Climate change forecasts suggest temperature increases and lower rainfall rates, both of which challenge viticulture, particularly in semi-arid areas where water availability is critical. In this scenario, the use of the genetic variability in grapevine varieties reported around the world represents an important strategy for the selection of climate-resilient cultivars. In this work, physiological and metabolomics analyses were conducted to compare the water deficit stress (WDS) responses of red and white, local and widespread grapevines cultivars. Leaf gas exchange, water use efficiency (WUE) and water relation parameters were determined in plants under well-watered and WDS conditions alongside assessment of the levels of foliar primary metabolites using gas-chromatography coupled to mass-spectrometry. Results denote that red and white local cultivars displayed more adapted physiological performance under WDS as compared to the widely-distributed ones. Multivariate analyses and specific changes in leaf primary metabolites indicate genotype-specific responses of local cultivars as compared to widespread ones. Differences in ascorbate-related and shikimate/phenylpropanoid metabolism could explain the better physiological performance under WDS in red local as compared to widespread cultivars. On the other hand, coordinated changes in respiratory- and stress-related sugars and amino acids could underlie the better WUE under WDS in the white local cultivar. All these results suggest several metabolic targets that could be useful as metabolic markers or for metabolic engineering in grapevine breeding programs to improve drought tolerance.

Almond cultivation has a long-standing tradition on the island of Majorca, traditionally practiced under rainfed conditions. Currently, new plantations are established with irrigation; however, due to present conditions and the impacts of climate change, water availability is limited. The Government of the Balearic Islands permits a maximum water supply of 3000 m³ ha⁻¹ per year for almond cultivation. In this study, a 6-year field trial was conducted to investigate the adaptation of fourteen almond cultivars obtained from different research centers under deficit irrigation practices in the soil and climatic conditions of Majorca Island. The cultivars had a significant effect on trunk cross-sectional area TCSA, cumulative almond in-shell yield, cumulative kernel yield, yield efficiency, and shelling percentage. The ‘Marta’ and ‘Tarraco’ cultivars exhibited the highest TCSA values. Regarding cumulative almond in-shell yield, ‘Glorieta’ and ‘Constantí’ produced the highest yields, whereas the lowest yields were observed in ‘Mardía’ and ‘Tarraco’. In terms of shelling percentage, ‘Ferragnès’ exhibited the highest value. Kernel quality parameters were cultivar-specific. Additionally, oleic acid content was strongly negatively correlated with linoleic acid content. All cultivars exhibited an unsaturated fatty acid content exceeding 90%, with ‘Masbovera’ showing the highest value.

Carob pulp powder (CPP), a by-product of Ceratonia siliqua L., is rich in bioactive compounds with potential for functional foods. This study evaluated how genetic variability among cultivars affects the nutritional composition and functional quality of CPP. Nineteen cultivars from Majorca (13), Ibiza (4), and two open-flowering selections were grown under identical conditions in Majorca, Spain. CPP samples showed high dietary fibre (22.6–47.4 g/100 g dry matter), total sugars (22.5–62.5 g/100 g dm), and antioxidant activity (11.1–78.4 µmol TE/g dm, CUPRAC method). Significant differences among cultivars were observed in protein and fructose content, fatty acid profiles, antioxidant activity, colour, acidity, and functional properties like water- and oil-holding capacities. Principal component analysis distinguished the Ibiza cultivars by higher soluble solids, fructose, and stearic acid content but lower antioxidant activity. Open-flowering selections exhibited the highest antioxidant and water retention capacities. These results confirm that genetic origin strongly influences CPP’s nutritional and functional traits, endorsing its use as a natural, health-promoting ingredient for functional food development.

