Predicting the behavior of chestnut cultivars grafted on ColUTAD under different edaphoclimatic conditions

The aim of this research was to describe how some chestnut cultivars respond to temperature changes. Eight main Portuguese cultivars and two Spanish cultivars were installed in six demonstration orchards located in councils representing the main Portuguese regions where chestnut is grown under contrasting edaphoclimatic conditions: Vinhais, Bragança, Valpaços, Penedono, Ponte de Lima, and Marvão. According to the results, the trees from Bragança and Vinhais orchards presented the lowest photosynthetic rates values compared to the other locations, as well as the water potential behind the threshold level (-1.2 MPa), contrarily to the other locations where water potential was above that level. It suggests that water nutrition might be one of the most significant strategies for the future to face weather conditions, promoting more stability on photosynthetic rate which is a critical component to plant productivity. Results also indicate the studied cultivars, which were grafted on ColUTAD, presented higher stability on these parameters, than control trees of ColUTAD. This suggests a strong epigenetic effect at the union between rootstock and scion, ‘Longal’ and ‘Judia’ being the strongest influencers.