

1

Weeds

0.2

Forage rye outperformed the vetch in this mixture and produced a remarkable 6.6 t/ha DM. Relatively good weed suppression with only some ramnas (R. raphanistrum L.) on the plot. Cost: R965/ha

Moby forage barley Arvika forage peas Tajuna fodder radish Total mix

Cereal Legume Brassica

30 20 2 52

3.5 0.8 3.8 8.1

2

Weeds

0.2

This mixture developed a good stand with the fodder radish creating as much biomass as the forage barley and large taproots. The forage barley performed well despite it being harvested at the end of its growth cycle. The growth of the peas was average to good. Some weed growth was present. Cost: R885/ha

US 2014 triticale Fiesta faba beans Stala phacelia Total mix

Cereal Legume Forb

60 20 2 82

7.1 0.1 1.3 8.5

3

Weeds

0.2

At 8.5 t/ha, this mixture outperformed the others at this site in terms of DM production. The triticale (US 2014) in its soft-dough stage produced 7 t/ ha DM, while the phacelia, although not a big biomass producer, attracted pollinators and insects. The faba beans were less successful in their growth. “Koperdraad” (knotweed) made up the weed component harvested. Cost: R1 395/ha

* DM = Dry Matter Production (tons/hectare). Although all three mixes performed well at this site, plot 3 with the triticale, faba beans and phacelia produced the most biomass. Phacelia has been somewhat inconsistent in its performance at various demo sites in previous seasons, but is an excellent addition to a mix if aesthetics and insect attraction are prerequisites. In this district, cool soils make cover crop implementation a challenge, but the above three mixtures showed good growth and biomass production in 2021.

REFERENCE https://www.wineland.co.za/gen-z-2021-cover-crop-demos/

For more information on the Gen-Z Vineyard Project and cover crop demos, contact Emma Carkeek at emma@vinpro.co.za. For more information about cover crop seed and the above demo recommendations, contact Ivan Jansen van Rensburg at ijvr@barenbrugsa.co.za. Thank you to Barenbrug, Agricol, Winetech and the participating growers for their continued support for the Gen-Z cover crop demo programme.

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WINETECH TECHNICAL YEARBOOK 2022