Abstract True cost accounting (TCA) provides a holistic and systemic approach to evaluating the hidden costs of our prevailing food system on the environment, health and society. Globally, Food and Agriculture Organisation (FAO) estimates that these hidden costs currently approach some USD 12.7 trillion per annum, with FAO and the Food Systems Economics Commission (FSEC) estimating the cost of rectifying the damage to be between USD 200 and 500 billion per annum to 2050. Fortuitously, there is an increasing international recognition of the need to transform agrifood systems towards greater efficiency, resilience, inclusiveness and sustainability as a necessary condition for realizing the 2030 Agenda for Sustainable Development. TCA can contribute to this process by assisting governments, businesses and other stakeholders in making more informed decisions to improve sustainability. Significance of the study What is already known on this subject? Evaluating the performance of food systems purely on the basis of productivity per unit area ignores significant environmental, biodiversity, health, and social costs. True Cost Accounting (TCA) is increasingly recognized as a framework for capturing these hidden impacts. What are the new findings? This article highlights the scale of hidden agrifood system costs and discusses how TCA can support more informed decision-making and accelerate the transition to sustainable agrifood systems. What are the expected impacts on horticulture? Horticulture is well placed to benefit from the transition to more healthy diets and TCA can help demonstrate the broader value of horticultural products.
Tomatoes (Lycopersicon esculentum) are widely consumed and economically important vegetable crops worldwide. However, their high perishability and short postharvest life result in substantial losses. Typically, tomatoes remain marketable for only 4-8 days at ambient conditions due to rapid physiological and biochemical changes, including moisture loss, softening, pigment development and compositional alterations. These postharvest losses not only affect farmers' income but also contribute to food insecurity. This study evaluated the effectiveness of edible chitosan coatings derived from fish scales in extending the shelf life and preserving the quality of tomatoes during storage. Fruits were treated with 0% (control), 1% chitosan and 2% chitosan solutions and stored at room temperature for 14 days. Physical, chemical and organoleptic data were analysed throughout the storage period. The results demonstrated that chitosan coatings significantly delayed deterioration compared to the control. By day 10, control fruits exhibited severe wrinkling, soft rot and dark spots, whereas 2% chitosan showed moderate damage and 1% chitosan showed no visible deterioration. Weight loss was reduced from 9.1% in control to 6.7-6.9% in treated samples. The 1% chitosan treatment retained the highest vitamin C content (31.53%), whereas the control recorded the lowest (14.65%). Treated tomatoes also exhibited 16-23% higher titrable acidity. Total soluble sugars increased by approximately 45% in control fruits but decreased by 26-28% in treated samples, indicating delayed ripening. Pigment development was significantly higher in untreated fruits (86%) compared to treated ones (64%). Nitrate content decreased in all samples, with a greater reduction observed in control fruits (73%) than in treated ones (54%). Organoleptic evaluation indicated that 1% chitosan-coated tomatoes were most acceptable. Overall, our research indicates that chitosan coating successfully extends the shelf life of tomato fruit and preserves fruit quality while it is in storage. It also presents a great opportunity for the edible coating to be successfully commercialized for tomato producers and the waste management sector.
ABSTRACT In two sequential years, we showed in a 450 m2 greenhouse in Bleiswijk (the Netherlands) that low chill strawberry can be grown with low energy and CO2 input. The ETFE greenhouse cover provided high transmission of diffused light. With a swinging gutter system, the distance between the plant rows was kept lower, causing a higher plant density. Maximal insulation by intensive use of screens prevented heat loss. Especially a lot of energy was saved by closing the windows and screens at the end of the day instead of opening them to come fast to a low night temperature. We even showed that if the heat from the dehumidification in summer could be stored in a seasonal buffer to be used in winter, we could grow low-chill strawberries energy neutral by only input of ‘green’ electricity. Day length reduction resulted in a prolonged picking season, but prolongation till autumn with high yield was not possible with 12-h day length for both of the used varieties Inspire and Fandango. Powdery mildew control on the fruit was a challenge in such a long picking season and needs attention in new research projects. Significance of the study What is already known on this subject? Strawberry production in greenhouses is much higher than in open field because growing conditions are optimized and growing seasons are shifted. Because of that, the acreage of protected strawberry crops in the Netherlands did increase from 255 ha in 2010 to 602 ha in 2024 (CBS). To realize the high production potential input of energy and CO2 is needed. For several greenhouse crops it is shown that energy and CO2 input can be reduced by smart climate control, insulation and dehumidification. What are the new findings? Low chill strawberry varieties fit well in a sustainable production system in which heat input, and therefore CO2 emission, is reduced. They perform well at relatively high night temperatures. Therefore less energy is needed to heat the greenhouse in the morning. In two sequential years we showed that we could produce low chill strawberries with much lower energy and CO2 input than what is common in practice. In addition, we have found that reducing the daylength stimulates flower induction in spring and early summer, resulting in elongation of the picking period till end of August. What are the expected impacts on horticulture? Sustainability will become more and more important for horticultural sector because governments, society and consumers demands. This research shows that strawberry sector can meet these sustainability demands by cultivar choice, smart climate control, and greenhouses that are equipped with insulation screens and active dehumidification systems.
