Horticulturae

12 pages, 1582 KiB

Open AccessArticle

Anthocyanin Accumulation and Differential Expression of the Biosynthetic Genes Result in a Discrepancy in the Red Color of Herbaceous Peony (Paeonia lactiflora Pall.) Flowers

by Yanqing Wu, Zhaojun Hao, Yuhan Tang and Daqiu Zhao

Horticulturae 2022, 8(4), 349; https://doi.org/10.3390/horticulturae8040349 - 18 Apr 2022

Cited by 5 | Viewed by 2217

Abstract

Herbaceous peony (Paeonia lactiflora Pall.) is an ornamental plant with huge potential in the international flower market. Similar to the flowers of most other ornamental plants, the top sellers of P. lactiflora are those with red or pink flowers. However, most studies [...] Read more.

Herbaceous peony (Paeonia lactiflora Pall.) is an ornamental plant with huge potential in the international flower market. Similar to the flowers of most other ornamental plants, the top sellers of P. lactiflora are those with red or pink flowers. However, most studies on flower colors have focused on the novel colors and have neglected the most common red flowers. In this study, a red cultivar of P. lactiflora (‘Dafugui’) and a pink cultivar (‘Qingwen’) were selected in order to study the discrepancy in the red color of the flowers. The results demonstrate that these two cultivars have the same compositions as anthocyanins, flavones, and flavonols but different contents. ‘Dafugui’ was found to have a high accumulation of upstream substances due to the higher expression of the early genes encoding phenylalanine ammonialyase (PlPAL) and flavonoid 3′-hydroxylase (PlF3′H). Moreover, the anthocyanidin synthase gene (PlANS) and UDP-glucose flavonoid 3-O-glucosyltransferase gene (PlUF3GT) encoding enzymes catalyze these upstream substances into anthocyanins, resulting in more redness in ‘Dafugui’ than in ‘Qingwen’. Our study thus provides a better understanding of the anthocyanin accumulation and coloring mechanism of P. lactiflora and can serve as a theoretical basis for breeding more red flowers using genetic engineering techniques to cater to consumers’ preferences. Full article

(This article belongs to the Section Genetics, Genomics, Breeding, and Biotechnology (G2B2))

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10 pages, 1648 KiB

Open AccessArticle

Effect of Genotype and Harvest Date on Fruit Quality, Bioactive Compounds, and Antioxidant Capacity of Strawberry

by Yunting Zhang, Min Yang, Guoyan Hou, Yong Zhang, Qing Chen, Yuanxiu Lin, Mengyao Li, Yan Wang, Wen He, Xiaorong Wang, Haoru Tang and Ya Luo

Horticulturae 2022, 8(4), 348; https://doi.org/10.3390/horticulturae8040348 - 18 Apr 2022

Cited by 5 | Viewed by 2434

Abstract

Fruit quality is strongly affected by genotype and harvest date. In this study, parameters regarding fruit quality, bioactive compounds, and antioxidant capacity of different strawberry cultivars at three harvesting dates were quantified to elucidate the influence of genotype and harvest date on strawberry [...] Read more.

Fruit quality is strongly affected by genotype and harvest date. In this study, parameters regarding fruit quality, bioactive compounds, and antioxidant capacity of different strawberry cultivars at three harvesting dates were quantified to elucidate the influence of genotype and harvest date on strawberry quality. The results showed that harvest date was the major contributor to appearance color, TSS, TA, and TSS/TA ratio of strawberries, while genotype mainly affected firmness, anthocyanin content, and antioxidant capacity. Moreover, the interaction of genotype and harvest date had a primary influence on the content of ascorbic acid. The content of total phenolics and amino acids received the similar influence caused by genotype and harvest date. However, the interaction of genotype and harvest date significantly affected total phenolic content as well. These findings give a better understanding of the influence of the genotype and harvest date on strawberry, which might contribute to breed cultivars with more attractive fruits in terms of quality acceptance and nutritional value. Full article

(This article belongs to the Special Issue Berry Crops Production: Cultivation, Breeding and Health Benefits)

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15 pages, 1763 KiB

Open AccessEditor’s ChoiceArticle

The True Identity of the “Second Pollen Morphology” of Camellia oleifera—Stomium Cells

by Yang Hu and Chao Gao

Horticulturae 2022, 8(4), 347; https://doi.org/10.3390/horticulturae8040347 - 18 Apr 2022

Cited by 1 | Viewed by 2209

Abstract

Previous studies on Camellia oleifera pollen morphology have indicated dual morphologies, defined as “dimorphism”. However, they were limited to morphological studies at the end of final development and did not elucidate the origin, structure, and function of the second pollen morphology (striate pollen). [...] Read more.

Previous studies on Camellia oleifera pollen morphology have indicated dual morphologies, defined as “dimorphism”. However, they were limited to morphological studies at the end of final development and did not elucidate the origin, structure, and function of the second pollen morphology (striate pollen). In this study, the differences between the two “pollen” types were compared by paraffin sections, scanning electron microscopy (SEM), fluorescence microscopy, and in vitro germination. The results clearly showed that the second pollen type was formed by stomium cells of the anther, which is responsible for anther dehiscence. The nucleus and vesicles of the stomium cell were specifically distributed during anther development, which may be related to the formation of the septum, pollen dispersal activity, and the increase in stomium cell count; at the microscopic level, the stomium cell mainly consisted of the cell wall, large vesicles, and nucleus. The large vesicles facilitate the rapid dehydration of stomium cells under suitable conditions for anther dehiscence. Furthermore, studies on other species of the genus Camellia have suggested that the second type of pollen morphology is pseudopollen, which is capable of partaking in deceptive pollination. The present study refuted this theory and suggested that the pseudopollen are stomium cells, whose structure relates to their function. These results provide the basis for further research on C. oleifera pollen physiology toward the improvement of pollination rates with agricultural practices or breeding interventions. Full article

(This article belongs to the Section Propagation and Seeds)

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7 pages, 922 KiB

Open AccessEditor’s ChoiceArticle

Growth Characteristics of Lettuce Relative to Generation Position of Air Anions in a Closed-Type Plant Factory

by Jin-Ho Won, Byeong-Hyo Cho, Yong-Hyeon Kim and Jung-Hyun Lee

Horticulturae 2022, 8(4), 346; https://doi.org/10.3390/horticulturae8040346 - 18 Apr 2022

Cited by 1 | Viewed by 2015

Abstract

(1) Background: We studied how the generation position of air anions in a closed-type plant factory affects the growth characteristics of lettuce and identified the optimal position. (2) Methods: We used LEDs (red/green/blue = 8:1:1) as a light source and set the temperature [...] Read more.

(1) Background: We studied how the generation position of air anions in a closed-type plant factory affects the growth characteristics of lettuce and identified the optimal position. (2) Methods: We used LEDs (red/green/blue = 8:1:1) as a light source and set the temperature and RH of the plant factory to 20 ± 2 ℃ and 50% ± 5%, respectively. We grew lettuce under three air anion conditions—sideward, upward, and downward—and compared the growth characteristics to those of a control grown without air anions. We measured the growth characteristics of the lettuce at 3 and 4 weeks after sowing, and the measurement items were shoot fresh weight (FW) and dry weight (DW); leaf area (LA), length (LL), and width (LW); SPAD; antioxidant capacity; and total phenol content. (3) Results: At 4 weeks, FW in the downward treatment condition was 25.3% higher than in the control, and DW showed a similar difference. LA was about 1943.94 cm²/plant in the downward treatment condition, which was about 15.5% higher than in the control. (4) Conclusions: We conclude that air anion generation has a positive effect on lettuce growth, and the optimal generation position for air anions is downward. Full article

(This article belongs to the Section Vegetable Production Systems)

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15 pages, 2127 KiB

Open AccessEditor’s ChoiceArticle

Irrigation Levels and Fertilization Rates as Pre-Harvest Factors Affecting the Growth and Quality of Hippeastrum

by Chaiartid Inkham, Kanokwan Panjama and Soraya Ruamrungsri

Horticulturae 2022, 8(4), 345; https://doi.org/10.3390/horticulturae8040345 - 18 Apr 2022

Cited by 1 | Viewed by 2228

Abstract

Growing Hippeastrum in an open field or a greenhouse requires precision irrigation and fertilizer to promote plant growth and development. Therefore, this research aimed to study the effect of irrigation level combined with fertilization rate on the growth and development of Hippeastrum. [...] Read more.

