Review: critical appraisal of methods to investigate the effect of temperature on grapevine berry composition

Abstract

The grapevine is an economically important crop and a model species of long‐lived perennials widely used in bioclimatic studies. Ambient temperature modulates berry composition, hence the significant research effort in establishing links between temperature, berry composition and wine attributes. Our current understanding of the effect of temperature on berries and wines has been largely gained from indirect methods or direct methods in controlled conditions. Indirect methods include comparisons of thermally contrasting locations and vintages; this approach is of value but is bound to be inconclusive as the effect of temperature is often confounded with other weather and climate factors (solar radiation, vapour pressure deficit and rainfall), management practices and soils. Direct experimental methods comparing fruit grown at a range of temperature are required to prove cause‐and‐effect, but attempts to modify the thermal regime of the plant often generate secondary effects. Experimental artefacts in controlled environments often include small soil volume, lack of wind and altered radiation regimes, with direct implications for plant physiology and berry composition. Experiments involving controlled temperature in vineyards aim at a higher degree of realism, but are constrained by cost, issues of scale in space and time, and are not necessarily free from artefacts. Indirect and direct methods are of course non‐mutually exclusive but complementary. This review critically assesses the methods used to elucidate the effect of temperature on grape berry composition. It emphasises the limitations of studies where confounded effects are overlooked. With the focus on selected berry traits (total soluble solids, total and titratable acidity and anthocyanins), we analyse the dominant effect of temperature and highlight discrepancies and agreements between indirect and direct research methods.

Grape Ripening Is Regulated by Deficit Irrigation/Elevated Temperatures According to Cluster Position in the Canopy

“…The effect of temperature on berry composition has been studied extensively and the negative impact of high temperature on anthocyanin content was reported (Spayd et al, 2002; Mori et al, 2007; Sadras and Moran, 2012; Bonada and Sadras, 2014; Bonada et al, 2015). Nonetheless, to date, there appears to be a scarcity of knowledge of the performance of different varieties exposed to a combination of high temperatures and water stress during the growing seasons and under vineyard conditions (Greer and Weedon, 2013).…”

High Temperature Effects on in vitro Pollen Germination and Seed Set in Field Pea

“…Interestingly, the maximum temperature threshold affecting pea growth performance and yield formation under environmentally controlled conditions is higher than that threshold in the field. Under field conditions, heat stress is often confounded by other environmental and management factors such as solar radiation, vapour pressure deficit, precipitation, soils, and cultural practices (Bonada and Sadras, 2015). For example, temperatures over 25°C caused seed yield loss in field-grown peas in Australia (Sadras et al, 2012).…”

Water stress and ripeness effects on the volatile composition of Cabernet Sauvignon wines

“…variety, ripeness at harvest and irrigation practices), are known to influence grape composition . Regarding irrigation, controlled water deficits are a common viticultural practice worldwide, particularly in red grape varieties cultivated in Mediterranean climates because of their well‐known effects on wine . Water deficits positively impact the grape through lower berry sizes, with a concomitant increase in the skin to pulp ratio, concentrating secondary metabolites .…”