Abstract Pumpkins (Cucurbita spp.) are globally valued for their nutritional, medicinal and economic importance, yet morpho-agronomic diversity among Uganda’s pumpkin landraces remain under-documented despite the favorable agroecological conditions for growth. This study examined 40 landraces (29 of Cucurbita moschata and 11 of Cucurbita pepo) collected from 18 districts in Uganda under uniform field conditions at Muni University, using 31 morpho-agronomic descriptors. Germination across landraces was conserved, with most sprouting in 6–7 days, while seed weight varied significantly (19.7–52.2 g per 100 seeds), with district-level differences in Central (F₇,₁₂ = 3.24, P = 0.03) and Eastern regions (F₂,₆ = 6.46, P = 0.03). Seedling traits showed strong differentiation in cotyledon shape, with χ² analysis confirming significant district-level differences in the Central region (χ² = 30.4, P = 0.02). Stem and growth habits ranged from bush to trailing types, with variable branching degree and χ² tests revealed significant differences in landraces among districts from Eastern (χ² = 18.0, P = 0.02). Leaf traits also exhibited notable diversity in blade size, colour intensity, petiole prickles and dimensions, with χ² analysis detecting significant variation in leaf colour intensity of landraces within Northern districts (χ² = 12.0, P = 0.02). Early germination correlated with shorter fruits and smaller seeds; seed weight with seed size; branching with longer petioles and larger leaves. Fruit length and diameter were independent. PCA of 11 traits across 40 landraces explained 38.6% of variation (PC1: 22.0%, PC2: 16.6%). These findings highlight Uganda’s rich but underexplored pumpkin diversity, underscoring the importance of systematic characterization for breeding. The results provide opportunities for selecting high-yielding, disease-resistant and nutritionally superior lines tailored to specific agro-ecological zones. Ultimately, conservation and utilization of these landraces enhances food security, farmer productivity and value chain development, positioning pumpkins as a vital crop for nutrition, livelihoods and sustainable agriculture in Uganda and beyond. Significance of the study What is already known on this subject? Uganda’s pumpkins remain under-documented despite favourable agro-ecological diversity. Local landraces show substantial morphological diversity, offering untapped potential for breeding, food security, nutrition and sustainable agricultural value chain development. What are the new findings? Ugandan pumpkin landraces show conserved germination but significant district-level variation in seed weight, cotyledon, stem, leaf, flower, fruit and seed traits, revealing rich diversity crucial for breeding, conservation and food security. What are the expected impacts on horticulture? The rich morpho-agronomic diversity of Ugandan landraces enables breeding of superior varieties, enhancing productivity, market preference, food security and strengthening horticultural value chains.
Abstract Solanum torvum (turkey berry) is an underutilized vegetable with nutritional, medicinal and agronomic importance. Its fruits are rich in iron, calcium, fibre and antioxidants, while the plant serves as a rootstock in grafting for tomato and eggplant due to its resistance to soil-borne pathogens and tolerance to abiotic stresses. Despite these benefits, large-scale cultivation is constrained by poor and inconsistent seed germination, largely attributed to seed dormancy and uncertainty regarding optimal seed maturity. This study aimed to identify the ideal physiological maturity stage for seed extraction and evaluate priming treatments to enhance germination and seedling development. A completely randomized design (CRD) with a 3 × 5 factorial arrangement was used. Fruits were harvested at 12, 14 and 16 weeks after-flower opening (WAF) for seed extraction. Seeds were extracted and subjected to priming with polyethylene glycol (PEG 6000), potassium nitrate (KNO₃), gibberellic acid (GA₃), sodium chloride (NaCl) or distilled water. Germination indices (percentage, mean germination time, rate, synchrony and uncertainty) and seedling growth parameters (height, chlorophyll content and biomass) were assessed. Seed maturity and priming significantly influenced germination and seedling vigour. Seeds harvested at 12 WAF and primed with 15% PEG were among the treatments with the highest germination percentage (100%), while seeds harvested at 16 WAF and primed with 0.5% KNO₃ improved germination and synchrony, while GA₃ enhanced germination rate and vegetative growth. In contrast, NaCl treatments consistently resulted in low germination. PEG and GA₃ priming also improved root biomass and shoot elongation. This study demonstrates that both seed age and priming treatments are critical for overcoming dormancy and improving S. torvum propagation. While 12 WAF combined with 15% PEG produced the highest germination, 16 WAF is identified as the optimal harvest stage overall, as seeds at this stage exhibited consistently high germinability across the broadest range of priming treatments, whereas the 12 WAF response was achieved only under a specific, narrow osmopriming regime. Together with PEG priming as the most broadly effective treatment, these findings provide practical strategies to support domestication, enhance cultivation and expand the horticultural and medicinal use of S. torvum. Significance of the Study What is already known on this subject? Solanum torvum (turkey berry) is valued as a nutritionally rich fruit crop and as a disease-resistant rootstock for grafting tomato and eggplant. Despite this recognized value, the crop remains underutilized because of poor and erratic seed germination linked to physiological dormancy. Growers lack clear guidance on optimal seed harvest timing or effective priming protocols, even though such techniques are well established in related Solanaceae crops like tomato and pepper. What are the new findings? This study shows that seeds harvested at 16 weeks after flower opening gave the most consistent germination across a broad range of priming treatments. Seeds harvested earlier, at 12 weeks, can achieve exceptionally high germination, but only under a narrow, precisely calibrated PEG osmopriming regime. Priming agents were also found to act through distinct mechanisms, with GA₃ best for germination speed and growth, KNO₃ best for synchrony, and PEG best for breaking dormancy in early-harvested seed, while NaCl was consistently detrimental. What are the expected impacts on horticulture? Collectively, this work strengthens the foundation for broader domestication and cultivation of this nutritionally and medicinally valuable but currently underutilized crop.
