Production Of High Quality Fruits Research Articles

Effect of Pit and Soil Types on Growth and Development, Nutrient Content and Fruit Quality of Pomegranate in the Central Deccan Plateau Region, India

To enhance pomegranate production on marginal gravelly lands, standardized planting techniques were evaluated in an 8-year-old orchard. Trenching, wider pit excavation, pit digging, and auger digs with dimensions of 1 and 2 m were employed. Utilizing native soil from barren land, with or without spent wash, and mixing it with black soil up to 1 m deep, growth parameters, leaf nutrients, fruit production, and fruit quality were assessed. The trench and wider pit methods outperformed others, yielding greater above-ground biomass (>70.3 kg tree−1), root biomass (>24.5 kg, tree−1), and cross-sectional area (>3.30 m2 tree−1). These methods also produced longer roots (>4.0 m tree−1) and higher leaf phosphorus (>0.28%) and potassium (>1.81%) levels, fruit juice content (>48.50%), and total soluble solids (>16.05°) compared to other planting methods. This resulted in higher and more sustainable fruit yield production under the trench and wider pit planting methods (>7.21 t ha−1). Similarly, the native and black soil mixture produced healthy fruit trees, improved fruit quality, and sustainably higher fruit yield over the native soil alone. In summary, the trench and wider pit methods (2–3 m3), combined with a soil mixture, are recommended for sustainable, high-quality fruit production in shallow gravelly terrains, thereby improving food security and the livelihoods of farmers in arid regions.

Fruit sugar hub: gene regulatory network associated with soluble solids content (SSC) in Prunus persica

Chilean peach growers have achieved worldwide recognition for their high-quality fruit products. Among the main factors influencing peach fruit quality, sweetness is pivotal for maintaining the market's competitiveness. Numerous studies have been conducted in different peach-segregating populations to unravel SSC regulation. However, different cultivars may also have distinct genetic conformation, and other factors, such as environmental conditions, can significantly impact SSC. Using a transcriptomic approach with a gene co-expression network analysis, we aimed to identify the regulatory mechanism that controls the sugar accumulation process in an 'O × N' peach population. This population was previously studied through genomic analysis, associating LG5 with the genetic control of the SSC trait. The results obtained in this study allowed us to identify 91 differentially expressed genes located on chromosome 5 of the peach genome as putative new regulators of sugar accumulation in peach, together with a regulatory network that involves genes directly associated with sugar transport (PpSWEET15), cellulose biosynthesis (PpCSLG2), flavonoid biosynthesis (PpPAL1), pectin modifications (PpPG, PpPL and PpPMEi), expansins (PpEXPA1 and PpEXPA8) and several transcription factors (PpC3H67, PpHB7, PpRVE1 and PpCBF4) involved with the SSC phenotype. These results contribute to a better understanding of the genetic control of the SSC trait for future breeding programs in peaches.

Arbuscular mycorrhizal fungi improves yield and quality attributes of melon fruit grown under greenhouse

ABSTRACT Melon (Cucumis melo) is the most popular fruit with indisputable socio-economic and nutritional value, as evidenced by its significant acreage (1 Mha) and production (28 Mt) worldwide. However, melon farming is facing the triple challenge of producing enough to meet growing consumer demand, improving the concentration of human wellness compounds, while minimising chemical inputs. This scientific research was carried out to assess the effectiveness of two arbuscular mycorrhizal fungi (AMF), Rhizophagus irregularis (Ri), R. fasciculatus (Rf), and their complex, in improving yield and quality attributes in melon variety ‘Ananas’ grown in greenhouse. Results showed that production and fruit quality were significantly improved in mycorrhizal plants (M-plants) compared to non-mycorrhizal (NM-plants) ones, regardless of AMF treatments. M-plants performance varied according to AMF strains. Indeed, Ri-plant exhibited the highest increases in yield (54%), fresh weight (65%), longitudinal (20%) and equatorial (33%) perimeters, Brix degree (20.6%), polyphenols (315.4%), carotenoids (353%), proteins (209.1%), flavonoids (114.38%), ascorbic acid (31.3%), reducing power (77.04%), DPPH radical inhibition (16.43%), and the highest decrease in titrable acidity (62.5%). In addition, Ri-plant fruits were highly rated by participants in the sensory evaluation test. Therefore, R. irregularis application could be recommended for the sustainable production of high-quality fruits of melon.

