Interactive Effect of Ethephon and Shading on the Anthocyanin Composition of Vitis vinifera L. cv. Crimson Seedless

  • M.A. Human Department of Viticulture and Oenology, University of Stellenbosch, Stellenbosch 7600, South Africa
  • K.A. Bindon Department of Viticulture and Oenology, University of Stellenbosch, Stellenbosch 7600, South Africa

Abstract

The Vitis vinifera cultivar Crimson Seedless primarily accumulates the anthocyanin peonidin-3-glucoside. The
research undertook the study of two factors which could influence the accumulation of anthocyanin in grape berry
skins: ethephon application and shade. Ethephon treatment at 200ppm applied one week post-véraison significantly
increased the concentration of all anthocyanins in berry skins. Peonidin-3-glucoside was found to increase most
significantly in response to ethephon application, and was increased 150% compared with an untreated control. The
proportion of 3‑monoglucoside anthocyanins increased in response to ethephon application. A shading treatment did
not affect total anthocyanin concentration in berry skins, but the anthocyanin cyanidin-3-glucoside was decreased
significantly by shade. Its content was 50% of a sun-exposed control. The observed effects were found to occur at
two sites at which the experiment was performed in the Hex River and Paarl regions. Colour development in the
Vitis vinifera cultivar Crimson Seedless does not appear to be influenced significantly by bunch shading. The use of
commercial growth regulators like ethephon exert a strong influence on anthocyanin production in grape skins of
this cultivar, and are therefore a more likely solution to overcome poor colour development in its production.
Published
2016-12-13
Section
Articles