Abstract In plant factories with artificial lighting (PFAL), light-emitting diodes (LEDs) are the sole light source, essential for photosynthesis. Changing light features (e.g. spectrum, photoperiod and intensity) can optimize crop quality and yield, reduce energy consumption and production costs and increase energy use efficiency (EUE). Individually inspecting light features has been extensively explored, whereas comprehensive analyses of varying light features while maintaining a similar daily light integral (DLI, the total daily amount of mol received by plants) have been limited. This study aimed to investigate the influence of different combinations of photoperiod and light intensity on the yield, growth and lighting-energy use efficiency (L-EUE) while maintaining a constant DLI on four leafy vegetable crops, namely crispy lettuce (Lactuca sativa L.), green kale (Brassica oleracea L.), pak choi (Brassica rapa L.) and lettuce var. canasta (L. sativa L.). The experiment took place in a commercial vertical farm equipped with full white spectrum LED light fixtures. Three different light regimes with a DLI (9.75 ± 0.15 mol m−2 day−1) were used for the experiment, obtained by simultaneously varying photoperiod and light intensity, as follows: 14 h day−1 and 190 μmol m−2 s−1 (14/190), 18 h day−1 and 150 μmol m−2 s−1 (18/150), and 24 h day−1 and 115 μmol m−2 s−1 (24/115). Continuous light exposure (24/115) yielded the best morphological results for both lettuce cultivars, whereas pak choi showed higher leaf width at higher light intensity and a shorter photoperiod. L-EUE was not affected by light treatments in crispy lettuce, whereas differences were evident in the other three crops in which the shortest photoperiod with the highest intensity was associated with the lowest L-EUE values. Conversely, differences in light use efficiency (LUE) were observed only in pak choi with the shorter photoperiod (14/190), resulting in higher LUE values than in the continuous day (24/115) treatment. The use of 24/115 and 18/150 is a valid strategy to increase L-EUE for the crops used in this study, but additional research with higher DLI is needed to further investigate the effects of different combinations of light intensity and photoperiod in commercial settings. Significance of the study What is already known on this subject? Light intensity and photoperiod independently affect crop growth and energy-use efficiency in vertical farms. However, their combined effects at constant daily light integral (DLI) need to be deeply investigated, especially in commercial settings. What are the new findings? Reducing light intensity while extending the photoperiod at constant DLI improved lighting-energy use efficiency (L-EUE) by approximately two-fold in canasta lettuce, pak choi and green kale, without compromising yield. Species-specific morphological responses were observed, with lettuce showing increased plant height under continuous light. Additionally, pak choi exhibited higher light use efficiency (LUE) under shorter, more intense exposure. What are the expected impacts on horticulture? These results demonstrate that extending photoperiods at lower light intensities can reduce energy consumption in vertical farms without affecting productivity. The species-specific responses highlight the importance of developing crop-specific light recipes to optimize both yield and energy efficiency in indoor commercial production systems.
ABSTRACT Exploration of the natural microbial diversity of indigenous fruits can lead to the discovery of promising candidate yeasts that bring diversity and unique characteristics to commercial brews compared with commercial strains. These properties have been domesticated through thousands of generations of adaptive selection. This study investigated the potential of yeasts isolated from marula fruit wine in South Africa in beer production and the attributes these yeasts contribute during the brewing process. This was achieved by fermenting wort with three yeast isolates in separate processes. Different parameters, such as microbial enumeration, sensory evaluation, yeast attenuation and chemical profiling, were analysed. The performance of the Saccharomyces NY23 strain was higher than that of the commercial yeast strain AEC1 and Saccharomyces OY15 strain in terms of ethanol production, which was 57.13 g/l despite its lower attenuation. The non-Saccharomyces yeast isolates Meyerozyma AlC and Meyerozyma 15M5 produced beers with lower ethanol concentrations of 29 and 30 g/l, respectively. The beer that was fermented with Meyerozyma AlC yeast contained the highest acidity levels of above 0.30 g/l and the lowest pH level below 3.9, whereas the beers that were fermented with other yeast strains contained the recommended beer acidity levels between 0.5 and 0.25 g/l and pH level of between 4.6 and 4.9. The tasting panellists described the beers as pleasant, including those from the non-Saccharomyces strain, which had a low alcohol concentration and a higher sugar content of above 40 g/l. The results indicated that marula fruit wine yeasts have the potential for applicability in beer production. Further studies on co-inoculations of both Saccharomyces and non-Saccharomyces for flavour diversity and low alcohol content according to consumer preferences should be envisaged in the future. Significance of the study What is already known on this subject? Beer production is traditionally dominated by Saccharomyces cerevisiae. Non-Saccharomyces yeasts generally have lower fermentation efficiency; they coexist in fermented beverages and are known to enhance flavours and aroma. What are the new findings? Wild yeasts isolated from marula fruit demonstrated potential for beer production, particularly the non-Saccharomyces yeasts, which demonstrated the ability to produce low-alcohol beers with unique sensory characteristics such as fruity and floral aroma. What is the expected impact on horticulture? The findings highlight marula fruit as a valuable source of novel fermentation yeasts. This may increase the value of utilization of indigenous fruits and promote the development of value-added horticultural products.
To realize the relationship between changes in polyamines (PAs) and barberry fruit growth, the free endogenous PAs of the fleshy part (pericarp) of fruit were measured. To this end, sampling was performed in three replications in six fruit development stages, including 35, 54, 71, 98, 125 and 155 days after full bloom (DAFB) during the ON (2018) and OFF (2019) year. Four growth stages (S1-S4) were observed in barberries. The fruit growth curve in seedless barberries was identified as double sigmoid. The results showed that despite the similarity in the processing of changes in the level of PAs and gaining fresh weight in both years, a significant difference was observed throughout the sampling stages. In both years, differences in increasing the length and diameter of the fruit after the first and second stages of sampling were observed, and a significant difference was found between the sampling stages and the fruiting years by the end of growth. Total PAs content in the ON year was higher than the OFF year. In the OFF year, the decreased spermidine concentration at 54th DAFB was found to be responsible for the abscission of berries formed at this stage. In pericarp, the level of putrescine was higher during early development than the other PAs in both years and then gradually decreased. Despite the relationship between increased spermidine and the length and diameter of berries, fresh fruit weight and soluble solids, the results of this study cannot exactly identify a specific polyamine responsible for changes in the traits of barberry fruit.
