Spatial variability in climate, phenology, and fruit composition across a reference vineyard network in Southern Oregon

Gregory V Jones

doi:10.1051/e3sconf/20185001018

Abstract

This paper provides a summary of observational data from a reference vineyard network in the Southern Oregon American Viticultural Area (AVA). The network was established to collect baseline data on spatial variations in temperature, grapevine phenology, and composition characteristics across a collection of varieties grown in the region. The results from the period 2003 through 2017 show a wide diversity of climate types for winegrape production ranging from relatively cool to relatively warm conditions (GST 14.8 to 17.5°C and GDD 1109 to 1657). One unique climate aspect is that the region experiences higher diurnal temperature ranges during the growing season than regions in Europe and many others in the western US. Grapevine phenological timing and intervals between events are similar to other wine regions with budbreak averaging 14-Apr, flowering 14-Jun, véraison 19-Aug. However, harvest dates are up to ten days to two weeks later than many regions in Europe. Ripening period and harvest composition observations reveal the diversity of potential varieties that the region can ripen. Over all varieties, sites and vintages observed harvest composition averages 23.7 °Brix, 6.4 g/L total acidity, a pH of 3.44, and yields of 2.7 tons/acre.

Highlights

Within region weather and climate controls on site plant growth and fruit composition are evident in every wine region worldwide [1]
To understand spatial variations in climate, grapevine phenology and fruit characteristics numerous reference vineyard networks have been developed in regions worldwide (e.g., Bordeaux, Italy, etc.) [2,3,4]
Precipitation varies from 300650 mm in most of the vineyard areas in the Rogue, declining in amount from west to east

Summary

Introduction

Within region weather and climate controls on site plant growth and fruit composition are evident in every wine region worldwide [1]. Especially in the western portion of the Rogue Valley AVA and southern portion of the Umpqua Valley AVA, can produce large variations in soil types over areas the size of a vineyard. The Rogue Valley AVA has the higher elevations, that along with their general north-south tending valleys, and their proximity to the Pacific Ocean and intervening topographical barriers create a climate transect of wetter and cooler conditions in the western parts of the region to the warmer and drier eastern areas. Precipitation varies from 300650 mm in most of the vineyard areas in the Rogue, declining in amount from west to east (all of the Southern Oregon AVA experiences less than 15 percent of the total precipitation occurring during the growing season of April through October). This paper will provide a description of the observations from this network during 20032017

Data and Methods

Results

Discussion and Conclusions