Growing Hippeastrum in an open field or a greenhouse requires precision irrigation and fertilizer to promote plant growth and development. Therefore, this research aimed to study the effect of irrigation level combined with fertilization rate on the growth and development of Hippeastrum. Two experiments were carried out to determine the influence of irrigation and fertilizer on the growth, flowering, and bulb quality of Hippeastrum. In the first experiment, bulbs of Hippeastrum ‘Red Lion’ with circumferences of 25 cm were grown in plastic plots using mixed soil as growing media under a 50% shading net. Plants were irrigated daily until drainage and water contained in macropores by gravity action (Field capacity: FC) for 90 days after planting (DAP) and supplied with three different 15N-15P₂O₅-15K₂O fertilization rates, i.e., 0, 2.5, and 5 g per pot. Plant growth and water use efficiency were measured at 45, 60, and 90 DAP. The results showed that plants supplied with 0 g of fertilizer had the lowest plant height and number of leaves per plant at 90 DAP, whereas there was no significant effect of fertilizer rate treatments on flower quality. The water use efficiency, evapotranspiration rate (ET), crop evapotranspiration under standard condition (ETc), crop coefficient (Kc), photosynthetic rate, and stomatal conductance were decreased when plants were supplied with fertilizer at a rate of 0 g per pot at 90 DAP. In the second experiment, plants were irrigated with four levels, i.e., 100, 75, 50, and 25% ETc combined with three fertilization rates, i.e., 0, 2.5, and 5 g per pot. At 180 DAP, the results showed that water deficit treatment (50 and 25% ETc) decreased plant growth and bulb quality. Irrigation with 100% ETc combined with 2.5 or 5 g per pot and irrigation with 75% ETc combined with 5 g per pot were the optimum levels to promote plant growth and bulb quality in Hippeastrum. Full article

(This article belongs to the Special Issue Factors Affecting Export Flower Quality and Strategies for Prolonging Flowers Vase Life)

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12 pages, 626 KiB

Open AccessArticle

Evaluation of Sacha Inchi (Plukenetia volubilis L.) By-Products as Valuable and Sustainable Sources of Health Benefits

by Suwapat Kittibunchakul, Chatrapa Hudthagosol, Promluck Sanporkha, Suwimol Sapwarobol, Piya Temviriyanukul and Uthaiwan Suttisansanee

Horticulturae 2022, 8(4), 344; https://doi.org/10.3390/horticulturae8040344 - 17 Apr 2022

Cited by 10 | Viewed by 4902

Abstract

By-products from sacha inchi (Plukenetia volubilis L.) oil extraction as the husk and shell are used as low value fertilizer or animal feed. The nutritive values, antioxidant activities, phenolics, and in vitro health-related activities of the sacha inchi husk and shell were [...] Read more.

By-products from sacha inchi (Plukenetia volubilis L.) oil extraction as the husk and shell are used as low value fertilizer or animal feed. The nutritive values, antioxidant activities, phenolics, and in vitro health-related activities of the sacha inchi husk and shell were investigated and compared to increase their economic potential as future food sources. Higher protein, carbohydrates, and total dietary fiber content were detected in the husk, while higher fat content and energy were found in the shell. Several phenolics were also detected in both the husk and shell, with p-coumaric acid being the most abundant phenolic in the shell and caffeic acid in the husk. Total phenolic content was 1.6-fold greater in the shell than in the husk, leading to 1.8–2.7-fold higher antioxidant activity and 1.2-fold higher anti-glycation activity. Various types and quantities of phenolics also led to diverse in vitro enzyme inhibitory activities in the husk and shell. Knowledge received from this research might be useful to maximize the utilization of by-products from sacha inchi oil extraction as future food sources with valuable nutritional compositions, phenolics, and potential health benefits. Further investigations on the health properties of the sacha inchi husk and shell should include toxicity, bioaccessibility, and in vivo experiments. Full article

(This article belongs to the Special Issue Horticultural Plants and By-Products as Sources of Biological Active Compounds)

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29 pages, 11011 KiB

Open AccessFeature PaperArticle

Six First Reports of Pin Nematodes from Portugal, with an Update of the Systematics, Genetic Diversity, and Phylogeny of the Genus Paratylenchus (Nematoda: Tylenchulidae)

by Teresa Rosmaninho, Manuel Mota, Maria L. Inácio, Jonathan D. Eisenback and Carlos Gutiérrez-Gutiérrez

Horticulturae 2022, 8(4), 343; https://doi.org/10.3390/horticulturae8040343 - 17 Apr 2022

Cited by 3 | Viewed by 3278

Abstract

Pin nematodes (Paratylenchus spp.) currently comprise 132 species of polyphagous plant ectoparasites with at least seven species that are plant pathogenic emphasizing the need for correct identification to establish an appropriate management strategy. Sequences of highly conserved regions of ribosomal and mitochondrial [...] Read more.

Pin nematodes (Paratylenchus spp.) currently comprise 132 species of polyphagous plant ectoparasites with at least seven species that are plant pathogenic emphasizing the need for correct identification to establish an appropriate management strategy. Sequences of highly conserved regions of ribosomal and mitochondrial RNA genes are a powerful species-level diagnostic tool within Tylenchulidae. A nematological survey was conducted from 2019 to 2021 in commercial vineyards distributed in four major wine-producing regions in the Central and South Portugal. Nine populations of Paratylenchus spp. were isolated from the rhizosphere of grapevines that were characterized from morphological data and molecular phylogenetic analysis using two rRNA genes (D2–D3 expansion segments of the 28S, and partial 18S) and a region partial of the COI mtRNA gene. Contrasting morphological hypotheses with molecular data provided rapid detection of six species, specifically P. goodeyi, P. hamatus, P. pedrami, P. tenicaudatus, P. variabilis, and P. veruculatus. Bayesian inference (BI) phylogenetic trees for these molecular markers established phylogenetic relationships underscore the importance of using genomic and molecular phylogenetic data for accurate pin nematode identification at the species level. To our knowledge, this is the first report of Paratylenchus spp. in Portugal, extending the geographical distribution of these species in the Mediterranean Basin, and the first record of P. goodeyi, P. pedrami, P.variabilis, P. veruculatus and P. tenicaudatus parasitizing grapevine. Full article

(This article belongs to the Special Issue Recent Advance in the Identification and Diagnostics of Plant-Parasitic Nematodes)

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16 pages, 3426 KiB

Open AccessArticle

Optimization of Infrared Postharvest Treatment of Barhi Dates Using Response Surface Methodology (RSM)

by Diaeldin O. Abdelkarim, Khaled A. Ahmed, Mahmoud Younis, Hany M. Yehia, Assem I. Zein El-Abedein, Abdulla Alhamdan and Isam A. Mohamed Ahmed

Horticulturae 2022, 8(4), 342; https://doi.org/10.3390/horticulturae8040342 - 17 Apr 2022

Cited by 5 | Viewed by 2060

Abstract

Barhi dates are widely consumed at Khalal maturity stage and preserving the freshness quality of Barhi at this stage is a challenging task as this period is short and the fruits are more perishable. In this study, response surface methodology (RSM) was applied [...] Read more.

