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Root rot of hydroponically grown Welsh onion has caused considerable economic losses every year since commercial cultivation began in 1988 in Hiroshima Prefecture, Japan. The primary pathogens, which have not been reported to form sexual structures, are Pythium spp. including Pythium clusters B2a sp., which is most prevalent, and B1d sp. and Pythium clade A sp. These pathogens infect Welsh onion roots by producing sporangia and zoospores. The objective of this study was to elucidate the inhibitory effects of low-pH solutions on root-rot pathogens of hydroponically grown Welsh onion. Naturally occurring disease was significantly lower after treatment with nutrient solutions with a pH maintained at 4.3–4.9 than with conventional unmanaged solutions (pH 5.4–6.4). In a greenhouse after inoculation of infected Welsh onion with Pythium cluster B2a sp., low-pH solutions (pH 4.0 and 4.5) significantly suppressed zoospore production and reduced the percentage of root infections compared to the conventional solution (pH 5.5). In other greenhouse inoculation tests with Pythium clusters B2a sp. and B1d sp. and Pythium clade A sp., the low-pH solution (pH 4.0) substantially decreased zoospore density and root infection compared to the conventional solution (pH 5.5). The low-pH solutions did not negatively impact crop yield in the greenhouse tests and thus can be used to suppress root rot in hydroponically grown Welsh onions. [ABSTRACT FROM AUTHOR]

Onions (Allium cepa L.) are one of the main vegetable crops worldwide. As an allogamous species with entomophilous pollination, floral traits play a critical role in seed production. Improving seed yield, especially for hybrid seed production, is very important. In this work, we obtained genetic information for floral traits using segregating populations from three male‐sterile lines and one open‐pollinated variety. Data on 16 floral traits, including perianth, gynoecium, stamens, and receptacle structures, were collected from the parental cultivars, their hybrids, and from segregating populations in the F2 and F3 generations. This dataset underpinned a comprehensive analysis of genetic variability, broad‐ and narrow‐sense heritability estimation, genetic gain predictions, and trait correlations. The evaluated traits exhibited high broad‐sense heritability values (0.08–0.85), but moderate narrow‐sense heritability values (0.01–0.68), implying that the observed phenotypic variance is mainly explained by genetic factors, with a minor additive genetic factors contribution. Consequently, the study revealed effective genetic gain for the analyzed traits. The phenotypic correlations observed in the parental cultivars were not always maintained in the segregating populations, suggesting random correlations. Meanwhile, genetic correlations were moderate to low, suggesting that the analyzed traits can be independently selected without affecting the expression of other floral traits. Notably, correlations among floral traits were significant in stable cultivars but weak in segregating populations, excluding pleiotropic effects. This work has successfully demonstrated the heritability of onion floral traits and provided a sound basis for selecting individuals with desirable attributes, with valuable practical implications for onion breeding and seed production. Core Ideas: The phenotypic variance found for onion floral traits is mostly due to genetic factors.Onion floral trait phenotypic variance is explained to a lesser extent by additive genetic factors.Onion floral traits exhibit moderate narrow‐sense heritability.The selection of onion floral traits can be done independently. [ABSTRACT FROM AUTHOR]

Background: Purple blotch disease is a devastating disease, resulting in significant yield losses in onion. Application of synthetic fungicides is a rapid approach for the control of this disease, but extensive use of synthetic fungicides results in resistance development in pathogen. Thus, it is mandatory to explore alternative approaches to overcome the fungicide resistance challenges. The present study focused on a sustainable biocontrolling approach by using biocontrol yeast. The objective was to develop a management strategy that offers an environmentally acceptable alternative to commonly used fungicides. Results: A total of six pathogenic isolates were obtained from the infected onion leaves, out of all tested isolates, OP-4 recorded as highly virulent with disease incidence (75.2%). Filobasidium wieringae and Pichia kluyveri drastically reduced the in vitro mycelial growth of Alternaria porri (14 and 21 mm, respectively). In the greenhouse experiment, plant inoculated with P. kluyveri suspension was the most effective, resulting in considerable reduction (77.1%) in disease severity, before two days of pathogen inoculation. However, F. wieringae showed a considerable reduction (84.5%) in disease severity when applied in combination with P. kluyveri two days post-inoculation. Conclusions: These findings highlighted the strong biocontrol potential of P. kluyveri and F. wieringae in managing the purple blotch disease of onion and can reduce the reliance on synthetic fungicides. Further research and field trials should be conducted to optimize the application methods and evaluate the long-term effectiveness of these bioagents. [ABSTRACT FROM AUTHOR]