Abstract The litchi fruit borer (Conopomorpha sinensis Bradley) is a major pest threatening litchi (Litchi chinensis Sonn.) production by causing substantial fruit infestation and drop. Although pesticides are widely used, optimal application timing is debated due to imprecise descriptions of fruitlet stages and limited knowledge of pest behaviour in orchards. To address this, we aligned fruitlet development with litchi fruit borer behaviour to identify ideal pest-control timing that balances control intensity while maintaining productivity. Oviposition increased sharply during mid-development in both pesticide-treated and pesticide-free trees. Fruit abscission and fruitlet infestation rates were similar during this period, indicating that physiological factors largely determine early abscission despite borer attacks. Subsequently, pesticide-free trees exhibited higher infestation. During late development, 75–100% of shed fruitlets were damaged by the borer, suggesting the pest is the dominant factor in late fruit drop. Further analysis showed that fruit weight is the principal factor correlated with oviposition, while meteorological factors modulate the occurrence of damage. Using a fruit length of approximately 20 mm as a phenology-based indicator optimizes the timing of pesticide application. Furthermore, because insecticides primarily reduce post-oviposition survival rather than deterring oviposition itself, targeting this specific developmental stage is crucial for effectively preventing late-stage fruit loss. Significance of the Study What is already known on this subject? Litchi fruit borer (Conopomorpha sinensis Bradley) is a major pest that causes substantial pre-harvest fruit drop and yield loss in litchi production. Currently, growers primarily rely on calendar-based pesticide applications, which often fail to align with the fruit's physiological susceptibility, leading to ineffective control, unnecessary chemical use and an increased risk of pesticide resistance. What are the new findings? Our high-frequency field monitoring combined with robust modelling identified a precise phenology-based indicator for pest control. We found that the borer predominantly causes late-stage fruit drop, whereas early-stage drop is mainly physiological. A fruitlet length of approximately 20 mm provides a practical early-warning reference for optimizing chemical interventions. Furthermore, applied insecticides were shown to primarily reduce post-oviposition survival (acting as ovicides or targeting young larvae) rather than deterring adult oviposition. What are the expected impacts on horticulture? These findings provide orchard managers with a simple, actionable visual metric (20 mm fruitlet length) to optimize the timing of pesticide applications. This approach effectively eliminates wasted early-season sprays, promotes targeted chemical selection based on ovicidal activity and supports the development of more sustainable integrated pest management strategies for litchi and potentially other tropical fruit tree crops.
Abstract Sclerocarya birrea has long played a central role in rural communities’ livelihoods, culture and spirituality. This study assessed the morphological variation in Sclerocarya birrea by integrating local knowledge with morphological studies to inform domestication strategies. Semi-structured individual interviews with 336 informants across two phytogeographic sectors were conducted to collect data on perceived morphological variation and preferred traits. Quantitative morphological data on 1126 fruits from 60 trees were recorded. Univariate and multivariate methods were used for data analysis. Ten criteria were used to describe morphological variation in Sclerocarya birrea based on fruit, leaf, seed and whole-tree characteristics. The preferred variants, cited most frequently, were female trees (100%), large fruits (71.65%), sweet pulp (61.29%), high pulp volume (49.36%) and a high number of seeds (63.32%). Morphological descriptors of fruits showed significant variation between trees within locations at the phytogeographic level (p < 0.001). Four morphotypes were distinguished through hierarchical clustering. Morphotypes 1 and 2 had the smallest fruits, Morphotype 3 had intermediate fruits and Morphotype 4 had the largest fruits. This study highlights that local people hold valuable knowledge of the phenotypic variation of Sclerocarya birrea. High convergence between farmers’ perceptions and morphological data highlights the value of local knowledge for guiding further domestication programmes of this species. Significance of the study What is already known on this subject? Sclerocarya birrea is a key indigenous fruit tree in sub-Saharan Africa, widely used for food, income and cultural purposes. Previous studies have documented its nutritional value and some morphological variability. However, limited research has integrated local knowledge with quantitative morphological analysis to guide domestication. What are the new findings? This study demonstrates a strong convergence between farmers’ perceptions and measured morphological traits. Four distinct morphotypes were identified, with Morphotype 4 characterized by significantly larger and heavier fruits. The study also identifies the north Sudanian sector, particularly Wayen, as a priority area for germplasm collection. What are the expected impacts on horiticulture? The findings provide a scientific basis for selecting superior morphotypes for domestication and improvement programmes. Integrating local knowledge with morphological data can accelerate varietal selection, enhance fruit yield and pulp production and support the sustainable cultivation and conservation of Sclerocarya birrea in West Africa
Abstract Purslane (Portulaca oleracea L.) is a cosmopolitan annual herb with succulent foliage, widely consumed raw, cooked or pickled, and distinguished by its high α-linolenic acid (ALA) content, higher than that of common leafy greens. Purslane also provides linoleic acid (LA), diverse minerals, as well as vitamins A, C and E, underscoring its nutritional potential. Although cultivated commercially in parts of Asia, Europe and Mexico, purslane is often treated as a weed among conventional farmers. In temperate and cold climates, greenhouse production of purslane is essential to ensure year-round supply, yet research on promising varieties has been limited. We evaluated five commercially available purslane varieties (‘Red Gruner Microgreen Seed’, ‘Green Purslane’, ‘Scarlet’, ‘French Green Leaf’ and ‘Heirloom Verdolaga’) for growth, biomass and fatty acid profiles under greenhouse conditions. In addition to dry biomass, we measured plant height and diameter, which were integrated into a z-score growth index to assess temporal growth dynamics. The fatty acid profile of each variety was quantified using the Folch method. Biomass differed among varieties. ‘Green Purslane’ produced the highest yield (0.68 g plant−1), exceeding ‘Scarlet,’ ‘Heirloom Verdolaga’ and ‘Red Gruner,’ while ‘French Green’ showed intermediate yield. Growth trajectories were fastest for ‘French Green’ and ‘Red Gruner’. Although statistical analysis of this parameter was not performed, fatty acid composition of ‘Green’ showed a trend towards superiority, with 421 mg kg−1 LA, an exceptional 1625 mg kg−1 ALA, the lowest LA/ALA ratio of 0.26, and the highest polyunsaturated fatty acid proportion (73%), exceeding published ranges. We identified ‘Green’ as a strong candidate for indoor purslane production. Significance of the study What is already known on this subject? Our study addressed the research gap of purslane variety trials in greenhouse conditions. The availability of commercially bred purslane varieties is scarce; and the majority of existing studies that discuss purslane varieties either has an ethnobotanical background or deals with management or growth environments, such as saline conditions, while variety comparisons are only a secondary aspect. What are the new findings? Our study was limited to one single production cycle and by the small number of commercially grown purslane varieties accessible in the US which led to only five examined cultivars, which we examined regarding their yield. The fatty acid composition of each cultivar was measured from a composite sample. Based on this input, we identified the variety ‘Green’ as a promising material for indoor production, due to a satisfactory yield and a promising fatty acid profile by trend. What are the expected impacts on horticulture? The latter is relevant as health motivations, specifically omega-3 fatty acid content, may be central for a potentially growing customer base of the nutritious and tasty leafy green, which, in turn, could increase the number of commercial producers. Research comparing different seeding densities, fertilization managements, and light and watering regimes, and their impact on different purslane varieties could further improve purslane variety development and overall commercial production.