Barhi dates are widely consumed at Khalal maturity stage and preserving the freshness quality of Barhi at this stage is a challenging task as this period is short and the fruits are more perishable. In this study, response surface methodology (RSM) was applied to optimize the infrared (IR) treatment and storage conditions for preserving the physicochemical, microbial, and bioactive attributes of fresh Barhi dates. The effect of four factors, IR temperature (50, 70, 90, and 110 °C), IR time (1, 2, 3, and 4 min), storage temperature (1, 5, 15, and 25 °C), and storage time (1, 6, 11, 16, and 21 days), on the responses of total soluble solids (TSS), hardness, total color change (ΔE), total viable count (TVC), total phenolic content (TPC), antioxidant activity (DPPH), and glucose content were evaluated following central composite design (CCD). IR temperature, IR time, storage temperature, and storage time significantly affected the physical, microbial, and bioactive attributes of Barhi dates. The optimal conditions for minimizing the physical changes and microbial load and maximizing the bioactive attributes were IR temperature of 50 °C, IR time of 1.2 min, storage temperature of 1 °C, and storage time of 20 days. At the optimum conditions, the values of TSS, hardness, ΔE, TVC, TPC, DPPH, and glucose were 37.22%, 70.17 N, 11.12, 2.9 log CFU/g, 36.1 mg GAE/g, 65.31%, and 25.38 mg/g, respectively and these values were similar to predicted values. In conclusion, this study identified the ideal IR treatment and storage conditions for maintaining the overall quality attributes of Barhi dates during prolonged storage. Full article

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19 pages, 2538 KiB

Open AccessEditor’s ChoiceArticle

Combining Cultural Tactics and Insecticides for the Management of the Sweetpotato Whitefly, Bemisia tabaci MEAM1, and Viruses in Yellow Squash

by Angela Gabrielle LaTora, Clarence Bagayao Codod, Saioa Legarrea, Bhabesh Dutta, Robert C. Kemerait, Jr., Scott Adkins, William Turechek, Timothy Coolong, Andre Luiz Biscaia Ribeiro da Silva and Rajagopalbabu Srinivasan

Horticulturae 2022, 8(4), 341; https://doi.org/10.3390/horticulturae8040341 - 17 Apr 2022

Cited by 8 | Viewed by 3017

Abstract

The sweetpotato whitefly, Bemisia tabaci MEAM1 Gennadius (Hemiptera: Aleyrodidae), and the complex of viruses it transmits are major limiting factors to squash production in the southeastern United States. At this time, insecticides are extensively relied upon for the management of whiteflies and, indirectly, [...] Read more.

The sweetpotato whitefly, Bemisia tabaci MEAM1 Gennadius (Hemiptera: Aleyrodidae), and the complex of viruses it transmits are major limiting factors to squash production in the southeastern United States. At this time, insecticides are extensively relied upon for the management of whiteflies and, indirectly, whitefly-transmitted viruses. The development of a multi-faceted, integrated pest management (IPM) program is needed to increase the sustainability and profitability of squash production. Experiments in 2018 and 2019 evaluated the effects of insect exclusion netting (IEN) in combination with selected pesticides on whitefly population dynamics and virus incidence in greenhouse-grown squash seedlings. Field experiments from 2018 to 2021 evaluated the effects of mulch type (UV-reflective mulch, live mulch, and white plastic mulch), row covers, and insecticides on whitefly population dynamics, silver leaf disorder (SSL) intensity, virus symptom severity, and marketable yield. IEN significantly reduced whiteflies and virus incidence on squash seedlings in the greenhouse study. In the field mulch study, lower whitefly abundance and SSL intensity, as well as reduced virus symptom severity, were observed in plots with reflective mulch compared with white plastic or live mulch. In the insecticide/row cover study, whitefly abundance, SSL intensity, and virus symptom severity were lowest in the row cover and cyantraniliprole- and flupyradifurone-treated plots. Field plots with row covers and those with UV-reflective mulch consistently produced the greatest marketable yields. These findings demonstrate that growers can reduce whitefly and virus pressure and preserve yields in squash production in the southeastern United States by combining cultural and chemical tactics, including row covers, UV-reflective mulch, and select insecticides. Full article

(This article belongs to the Special Issue Implementation of IPM Measures in Vegetable Cropping Systems)

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13 pages, 1416 KiB

Open AccessArticle

Micropropagation from Inflorescence Nodal Segments of Phalaenopsis and Acclimatization of Plantlets Using Different Substrates

by Cesar Augusto Zanello, Willian Naves Duarte, Daniela Mangueira Gomes and Jean Carlos Cardoso

Horticulturae 2022, 8(4), 340; https://doi.org/10.3390/horticulturae8040340 - 16 Apr 2022

Cited by 1 | Viewed by 5396

Abstract

Phalaenopsis is an orchid genus of great economic value in world floriculture. In vitro clonal propagation is the only large-scale feasible method for Phalaenopsis propagation, but it is difficult because of the low multiplication rate. The aim of this study was to evaluate [...] Read more.

Phalaenopsis is an orchid genus of great economic value in world floriculture. In vitro clonal propagation is the only large-scale feasible method for Phalaenopsis propagation, but it is difficult because of the low multiplication rate. The aim of this study was to evaluate the effect of types and concentrations of N⁶-benzyladenine (6-BA) and gibberellic acid (GA₃) on the in vitro multiplication of shoots from inflorescence nodal segments (INS) of Phalaenopsis hybrids. INS with one axillary bud were inoculated in New Dogashima Medium with different combinations of BA and GA₃. The results show that the treatment containing 1.0 mg L⁻¹ BA and 1.5 mg L⁻¹ GA₃ showed the higher percentage of live inflorescence segments (71.48%) and a number of shoots (1.68 shoots/INS). The highest 6-BA concentration (4 mg L⁻¹) tested in this study resulted in the best shoot multiplication rate (4.3). Contamination and browning of the INS tissues were the main difficulties identified for clonal propagation of Phalaenopsis. Successful in vitro rooting occurred on half-strength Murashige and Skoog medium (100%), and acclimatization (100%) was obtained independent of the substrates. However, the best gains in number of roots, leaves, chlorophyll content, and fresh weight of plantlets were achieved using vermiculite. Full article

(This article belongs to the Special Issue Innovation in Propagation and Cultivation of Ornamental Plants)

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13 pages, 2431 KiB

Open AccessFeature PaperArticle

Plant Growth and Chemical Properties of Commercial Biochar- versus Peat-Based Growing Media

by Bruno Glaser and Angela Amma Asieduaa Asomah

Horticulturae 2022, 8(4), 339; https://doi.org/10.3390/horticulturae8040339 - 16 Apr 2022

Cited by 6 | Viewed by 2163

Abstract

Peatlands have been irreversibly destroyed by draining and mining for horticulture, in the course of which tremendous amounts of greenhouse gasses were released into the atmosphere. To avoid this in the future, sustainable alternatives are urgently needed to substitute peat as growing media. [...] Read more.

Peatlands have been irreversibly destroyed by draining and mining for horticulture, in the course of which tremendous amounts of greenhouse gasses were released into the atmosphere. To avoid this in the future, sustainable alternatives are urgently needed to substitute peat as growing media. An appropriate alternative could be biochar, because it has beneficial effects on nutrient availability and retention, water holding capacity, and organic matter stability. In this study, we compared three different commercially available biochar-containing growing media (Palaterra, Sonnenerde, Terra Magica) with three commercially available peat-based growing media (CompoSana, Dehner die leichte, Dehner mit Vorratsdünger), in a randomized greenhouse pot experiment. Pure sand was used as a control and, to test a potential amount effect, we mixed the used growing media with increasing amounts of pure sand (0, 25, 50, 75, and 100 volume % of individual growing media). The consecutive yields of several agronomically relevant cereals (barley, wheat, and maize) were measured in the mixtures mentioned previously. Additionally, the contents of biochar, amino sugar, and polycyclic aromatic hydrocarbons were measured in each pure growing media before and after the growth experiments. Only Sonnenerde exhibited an increased plant yield of 30–40% compared with peat-based growing media. The growing media exhibited no significant differences of chemical soil properties during the experiment. Only slight tendencies are recognizable towards higher fungal community in biochar- and peat-based growing media. A clear fungi contribution was observed in Palaterra, most probably due to the fact that fungi was a production ingredient. Surprisingly, peat-based growing media also contained about 30 g kg⁻¹ black carbon, a polycondensed aromatic carbon typical for biochar. Overall, our results indicated that biochar-containing growing media, especially Sonnenerde, is a potential alternative for peat-based growing media in horticulture and can enhance degraded soils. Full article

(This article belongs to the Special Issue Application of Chars in Growing Media)

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19 pages, 1748 KiB

Open AccessArticle

Manipulation of the Phenolic Quality of Assam Green Tea through Thermal Regulation and Utilization of Microwave and Ultrasonic Extraction Techniques

by Kanjana Singh, Somdet Srichairatanakool, Teera Chewonarin, Charles Stephen Brennan, Margaret Anne Brennan, Wannaporn Klangpetch and Niramon Utama-ang

Horticulturae 2022, 8(4), 338; https://doi.org/10.3390/horticulturae8040338 - 16 Apr 2022

Cited by 7 | Viewed by 2308

Abstract

The aim of this study was to investigate the catechin levels and antioxidant activities as manipulated by roasting temperature and roasting time of green tea. Roasting temperature and time varied between 100–300 °C and 60–240 s in green tea production. The main interactions [...] Read more.