Background: Maharashtra ranks first in onion (Allium cepa L.) production with a share of 28.32%. However, the productivity of onion is low as compared to other countries. In order to enhance onion productivity, new and innovative agri-inputs are being tried continuously like providing humic acid, fulvic acid, plant growth regulators (PGR), auxin/amino acid spray, seaweed extract, biofertilizers, sulphur application etc. PGRs are considered to be one of the novel inputs that can help in increasing the productivity of onion in India economically. Plant growth regulators are considered as a new generation of agrochemicals when added in small amounts, modify the growth of the plants usually by stimulation or modifying one part of natural growth regulatory system, thereby increasing the crop yield. Most of the research data available is based on biochemical, seaweeds etc. Almost negligible literature is available pertaining to a PGR made with formulation of Seaweed extract and Protein Hydrolysate. An attempt has been made in this research work to evaluate the effect of PGR formulated with seaweed extract and Protein Hydrolysate as major constituents on onion bulb yield through both foliar and drenching application. Methods: A field experiment for evaluating the effect of plant growth regulator (PGR) formulated by Research and Development Department, M/s Rashtriya Chemicals and Fertilizers Limited was conducted at Chilli and Vegetable Research Farm, Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola (MH). During the experiment, the effect of different concentration of PGR viz., 0.2%, 0.4%, 0.6% and 0.8% and 1.0%, 1.2%, 1.4% and 1.6% through foliar and drenching application, respectively were studied. Result: Statistically, significant results of plant growth regulator application on vegetative growth, yield and qualitative characters of onion crop were observed. Significantly, maximum bulb yield was observed in the treatment PGR @ 0.6% (255.41 kg/ha) through foliar application which is at par with the treatment PGR @ 1.4% (246.67 kg/ha) through soil drenching along with RDF. According to the results, the suitable PGR dose for studied characters of onion under prevailing conditions was 0.6% foliar spray and 1.4% soil drenching along with recommended dose of fertilizers. [ABSTRACT FROM AUTHOR]

On a worldwide scale, A. cepa is among the most commonly consumed vegetables. In Europe, the leading onion producers are Russia, the Netherlands, Spain, Poland and Germany. In this study, the bioaccumulation of heavy metals (Cr, Cu, Zn, Ni, Fe, Mn, Co, Sr, Cd and Pb) by Allium cepa L. plants was followed under hydroponic conditions. The heavy metals were applied at six concentrations (0, 25, 50, 100, 200 and 400 mg L−1) over three weeks. The quantitative analysis of selected heavy metals in plant tissues (bulbs, roots and assimilation leaves) was performed using atomic absorption spectrometry with flame atomization (F-AAS). The accumulation of metal ions was strongly dependent on their concentrations in the solution and the analyzed parts of plants. The highest accumulation of metal ions was confirmed for the roots and ranged from 8.48 to 5912.34 µg g−1 DW (dry weight). All parts of A. cepa were characterized by the high accumulation of Mn2+. The lowest accumulation was confirmed for Co2+ in the roots, Pb2+ in the assimilation leaves and Cu2+ in the bulbs of onion. Moreover, the study showed that the highest concentrations of heavy metals decreased the growth of bulbs and even caused them to die off. In contrast, lower concentrations of some elements stimulated plant development. [ABSTRACT FROM AUTHOR]