Review of modern methods for optimizing apple mineral nutrition to increase yield and fruit preservation

Achieving sustainable fruit production and ensuring quality preservation are paramount in modern apple orchards. This review delves into contemporary methods designed to optimize mineral nutrition, aiming to bolster both yield and fruit preservation. Various strategies for enhancing apple orchard management are examined, with a focus on maximizing the efficacy of mineral fertilizers, maintaining balanced nutrition, and understanding the critical role of key nutrients such as nitrogen, phosphorus, potassium, calcium, and boron. The review underscores the importance of comprehending plant nutrient requirements across different growth stages and phenological phases to attain sustainable, high-quality fruit production. Furthermore, it emphasizes the necessity of continuous diagnostic assessments to tailor mineral nutrition practices to the specific needs of apple orchards, ensuring optimal performance and economic viability.

Rootstocks for the Mediterranean citrus industry: current choices and new releases

Modern citriculture relies on the use of rootstocks to guarantee adaptability to environmental and biotic constraints and to speed up the establishment of a potentially unlimited number of homogeneous plants of a specific clone, which in turn ensures uniformity in the production of high-quality fruit. In this contribution, the status of rootstock availability for the Mediterranean citrus industry is described along with its evolution during the last decades. The major turning points in rootstock choice were caused by the spread of new diseases, such as Citrus Tristeza Virus (CTV), that hastened the use of resistant or tolerant rootstocks. In Italy, the growers decisions on rootstock replacement were facilitated by information from rootstock trials performed for more than 70 years in several areas of southern Italy, as well as information from other countries. However, there is still the need to find alternatives to sour orange (which was the most commonly used rootstock before the CTV outbreak), especially for cultivation under suboptimal growing conditions. Nowadays, the process of replacing standard rootstocks with new ones with better performance should be assisted by a long-term evaluation strategy, since negative characteristics can become evident after many years of evaluation in combination with specific scion varieties. Ongoing rootstock breeding programs in different parts of the world and in Italy are critically described.

Analysis of Degradability of Blackberry (Rubus glaucus) Subjected to Different Storage Conditions

The purpose of this study was to assess how different storage conditions and types of containers affect blackberries (Rubus Glaucus), fruits that are particularly susceptible to post-harvest deterioration. Comparisons were made between two temperature conditions: room temperature (19 °C) and refrigeration (4 °C), and three types of container materials: low-density polyethylene (LDPE), polypropylene (PP), and polylactic acid (PLA). The findings indicated that refrigeration is the most effective strategy for maintaining the quality of blackberries during storage. This method significantly preserved the weight and stability of the fruit, with PLA standing out in this respect. Additionally, a considerable reduction in microbial activity was observed under refrigeration, with LDPE proving to be the most effective at inhibiting mold growth. These results underscore the importance of properly controlling both temperature and container materials type to extend shelf life and preserve the quality of blackberries, which is crucial not only for the food industry, where maintaining freshness and flavor is imperative, but also for consumers who seek high-quality fruit products.

The fruit quality and nutrient content of kiwifruit produced by organic versus chemical fertilizers.