The aim of this study was to investigate the catechin levels and antioxidant activities as manipulated by roasting temperature and roasting time of green tea. Roasting temperature and time varied between 100–300 °C and 60–240 s in green tea production. The main interactions measured were effects on the antioxidant activities, total phenolic content, DPPH, ABTS, FRAP and catechin content (catechin (C), epigallocatechin gallate (EGCG), epigallocatechin (EGC), epicatechin gallate (ECG) and epicatechin (EC)). Optimum roasting conditions were determined as 270 °C for 240 s, since this enabled high catechin contents, antioxidant activities and production yield. The extraction methods for green tea including traditional extraction (TDE), microwave-assisted extraction (MAE) and ultrasonic-assisted extraction (UAE) using 60% ethanol as solvent were investigated to evaluate the highest bioactive compound and yield of extraction. MAE was found to be more efficient in green tea extraction compared to UAE and TDE. The extracts showed significant cytotoxic potential against the Huh-7 cell line, in concentrations ranging from 31.25 to 1000 µg/mL. The results are useful in understanding the relationship between thermal treatment and extraction conditions on the chemical and nutritional properties of tea catechins, making it possible to select the production and extraction conditions that maximize the levels of beneficial tea ingredients. Full article

(This article belongs to the Special Issue Advances in Tea Plant Biology and Tea Quality Regulation)

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19 pages, 2175 KiB

Open AccessArticle

Plant Regeneration Protocol for Recalcitrant Passionflower (Passiflora quadrangularis L.)

by Paula Boboc Oros, Maria Cantor, Mirela Irina Cordea and Corina Cătană

Horticulturae 2022, 8(4), 337; https://doi.org/10.3390/horticulturae8040337 - 16 Apr 2022

Cited by 2 | Viewed by 2558

Abstract

This research was designed to provide the first protocol to establish an efficient solution for direct organogenesis regeneration in Passiflora quadrangularis using nodal explants from young shoots. Passifloraceae tissue culture has been associated with problems such as recalcitrance, sensitivity to ethylene accumulation and [...] Read more.

This research was designed to provide the first protocol to establish an efficient solution for direct organogenesis regeneration in Passiflora quadrangularis using nodal explants from young shoots. Passifloraceae tissue culture has been associated with problems such as recalcitrance, sensitivity to ethylene accumulation and browning of explants due to the presence of phenols in the tissues. Due to the high rate of endogenous contamination of the explants, a preliminary experiment was performed. The best results of surface sterilization were obtained using the pretreatment with 70% EtOH, 1 min and 50% NaOCl, 10 min along with the treatment of Rifampicin 15 µg/mL and Benomyl 2 g/L. The effects of plant growth regulators on the induction of direct organogenesis, multiplication of shoots in subcultures and in vitro rooting were evaluated. Additional compounds such as AgNO₃ and Pluronic F-68 were added to the culture media in order to reduce the effects of phenols and the sudden browning of the explants. Shoot proliferation increased to the sixth subculture after which it decreased. A maximum of 7.17 shoots were obtained from one shoot on Murashige and Skoog (MS) medium supplemented with 2 mg/L 6-benzylaminopurine and 1 mg/L thidiazuron. Supplementation of ½ MS medium with 1 mg/L 1-naphthaleneacetic acid was conducing to root formation in 61.11% of shoots. After acclimatization, the plants showed vigorous growth, green leaves, and well-developed roots. Although this species has previously shown difficulty in in vitro propagation, this protocol established based on the results proved to be efficient and reproducible. Full article

(This article belongs to the Section Propagation and Seeds)

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14 pages, 14388 KiB

Open AccessEditor’s ChoiceArticle

Impact of Pseudomonas sp. SVB-B33 on Stress- and Cell Wall-Related Genes in Roots and Leaves of Hemp under Salinity

by Roberto Berni, Jean-Francois Hausman, Silas Villas-Boas and Gea Guerriero

Horticulturae 2022, 8(4), 336; https://doi.org/10.3390/horticulturae8040336 - 15 Apr 2022

Cited by 5 | Viewed by 1988

Abstract

Salinity is a type of abiotic stress that negatively affects plant growth and development. Textile hemp (Cannabis sativa L.) is an important multi-purpose crop that shows sensitivity to salt stress in a genotype- and developmental stage-dependent manner. The root and shoot biomasses [...] Read more.

Salinity is a type of abiotic stress that negatively affects plant growth and development. Textile hemp (Cannabis sativa L.) is an important multi-purpose crop that shows sensitivity to salt stress in a genotype- and developmental stage-dependent manner. The root and shoot biomasses decrease in the presence of NaCl during vegetative growth and several stress-responsive genes are activated. Finding environmentally friendly ways to increase plant health and resilience to exogenous stresses is important for a sustainable agriculture. In this context, the use of beneficial bacteria, collectively referred to as plant growth-promoting bacteria (PGPB), is becoming an attractive and emergent agricultural strategy. In this study, data are provided on the effects of a Pseudomonas isolate (Pseudomonas sp. SVB-B33) phylogenetically closely related to P. psychrotolerans applied via roots to salt-stressed hemp. The application of both living and dead bacteria impacts the fresh weight of the root biomass, as well as the expression of several stress-related genes in roots and leaves. These results pave the way to future investigations on the use of Pseudomonas sp. SVB-B33 in combination with silica to mitigate stress symptoms and increase the resilience to other forms of exogenous stresses in textile hemp. Full article

(This article belongs to the Special Issue Cell Wall Composition and Extract)

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12 pages, 1360 KiB

Open AccessArticle

Performance of Cowpea under Different Water Regimes in Amazonian Conditions

by Denis de Pinho Sousa, Hildo Giuseppe Garcia Caldas Nunes, Denilson Pontes Ferreira, Vandeilson Belfort Moura, William Lee Carrera de Aviz, Helane Cristina Aguiar Santos, João Vitor de Novoa Pinto, Igor Cristian de Oliveira Vieira, Gabriel Siqueira Tavares Fernandes, Ewelyn Regina Rocha Silva, Lucas Tavares Belém, Jaime Borges da Cunha Junior, Marcus José Alves de Lima, Adriano Marlisom Leão de Sousa, Vivian Dielly da Silva Farias, Joyse Tatiane Souza Santos and Paulo Jorge de Oliveira Ponte de Souza

Horticulturae 2022, 8(4), 335; https://doi.org/10.3390/horticulturae8040335 - 15 Apr 2022

Cited by 1 | Viewed by 1786

Abstract

Water availability is a crucial factor in the final productivity of cowpea. The objective of this work was to evaluate the production and productivity components of cowpea under different irrigation depths in Amazonian conditions. The experiment was carried out at the School Farm [...] Read more.