The study presents a characterization of the volatile organic compounds found in both raw and the essential oil of the "Pereirana Onion," an endemic Colombian Welsh onion variety for which the composition has not been previously reported. The analysis was conducted using four distinct fibers through the HS-SPME/GC-MS method. The results revealed that chopped Pereirana onions release as many as 29 different compounds, with concentrations up to 20 times higher than those observed in other evaluated onion species (Biónica, Veleña, and Veleña Sonsón). Most of these compounds are sulfur-based, including dipropyl disulfide, (E)-1-(Prop-1-en-1-yl)-2-propyldisulfane, disulfide, methyl 1-(methylthio) propyl, dipropyl trisulphide, and (E)-1-(Prop-1-en-1-yl)-3-propyltrisulfane. Furthermore, steam extraction of essential oils from Pereirana onions led to the identification of up to 70 different compounds. Simple correspondence analysis (SCA) revealed that Veleña and Veleña Sonsón onion species share common compounds but significantly differ from Biónica and Pereirana varieties cultivated in Risaralda, Colombia. These findings suggest potential applications in the pharmaceutical, agricultural, and food industries, paving the way for future research and industrial utilization. [ABSTRACT FROM AUTHOR]

This study aims at assessing the effect of limestone mining by-product from the Irati Formation on soil calcium, magnesium, and sulfur contents, as well as their accumulation in the onion biomass. The study was carried out in a greenhouse. A Eutrophic Haplic Planosol (SXe) and a Eutrophic Yellow Argisol (PAe) soil were used. The treatments included the control, limestone by-product, dolomitic limestone, calcium (Ca) + magnesium (Mg) carbonates, and Ca + Mg carbonates + gypsum. Onions were grown in pots containing 10 dm3 of soil kept at a moisture level close to the field capacity. The onion biomass harvest (bulb + leaves) was performed 77 days after transplanting. Afterwards, the soil macronutrient content and the dry onion biomass were determined, as well as its production. The by-product application increased Mg2+ content in both soils (+74% in SXe and + 182% in PAe) and Ca2+ and sulfate (S-SO42-) contents, respectively, in the PAe (+62%) and SXe (+124%). There was an increase in S accumulation due to the onion biomass cultivated in both soils (about 85%). Regarding Ca and Mg accumulations, no difference was observed in the by-product treatment when compared to the control. Therefore, it is possible to infer that the limestone mining by-product from the Irati Formation is potentially useful as a source of secondary macronutrients and proves to be a clean environmental solution for soil fertilization, increasing the sustainability of the local production system. [ABSTRACT FROM AUTHOR]

Onion (Allium cepa L.) is a cross-pollinated crop with severe inbreeding depression. Inbred breeding lines are thus commonly maintained through sib-mating or a combination of sib-mating and self-pollination. Therefore, the homozygosity levels of onion inbred lines are generally low compared with self-pollinated crops. To evaluate the homozygosity levels of inbred lines, 43 high-resolution melting markers that were evenly distributed throughout eight onion linkage groups were selected among 652 markers consisting of a high-resolution linkage map. Eight individual plants from 119 inbred lines collected from five onion-breeding institutes were analyzed using the 43 HRM markers, resulting in an average homozygosity level of 0.55. This indicates that almost half of the 43 markers were still segregating in those inbred lines. The homozygosity levels of inbred lines varied between the onion-breeding institutes but they were generally higher than those of the Plant Introduction (PI) accessions. Additionally, the average proportion of genotypes fixed as either homozygous or heterozygous was 0.46 in 12 F1 cultivars, indicating that their parental lines had low homozygosity levels. Phylogenetic analyses based on the pairwise genetic distances of all entries did not show clear clustering of related entries. This lack of clear clustering patterns was attributed to the relatively large within-population variations and low genetic diversity of the analyzed entries. The observed heterozygosity of the 43 markers was generally higher than the expected heterozygosity. Moreover, one marker exhibited a marked increase in observed heterozygosity, suggesting the possible involvement of this genomic region in inbreeding depression. [ABSTRACT FROM AUTHOR]