Abstract Bhendi Yellow Vein Mosaic Virus (BYVMV) is an emerging threat to okra (Abelmoschus esculentus L.) production, causing severe yield losses. To develop high-yielding BYVMV-resistant okra cultivars, a full hybridization experiment was conducted using two local varieties Selection-21 (S-21) and Sobuj-Sathi (SS) and five BYVMV-resistant lines (M6L3, M6L4, M6L5, M6L6 and M6L7). Six hybrids – M6L3 (M) × S-21 (F), M6L6 (M) × S-21 (F), M6L3 (M) × M6L6 (F), M6L4 (M) × SS (F), M6L3 (F) × M6L4 (M) and M6L4 (F) × M6L3 (M) – were found to be largely free from BYVMV infection. Additionally, data were recorded for plant height (cm), number of flowers per plant, number of fruits per plant, average fruit weight (g), number of seeds per fruit, 100-seed weight (g), disease incidence, disease severity index and yield (g/plant). The results revealed that, five of the six hybrid combinations – M6L6 × S-21, M6L3 × M6L6, M6L4 × SS, M6L3 × M6L4 and M6L4 × M6L3 – were resistant to BYVMV, each showing 0% disease incidence. The hybrid M6L3 × S-21 exhibited moderate resistance with a disease incidence of 13%. The highest yields were obtained from M6L6 × S-21 and M6L3 × M6L6, both significantly outperforming their parental lines. An examination of the disease severity index of begomoviruses and whitefly (Bemisia tabaci) population dynamics revealed that first whitefly incidence on parental lines was observed in early March, peaking in May and disappearing by June. The lines M6L7 and M6L6 had the highest (6.82) and lowest (1.61) whiteflies observed on leaves, respectively, which corresponds to a contrasting disease incidence in M6L7 (PDI = 73.3%) and M6L6 (PDI = 13%), respectively. Collectively, these findings demonstrate that hybridization is an effective approach for developing BYVMV-resistant okra varieties with enhanced productivity. Significance of the study What is already known regarding this topic? Bhendi Yellow Vein Mosaic Virus (BYVMV) of okra is transmitted by a small insect vector known as the whitefly (Bemisia tabaci). This virus causes a significant yield loss in okra production in Bangladesh. Infected plants may exhibit varying degrees of stunting, leaf curling and yellowing of leaf veins. The fruit skin is leathery, rough and yellowish. A hybridization programme aimed at developing disease-resistant okra lines could be an effective strategy for producing BYVMV-free okra cultivars. An important method for developing a BYVMV-free okra is to create F1 hybrids. What are these new findings? Desirable traits from both parents can produce superior F1 hybrid offspring. In this study, the hybrid offspring were resistant to BYVMV and exhibited superior yields and other morphological characteristics compared with their parents. What were the expected effects of horticulture? These findings are expected to significantly affect the production of BYVMV-free okra, a disease causing significant threat to okra production. Moreover, hybridization is anticipated to provide a viable strategy for improving both okra pod yield and quality. Farmers can grow high-yielding better-quality okra without using chemical control (health hazards). This approach also offers economic benefits for growers by promoting sustainable, eco-friendly farming practices and greater profitability through using BYVMV-resistant germplasm. The ultimate goal of the okra breeding programme is to release new varieties that possess elite combinations of desirable horticultural characteristics, including BYVMV disease resistance.