Water availability is a crucial factor in the final productivity of cowpea. The objective of this work was to evaluate the production and productivity components of cowpea under different irrigation depths in Amazonian conditions. The experiment was carried out at the School Farm of the Federal Rural University of Amazonia, in the municipality of Castanhal-PA, using the cultivar BR3 Tracuateua, from September to November 2014, 2015, and 2016. The experimental design was conducted on six blocks and four treatments, where the four irrigation depths of 0, 25, 50, and 100% of crop evapotranspiration were tested. The productivity analysis was performed when 90% of the plants were in the phenological stage R9. The evaluated production components were pod length, number of pods per plant, number of grains per pod, mass of one hundred grains, and harvest index. There was a statistical difference among all treatments for the components of production and among productivities. An average reduction of 827 kg ha⁻¹ in cowpea productivity was observed during the three years of study, when the treatment without irrigation was compared with the treatment irrigated with 100% of the crop’s water demand. It was found in this research that the simple fulfillment of the nutritional and phytosanitary demands of the crop, associated with an adequate planning of when to plant in the region, would already help in the improvement of local production when choosing times where the water deficit in the reproductive phase is less than 33 mm. Full article

(This article belongs to the Section Plant Nutrition)

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19 pages, 336 KiB

Open AccessArticle

Integrative Seed and Leaf Treatment with Ascorbic Acid Extends the Planting Period by Improving Tolerance to Late Sowing Influences in Parsley

by Sudad K. Al-Taweel, Hussein E. E. Belal, Dalia M. El Sowfy, El-Sayed M. Desoky, Mostafa M. Rady, Khaled E. Mazrou, Ahmed R. M. Maray, Mohamed E. El-Sharnouby, Khalid H. Alamer, Esmat F. Ali and Alaa I. B. Abou-Sreea

Horticulturae 2022, 8(4), 334; https://doi.org/10.3390/horticulturae8040334 - 15 Apr 2022

Cited by 3 | Viewed by 1914

Abstract

Abnormal production of reactive oxygen species (ROS) is an undesirable event which occurs in plants due to stress. To meet this event, plants synthesize ROS-neutralizing compounds, including the non-enzymatic oxidant scavenger known as vitamin C: ascorbic acid (AsA). In addition to scavenging ROS, [...] Read more.

Abnormal production of reactive oxygen species (ROS) is an undesirable event which occurs in plants due to stress. To meet this event, plants synthesize ROS-neutralizing compounds, including the non-enzymatic oxidant scavenger known as vitamin C: ascorbic acid (AsA). In addition to scavenging ROS, AsA modulates many vital functions in stressed or non-stressed plants. Thus, two-season (2018/2019 and 2019/2020) trials were conducted to study the effect of integrative treatment (seed soaking + foliar spray) using 1.0 or 2.0 mM AsA vs. distilled water (control) on the growth, seed yield, and oil yield of parsley plants under three sowing dates (SDs; November, December, and January, which represent adverse conditions of late sowing) vs. October as the optimal SD (control). The ion balance, osmotic-modifying compounds, and different antioxidants were also studied. The experimental layout was a split plot in a completely randomized block design. Late sowing (December and January) noticeably reduced growth traits, seed and oil yield components, and chlorophyll and nutrient contents. However, soluble sugar, proline, and AsA contents were significantly increased along with the activities of catalase (CAT) and superoxide dismutase (SOD). Under late sowing conditions, the use of AsA significantly increased growth, different yields, essential oil fractions, CAT and SOD activities, and contents of chlorophylls, nutrients, soluble sugars, free proline, and AsA. The interaction treatments of SDs and AsA concentrations indicated that AsA at a concentration of 2 mM was more efficient in conferring greater tolerance to adverse conditions of late sowing in parsley plants. Therefore, this study recommends 2.0 mM AsA for integrative (seed soaking + foliar spraying) treatment to prolong the sowing period of parsley seeds (from October up to December) and avoid damage caused by adverse conditions of late sowing. Full article

(This article belongs to the Special Issue Plants Response to Abiotic Stresses: Strategies for Adaptations and Survival)

11 pages, 1830 KiB

Open AccessArticle

Potential Uses of Scallop Shell Powder as a Substrate for the Cultivation of King Oyster Mushroom (Pleurotus eryngii)

by Yuanyuan Zhou, Zihao Li, Haijun Zhang, Qingxiu Hu and Yajie Zou

Horticulturae 2022, 8(4), 333; https://doi.org/10.3390/horticulturae8040333 - 14 Apr 2022

Cited by 5 | Viewed by 2651

Abstract

Scallop shells are currently a major form of waste generated in the Chinese fishing industry. However, they have the potential to be used as important industrial products. This study was conducted to assess the utility of scallop shell powder (SSP) supplementation in improving [...] Read more.

Scallop shells are currently a major form of waste generated in the Chinese fishing industry. However, they have the potential to be used as important industrial products. This study was conducted to assess the utility of scallop shell powder (SSP) supplementation in improving the growth of king oyster mushrooms (Pleurotus eryngii) grown on sawdust and sugarcane bagasse substrates. The outcomes of interest included mycelial growth, yield, biological efficiency, fruiting body traits, nutrient supply, and the mineral composition of P. eryngii. Supplementation with SSP accelerated the mycelial growth of P. eryngii. The yield of fruiting bodies (399.5 g/bag) and the biological efficiency (84.6%) were 14% higher after supplementation of the substrate with 2% SSP compared with those of mushrooms grown on substrates not supplemented with SSP (349.8 g/bag and 74.0%, respectively). Moreover, the crude protein and fiber contents of the fruiting bodies significantly improved after growth with SSP. Furthermore, supplementation with 2% SSP increased the calcium (Ca) content of the fruiting bodies of P. eryngii by 64% (to 67.2 ± 15.7 mg kg⁻¹) compared with that of mushrooms grown on a control substrate (41.0 mg kg⁻¹). This study revealed that P. eryngii can efficiently use the Ca provided by raw SSP, generating higher Ca contents in their fruiting bodies. Our results demonstrate that the supplementation of substrates with SSP can be useful for enhancing both the yield and nutritional content of P. eryngii. Full article

(This article belongs to the Topic Mycorrhizal Fungi Mediated Sustainable Crop Production)

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14 pages, 2230 KiB

Open AccessArticle

PpMYB39 Activates PpDFR to Modulate Anthocyanin Biosynthesis during Peach Fruit Maturation

by Irshad Ahmad Khan, Masood Ur Rahman, Shazia Sakhi, Ghazala Nawaz, Aftab Ahmad Khan, Tanveer Ahmad, Mohammad Adnan and Shah Masaud Khan

Horticulturae 2022, 8(4), 332; https://doi.org/10.3390/horticulturae8040332 - 14 Apr 2022

Cited by 8 | Viewed by 2482

Abstract

Anthocyanins are a class of water-soluble flavonoids widely present in fruits and vegetables responsible for the red flesh formation of peach fruit. Previously, several genes of the MYB family have been reported as transcriptional regulators of the anthocyanin biosynthetic pathway of structural genes [...] Read more.

Anthocyanins are a class of water-soluble flavonoids widely present in fruits and vegetables responsible for the red flesh formation of peach fruit. Previously, several genes of the MYB family have been reported as transcriptional regulators of the anthocyanin biosynthetic pathway of structural genes in plants. In this study, through comparative transcriptome analysis of the white and red flesh peach cultivars of Harrow Blood and Asama Hakuto, a predicted transcription factor of the R2R3MYB family, PpMYB39, was identified to be associated with anthocyanin biosynthesis in peach fruit. In red-fleshed peach cultivars, the maximum amount of anthocyanin accumulated 95 days after full bloom (DAFB), at full maturity near ripening. Our results showed that, at this stage, PpMYB39 had the highest expression level among the 13 differentially expressed genes (DEGs) found in both red- and white-fleshed fruits, as well as a high correlation with total anthocyanin content throughout fruit development. Moreover, the expression analysis of the structural genes of the anthocyanin biosynthetic pathway in peach fruit revealed that Prunus persica Dihydroflavonol-4-reductase (PpDFR) was co-expressed and up-regulated with PpMYB39 at 95 DAFB, suggesting its possible role as a transcriptional activator of MYB39. This was further confirmed by a yeast one-hybrid assay and a dual luciferase reporter assay. Our results will be helpful in the breeding of peach cultivars and the identification and significance of color in peaches and related fruit species, in addition to providing an understanding of color formation in peach fruit for future research. Full article

(This article belongs to the Topic Plant Breeding, Genetics and Genomics)

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14 pages, 284 KiB

Open AccessFeature PaperArticle

Bioconversion of Agricultural Wastes into a Value-Added Product: Straw of Norwegian Grains Composted with Dairy Manure Food Waste Digestate in Mushroom Cultivation

by Agnieszka Jasinska, Ewelina Wojciechowska, Ketil Stoknes and Michał Roszak

Horticulturae 2022, 8(4), 331; https://doi.org/10.3390/horticulturae8040331 - 14 Apr 2022

Cited by 4 | Viewed by 2822

Abstract

Commercial mushroom production is based on composted locally available agro-industrial wastes rich in carbon and nitrogen such as wheat straw supplemented with chicken manure. Either component can be replaced by other kinds of grain straw: barley, oat, or a mixture of different straw [...] Read more.