Several Fusarium species cause disease in onion (Allium cepa), resulting in significant yield losses. In this study, isolates of Fusarium oxysporum and Fusarium proliferatum from diseased and symptomless mature onion bulbs were tested for pathogenicity on onion seedlings and mature bulbs. For F. oxysporum isolates, the outcome of the test on mature bulbs correlated well with the symptom status of the original bulb, whereas for F. proliferatum, such a correlation was not seen, suggesting a different mechanism of symptom development. Those F. oxysporum isolates that carried the Secreted In Xylem (SIX) genes, CRX genes and C5 gene were significantly more aggressive on both seedlings and mature bulbs. However, the SIX‐negative F. oxysporum isolates also significantly reduced the emergence of onion seedlings, and thus a division into pathogenic and nonpathogenic F. oxysporum isolates was not obvious. On mature bulbs, those SIX‐negative isolates that carried the gene CRX2 were significantly more virulent than those without CRX2. The F. proliferatum isolates were all pathogenic to onion and carried one SIX2 gene homologue, SIX2‐1. The majority of F. proliferatum isolates also carried another homologue, SIX2‐2. Several isolates negative for SIX2‐2 had another potential virulence gene, CRX2, suggesting that these two genes could encode overlapping functions. The SIX2‐2 sequence was identical in all those isolates harbouring it, while SIX2‐1 showed variation that agreed with the phylogeny based on the translation elongation factor 1‐α sequence. This suggests that the two SIX2 genes of F. proliferatum might have been acquired separately. [ABSTRACT FROM AUTHOR]

Simple Summary: Onion maggot (Delia antiqua) can be a devastating pest of onion and related crops around the world. While management of this pest typically relies on insecticides to control these pests, growing resistance and desire for alternative control strategies has motivated a search for new methods to manage them effectively. We investigated the potential of using tiny beneficial roundworms called entomopathogenic nematodes to control onion maggots. We conducted surveys in onion-growing areas to see if these nematodes were naturally present, and also tested their compatibility with commonly used insecticides. Our field trials demonstrated that applying entomopathogenic nematodes can significantly reduce the number of onion plants destroyed by onion maggots, leading to higher crop yields. These nematodes could be a useful tool for onion farmers, whether they practice conventional or organic farming. When combined with other strategies like insecticide seed treatments, the use of entomopathogenic nematodes can provide effective control of onion maggots while boosting crop productivity. Onion maggot (Delia antiqua) is a prominent pest of allium crops in temperate zones worldwide. Management of this pest relies on prophylactic insecticide applications at planting that target the first generation. Because effective options are limited, growers are interested in novel tactics such as deployment of entomopathogenic nematodes. We surveyed muck soils where onions are typically grown to determine if entomopathogenic nematode species were present, and then evaluated the compatibility of entomopathogenic nematode species with the insecticides commonly used to manage D. antiqua. We also evaluated the efficacy of these entomopathogenic nematodes for reducing D. antiqua infestations in the field. No endemic entomopathogenic nematodes were detected in surveys of muck fields in New York. Compatibility assays indicated that, although insecticides such as spinosad and, to some extent, cyromazine did cause mortality of entomopathogenic nematodes, these insecticides did not affect infectivity of the entomopathogenic nematodes. Field trials indicated that applications of entomopathogenic nematodes can reduce the percentage of onion plants killed by D. antiqua from 6% to 30%. Entomopathogenic nematodes reduced D. antiqua damage and increased end of season yield over two field seasons. Applications of entomopathogenic nematodes may be a viable option for reducing D. antiqua populations in conventional and organic systems. Together with other management tactics, like insecticide seed treatments, applications of entomopathogenic nematodes can provide a yield boost and a commercially acceptable level of D. antiqua control. [ABSTRACT FROM AUTHOR]