Abstract Anthracnose disease, caused by the fungal pathogen Colletotrichum spp., constitutes a major postharvest challenge to the quality and commercial viability of ‘Namdokmai Sithong’ mangoes. Traditional methods for disease detection, which often rely on subjective visual inspection, are only effective once symptoms are externally visible. This study was conducted to develop a rapid, objective and non-destructive method for the early classification of this latent disease using near-infrared spectroscopy (NIRS). Mango fruits at commercial maturity (100–105 days after flowering) with export-grade quality from a certified orchard were used to simulate natural infection. Each fruit was half-dipped horizontally for 1 min in a 1.4 × 105 spores/ml suspension of Colletotrichum spp. Near-infrared reflectance spectra (800–2500 nm) were subsequently acquired from 52 inoculated and 48 uninoculated mango fruits at 24 h over a 4-day period. An artificial neural network (ANN) classifier with k-fold cross-validation (k = 5) achieved a precise classification result through the first-derivative (1D) spectra at the early stage of inoculation (24 h). A key finding was the absence of any false positive predictions from the 1D-ANN model during the crucial initial incubation period (24, 48 and 72 h), which is critical for preventing the unnecessary rejection of healthy fruit. While the overall accuracy of most ANN models exhibited a slight decline at 96 h, the 1D-ANN classifier maintained a perfect accuracy of 100% without generating any false negatives. This study conclusively demonstrates the feasibility of using reflectance spectroscopy for the early and accurate detection of anthracnose disease, offering a valuable and reliable tool for effective postharvest disease management and mitigating significant financial losses within the Thai mango industry. Significance of the study What is already known on this subject? Anthracnose disease, a significant postharvest disease caused by the fungal pathogen Colletotrichum spp., typically leads to quality degradation and postharvest losses in various fruits globally. The traditional method for disease detection generally relies on visual inspection, which is ineffective for latent infections, as it often fails to identify the disease before external symptoms appear. For this reason, near-infrared spectroscopy (NIRS) has been considered as a promising non-destructive technique, performed by measuring a sample’s light absorption and scattering to reveal its chemical composition. The resulting spectral data are subsequently analysed using artificial neural networks (ANN), the powerful classifiers for identifying and analysing complex data to enable the early detection of the disease at a non-visible stage. What are the new findings? This study confirms that early and non-invasive detection of anthracnose disease is possible using near-infrared spectral information along with an ANN as a classifier. The research found that the first-derivative (1D) data pre-processing method was crucial for achieving high classification accuracy, as it enhanced the subtle spectral alterations that occurred at early infection. The developed 1D-ANN model was highly robust and reliable, giving 100% accuracy and providing no false negatives for up to 96 h after inoculation. Furthermore, the ANN classifier also provided no false positive predictions, which is a significant advancement over current visual inspection methods and is critical for preventing the unnecessary rejection of healthy fruit. What are the expected impacts on horticulture? Implementing early anthracnose disease classifiers can significantly reduce postharvest losses in mango export and import markets. The NIRS-ANN classification model allows the selection of infected fruit at packinghouses, aiding operators in managing the commodity efficiently. It also prevents the further spread of fungal pathogens through the supply chain. This objective and quantitative method for assessing fungal infestation in mango also leads to improved quality control, providing more consistent product quality and building consumer trust in competitive global markets.
Abstract Banana (Musa spp.) is a vital staple and cash crop in tropical regions, sustaining millions of people and contributing significantly to food security and income. In Tanzania, the Mchare variety is particularly important as a staple crop and serves as a key progenitor for globally significant cultivars such as Cavendish and Gros Michel. Despite its importance, Mchare faces several challenges, including susceptibility to pests and diseases and, notably, low seed set and poor seed viability, which constrain breeding. This study investigated the impact of supplemental irrigation on seed production and viability in Mchare bananas ‘Huti-White’ under controlled field conditions. The experiment was conducted at the Nelson Mandela African Institution of Science and Technology. A total of 320 ‘Huti-White’ suckers were planted under a randomized complete block design with factorial combinations of irrigation (supplemental irrigation (IR) vs rainfed (RF)), planting cycle and season. Supplemental irrigation was applied through drip irrigation, delivering 1360 mm of water over 17 weeks during the dry season and resulting in a total annual input of 2263 mm per mat (banana mat is a cluster of banana plants growing from the same corm). Data were analysed in R (v4.3.0) using ANOVA, with mean separation performed using least significant difference (LSD) tests at the 5% level. Results showed that supplemental irrigation significantly affected both seed quantity and quality. Total seeds extracted were significantly affected by supplemental irrigation (p < 0.001, LSD = 2.26), with RF mats producing more seeds. However, seed quality was markedly lower under RF conditions, with 55.9% of seeds lacking embryos compared with 6.9% under supplemental irrigation (p < 0.001, LSD = 1.37). Germination efficiency relative to total seeds was higher under supplemental irrigation (85.2%) than RF (33.7%), and seed viability was significantly greater (p = 0.015, LSD = 7.55%), with 91.5% of embryo-bearing seeds germinating compared with 76.3% under RF conditions. Cycle and seasonal effects were not significant, identifying supplemental irrigation as the dominant factor affecting reproductive success. Although RF plants produced more seeds numerically, most were non-functional, whereas supplemental irrigation markedly improved embryo retention, germination efficiency and seed viability, with clear implications for banana breeding and germplasm development. Significance of the study What is already known on this subject? Banana (Musa spp.) improvement, particularly in East African Mchare types, is constrained by low seed viability, which limits the efficiency of breeding programmes. Previous studies have established that environmental factors, especially water availability, play a critical role in influencing seed set and reproductive success. Despite this understanding, most research has focused on increasing seed quantity rather than improving seed quality. What are the new findings? This study demonstrates that water availability during the reproductive stage is the primary determinant of seed quality rather than seed quantity, revealing a clear quantity–quality trade-off regulated by irrigation. Under rainfed conditions, plants produced a higher number of seeds, indicating that fertilisation processes such as pollen deposition and stigma receptivity were not completely inhibited. However, a large proportion of these seeds lacked embryos or failed to germinate, suggesting substantial post-fertilisation failure. In contrast, supplemental irrigation resulted in fewer seeds but significantly improved embryo formation, germination rates, and overall seed viability. This resulted in a higher proportion of functional seeds, even when total seed output was lower. What is the expected impact on horticulture? The findings provide a practical and impactful strategy for improving banana breeding efficiency, particularly in water-limited environments. By applying targeted supplemental irrigation during the reproductive phase, breeders can significantly enhance seed viability, increase the proportion of embryo-bearing seeds, and reduce the production of non-functional seeds. This represents a paradigm shift in horticultural practice from maximising seed quantity to optimising seed quality. These insights have direct implications for breeding programmes, where seed viability is a critical limiting factor. Integrating irrigation into reproductive-stage management can accelerate breeding cycles, improve hybridisation success, and enhance the development of improved banana cultivars.