Commercial mushroom production is based on composted locally available agro-industrial wastes rich in carbon and nitrogen such as wheat straw supplemented with chicken manure. Either component can be replaced by other kinds of grain straw: barley, oat, or a mixture of different straw types and combined with diary manure—food waste digestate after anaerobic biogas digestion. Original, unseparated liquid digestate is nutritious, rich in nitrogen and organic matter. This research aimed to investigate the effect of digestate and different straw ratios on the composting process and productivity and their consequent effect on mushroom cultivation parameters of Agaricus subrufescens. All investigated experimental mushroom compost (EMC) types worked well during the composting process, reaching the desired moisture of 65–75%, N content of 1.43–1.93%, and a C/N ratio ranging from 21.5 to 29.1, supporting growth of mycelium and producing mushrooms. Supplementation with barley straw resulted in better EMC structure with the highest yield and biological efficiency (BE) (157.9 g kg⁻¹; 64%), whereas oat addition gave the lowest yield and BE (88.6 g kg⁻¹ and 38%). Precociousness (yield at mid-cycle of the crop development) was higher for oat substrates (68.9%), while earliness (days to harvest from casing) was lower for barley EMC. Full article

(This article belongs to the Collection Sustainable Mushroom Cultivation)

16 pages, 30508 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Woody Canker and Shoot Blight Caused by Botryosphaeriaceae and Diaporthaceae on Mango and Litchi in Italy

by Dalia Aiello, Vladimiro Guarnaccia, Mariangela Benedetta Costanzo, Giuseppa Rosaria Leonardi, Filomena Epifani, Giancarlo Perrone and Giancarlo Polizzi

Horticulturae 2022, 8(4), 330; https://doi.org/10.3390/horticulturae8040330 - 14 Apr 2022

Cited by 9 | Viewed by 2662

Abstract

In recent years, the cultivation of tropical fruit crops has increased in the Mediterranean basin, especially in southern Italy. In surveys conducted from 2014 to 2019 woody canker and shoot blight were observed on mango plants (cvs. Kent, Keitt, Sensation, Osteen, and Kensington [...] Read more.

In recent years, the cultivation of tropical fruit crops has increased in the Mediterranean basin, especially in southern Italy. In surveys conducted from 2014 to 2019 woody canker and shoot blight were observed on mango plants (cvs. Kent, Keitt, Sensation, Osteen, and Kensington Pride) and litchi plants (cvs. Way Chee and Kwai Mai Pink) cultivated in Sicily. Botryosphaeriaceae and Diaporthaceae were consistently isolated from symptomatic samples. Morphological characterization and multi-locus phylogenies using three genomic loci (a portion of translation elongation factor 1-α gene, a portion of the β-tubulin gene, and an internal transcribed spacer) identified these fungi as Neofusicoccum parvum, Lasiodiplodia theobromae, Botryosphaeria dothidea, Diaporthe foeniculina, and Diaporthe baccae on mango and Diaporthe foeniculina and Diaporthe rudis on litchi. Pathogenicity tests on healthy mango (cv. Kensington Pride) and litchi (cv. Way Chee) plants demonstrated the pathogenicity of the isolates used in the study, and Koch’s postulates were fulfilled for all pathogens. To our knowledge, this is the first report of L. theobromae, B. dothidea, and Diaporthe species on mango in Italy and the first report worldwide of woody canker and shoot blight caused by D. foeniculina and D. rudis on litchi plants. Full article

(This article belongs to the Special Issue Pathogens and Disease Control of Fruit Trees)

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2 pages, 156 KiB

Open AccessEditorial

Best Papers Introduction

by Luigi De Bellis

Horticulturae 2022, 8(4), 329; https://doi.org/10.3390/horticulturae8040329 - 14 Apr 2022

Viewed by 1046

Abstract

I am pleased to announce three articles published in Horticulture in 2020 which were considered eligible for the Best Paper Award 2022 by the Editorial Board among the many excellent papers from that year [...] Full article

14 pages, 1506 KiB

Open AccessArticle

Impact of Different Methods of Root-Zone Application of Biochar-Based Fertilizers on Young Cocoa Plants: Insights from a Pot-Trial

by Johannes Meyer zu Drewer, Mareike Köster, Issaka Abdulai, Reimund Paul Rötter, Nikolas Hagemann and Hans Peter Schmidt

Horticulturae 2022, 8(4), 328; https://doi.org/10.3390/horticulturae8040328 - 13 Apr 2022

Cited by 3 | Viewed by 5130

Abstract

Effective and efficient nutrient management is central to best-practice agriculture, facilitating sustainable intensification while reducing negative externalities. The application of biochar-based fertilizers (BBF) in tropical agronomy has the potential to improve nutrient management by enhancing nutrient availability and uptake. Here, we performed pot-trials [...] Read more.

Effective and efficient nutrient management is central to best-practice agriculture, facilitating sustainable intensification while reducing negative externalities. The application of biochar-based fertilizers (BBF) in tropical agronomy has the potential to improve nutrient management by enhancing nutrient availability and uptake. Here, we performed pot-trials with Theobroma cacao L. seedlings planted in an Oxisol with critically low phosphorus levels. Four fertilizer levels were deployed, including BBFs using micro-dosed biochar (16 g plant⁻¹ i.e., 0.3% soil amendment w/w) charged with mineral fertilizer. Three different fertilizer-placement levels (topsoil, root-zone hotspot and root-zone layer) were evaluated. The results from the topsoil application of mineral fertilizer (farmer practice) served as the reference data. The root-zone layer application of BBF increased the aboveground biomass, total leaf area and chlorophyll content index by 56%, 222%, and 140% respectively. Foliar phosphorus levels were also significantly elevated by 53%. The N:P ratio of the foliar tissue was improved, indicating the potential of BBF to ameliorate P limitations. Thus, low dosages of biochar, which is upgraded to BBF, can considerably improve plant nutrition. Small scale technology to produce biochar can be easily adopted and integrated in T. cacao systems. We suggest that BBF production and application within tropical, perennial systems can contribute to achieving a range of sustainable development goals (SDGs), including climate action. Full article

(This article belongs to the Special Issue Application of Chars in Growing Media)

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13 pages, 3678 KiB

Open AccessArticle

Production, Composition, and Ecological Function of Sweet-Basil-Seed Mucilage during Hydration

by Dongfang Zhou, Jacob N. Barney and Gregory E. Welbaum

Horticulturae 2022, 8(4), 327; https://doi.org/10.3390/horticulturae8040327 - 13 Apr 2022

Cited by 4 | Viewed by 3091

Abstract

The sweet-basil (Ocimum basilicum L.) fruit/pericarp produces mucilage that engulfs the fruit and seed within minutes of hydration. Seed mucilage is produced by plant species that have adapted to arid, sandy soils. This study was conducted to determine how basil-seed mucilage improves [...] Read more.

