Ana Paula Silva

The increased demand for higher-quality, longer-lasting blueberries has led to the development of preharvest strategies to improve their structural integrity sustainably. This study analysed the effects of the foliar application of two biostimulant–calcium (Ca) combinations, using Ecklonia maxima extract (EM + Ca) and glycine betaine (GB + Ca), on yield, biometric, mechanical, and histological properties, as well as cuticular wax composition of blueberries. Both biostimulants increased yield per plant and fruit weight and size in ‘Duke’, with superior results for GB + Ca. Fruit yield increased by 80% with GB + Ca and 40% with EM + Ca. Histological analysis showed increases in cuticle thickness, epidermal cell area and thickness, and hypodermal cell area and area/perimeter ratio. This thicker, denser tissue ultimately improved blueberries’ mechanical properties. Specifically, ‘Draper’ berries treated with GB + Ca had 36%, 15%, and 20% higher values for flesh firmness, stiffness, and deformation work, respectively, relative to the control. However, cuticular wax accumulation was more pronounced with EM + Ca for the ‘Duke’ cultivar, increasing by 12%. Overall, GB + Ca had the greatest impact on blueberry structural quality and may represent a promising strategy to improve postharvest quality and commercial production.

Blueberries are rich in bioactive compounds and antioxidants whose contents can be significantly affected by pre-harvest agronomic practices. Thus, using natural biostimulants like Ecklonia maxima (EM) extract and glycine betaine (GB) is a promising strategy to improve blueberry quality. The effect of foliar pre-harvest application of EM and GB on bioactive compounds and antioxidant capacity (AC) of ‘Duke’ and ‘Draper’ blueberries was investigated in 2022 and 2023. Blueberries treated with GB had higher polyphenol contents and AC by the ABTS^•+ and CUPRAC methods, particularly at higher doses. Vitamin C in ‘Duke’ was decreased by both doses of GB and low-dose EM + GB by 10–30% over two years, whereas in ‘Draper’, both doses of GB increased vitamin C in 2023 by 40–80%. High GB and EM + GB doses improved the AC of ‘Duke’ blueberries by 7–12% (CUPRAC) in both seasons. In 2022, the high dose of EM increased the levels of polyphenols in both cultivars by 14–21% and AC by ABTS^•+ and CUPRAC in cv. ‘Draper’. As a result, blueberries’ nutritional value and AC can be enhanced by biostimulants, whose application must be adjusted according to cultivar and dose to optimize their use.

Sweet cherry (Prunus avium L.) is a highly valued fruit, and optimal nutrient management is crucial for enhancing yield and fruit quality. However, the over-application of chemical fertilizers in cherry cultivation leads to environmental issues such as soil degradation and nutrient runoff. To address this, foliar application, a more targeted and eco-friendly fertilization method, presents a promising alternative. This study evaluates the effects of pre-harvest foliar application of calcium (Ca) (150 and 300 g hL⁻¹) and seaweed extracts (75 and 150 mL hL⁻¹), both individually and in combination, on the physiological and biochemical responses of ‘Burlat’ sweet cherry trees. Key physiological parameters, including plant water status, photosynthetic performance, and leaf metabolites, were analyzed. Results show that trees treated with seaweed extracts or with combined Ca and seaweed application had improved water status, higher sugar, starch, and protein content, as well as enhanced antioxidant activity and phenolic content compared to those treated solely with calcium. However, the combined treatment did not significantly enhance overall tree performance compared to individual applications. This study highlights the potential of seaweed-based biostimulants in sustainable cherry production.

This review paper explores the multifaceted relationship between sweet cherry nutrients and human health, aiming to uncover the comprehensive impact of these bioactive compounds from orchard to wellness. Furthermore, it highlights how advanced crop techniques can be pivotal in optimizing these beneficial compounds. Synthesizing existing literature, the paper examines the diverse bioactive nutrients in sweet cherries, including antioxidants, polyphenols, vitamins, and minerals, and elucidating their mechanisms of action and potential health benefits. From antioxidant properties to anti-inflammatory effects, the paper elucidates how these nutrients may mitigate chronic diseases such as cardiovascular disorders, diabetes, and neurodegenerative conditions. Additionally, it explores their role in promoting gastrointestinal health, enhancing exercise recovery, and modulating sleep patterns. The review discusses emerging research on the potential anti-cancer properties of sweet cherry compounds, highlighting their promising role in cancer prevention and treatment. Furthermore, it delves into the impact of sweet cherry consumption on metabolic health, weight management, and skin health. By providing a comprehensive overview of the current understanding of sweet cherry nutrients and their health effects, this paper offers valuable insights for researchers, healthcare professionals, and consumers interested in utilizing nature’s bounty for holistic wellness.

The consumption of blueberries has increased in recent years due to their excellent flavor and high antioxidant activity, which promote human well-being and health. Several sustainable cultural practices, such as biostimulants, have been applied to increase crop performance. The pre-harvest foliar application of two doses of a biostimulant based on the macroalgae Ecklonia maxima (EM), two doses of a glycine–betaine (GB) biostimulant, and two doses of the combination of the biostimulants in ‘Duke’ and ‘Draper’ blueberry cultivars in 2022 and 2023 were studied. The application of 4 L ha⁻¹ EM significantly increased the yield of ‘Draper’ blueberries, while the same occurred in ‘Duke’ fruits treated with 4 L ha⁻¹ EM + 4 kg ha⁻¹ GB. The blueberries sprayed with both doses of EM + GB were heavier and larger. ‘Duke’ fruits treated with EM were firmer and, following 4 L ha⁻¹ EM + 4 kg ha⁻¹ GB treatment, presented a lower concentration of organic acids, determined by HPLC, greater sensorial sweetness, and lower acidity. Therefore, these biostimulants are recommended for a more environmentally friendly production perspective, as they may increase blueberry yield and improve fruit quality.

