Heterogeneity in root-zone temperature both vertically and horizontally may contribute to the unevenvegetative and reproductive growth often observed across vineyards. An experiment was designed to assess whetherthe warmed half of a grapevine root zone could compensate for the cooled half in terms of vegetative growth andreproductive development. We divided the root system of potted Shiraz grapevines bilaterally and applied either acool or a warm treatment to each half from budburst to fruit set. Shoot growth and inflorescence development weremonitored over the season. Simultaneous cooling and warming of parts of the root system decreased shoot elongation,leaf emergence and leaf expansion below that of plants with a fully warmed root zone, but not to the same extent asthose with a fully cooled root zone. Inflorescence rachis length, flower number and berry number after fertilizationwere smaller only in those vines exposed to fullycooled root zones. After terminating the treatments, berryenlargementand the onset of veraison were slowed in those vines that had been exposed to complete or partial root-zone cooling.Grapevines exposed to partial root-zone coolingwere thus delayed in vegetative and reproductive development, but theinhibition was greater in those plants whose entire root system had been cooled.