The relationship between “effective leaf area to fruit weight ratio” and grape and wine composition and wine style for the varieties Shiraz and Pinot Noir

Abstract

The relationship between "effective leaf area to fruit weight ratio" and grape and wine composition and wine style for the varieties Shiraz and Pinot Noir

Summary

In 1991 an irrigation experiment was established on Vitis vinifera cv. Shiraz in a mature vineyard in the Waikerie region of South Australia, a region characterised by dry to hot summers. The experiment was set up by Dr Michael McCarthy of SARDI and formed the basis for two Wine Australia funded projects which investigated the effects of irrigation scheduling on vine growth, berry composition and wine sensory properties. The experiment was conducted over four growing seasons (1991-95).

The randomised complete block experiment included a treatment in which no water stress occurred (fully irrigated) (Trt 1), an unirrigated treatment (rainfall only) (Trt 8), and six other treatments irrigated as in the fully irrigated treatment apart from specific periods without irrigation. Four of these six treatments had periods of about four weeks duration where irrigation water was withheld:- after anthesis (Trt 2), before veraison (Trt 3), after veraison (Trt 4) or before harvest (Trt 5). In the other two treatments vines received no irrigation water for either the entire period between anthesis and veraison (Trt 6) or for the entire period between veraison and harvest (Trt 7). At the end of each period where irrigation water was withheld, sufficient irrigation water was applied to refill the top 1.2 metres of soil to a predetermined full point.