Currently, organic farming has become a feasible approach for the production of high-quality fruits. To evaluate the response of fruit quality and mineral nutrition contents of Hayward Kiwifruit affected by different organic and inorganic fertilizers, the present study was conducted in Citrus and Subtropical Fruits Research Center, Iran, in 2017-2021, as a randomized block design with three replications. The studied treatments were organic fertilizers (cow, vermicompost and Azolla) and chemical fertilizers. After 4 years of fertilization, the fruit's nutritional elements content and some fruit bioactive compounds were evaluated after 3 months of cold storage and then analyzed by the principal component analysis (PCA) method. The use of organic amendments boosted the calcium, phosphorus, potassium and iron content of the kiwifruits compared to chemical fertilizers. The highest fruit potassium and phosphorus content were recorded in the cow manure treatment. The lowest amount of nitrate and the highest calcium, zinc, copper and manganese accumulation were recorded in the fruits treated with vermicompost. In addition to mineral nutrients, the dry matter, total soluble solids, total phenolic and antioxidant capacity of kiwifruit were improved by the application of vermicompost amendment compared to the other fertilizer sources. However, the highest fruit vitamin C and total soluble carbohydrates were measured in the cow manure treatment. The PCA results of the fruit quality indices indicated that fertilization treatments were ranked as vermicompost (1.88) > cow manure (1.63) = chemical (1.60) > Azolla (1.54). It is concluded that the application of 40 kg of vermicompost or 40 kg of cow manure in the next rank in Hayward kiwifruit orchards in March (growth stage beginning of bud swelling) may be a more suitable approach for improving the nutritional quality of the fruit. © 2024 Society of Chemical Industry.

Water deficit drip irrigation promotes citrus sugar accumulation during the late growth stages

Water deficit drip irrigation (WDDI) in citrus orchards was found has a positive effect on fruit quality, particularly enhancing the soluble sugar content during the late period of fruit growth. However, the underlying molecular mechanism remains unclear. In this study, four deficit irrigation levels of D-60%, D-45%, D-30%, and D-15% were set at fruit expansion stage (stage III) and maturation stage (stage IV), respectively, and a fully irrigated treatment was set as the control (CK). Combined analysis of metabolomics and transcriptomics was used to reveal the molecular mechanism of sugar accumulation changes under different water deficit (WD) treatments. The results showed that sugar metabolism was growth stage dependent: stage III is a key period of sucrose metabolism and synthesis, while for stage IV, the accumulation of glucose and fructose increased significantly. Importantly, III-D15% and IV-D30% treatments were identified as optimal strategies for enhancing sugar content of citrus fruits. WDDI during the late growth stages up-regulated the expression of sugar metabolism-related differential expression genes (DEGs), consequently increasing the content of sugar-related differential expression metabolites (DEMs), and ultimately enhancing sugar accumulation in citrus fruits. For III-D15% treatment, DEMs related to sugar metabolism were mainly enriched in ‘carbon metabolism’, with significant increases in Sucrose, ɑ-D-Glucose-6 P and ß-D-Fructose-6 P content observed. SPS showed significant up-regulation, wihle BGLU, GN, TPS11, TPPF and TPPJ were down-regulated. For IV-D30% treatment, most DEMs were significantly enriched in ‘Glycolysis/Gluconeogenesis’. Key DEMs (Sucrose, D-Glucose-6 P, ß-D-Fructose-6 P) and DEGs (SUS, SPS, BGLU, HXK) involved in the metabolism and synthesis of sucrose, fructose and glucose were significantly increased. This study sheds light on the molecular mechanisms of sugar accumulation in citrus fruit under appropriate WDDI, providing valuable guidance for high-quality fruit production.

Phenological growth stages of a new kiwifruit cultivar (Actinidia deliciosa ‘Jinfu’)

The BBCH scale is employed to describe the phenological growth stages of Actinidia deliciosa ‘Jinfu’ kiwifruit. This study provides comprehensive descriptions of the key growth stages encompassing bud, leaf, and shoot development, inflorescence emergence, flowering, fruit development, fruit ripening, senescence, and 41 additional secondary growth stages. Furthermore, the investigation encompasses changes in fruit taste, volatile compounds, antioxidant activities, and ethylene production across five different firmness stages during the eating window, with the aim of determining the optimum time for consumption. Principal component analysis of the collected data indicated that fruit firmness ranging from 12 N to 8 N represented the optimal eating window for ‘Jinfu’ kiwifruit. Additionally, this study explored the practical applications of the BBCH scale in orchard management and the production of high-quality fruit. Overall, the insights derived from this research provide valuable and substantial information that can effectively support the introduction and promotion of the new ‘Jinfu’ cultivar.