The sweet-basil (Ocimum basilicum L.) fruit/pericarp produces mucilage that engulfs the fruit and seed within minutes of hydration. Seed mucilage is produced by plant species that have adapted to arid, sandy soils. This study was conducted to determine how basil-seed mucilage improves ecological fitness. A second objective was to find ways to remove mucilage, which may interfere with commercial planting. Basil fruit/seeds were examined using light and environmental scanning electron microscopy. Columnar structures of basil mucilage rapidly unfolded from the pericarp upon initial hydration. Dilute hydrochloric acid removed the mucilage, which decreased the water content four-fold but did not inhibit seed germination in a laboratory test. Nondestructive Fourier-transform mid-infrared (FTIR) spectroscopy confirmed that the mucilage was primarily composed of hemicellulose that anchored the basil seed to resist movement. The fully hydrated seeds approached zero water potential, so the mucilage did not interfere with hydration. The seeds that were planted in growing media with mucilage had from 12 to 28% higher seedling emergence and survival percentages after 10 days than seeds without mucilage. Basil-fruit/seed mucilage provides a reservoir of loosely bound water at high water potential for seed germination and early seedling development, thus improving survivability under low moisture. Full article

(This article belongs to the Topic Physiological and Molecular Characterization of Crop Tolerance to Abiotic Stresses)

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14 pages, 1289 KiB

Open AccessArticle

Physicochemical Characteristics and Nutritional Composition during Fruit Ripening of Akebia trifoliata (Lardizabalaceae)

by Shuaiyu Zou, Puxin Gao, Tianjiao Jia and Hongwen Huang

Horticulturae 2022, 8(4), 326; https://doi.org/10.3390/horticulturae8040326 - 13 Apr 2022

Cited by 6 | Viewed by 2044

Abstract

Akebia trifoliata is a high-value medicinal and edible fruit crop in China, and it has begun to be widely cultivated as a new fruit crop in many areas of China. Its fruits crack longitudinally when fully ripe and should be harvested before fruit [...] Read more.

Akebia trifoliata is a high-value medicinal and edible fruit crop in China, and it has begun to be widely cultivated as a new fruit crop in many areas of China. Its fruits crack longitudinally when fully ripe and should be harvested before fruit cracking. Physicochemical characteristics and nutritional composition of the ripening process are prerequisites to establishing proper harvest maturity windows. In the current study, we have investigated the fruit quality characteristics of two A. trifoliata clonal lines (‘Luqing’ and ‘Luyu’) that were harvested at four time points (S1: 120 days after full bloom (DAFB), S2: 134 DAFB, S3: 148 DAFB, S4: 155 DAFB). An increase in fruit size (fruit weight, fruit length, and fruit diameter) was associated with delayed harvest maturity. The firmness of A. trifoliata fruit exhibited a decreasing trend with delaying the harvest stage. In particular, the firmness decreased sharply from S2 to S3 stage. The TSS, fructose, and glucose content in A. trifoliata fruit continuously increased from the S1 to S4 stage and accumulated sharply from S2 to S3 stage. However, the sucrose and starch content showed an increasing trend from the S1 to S2 stage but declined sharply in the S3 or S4 stage. Ascorbic acid progressively increased with the advancement of A. trifoliata maturity stages, while total phenolics and total flavonoids levels declined with fruit ripening. Considering the results of all quality parameters mentioned above, the A. trifoliata fruit harvested at the S3 maturity stage was the ideal harvest maturity for long-distance transportation and higher consumer acceptability before fruit cracking. Our research reveals the dynamic changes in physicochemical characteristics and nutritional composition during fruit ripening of A. trifoliata. Results in this study reflect the importance of maturity stages for fruit quality and provide basic information for optimal harvest management of A. trifoliata. Full article

(This article belongs to the Special Issue Preharvest and Postharvest Factors Improving Horticultural Crops Quality and Shelf-Life)

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15 pages, 3007 KiB

Open AccessFeature PaperArticle

Benefits and Limitations of Using Hydrochars from Organic Residues as Replacement for Peat on Growing Media

by Gianluigi Farru, Chau Huyen Dang, Maja Schultze, Jürgen Kern, Giovanna Cappai and Judy A. Libra

Horticulturae 2022, 8(4), 325; https://doi.org/10.3390/horticulturae8040325 - 13 Apr 2022

Cited by 17 | Viewed by 2362

Abstract

New technologies for the production of peat-substitutes are required to meet the rising demand for growing media in horticulture and the need to preserve natural peatlands. Hydrothermal conversion of organic residues into char materials, hydrochars, with peat-like properties may produce such substitutes, reducing [...] Read more.

New technologies for the production of peat-substitutes are required to meet the rising demand for growing media in horticulture and the need to preserve natural peatlands. Hydrothermal conversion of organic residues into char materials, hydrochars, with peat-like properties may produce such substitutes, reducing environmental impacts and CO₂ emissions from improper management. To assess their potential as a component in growing media, cress seed germination tests are used to assess hydrochars from digestate (D), spent coffee grounds (SCG), and grape marc (GM). Pre- and post-treatments (extraction, washing, and drying) are applied to remove phytotoxic compounds associated with process waters retained on the hydrochars, and a nitrification bioassay with process water is used to predict their toxicity. All hydrochars achieve similar or better germination results compared to their feedstock, showing a potential to replace at least 5% of peat in growing media. SCG and GM hydrochars show inhibition above 5%, while all post-treated D-hydrochar mixtures produce >3 times longer roots than the control. The nitrification test shows a high sensitivity and good agreement with the high inhibition trends found in the germination tests with process water. Such tests can be a good way to optimize process combinations for the hydrothermal production of peat replacements. Full article

(This article belongs to the Special Issue Application of Chars in Growing Media)

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17 pages, 2010 KiB

Open AccessArticle

Physiological and Biochemical Adaptive Traits in Leaves of Four Citrus Species Grown in an Italian Charterhouse

by Maurizio Curadi, Ilaria Marchioni, Matteo Mancino, Luisa Pistelli, Laura Pistelli and Andrea Scartazza

Horticulturae 2022, 8(4), 324; https://doi.org/10.3390/horticulturae8040324 - 12 Apr 2022

Cited by 2 | Viewed by 1771

Abstract

Citrus trees are a very important crops that are cultivated worldwide, but not much knowledge is known about the ecophysiological responses to climatic changes in trees under natural conditions. The aim of this study was to investigate their adaptive capacity in response to [...] Read more.

Citrus trees are a very important crops that are cultivated worldwide, but not much knowledge is known about the ecophysiological responses to climatic changes in trees under natural conditions. The aim of this study was to investigate their adaptive capacity in response to seasonal phenological and environmental changes. The trial included Citrus trees (sweet orange, bitter orange, lemon, mandarin) growing under non-regular cropping conditions in a Monumental Charterhouse in Tuscany, in a subtropical Mediterranean climate with hot summer conditions. During a 1-year field trial, we determined the variations in chlorophyll fluorescence parameters and leaf biochemical traits (content of chlorophylls and carotenoids, total phenolic content (TPC), total antioxidant capacity (TAC), and total non-structural carbohydrates). In all Citrus spp., interspecific mean values of photochemical efficiency peaked during the summer, while a marked photoinhibition occurred in the winter in concomitance with higher interspecific mean values of leaf TPC, TAC, and non-structural carbohydrates. The trees showed the pivotal role played by photosynthetic acclimation as a survival strategy to tolerate abiotic stress in the climate change hotspot of Mediterranean environment. This study is included in a wider project aimed at a new valorization of Citrus trees as genetic resource and its by-products with added-value applications for innovative functional foods. Full article

(This article belongs to the Special Issue An Update of the Crop Management Practices Enhancing Yield and Quality in Citrus)

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31 pages, 1110 KiB

Open AccessReview

Fungal and Oomycete Diseases of Minor Tropical Fruit Crops

by Latiffah Zakaria

Horticulturae 2022, 8(4), 323; https://doi.org/10.3390/horticulturae8040323 - 11 Apr 2022

Cited by 5 | Viewed by 5896

Abstract

Minor tropical fruits are grown on a small scale and provide income to smallholder farmers. The cultivation of these fruit crops indirectly contributes to the economy of producing countries as well as to food and crop security. Dragon fruits, guava, passionfruit, lychee, longan, [...] Read more.

