Winter warming delays dormancy release, advances budburst, alters carbohydrate metabolism and reduces yield in a temperate shrub

Winter warming reduces fruit yield of blackcurrant cultivars ‘Narve Viking’ (photo) and ‘Titania’ the following summer. Photo by Connie Krogh Damgaard, Aarhus University.
Winter warming reduces fruit yield of blackcurrant cultivars ‘Narve Viking’ (photo) and ‘Titania’ the following summer. Photo by Connie Krogh Damgaard, Aarhus University.

Global climate models predict an increase in the mean surface air temperature, with a disproportionate increase during winter. Since temperature is a major driver of phenological events in temperate woody perennials, warming is likely to induce changes in a range of these events. A recent study in AoB PLANTS by Pagter et al. documents that even a very modest temperature increase during the colder periods of a plant´s annual cycle may delay dormancy release and advance bud burst and flowering in blackcurrant, but the magnitude of the responses varies between genotypes differing in chilling requirement. Winter warming additionally has a large carryover effect into the growing season by reducing fruit yield the following summer.