Abstract Seedlings of Andrographis paniculata (Burm.f.) Wall. ex Nees cv. Phichit were cultivated in 8-inch pots containing a growing medium composed of coconut coir and peat moss at a ratio of 70:30 (v/v). The pots were placed on cultivation shelves in a plant factory system equipped with five light-emitting diode (LED) lighting treatments: (i) red and blue light in an 8:2 ratio (RB), (ii) RB supplemented with additional red light (RBR), (iii) RB supplemented with additional blue light (RBB), (iv) RB supplemented with warm white light (RBW) and (v) RB supplemented with daylight LEDs (RBD). Five pots were assigned to each lighting treatment and exposed to a 16-h photoperiod for 7 weeks. The results indicated that plant height, leaf dimensions, canopy width, stem diameter, number of leaves and flowering showed no significant differences among the lighting treatments. However, the spectral quality of light significantly influenced the accumulation of secondary metabolites. The RBR treatment produced the highest total phenolic content (TPC) (7.00 ± 0.23 mg GAE g−¹ extract), whereas the RB treatment resulted in the highest total flavonoid content (TFC) (13.83 ± 1.10 mg CE g−¹ extract). Total lactone content was also enhanced under the RBR and RBB treatments, reaching (17.48 and 17.40 mg AE g−¹ extract), respectively. In addition, antioxidant activity was strongly affected by light quality. The RBW treatment exhibited high radical scavenging activity, with values of 84.41% for DPPH and 88.99% for 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays. Meanwhile, the RBB treatment demonstrated the greatest antioxidant potency, as indicated by the lowest IC₅₀ values (2.58 mg ml−¹ for DPPH and 2.46 mg ml−¹ for ABTS). Lower phenolic contents were observed under the RBW and RBD treatments. Overall, these findings suggest that LED spectra enriched with red and blue wavelengths can enhance phytochemical accumulation in A. paniculata without negatively affecting plant growth. Significance of the Study What is already known on this subject: Light quality, especially red and blue wavelengths, strongly affects plant growth and the production of important bioactive compounds. Light-emitting diode (LED) lighting is widely used in horticulture for its efficiency and ability to customize light spectra. While many studies show benefits in various medicinal plants, how different light spectra affect specific cultivars like Andrographis paniculata cv. Phichit is still not well understood. What are the new findings: This study provides new evidence that different LED spectra can be used as an effective production strategy to improve the medicinal quality of A. paniculata cv. Phichit in plant factory systems. Red–blue lighting, particularly when enriched with additional red or blue wavelengths, enhanced flavonoid and lactone accumulation without compromising plant growth. Notably, supplemental blue light (RBB) maximized antioxidant activity, highlighting its potential application for controlled-environment medicinal plant production of high-value medicinal herbs. What are the expected impacts on horticulture: This study offers a practical approach for improving the quality of medicinal crops produced in plant factories and vertical farming systems. The use of optimized LED light spectra allows growers to enhance bioactive compound accumulation without additional cultivation time, energy or inputs. These findings support the adoption of controlled LED lighting strategies tailored to specific cultivars and reinforce the role of smart LED technologies in sustainable, high-value horticultural production.
Abstract Micronutrient malnutrition, particularly selenium (Se) deficiency, remains a major challenge. Controlled environment agriculture (CEA) and totally controlled environment agriculture (TCEA) systems offer innovative platforms for resource-efficient food production and nutritional enhancement through precise environmental regulation. Among the available agronomic strategies, Se biofortification has proven to be highly effective in improving the Se-related nutritional and functional quality of vegetables and herbs. Concurrently, light-emitting diode (LED) technologies facilitate the dynamic control of spectral quality, intensity and photoperiod to optimize photosynthesis and secondary metabolism. This review summarizes the current evidence regarding the combined effects of Se biofortification and LED spectral management on plant physiology, mineral nutrition and bioactive compound accumulation. Research indicates that appropriate Se concentrations, typically in the micromolar range, enhance antioxidant activity, phenolic and flavonoid content and stress tolerance, whereas excessive Se levels induce phytotoxic responses. LED light spectra, particularly the red-to-blue ratio, have been shown to regulate Se concentration, translocation and nitrate metabolism, thereby influencing both growth and nutritional quality. The integration of Se biofortification with optimized lighting regimes enhances crop yield stability, resource-use efficiency and Se-driven nutritional attributes in hydroponic systems, microgreens and baby-leaf vegetables. Despite these advancements, substantial knowledge gaps persist regarding Se speciation, metabolic regulation under different light spectra and post-harvest bioavailability. Future research should integrate omics technologies, high-resolution analytics and dynamic light modelling to elucidate Se–light interactions at the molecular and physiological levels. This integration represents a decisive step towards reproducible and economically viable Se biofortification protocols applicable to next-generation indoor farming. Significance of this study What is already known on this subject? Biofortification of crops with essential micronutrients, such as selenium (Se), is an effective strategy for enhancing nutritional quality and human health. Controlled environment agriculture (CEA) systems, using light-emitting diode (LED) technologies, enable precise control of spectral quality, intensity and photoperiod, which are known to influence nutrient uptake, redox regulation and secondary metabolism. However, most studies have examined Se nutrition and light quality as separate factors without fully exploring their combined physiological and biochemical effects in controlled environments. What are the new findings? This review provides an integrated synthesis of how LED spectral management, particularly variations in the red-to-blue (R:B) ratio, affects Se uptake, translocation and metabolism in hydroponically and indoor-grown crops. This highlights that optimized Se concentrations (2–10 µmol L−1) combined with balanced R:B light spectra increase antioxidant enzyme activity, phenolic biosynthesis and nitrate reduction while maintaining the yield. This work also identifies key gaps in the current research, including Se speciation, genotype-dependent responses and the influence of dynamic or polychromatic light regimes. What is the expected impact on horticulture? Integrating Se biofortification with LED spectral optimisation in CEA and TCEA systems offers a practical pathway for producing high-quality micronutrient-enriched crops in vertical and urban farms. These findings provide a framework for designing standardized and resource-efficient cultivation strategies that enhance crop value and nutritional integrity across species and developmental stages.