Minor tropical fruits are grown on a small scale and provide income to smallholder farmers. The cultivation of these fruit crops indirectly contributes to the economy of producing countries as well as to food and crop security. Dragon fruits, guava, passionfruit, lychee, longan, mangosteen, durian, and rambutan are common minor fruit crops. In recent years, the international trade of some of these minor tropical fruits, particularly dragon fruit, passionfruit, guava, and lychee, has increased due to their nutritional value, with various health benefits. Similar to other crops, minor fruit crops are susceptible to fungal and oomycete diseases. These diseases negatively affect the yield and quality of fruit crops, leading to substantial losses. In this context, the knowledge of disease types and causal pathogens is fundamental to develop suitable disease management practices in the field as well as appropriate post-harvest treatments. Full article

(This article belongs to the Section Plant Pathology and Disease Management (PPDM))

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9 pages, 216 KiB

Open AccessOpinion

What You May Not Realize about Vertical Farming

by Farzana A. Lubna, David C. Lewus, Timothy J. Shelford and Arend-Jan Both

Horticulturae 2022, 8(4), 322; https://doi.org/10.3390/horticulturae8040322 - 11 Apr 2022

Cited by 29 | Viewed by 10370

Abstract

Vertical farming (VF) is a newer crop production practice that is attracting attention from all around the world. VF is defined as growing indoor crops on multiple layers, either on the same floor or on multiple stories. Most VF operations are located in [...] Read more.

Vertical farming (VF) is a newer crop production practice that is attracting attention from all around the world. VF is defined as growing indoor crops on multiple layers, either on the same floor or on multiple stories. Most VF operations are located in urban environments, substantially reducing the distance between producer and consumer. Some people claim that VF is the beginning of a new era in controlled environment agriculture, with the potential to substantially increase resource-use efficiencies. However, since most vertical farms exclusively use electric lighting to grow crops, the energy input for VF is typically very high. Additional challenges include finding and converting growing space, constructing growing systems, maintaining equipment, selecting suitable plant species, maintaining a disease- and pest-free environment, attracting and training workers, optimizing the control of environmental parameters, managing data-driven decision making, and marketing. The objective of the paper is to highlight several of the challenges and issues associated with planning and operating a successful vertical farm. Industry-specific information and knowledge will help investors and growers make informed decisions about financing and operating a vertical farm. Full article

(This article belongs to the Special Issue Urban Horticulture - New Trends and Technologies)

12 pages, 1261 KiB

Open AccessArticle

Essential Oils from Leaves of Juniperus thurifera L., Exhibiting Antioxidant, Antifungal and Antibacterial Activities against Antibiotic-Resistant Microbes

by Soufyane Lafraxo, Azeddin El Barnossi, Abdelfattah El Moussaoui, Mohammed Bourhia, Ahmad Mohammad Salamatullah, Abdulhakeem Alzahrani, Aziz Ait Akka, Abderahmane Choubbane, Mohamed Akhazzane, Mourad A. M. Aboul-Soud, John P. Giesy and Amina Bari

Horticulturae 2022, 8(4), 321; https://doi.org/10.3390/horticulturae8040321 - 10 Apr 2022

Cited by 13 | Viewed by 2615

Abstract

The antioxidant, antibacterial and antifungal properties of essential oils (EOs) of Juniperus thurifera L., a plant utilized in traditional, herbal medicine, were investigated. The EOs were extracted by use of a Clevenger apparatus and phytochemicals identified by gas chromatography coupled with mass spectrometry [...] Read more.

The antioxidant, antibacterial and antifungal properties of essential oils (EOs) of Juniperus thurifera L., a plant utilized in traditional, herbal medicine, were investigated. The EOs were extracted by use of a Clevenger apparatus and phytochemicals identified by gas chromatography coupled with mass spectrometry (GC/MS/MS). The antioxidant capacity of EOs of J. thurifera was determined by 2,2-diphenyl-1-picrylhydrazil (DPPH), total antioxidant capacity (TAC), and ferric reducing antioxidant power (FRAP). Antimicrobial activity of EOs of J. thurifera was determined against four fungal strains, Candida albicans; ATCC 10231, Aspergillus niger; MTCC 282, Aspergillus flavus; MTCC 9606 and Fusarium oxysporum; MTCC 9913 and four bacterial strains, Staphylococcus aureus; ATCC 6633, Escherichia coli; K12, Bacillus subtilis; DSM 6333, and Pseudomonas aeruginosa; CIP A22, by use of the disk diffusion method, and microdilution method used to determine the minimum inhibitory concentration (MIC). EOs of J. thurifera consisted of 31 compounds and were dominated by α-thujene (25%), elemol (12%) and muurolol (12%). Antioxidant activity recorded an IC₅₀ of 24 ± 0.71 µg/mL (DPPF), EC50 of 0.19 ± 0.01 mg/mL (FRAP), and 9.3 × 10² ± 38 mg EAA/g (TAC). The EOs of J. thurifera exhibited significant antibacterial activity against all bacterial strains under investigation, especially P. aeruginosa; CIP A22 with an inhibition diameter of 28 ± 1.5 mm and MIC of 4.8 × 10⁻² ± 0. 001 µg/mL. EOs of J. thurifera also exhibited significant antifungal activity against C. albicans; ATCC 10231 and F. oxysporum; MTCC 9913 with an activity of 21 ± 2.1 mm, 32 ± 2.3%, and MIC of 9.5 × 10⁻² ± 0.001 Bioactive molecules found in EOs of J. thurifera could be used as an alternative solution to antibiotics available on the market to combat microbial resistance. Full article

(This article belongs to the Special Issue Phytochemicals of Natural Products: Analysis and Biological Activities)

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16 pages, 3467 KiB

Open AccessArticle

The Variation of Soil Phosphorus Fractions and Microbial Community Composition under Consecutive Cucumber Cropping in a Greenhouse

by Ting Bian, Shiwei Zheng, Xiao Li, Shuang Wang, Xiaolan Zhang, Zhen Wang, Xiaoxia Li, Hongdan Fu and Zhouping Sun

Horticulturae 2022, 8(4), 320; https://doi.org/10.3390/horticulturae8040320 - 10 Apr 2022

Cited by 2 | Viewed by 1969

Abstract

The distribution of phosphorus (P) fractions in soil plays a decisive role in soil P bioavailability; however, the characteristics of soil P fractions under consecutive cropping in a solar greenhouse remain unclear. To evaluate the effects of the long-term successive vegetable cropping on [...] Read more.

The distribution of phosphorus (P) fractions in soil plays a decisive role in soil P bioavailability; however, the characteristics of soil P fractions under consecutive cropping in a solar greenhouse remain unclear. To evaluate the effects of the long-term successive vegetable cropping on soil P fractions and the microbial community composition in greenhouse soil, a continuous long-term cropping experiment was conducted using cucumber (Cucumis sativus L.) in a solar greenhouse starting from 2006 to 2018. Soil P fractions and the microbial community composition were determined using the Hedley continuous extraction method and the phospholipid fatty acid (PLFA) method, respectively, in the 1st, 9th, 13th, and 21st rounds of cultivation. The soil total phosphorus (TP) content increased from 0.90 g·kg⁻¹ in the 1st round to 3.07 g·kg⁻¹ in the 21st round of cucumber cultivation. With an increase in continuous cropping rounds, soil available phosphorus (AP) increased and the phosphorus activation coefficient (PAC) decreased, with no significant difference between the 13th and 21st rounds. After 21 rounds of continuous cropping, the soil organic matter (SOM) content was 16.34 g·kg⁻¹, 1.42 times that of the 1st round. The abundance of soil bacteria, actinomycetes, Gram-negative bacteria (G⁻), Gram-positive bacteria (G⁺), and total PLFAs initially increased with continuous cropping rounds, but then decreased significantly, and the ratios of fungi:bacteria (F/B) and G⁺/G⁻ bacteria also increased significantly with continuous cropping rounds. The contents of soil labile P, moderately labile P, and non-labile P increased significantly over 21 continuous cropping rounds. Together, these results demonstrate that long-term continuous cropping can directly lead to the accumulation of P fractions, but it can also affect the abundance of actinomycetes through SOM enrichment, which indirectly leads to the accumulation of non-labile P. This study provides a theoretical basis for future soil P fertilizer management and vegetable production sustainability. Full article

(This article belongs to the Special Issue Mechanism Research and Comprehensive Prevention and Control of Continuous Cropping Obstacles of Horticultural Crops)

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Horticulturae, Volume 8, Issue 4 (April 2022) – 77 articles

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