Increasing chestnut resilience to climate change with innovative management practices

Abstract

Climate change is ongoing but the magnitude, extent and duration of its impacts is far from being known and, in particular, its consequence on Earth’s life is still under study. This article presents an overview about many research lines aiming to increase the resilience of chestnut in climate changes frame. In Europe, chestnut is considered a Mediterranean crop, facing nowadays significant heat and drought stresses with important consequences on species health. So, modelling its production is fundamental to project the future production and species area redistribution according to the new expected climatic conditions. These models are being developed based on specific meteorological variables and indices well related to different aspects and stages of the vegetative cycle. For example, the best range of growing degree days (GDD) for better ‘Judia’’s chestnut production was found to be within the range 2000-2200°D (between May and October). At orchard level, it is also demonstrated the benefits of preserving a good soil herbaceous vegetation cover, complemented with smart irrigation which can prevent the reduction on nut production by about 25-50%, depending on the annual precipitation, and increase the edible mushroom production. Results also clearly demonstrated the importance of bees on pollination, where a decrease of about 70% was observed when they were absent. New hybrid rootstocks are being developed (e.g., ColUTAD) aiming to face the new climatic context, namely to maximize photosynthesis rate at high air temperature (T100 = 34°C). Also in ‘Judia’, such plasticity was observed between genotypes from cold and warm localities. Calibers ranged between 58 and 107 nuts kg-1. The tolerance against blight disease (Chryphonectria parasitica) also significantly varied. Finally, additional mineral nutrition with silicon seems to lead to a lower mortality rate and phenol’s inhibition as well as to an increased tolerance of the specie to thermal and hydric stress. The addition of silicon appears to have protective effect on trees against ink (Phytophthora cinnamomi) and blight diseases as well as to prepare and adapt trees for a future climate that is expected to be warmer and drier.