The genetic diversity assessment of agricultural crops is crucial for breeding programs aimed at enhancing crop yield, resistance to diseases, and adaptation to changing environmental conditions. In the present investigation, a comparative genetic relationship in sixteen onion genotypes was assessed utilizing dominant (RAPD) and co-dominant (SSR) marker systems. Ten RAPD and nine SSR markers showed genetic diversity remarkably and produced 503 and 107 amplicons respectively. Spearman rank correlation was used to compare the different efficiency parameters in two marker systems with respect to sixteen onion genotypes. The genetic relationship based on similarity matrix values between a pair of cultivars was higher for SSR markers than for the RAPD marker system. OPC-04 (RAPD primer) and ACM-004 (SSR primer) witnessed the highest poly-morphic bands along with other polymorphic markers that proved to be useful in grouping onion genotypes. Finally, dendrograms were constructed and compared following the mantel test to find out the genetic diversity among the germplasms. This study will be effective for a selection of efficient primers and suitable marker systems to distinguish the onion genotypes in the future. [ABSTRACT FROM AUTHOR]

Influence of fungicides, nutrients and bioagents on yield, quality enhancement and management leaf twisting in onion was studied at Regional Agricultural Station, Vijayapur, Karnataka, during kharif and rabi 2021-22. The variety of 'Bhima Super' seeds collected from two sources (normal and twisting affected seeds) with nine treatments combination of polymer (3 ml kg-1), chemicals, captan (2 g/kg), carboxin 37.5 % + thiram 37.5 % (3 g kg-1), captan 70 % + hexaconazole 5 % (3 g kg-1) and bioagents of Trichoderma harzianum, Pseudomonas fluorescens, and Bacillus subtilis each @ 5 g kg-1. The results obtained from combination of all three bioagents recorded significantly higher bulb yield (23.82 t ha-1) followed by all three bioagents along with fungicides carboxin 37.5 % + thiram 37.5 % (3 g kg-1) (23.15 t ha-1) as compared to control (15.22 t ha-1) due to significant increase in the yield attributes. Kharif harvested bulbs treated with nine different treatment combinations and planted during Rabi season to know the effect of nutrients, fungicides and bioagents on field performance and management of leaf twisting. Among treatments application of N: P: K @ 125: 50: 125 kg ha-1 + Mg @ 30 kg ha-1 + S @ 45 kg ha-1 + B @ 3 kg ha-1 + Zn @ 4 kg ha-1 + foliar spray of hexaconazole 0.05 % at 30 and 60 days after planting recorded significantly higher plant growth parameters, lesser leaf twisting (17.44 %) and higher seed yield (504.49 kg ha-1) as compared to control (34.99 % and 312.47 kg ha-1 respectively). [ABSTRACT FROM AUTHOR]

Fusarium basal rot, caused by Fusarium oxysporum f.sp. cepae, is an important onion disease worldwide. Greenhouse pot experiments were conducted during two growing seasons to determine if field soils from New Zealand's main onion growing regions had different fusarium basal rot suppressive capabilities, and identified factors involved in disease suppression This study demonstrated that soils naturally suppressive to fusarium basal rot were present in New Zealand and that soil organic matter content, total soil carbon, total nitrogen and soil phosphorous concentrations were associated with disease incidence. Soil microorganisms were shown to be involved in disease suppression since when they were eliminated or reduced by soil heat treatment, fusarium basal rot incidence markedly increased. This study provided an increased understanding of how soil physical, chemical and biological factors affect the suppressiveness of selected New Zealand soils to fusarium basal rot of onion, and demonstrated that certain bacterial and fungal taxa may be involved in suppression of this disease. [ABSTRACT FROM AUTHOR]

In semi-arid areas of Ethiopia, water is the most limiting factor for crop production. Due this introducing different water saving technologies in needed. This on farm demonstration was done in Meskan passidp-II target irrigation scheme to assess AFI and conventional furrow irrigation effect on Onion yield and water productivity. Six clustered model farmers field used as sample demonstration site. The comparative treatments were AFI full irrigation application (100% ETc) (4 days irrigation interval) and Conventional/Farmer Practices (6 days irrigation interval) as control. Plot size was 10m by 10m on each farmer’s field. One year conducted result shows that maximum Onion bulb yield (9.082 ton/ha) and WP (3.79 kg/m³) were recorded on AFI application in 4 days irrigation interval. Minimum onion bulb yield (6.94 ton/ha) and WP (1.97 kg/m³) were obtained at conventional/farmers practice in 6 days irrigation interval. Therefore, using AFI application, there was significant yield difference between AFI and Farmers’ practice. Therefore, AFI practice is recommended to improve Onion production and WP in study area/scheme with recommended full packages. [ABSTRACT FROM AUTHOR]