Micro Nutrient Management for Enhanced Growth, Yield, and Quality of Mango: A Comprehensive Review

This review paper delves into the intricate interrelationships among micronutrient interventions, carbohydrates, and osmostimulants, investigating their collective influence on diverse aspects of mango tree growth and fruit characteristics. Micronutrients, essential elements required in small quantities for plant health, play a pivotal role in shaping optimal plant development. The paper underscores the significance of these micronutrients by highlighting their roles in stimulating vegetative growth, influencing flowering dynamics, regulating fruit set processes, impacting yield metrics, and contributing to the nuanced attributes of fruit quality. This synthesis illuminates the complex network of processes governing mango tree growth and fruit production. Moreover, the study underscores the potential of well-structured nutrient management strategies as key catalysts for optimizing mango production outcomes. By carefully balancing the imperative of yield quantity and fruit quality, such strategies hold the promise of enhancing overall agricultural efficiency. Drawing insights from a comprehensive review of pertinent studies, this research paper contributes to a holistic comprehension of the intricate interactions involving micronutrients, carbohydrates, and osmostimulants, intricately connected with the diverse growth and fruit parameters within mango trees. Through this endeavor, the paper provides valuable insights into the intricate interplay of micronutrients within mango cultivation, offering a knowledge foundation for informed agricultural practices geared towards sustainable and high-quality fruit production. The paramount importance of micronutrients in fostering robust crop health and productivity underscores the broader implications of these findings for contemporary agricultural methodologies.

Pruning and Fruit Thinning of Psidium guajava cv. Paluma under a Seasonal Tropical Climate

Maintaining the plant architecture of Psidium guajava L. (guava tree) is essential for enhancing capture and distribution in the plant, directly affecting the fruit quality. The lifespan of the harvest period can be extended by proper pruning. Both timeliness and proper pruning play crucial roles in achieving high-quality fruit production and in maintaining a consistent fruit size while stimulating ascorbic acid levels, sugar content, total soluble solids (TSS), and titratable acidity. From this perspective, this study aimed to characterize the influence of different intensities of fruit pruning and thinning on guava trees grown under a seasonal tropical climate in two growing seasons in Currais, Piauí, Brazil. The experiment was set up in a randomized block design with a 3 × 3 × 2 factorial arrangement corresponding to short, medium, and long pruning intensities and 0%, 10%, and 20% thinning intensities during the two growth seasons, respectively. An analysis was performed to discriminate the treatment groups according to the physicochemical variables of the guava tree cv. Paluma and canonical discriminant analysis. There was significant variation in the SS, titratable acidity, ascorbic acid, and pH contents. Cluster analysis of all treatments allowed division into five different groups for the two pruning times. Canonical discriminant analysis showed that the first two canonical variables explained 91% of the total variance. The fruits of the second harvest exhibited a lower level of acidity, higher levels of soluble solids, and higher levels of ascorbic acid contents. In addition, these fruits also obtained better nutrient contents. Short pruning with up to 20% thinning, medium pruning with up to 10%, and long pruning without thinning favored better levels of macronutrients and micronutrients and, consequently, better fruit quality. Medium or long pruning with up to 20% thinning resulted in higher average fruit weights and nutrient contents (especially of Fe and Cu), lower acidity, and higher ascorbic acid contents. Thus, in general, the importance of production pruning in guava plants is evidenced and thinning of 20% is recommended to improve the fruit quality.