Many cultivars of almond (Prunus dulcis Mill. D. A. Webb) suffer from a disorder known as non-infectious bud failure, in which preformed meristematic tissue becomes necrotic during dormancy, then fails to emerge in the following growing season. While the cause of the disorder is unknown, previous research has shown possible connections between DNA methylation and symptoms of the disorder. Additionally, non-infectious bud failure has been mitigated through propagation from basal epicormic buds, which show reduced non-infectious bud failure in clonal progeny relative to the axillary canopy buds typically used for propagation. In this study, we explored variation in DNA methylation between epicormic and axillary shoots that may provide insight into the spread and origins of non-infectious bud failure. We hypothesized that shoots derived from different tissues (epicormic and axillary buds) and growing environments would have distinct genome-wide patterns of DNA methylation. We sampled leaf tissue from epicormic and axillary canopy shoots from two almond varieties at four locations, then used whole-genome enzymatic methyl-sequencing to determine global methylation levels and differentially methylated regions between tissues. We found no significant differences in genome-wide methylation levels between different shoot types, locations and varieties. Epicormic and axillary shoots displayed 23 differentially methylated regions in one variety and 45 in the other, with no overlap in these regions between varieties. In addition, we identified 4546 regions that appeared differentially methylated between varieties; however, DNA polymorphism may account for some of these differences. In pairwise comparisons between locations, we identified 312 regions, with overlapping regions between some, but not all, locations. The remarkable stability of DNA methylation patterns across tissues and locations motivates further investigation into possible perturbations of these patterns by non-infectious bud failure and related genetic disorders in perennial plants.
Abstract While taking big steps to increase the sustainability of soilless production systems through the integration of organic fertilization sources, the drivers and premises for their implementation do not seem to be entirely covered. There has been a scattered experimental approach to finding suitable organic sources and nutrient recovery technologies to overcome technical limitations, which seem relevant in the system’s footprint. Although recognized by some, the acceptance of soilless agriculture under the organic label is still under debate. This brief commentary addresses the concept of organic fertilizers in soilless agricultural systems, highlighting the importance of common premises to move forward. These include the local context of implementation, the choice of technology, scale and organic fertilizer source, as well as the employment of tools to integrate agronomic optimization with accurate analysis of environmental and economic sustainability performances. The importance of the organic waste source is discussed, considering it pertinent to align with the underlying principles of low-input farming, avoiding the generation of non-sustainable market chains or new waste for the sake of its circularity. Finally, it is proposed to strive for an alternative certification system for low-input and circular farming systems with common goals, also based on needs and available resource flow in urban and industrial settings. Significance of the study What is already known on this subject? The subject of organic fertilization in soilless agriculture is being greatly explored, while the strategic pathway and the requirements for the implementation can be unclear and underrepresented. What are the new findings? The present text does not present new data but intends to shed light on the challenges and inconsistencies of the current research direction, as well as encourage the definition of separate goals for certification in circular soilless systems. What are the expected impacts on horticulture? The present document aims to foster critical thinking on the choice of organic sources, emphasizing scalability and contextual awareness while avoiding reliance on unsustainable sources.
Introduction: Agroecological farming has emerged as a promising approach for managing crop pests, including the 'true' fruit fly (Diptera: Tephritidae), in cucurbit production. Cucurbits are importantfor both nutrition and income generation, making effective pest management critical to ensure sustainable yields and improved farmer livelihoods. Despite the growing promotion of agroecological practices as alternatives to synthetic pesticides, evidence on their economic benefits remains limited. Methods: This study was conducted in Morogoro Region, Tanzania, through field experiments, to compare the economic impacts of agroecological and conventional management practices in cucurbit crop production. Discussion: Results showed that management practices significantly (P < 0.05) influenced both marketable fruit weight and production costs. For squash, agroecological plots yielded significantly higher marketable fruit weights compared to conventional plots, while for watermelon and cucumber, yields were comparable across the two practices. Production costs were consistently higher under conventional management for all three cucurbit crops. Furthermore, the net profit and cost-benefit ratio were significantly higher (P < 0.05) in agroecological systems. Conclusion: The findings indicate that agroecological pest management presents significant economic benefits compared to conventional methods. This approach offers a sustainable and cost-effective alternative for reducing reliance on synthetic pesticides in cucurbit production systems and agriculture.
To improve the quality of peach fruits, foliar sprays of algal biostimulant at different concentrations (600-, 900-, 1200-and 1500-fold dilutions) were applied to peach trees, aiming to investigate the effects of the biostimulant on peach fruit quality. The 900-and 1200-fold dilutions of algal biostimulant resulted in increases in single fruit weight, fruit transverse diameter, total soluble solid content, vitamin C content and solid:acid ratio to some extent. Furthermore, only the 1200-and 1500-fold dilutions of algal biostimulant led to an increase in fruit firmness. The 900-fold dilution of algal biostimulant produced the highest levels of total soluble solids and vitamin C, with a 49.42% and 46.12% increase compared with control. Additionally, the 900-and 1200-fold dilutions of algal biostimulant decreased the titratable acid content by 15.72% and 20.13%, respectively, compared with control. Algal biostimulant also raised sugar content and the activities of lipoxygenase, ascorbate peroxidase, and phenylalanine ammonia lyase to some extent, while lowering the activity of polyphenol oxidase. Moreover, the strong relationship between fruit shape index, titratable acid content, polyphenol oxidase activity and hardness, while other parameters showed close associations. In conclusion, algal biostimulant can improve the quality of peach fruits, with the 900-fold dilution being the most effective concentration.