The nutrition of onion grown in a no-tillage system with compost requires research to provide alternatives to mineral fertilizers. Our objective was to evaluate the effect of compost rates on the nutrient content in the tissue of onion grown in a no-tillage system. We conducted a field experiment with the following treatments: 0, 10, 20, 30, and 60 Mg ha−1 of compost and mineral fertilization. We applied these treatments in 2018, 2019, and 2020 for onion cultivation. We used a 3 × 6 factorial scheme (year x treatment) and four replications. We evaluated the bulbs and whole plant nutrient contents of N, P, K, Ca, Mg, S, Fe, Mn, Zn, Cu, and B. In 2020, nutrient content in the bulb from 10 Mg ha−1 of compost was similar to the mineral fertilizer's treatment. Therefore, compost can replace mineral fertilizers to supply nutrients to the onion. However, the continuous application of compost requires soil monitoring due to nutrient accumulation. [ABSTRACT FROM AUTHOR]

Severe root rot was observed in onion seedlings growing in nursery seedbeds in Changnyeong, South Korea in September 2021. The diseased onion seedlings showed symptoms including water-soaking, browning and blight, followed by seedling collapse. Three isolates were obtained from diseased onion seedlings, and their morphological characteristics were found to be similar to previously described Pythium species. Artificial inoculation with isolates produced identical symptoms to those observed in the original infection. Based on morphological characteristics, sequencing of rRNA gene internal transcribed spacer, ribosomal large subunit gene region, and cytochrome c oxidase subunit I gene region, and pathogenicity testing, the causative agent of root rot on the onion seedlings was identified as Globisporangium irregulare (formerly Pythium irregulare). This is the first report of root rot caused by G. irregulare on onion seedlings in Korea. The results of this study suggest that root rot may pose a severe threat to onion seedling cultivation. [ABSTRACT FROM AUTHOR]

A better understanding of the physiological mechanisms by which zinc (Zn) is absorbed by plant leaves may provide additional basic information to help in the improvement of Zn foliar application programs. In this two-year field experiment, apoplastic and symplastic distribution of Zn in the leaves and re-translocation from the leaves to the bulb of onion (Allisum cepa L. cv. Behbahan) as affected by foliar application of different Zn fertilizer sources was investigated. Four Zn fertilizer sources, i.e., ZnSO4 and Zn-lysine (Zn-Lys), Zn-methionine (Zn-Met), and Zn-threonine (Zn-Thr) were applied as foliar spray at a concentration of 0.5% Zn. Free amino acids (i.e., Lys, Met, and Thr) were used to separate the effect of Zn and accompanying amino acids. A free of Zn and amino acid treatment was also considered as control. The Zn-form revealed significant influence on apoplastic Zn concentration. Foliar application of Zn-amino chelates particularly Zn-Lys increased contribution of symplastic to apoplastic Zn in onion leaves by decreasing the Zn retention on the apoplastic spaces. Higher leaf symplastic Zn in the plants supplied with the Zn-Lys in comparison with those supplied with the other Zn fertilizer sources was accompanied with higher bulb Zn accumulation. This was probably due to larger re-translocation of Zn from the leaves to the bulb at the Zn-Lys treatment. Spraying Zn and amino acids either free or complexed with Zn produced an increase in Zn concentration provoking a decrease of nitrate concentration in the bulbs and the highest effect was observed at the Zn-Lys treatment. According to the results, Zn-Lys was more effective than ZnSO4 in enhancing the symplastic to apoplastic Zn ratio in the leaves and resulted higher accumulation of Zn in the bulbs. [ABSTRACT FROM AUTHOR]