Agrobiological and consumer assessment of new cherry varieties of Dagestan breeding

The development of new varieties of cherries with a combination of economically important traits, along with the high nutritional value of the fruit, is an important trend in breeding research, which renews and expands the variety range of cherries. The agrobiological and consumer properties of seven new varieties of sweet cherries of Dagestan breeding (FSBSI Dagestan breeding experimental station of fruit crops) are presented: Bela, Dagestan red, Bigarro Krainsky, Garnet, Lyubimitsa Korvatskogo, Lezginka and Nike. The research was carried out using conventional methods for a variety research and biochemical methods of analysis. It was determined that the cherry varieties Lyubimitsa Korvatskogo, Pomegranate, White and Nike are highly resistant to spring frosts, with the subfreezing of flowers being less than 18.3%. The fruits of the varieties Nike, Bela, Pomegranate, Lezginka and Lyubimitsa Korvatskogo are the most resistant to dehiscence, since the index of dehiscence during ripening at high humidity for these varieties varied within 13.5–18.2 %. The susceptibility of new varieties to Coccomyces and monilial blight is insignificant (no more than 1.2 points). Varieties Bigarro Krainsky, Pomegranate, Lezginka and Nike are characterized by the highest content of soluble solids (12.4–16.3%) and sugars (11.01–12.02%) in fruits. Bigarro Krainski, Bela and Lezginka exhibited the highest vitamin C content (9.24– 9.70 mg %). With the exception of the Bela variety (5.0 g), all new varieties of cherries are characterised by large fruits (7.5–9.5 g). Tasting indicators were rated as high (within 4.7–5.0 points on a five-point scale) for the Lyubimitsa Korvatskogo, Pomegranate, Lezginka and Nike varieties. The average yield was the highest for Nike, Bela and Garnet (8.0–9.6 t/ ha). The study showed that new cherry varieties obtained a combination of economic and biologically valuable traits, along with improved consumer properties compared with the control varieties. Therefore, they are recommended as valuable parent materials for breeding programs and the expansion of commercial cherry orchards in Dagestan in order to obtain high-quality fruit products.

Synergistic Effect of Organic and Biofertilizers on Strawberry Cultivation

In the contemporary era, the excessive use of chemical fertilizers in areas where strawberries are intensively cultivated disrupts the balance of nature and reduces economic efficiency. Therefore, using organic and biofertilizers in sustainable agriculture can solve these problems. The effect of organic fertilizer and other treatments on the yield, quality, and plant growth of the Monterey strawberry variety was investigated. Solid farm manure and a liquid organic fertilizer of vegetable origin were used as basic fertilizers, while five different commercial fertilizers containing bacteria and mycorrhiza were used as complementary fertilizers. In addition, this study examined plant growth parameters, including root length, stem diameter, leaf area, yield per plant, fruit weight, pH in the fruit, SSC, acid, SSC-to-acid ratio, and plant nutrient content. The Biofarm+Botanica+Fontera microzone bacterial fertilizer (Azosprillium brasilense, Azotobacter vinelandii, Rhizobium trifollii, Pseudomonas fluorescens, Bacillus subtilis, Bacillus licheniformis, Azotobacter chroococcum, Bacillus amyloliquefaciens, and Bacillus mucilaginosus) treatment provided the best results; namely, it produced the highest total yield (250.17 g plant−1), largest fruits (18.13 g), highest SSC-to-acid ratio (18.05), and best nitrogen, phosphorus, potassium, calcium, and magnesium contents in the leaves. Similarly, the same treatment produced the longest root, thickest stem, and maximum leaf area. As a result of this study, it is recommended to use biofertilizers together with organic fertilizers to ensure high-quality fruit production.