Climate change is one of the most emergent environmental challenges, with rising global temperatures, changes in precipitation regimes, and an increased frequency and intensity of extreme weather events. Climate change impacts on the agrarian sector are being experienced across the world and are expected to be aggravated in the upcoming decades. Almond fruits are highly sought after due to their economic and nutritional interest, which contribute to their spread throughout the world. In 2021, the world almond production was approximately 3.9 × 10⁶ t with upward of 4.9 × 10³ t year⁻¹. Despite being relatively drought- and heat-resistant, this species is also vulnerable to climate change, particularly its production, which is highly dependent on soil water content and air temperature. To address the challenges of climate change, farmers and other stakeholders in the almond industry are increasingly adopting a range of adaptation measures, such as implementing irrigation systems and planting more drought-tolerant almond varieties. This manuscript describes the impacts of climate change on almond cultivation, reviewing the most recent studies on the subject. Furthermore, a comprehensive analysis of possible adaptation strategies against the potentially negative impacts is carried out, which might be of relevance to almond producers and other stakeholders operating in this value chain.

The Trás-os-Montes agrarian region (TM; north-eastern Portugal) is a traditionally growing area of almond trees. However, climate change may significantly alter the current growing conditions and threaten sustainability. Chilling and forcing conditions in TM are assessed herein, also considering different varietal phenological timings. The dynamic model/chill portions (CP) and chilling hour (CH) models are used to assess the chilling phase. For the forcing phase, growing degree hours (GDH) and growing degree days (GDD) models are selected, hinting at differences between simpler (CH and GDD) and more complex models (CP and GDH). Furthermore, the climate change projections for these models are assessed. The models are computed using daily temperatures for baseline (Iberia01, 1971–2015) and two future periods (EURO-CORDEX: medium-term, 2041–2060, and long-term, 2061–2080), following two anthropogenic forcing scenarios (RCP4.5 and RCP8.5). For the future, a five-member ensemble of regional-global climate model chains is used. Projections for CP and CH show decreases, mostly for RCP8.5, whereas projections for GDH and GDD reveal an increase in heat conditions until the beginning of summer. GDH shows that potentially damaging high temperatures during summer, effectively lead to a decrease in heat accumulation for almond trees. CP and GDH, more biologically effective, seem to be more accurate in capturing climate change impacts. For the three varietal groups, the late cultivar may experience a greater reduction of CP and GDH compared to early and mid-season varieties. Nonetheless, the increase in heat forcing should be more detrimental than the decrease in chilling conditions. Although almond production may be compromised in the future, adequate adaptation options are suggested to mitigate future losses of yield/quality and warrant its sustainability.

Orchard net cover improves plant physiology, yield and fruit quality, pest and disease control, and anticipates fruit ripening. Moreover, this crop technology has been used to reduce natural cherry cracking (NCC). This is a serious physiological disorder that cracks the epidermis, the hypodermis, and the storage parenchyma layers of the fruit due to rainfall events near the harvest and it is related to low fruit osmotic potential and/or high fruit water permeability. This work aims to study the effect of orchard net cover on sweet cherry trees, cv. Early Bigi, in two harvesting years (2019 and 2021). The NCC, the induced cracking index (CI), and the cracking type incidence were determined. In addition, epicuticular and intra-cuticular wax content, biometric and physicochemical parameters were also evaluated. Net cover reduced the natural cracking index by 40%. High fruit weight values were observed in covered trees comparing to the control ones, with increases of 45% and 13%, in 2019 and 2021, respectively. A positive correlation was observed between CI and total soluble solids and a negative correlation between CI and wax content. Therefore, with forecasts of worsening heavy precipitation events near harvest, protecting cherry trees with nets will increase resistance to fruit cracking.

Biostimulants, such as glycine betaine (GB), are a sustainable way to boost productivity and quality in fruit crops, even in adverse environment conditions. Sweet cherry (Prunus avium L.) is an important crop, which is very sensitive to abiotic stress. Known primarily for its fruits, its leaves are also rich in bioactive substances, which, however, still have no commercial value. There are no studies about the effects of GB exogenous application on biochemical parameters of sweet cherry leaves and few studies about effects in sweet cherry tree physiology. This study was conducted in a Portuguese sweet cherry commercial orchard. Lapins sweet cherry trees were treated with a commercial product based on GB, at two different concentrations (0.25% and 0.40%). The applications were performed at three different phenological stages, according to the BBCH (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) scale: 77, 81 and 86 BBCH. Both GB treatments improved leaf water status, photosynthetic pigments, soluble solids content, total phenolic contents, and antioxidant activity, resulting in better leaf water status regulation, greater photosynthetic capacity, and higher antioxidant activity. These results shows that GB can benefit sweet cherry tree physiology and provide new opportunities for sweet cherry leaves valorisation.