WINETECH Technical Yearbook 2021

be increased by 30% for the first season. Thereafter, adjust the N according to vigour and the P and K according to soil analyses. DISEASE AND WEED CONTROL Timely weed control is naturally very important, as the shoots that sprawl can be easily sprayed along with the weeds. It is therefore important to ensure that the weeds are sprayed before the shoots are positioned downward. With the Ballerina system, weeds are less problematic because the berm is overshadowed and weeds tend to not re-emerge. Mulch can also be used with great success to ease weed control. As far as disease control is concerned, more water has to be sprayed per hectare and more spray heads have to be opened to ensure the entire canopy is covered. GENERAL Increased yield of approximately 30% with the same or improved quality can be

expected from the Smart-Dyson systems. Yield can be improved even more with the Ballerina system. The Ballerina system is less suitable for red cultivars than the Smart-Dyson system due to the unevenness in ripening between the top and bottom bunch zones. It is preferable to plant these systems in accordance with the prevailing wind directions, as the canopy has a large surface that the wind will blow against. The canopy density of both these systems is good provided it is managed correctly and fertility is thus maintained. Both these systems can be harvested successfully with a mechanical harvester.

For more information,contact Hennie Visser at henniev@vinpro.co.za.

Colombar Ballerina.

further draw the canopy open as the season progresses. IRRIGATION AND NUTRITION As already mentioned, vigorous conditions and vigorous growing combinations are required with adequate water supply. These vineyards do not use more water

at the start of the growing season than a conventional VSP (vertical shoot po­ sitioned) vineyard. As soon as the canopy is divided however, the water consumption increases substantially and as much as 30% more water is required. Fertilisation also has to be adjusted for the additional canopy and grapes, and N, P and K can also

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