GABA shunt pathway is stimulated in response to early defoliation-induced carbohydrate limitation in Mandarin fruits

The regulation of sugar and organic acid metabolism during fruit development has a major effect on high-quality fruit production. The reduction of leaf area is a common feature in plant growth, induced by abiotic and biotic stresses and disturbing source/sink ratio, thus impacting fruit quality. Here, we induced carbohydrate limitation by partial leaf defoliation at the beginning of the second stage of mandarin development (before the citrate peak). Resulting changes were monitored in the short-term (48 h and 1 week) and long-term (7 weeks) after the defoliation. Short-term response to early defoliation implied metabolic settings to re-feed TCA for sustaining respiration rate. These features involved (i) vacuolar sucrose degradation (high acid invertase activity and mRNA expression level) and enhanced glycolytic flux (high ATP-phosphofructokinase activity), (ii) malic and citric acid utilization (increased phosphoenolpyruvate kinase and NADP-Isocitrate dehydrogenase) associated with vacuolar citric acid release (high mRNA expression of the transporter CsCit1) and (iii) stimulation of GABA shunt pathway (low GABA content and increased mRNA expression of succinate semialdehyde dehydrogenase). A steady-state proline level was found in ED fruits although an increase in P5CS mRNA expression level. These results contribute to a better knowledge of the molecular basis of the relationship between defoliation and sugar and organic acid metabolism in mandarin fruit.

The effect of fertilization with microfiltered liquid digestate on the quality parameters of Citrus fruits

Nowadays, the adoption of sustainable agricultural practices, including the reduction of synthetic fertilizers, has become a challenge for the agriculture sector. In this experimental work, the effect of the liquid fraction of digestate (by-product of the anaerobic digestion process) as a fertilizer was evaluated. The aim of the research was to verify to which extent digestate can affect growth and quality parameters of orange fruits, comparing the results to those obtained for fruits grown on soil treated with conventional mineral fertilizers. To assess the effectiveness of the treatments, different qualitative and quantitative parameters of Citrus fruits were measured. In particular, the results showed slight differences between the two treatments, suggesting that digestate may be used for the production of high-quality fruits. Moreover, in some orchards, the Citrus fruits of the plants treated with digestate showed a higher concentration of health-promoting compounds, such as vitamin C, flavonoids, phenolic content, when compared to the control group. Thus, digestate can be considered an optimal source of plant nutrients and can be used as a crop growth promoter, since it represents an effective strategy for reducing the mineral fertilizers input.

Body size as a proxy of probing time and visitation rates on cucumber by two African stingless bees increase fruit quality and seed quantity

Pollinators are of essential importance for sustainable agriculture. However, pollination efficiency depends on interacting factors such as pollinator behaviour and morphology. We compared the effect of probing time length and visit frequency of two distinct body size African stingless bee species (Meliponula bocandei, Dactylurina schmidti) as alternative pollinators to Apis mellifera scutellata on greenhouse cultivated cucumber. We found differences in morphometric characteristics, between a set of 9 body parameters. Bee body size was the morphological feature that varied the most among bee species. On average, body size was largest in honeybees, followed by M. bocandei, and finally D. schmidti, which was the smallest. Glossa length was different between the bee species: A. mellifera scutellata (2.86 ± 0.026 mm), M. bocandei (2.20 ± 0.031 mm), D. schmidti (0.72 ± 0.025 mm). Such differences among bee species in body parameters correspondingly affected nectar probing times during a single flower visit, which were different for the bee species. D. schmidti (3.34 ± 0.56 s) had the longest probing time, while M. bocandei (2.57 s) had the shortest. Fruit quality was strongly positively influenced by the visit duration during a single visit on female flowers. The slope of fruit quality produced was higher in flowers pollinated by M. bocandei. During a single flower visit, heavier and bigger fruits were obtained in the gold standard hand cross pollination and flowers pollinated by M. bocandei. The bee species and the number of visits significantly impacted fruit weight, fruit volume and number of seeds. Subsequent visit performed by M. bocandei positively impacted fruit quality. Three visits on a flower were enough to ensure the production of high-quality fruits. Fruit sweetness depended on the number of visits received by the flower, but not on the bee species that performed the visit. Altogether, our results indicate that the stingless bees M. bocandei is more an efficient pollinator of cucumber than A. m. scutellata and D. schmidti and can be recommended for use under greenhouse cultivation.