Biomass production in marginal lands represents one of the most challenging and promising alternatives to sustainably produce biofuels. Native species seem to be the most adequate option to obtain a profitable output when low-input techniques are applied, and biomass is grown in depleted soils and harsh climatic conditions. In this study, a 5-year field trial in the island of Majorca served to investigate different autochthonous and naturalized Mediterranean perennial grasses as novel candidate lignocellulosic bioenergy crops for the semi-arid Mediterranean area and compare them with commercial ones (both Mediterranean and non-Mediterranean). Species and growing season had a significant effect on biomass production, perennialism and biomass quality. Arundo donax (winter crops) and Piptatherum miliaceum (autumn crops) performed better than the commercial species tested (Panicum virgatum for winter crops and Festuca arundinacea for autumn crops) in biomass production and perennialism. In terms of biomass quality, Panicum virgatum was the best species, having high structural content (mainly cellulose and hemicellulose), low non-structural content and the lowest ash. However, Ampelodesmos mauritanicus and Arundo donax rendered similar results, with no significant difference in terms of cellulose production for this latter but with higher lignin content. For the autumn species, Festuca arundinacea was the species with the best biomass quality but with the highest ash production for all the species considered. Hence, both for winter or autumn regimes, native or naturalized plants seem to be better suited than the commercial commonly used for biomass production with energy-producing purposes. Further research must be conducted in terms of seed biology and physiology, seedbed preparation methods, sowing time, seedling density and weed control before they can firmly be proposed as adequate alternatives for energy purposes.

Xylella fastidiosa (XF) is a Gram-negative bacterium responsible for severe plant diseases affecting a wide range of host plants, some of them important crops. Since 2017, only the pauca subspecies (ST80) have been identified in Ibiza. XF is naturally transmitted by xylem sap-feeding insects; among them, only Philaenus spumarius (PS) and Neophilaenus campestris Fallén (NC) have been reported as potential insect vectors for XF in Ibiza. This study aims to investigate the dissemination of XF and to propose effective control strategies. The crops and the surrounding vegetation were sampled for potential vectors. DNA from insects was extracted and amplified by three qPCR methods, allowing subspecies identification. The results confirmed the continuous presence of adults of PS and NC in Ibiza and Formentera from May to December with important populations. During the summer period, PS captures predominantly took place within the surrounding woody vegetation adjacent to the plots. The main host plant for PS was Pinus halepensis Miller in Ibiza and Juniperus phoenicea subsp. turbinata (Guss.) Nyman in Formentera. In Ibiza, off the total PS captures, 4.47% tested positive for XF. These results confirm that PS is the main vector of XF on these islands, both in terms of captures and the percentage of positive insects for XF. In Formentera, despite the presence of potential vectors and the proximity and contact with Ibiza, no XF-positive insects were found, confirming the absence of the bacterium on the island.

Xylella fastidiosa (XF) is a gram‐negative bacterium naturally transmitted by xylem sap‐feeding insects that causes serious plant diseases. Since 2016, three subspecies of XF have been identified in Majorca: fastidiosa , multiplex , and pauca . Only the Aphrophoridae Philaenus spumarius (PS) and Neophilaenus campestris (NC) have been reported as potential insect vectors for XF in Majorca and the Balearic Islands. This study aims to understand the spread of XF and propose effective and feasible strategies for its control. Eight plots were studied from 2019 to 2021: four almond orchards and four vineyards. The crops and the surrounding vegetation were sampled for XF, phytoplasmas, and potential vectors. DNA from plants and insects was extracted and amplified by three quantitative PCR (qPCR) methods, allowing subspecies identification. The results confirmed the prevalence of PS on the island, with also the presence of NC at lower levels. During the summer months, PS captures were mainly in the wild woody vegetation surrounding the crops. Of the total PS captures, 22.83% tested positive for XF, while 12.24% of NC specimens also tested positive for XF. Phytoplasma detection was also performed on captured Auchenorrhyncha insect species and plants, with all samples testing negative. These results confirm that PS is the main vector of XF on Majorca Island, both in terms of captures and the percentage of positive insects for XF. PS remains infective primarily on wild hosts throughout the summer, making it a difficult target for insecticide treatments on the crops.