The sustainability of agriculture is seriously threatened by climate change. In Europe, chestnut ecosystems, which are growing mainly in Mediterranean climate, are facing during summertime increasing of heat and drought stresses. These induce fragilities on trees, leading to a reduction in productivity and predisposing them to pest and disease attacks. The plasticity of chestnut species under contrasting climate is known. Understanding the specific adaptation of cultivars to different climate features is now important to anticipating climate changes. Caucasian Region is considered the origin center of chestnut (Castanea sativa), which is characterized by climatic transition from the Mediterranean to the Euro-Siberian area. Mostly, areas of chestnut are concentrated in the countries around the Mediterranean Basin, thriving in regions with humid and Pré-Atlantic bioclimates. In Portugal, more than 95% of the chestnut area is located in the Center and North side of Portugal. This is an anisohydry species, characterized by good hydroplasticity: 90% reduction in A occurs when Ψ_wstem drops to −1.25 MPa, and a 50% reduction in A occurs at values of −1.7 MPa. The highest fatty acid contents in chestnut chloroplasts are a-linolenic acid (18:3), ranging between 40 and 50% of the total amount and being the unsaturated/saturated 2.27 for Longal. New strategies are being investigated in order to increase tolerance against those abiotic factors in chestnut species. They include the use of innovative irrigation techniques, which can increase production 22–37%. Fertilization with silicone (Si) has been investigated to promote the tolerance of plants against heat and drought stresses. Breeding programs, mostly (in Europe) against ink disease, have been performed since the middle of the XX century to create new genotypes (such the Portuguese ColUTAD^®). ClimCast, a network of orchards, was created in Portugal with the aim of responding to the new challenges facing orchards in the context of climate change.

The aim of this work was to evaluate the impact of Si fertilization on the resilience capacity of chestnut plants growing under high air temperatures and its recovery capacity after returning to optimal temperatures. Castanea sativa plants wer...

The increasing demand for healthy products rises the pressure on the chestnut production due to their nutritional qualities and beneficial health effects. Martaínha chestnut variety is most well-adapted with great economic importance due to its precocity and technological properties. The exogenous application of Silicon has an important role in agriculture because of improvement of plants nutrition. Nevertheless, the knowledge of impact of Silicon application in the production, sensory quality and chemical composition of chestnut fruits is limited. The application of Si in leaves (SL) and soil (SS) have important action on the prophylactic properties and the promotion of chestnuts health. Moreover, higher number of healthy fruits, caliber, fruits without rotten and tortrix infection and lower water loss in post-harvest chestnuts, in SL and SS samples, highlights the Si positive action. Additionally this study emphasizes some positive effects of Silicon on the chemical and sensory profile.

Different types of irrigation systems can be used in chestnut orchards. To understand which one grants higher yield values treatments were applied in adult trees: drip system - TI; micro-sprinkler system - SI; non-irrigated system - NI. The study covers two years in the northeast of Portugal. Irrigation was triggered every time stem water potential was lower than -1.2 MPa. The study considers costs with the equipment, water and labour, and the income from the chestnuts’ sale. Due to the hotter conditions of 2016 more water was supplied (93 mm) than in 2015 (47 mm). Little more water was furnished in SI (73 mm) than in TI (67 mm). Production was 27% higher in irrigated (48 kg/tree) than in NI trees (38 kg/tree) and in relation to the canopy’s area (kg/m²) the TI produced 18% and SI 29% more than NI. Annual costs were higher with irrigation (4654, 4549 and 1530 €/ha for SI, TI and NI, respectively) but the higher income (22126, 21984 and 16174 €/ha for TI, SI and NI respectively) made up for the investment. The profits from irrigated trees can be 22% or 37% higher than in non irrigated ones, for 1 ha or 5 ha, respectively.