Reducing Macronutrients and Increasing Micronutrient Fertilizers Are Key to Improving the Quality of Pomelo Citrus grandis (L.) Osbeck Cv. “Guanxi”

Due to long-term excessive fertilization, the fruit quality of the Guanxi pomelo (Citrus grandis) has been declining. The classification of fruit quality and its relationship with nutrients in soils and trees were studied to declaim the characteristics of nutrients in Guanxi pomelo orchards, ultimately guiding the fertilization for high-quality fruit production. By cluster analysis, 281 samples were grouped into four clusters. High-quality fruit (HF) showed a gourd shape with moderate weight size, high sweetness, edible rate (ER) up to 73%, and vitamin C content over 40 mg/100 g. Compared to sub-quality fruit (SF), common fruit (CF), and inferior fruit (IF), the content of magnesium (Mg) in the leaves of HF was 11.76, 11.76, and 18.75% higher, while the content of iron (Fe) was 6.45, 5.76 and 10.97% higher, respectively. Meanwhile, the contents of Zinc (Zn, 8.51, 6.44, and 11.22% higher than SF, CF, and IF, respectively) and Boron (B, 13.47, 13.83, and 25.40% higher than SF, CF, and IF, respectively) were also found to increase. However, the contents of Mn (35.34, 27.51, and 25.53% higher) and Cu (31.90, 31.99, and 5.64% higher) in IF were significantly higher than in HF, SF, and CF. Acid soils (4.24–4.40) with low OM content (23.00–26.71 g kg−1) led to an imbalance uptake of nutrients of citrus, ultimately resulting in poor quality. These results indicated that farmers should reduce the application of nitrogen (N), phosphorus (P), and K fertilizer and pesticides and increase micronutrient and organic fertilizer, which provides a theoretical basis for scientific fertilization to improve the fruit quality of Guanxi pomelo (Citrus grandis) of Pinghe County.

Effects of Nitrogen Deficiency and Resupply on the Absorption of Mineral Nutrients by Tangor Cultivar 'Shiranuhi' (Citrus unshiu × C. sinensis) Grown in a Hydroponic System.

Tangor (Citrus unshiu × C. sinensis) cultivars obtained through interspecific hybridization have gained popularity in various countries, including South Korea. However, tangor has a relatively short history of cultivation and thus has been less well researched in terms of physiology and opping technology compared to mandarin. In addition, although tangor grows more vigorously than mandarin and thus has high nutrient demands and longer harvest time, it is more prone to various physiological disorders. Furthermore, the demand for nutrients could vary depending on the cultivars even within the same species. Thus, the current study examined the effects of nitrogen deficiency and resupply on the uptake of mineral nutrients using a specific cultivar ‘Shiranuhi’ as a case study. In this study, the tangor cultivar ‘Shiranuhi’ was cultivated in a hydroponics system, which allows the control of nutrient contents, and changes in mineral nutrient contents under nitrogen deficiency and nitrogen resupply were examined. Based on this, the results show the straightforward relationship between nitrogen and other mineral nutrients under a hydroponic system applying the cultivation of tangor. This implies that the hydroponics system can be applied to tangor cultivation and efficiently and widely expanded in Northeast Asia, and the income of growers will increase through the production of high-quality fruits.