Background: Onion (Allium cepa L.) is a very important vegetable crop all over the world, particularly in Egypt for local consumption and exportation. White rot disease is the most serious disease of Allium spp. caused by the soil-borne fungus Sclerotium cepivorum Berk. Results: In this investigation, five tested isolates of Bacillus subtilis showed an antagonistic effect and significantly reduced the linear growth of the pathogen in vitro. B. subtilis isolates no. 2 and 4 caused the highest reduction of S. cepivorum growth, 75.78 and 74.33%, respectively, while isolate no. 3 was the least effective one, causing 66.67% growth reduction. Under field conditions at two successive seasons (2019/20 and 2020/21), all tested bioagent treatments reduced the percentage of infection than Folicure as an officially recommended fungicide. B. subtilis isolate no. 2 showed the highest efficacy (78.57 and 77.78%) followed by isolates no. 4 (74.29 and 72.22%), while B. subtilis isolate no. 3 showed the lowest efficacy (42.86 and 50.00%), respectively, for both successive seasons. All treatments increased dry onion bulb yield and improved its quality than the untreated control plants. The chemical changes of total carbohydrates, total nitrogen contents, total soluble solids (TSS %) and enzymes activity related to defense mechanisms in treated plants by biological treatments were considered. Conclusion: This study aimed to find effective biological agents of B. subtilis isolates against the white rot of onion and evaluate their effect on yield parameters, components and quality. [ABSTRACT FROM AUTHOR]

Tow field experiments were conducted during the seasons of 2020/2021 and 2021/2022 at the experimental farm Etay El-Baroud research station to investigate the effect of foliar application with gibberellic acid (GA3) at 50 and 100 ppm and the chitosan (CS) at of 100 and 200 ppm, in addition, to control for each to Giza Red onion. The results showed significant and positive effects of the examined concentrations of GA3 or CS on all the studied characters except leaves number and shape index, in both seasons. Concerning the interaction effect, all of the studied characters were enhanced significantly in all treatment combinations between GA3 and CS levels. The treatments of GA3 (50 ppm) with CS (200 ppm), GA3 (100 ppm) with CS (100 ppm), and GA3 (100 ppm) with CS (200 ppm) were found to give the highest mean values for all characters, in both seasons without significant differences among them. Also, the results revealed some kind of synergistic effect between GA3 and CS where the combined application was found to be more effective in onion plants performance thane the single ones that gave the ability to reduce the used doses of GA3 by 50%, which, consequently, reduce the expected hazardous of using gibberellins. [ABSTRACT FROM AUTHOR]

Onion flowers attract a wide range of visitors, including pollinators. Many factors influence the abundance of floral visitors in onion, such as flower size, shape, colour, weather parameters and the availability of floral rewards. Quality seed production in onion (Allium cepa L.) is mainly driven by insect pollinators because of its protandrous nature and cross-pollination. The type of flower visitors, their numbers and the time of their visitation determine the pollination efficiency. Bees are the major pollinating agents in onions under natural conditions. However, using chemical pesticides against pests and diseases of onions during bloom decreases the diversity in and around crop fields. Anthropogenic factors like urbanization could have negative impacts on insect pollination services. Therefore, it is critical to adopt a sustainable approach to retain and conserve the existing insect pollinators and their diversity in the onion ecosystem. In this study, we review the research work done so far on the diversity and role of flower visitors and pollinators in onion seed production and the various factors affecting their survival and services in the onion ecosystem. [ABSTRACT FROM AUTHOR]

The study was aimed to evaluate the effect of successive applications of increasing biochar rates along with other mineral fertilizers and poultry manure on onion nutrition and yield. The experiment consisted of 2 (agricultural year) × 11 (treatments) factorial combinations over two cropping years (2017 and 2018). Thus, 11 treatments were tested as follows: C = control; MF = mineral fertilizer; PM = poultry manure; B1+ MF = 1 Mg ha−1 of biochar+MF; B1+ PM = 1 Mg ha−1 of biochar+PM; B2+ MF = 2 Mg ha−1 of biochar+MF; B2+ PM = 2 Mg ha−1 of biochar+PM; B4+ MF = 4 Mg ha−1 of biochar+MF; B4+ PM = 4 Mg ha−1 of biochar+PM; B10+ MF = 10 Mg ha−1 of biochar+MF; B10+ PM = 10 Mg ha−1 of biochar+PM. The highest onion yield (39.9 Mg ha−1) was obtained in 2017 with the biochar rate of 5.9 Mg ha−1 while an increase of 308 kg ha−1 in onion yield was found for each Mg ha−1 of biochar added to soil in 2018. The use of biochar combined with mineral fertilizers increased onion yield; and the use of biochar combined with poultry manure improved soil fertility status. [ABSTRACT FROM AUTHOR]