Net primary production and carbon budget in peach orchards under conventional and low input management systems

Fruit tree orchards are an important land-use type in the Mediterranean regions despite limited information on their potential role as carbon sinks to mitigate climate change and their capacity to store soil organic carbon (SOC). The objective of this study was to evaluate the ability of peach orchards (Prunus persica (L.) Batsch) to fix and accumulate carbon (C) in three contrasting management systems. The first system was representative of the current management recommended to French producers with high yield objectives (REF). The second system was managed with a Low-Input strategy (LI-1) for chemical pesticide application (−70%), nitrogen fertilization and water irrigation (~−25%). Lastly, the third system (LI-2) had the same low-input strategy but included a higher planting density (~2-fold) and a new tree shape training system. The experiment was conducted in the South of France for 7 years from planting (2013–2019). The aboveground biomass and C repartitions in various components of systems (tree organs and grass growing in alleys) were carried out by destructive measurements each year to determine Net Primary Production (NPP), Net Ecosystem Production (NEP) and Net Ecosystem Carbon Balance (NECB).The REF system had very high productivity during the mature tree period with 45.9 Mg ha-1 yr-1 of fresh fruit yield and 16.8 Mg ha-1 yr-1 of aboveground biomass, corresponding to 7379 kg C ha-1 yr-1 (738 g C m-2 yr-1). Orchard NPP (tree and grass) reached 11,003 ± 353 kg C ha-1 yr-1 (1100 ± 35 g C m-2 yr-1) and soil respiration was 3366 ± 776 kg C ha-1 yr-1 (337 ± 78 g C m-2 yr-1) leading to an NEP of 7637 ± 853 kg C ha-1 yr-1 (764 ± 85 g C m-2 yr-1) and an NECB of 4919 ± 858 kg C ha-1 yr-1 (492 ± 86 g C m-2 yr-1). Carbon accumulation was distributed 53% in perennial biomass, and the soil had an annual SOC stock change of 3.8‰. In the LI-system, the reduction of inputs and chemical pesticides did not impact the average NEP and NECB, even though pest infestations reduced biomass in 2015 and 2019. The same input reductions in the LI-2 system but with increased planting density provided significant increases in NPP (+10.5%) and NEP (+20.0%), leading to an NECB of 5876 ± 890 kg C ha-1 yr-1 (588 ± 89 g C m-2 yr-1), or 19.4% greater than the REF system during the mature tree period. This positive C accumulation was distributed 46% in the perennial biomass, which could reach 35.5 Mg C ha-1 (3550 g C m-2) after 15 years of orchard life. The SOC stock change was 10.0‰ in the LI-2 system, greater than the 4‰ initiative of the Paris COP21. Innovative peach orchards with agroecological management can mitigate environmental impacts by combining high-quality fruit production with enhanced CO2 sink capacity objectives.

Will citrus geographical indications face different climate change challenges in China?

Global climate change resulting from human activities has brought opportunities and challenges to agricultural production. Therefore, we used the MaxEnt model to simulate habitat suitability for citrus geographical indications (GIs) based on nine environmental factors. Under four shared socioeconomic pathways (SSPs) in the 2050s, 2070s and 2090s, the potential suitable area changes in the four citruses (orange, pomelo, mandarin and tangerine) were studied. The results showed that the four citrus types were all severely affected by the precipitation in the driest month and the minimum temperature of the coldest month. The suitable area for citrus GIs moved north in future scenarios. It decreased in the South subtropical Humid Zone but increased in the North subtropical Humid Zone. The suitable habitats for citrus changed in three ways: (1) both the high- and low-suitability areas for the orange GI gradually increased; (2) the high-suitability areas for pomelo and mandarin GIs increased while their low-suitability areas decreased; and (3) the low-suitability area for the tangerine GI increased, while their high-suitability areas rapidly decreased. Under the SSP5–8.5 scenario in the 2090s, the highly suitable area for the tangerine GI decreased by 91.40%. The effects of climate change on the habitats of the four geographical indication-designated citruses varied. The four citrus types under the SSP1–2.6 scenarios all showed relatively minor changes when compared to the current suitable areas. Therefore, strengthening intergovernmental cooperation to achieve carbon neutrality, controlling global temperature increases and proposing a sustainable pathway under the SSP1–2.6 scenario can benefit high-quality fruit production.