A soybean cultivar, “Seonyu2ho” for double cropping using soy-paste and tofu was developed in 2011 using the pedigree method by crossing “Milyang235ho” and “Jungmo3004ho.” A promising line, YS2441-B-2S-11-3, was selected and named as “Milyang334.” It demonstrated prominent early maturing, shattering resistance, and high yield in regional yield trials (RYTs) from 2017 to 2019, and was released by the name “Seonyu2ho.” The cultivar showed a determinate growth habit, white flowers, grey pubescence, yellow seed coat, yellow hilum, flat-spherical seed shape, and large seed size (27.9 g per 100 seeds). “Seonyu2ho” matured on October 5 (112-growing day cycle) in RYT and was suitable for double cropping with winter crops, such as wheat, barley, and onion. It was resistant to bacterial pustule and soybean mosaic virus and tolerant to lodging in fields. Particularly, “Seonyu2ho” showed a high yield (3.34 ton/ha) and shattering resistance, even if the previously developed early matured cultivars exhibited low yield and easy shattering. Overall, “Seonyu2ho” can contribute to stable soybean production in double cropping. [ABSTRACT FROM AUTHOR]

Association between characters and path analysis in seventeen genotypes/lines of garlic (Allium sativum L.) was studied at the Vegetable Research Farm, BUAT, Banda during 2019 and 2020. The pooled data of correlation studies, revealed that gross yield plot-1 had positive and significant correlation with equatorial bulb diameter, weight of 20 bulbs and weight of 50 cloves at genotypic and phenotypic level respectively. This showed that improving these features could improve the crop's physiological capacity to mobilise and translocate photosynthates to economically valuable organs (the bulb), perhaps increasing bulb yield as seen in the study. Yield was significantly and negatively correlated with bulb shape index, number of cloves bulb-1, and thrips plant-1 at genotypic level. The genotypic path coefficient analysis showed that equatorial bulb diameter and plant height had the highest positive direct effect on bulb yield. Weight of 20 bulbs and collar thickness had negative direct effect on bulb yield. Positive direct effect of equatorial bulb diameter and plant height indicated good scope for improvement in bulb yield by selecting genotypes having bigger bulb along with increased plant height. [ABSTRACT FROM AUTHOR]

Onion thrips, Thrips tabaci Lindeman, is one of the most serious pests of onion throughout the world. Knowledge of spatial distribution is important for developing an effective sampling plan and ultimately for IPM strategies for a given pest. In the present study spatial distribution of T. tabaci was studied on onion, Allium cepa L. under three irrigation regimes of Egypt during 2021. Dispersion index like a variance to mean ratio (σ ²/X) revealed a negative binomial distribution, whereas the other dispersion indices like David Moore index (IDM = σ ²/X-1), mean crowding (X*), Lloyd’s mean crowding index (X*/X) and ‘k’ of negative binomial verified the aggregated nature of the spatial distribution of onion thrips at 10, 20 and 30-days irrigation intervals throughout the cropping season. Moreover, Taylor’s power equation was σ ²= 1.549X1.581, σ ²= 1.636X1.623 and σ ²= 1.872X1.504, while Iwao’s patchiness regression equation was X*= 2.973+1.432X, X*= 9.251+1.457X and X*= 9.161+1.352X for the three above-mention irrigation intervals, respectively. An optimum number of required samples varied with the mean density of the thrips. [ABSTRACT FROM AUTHOR]

Increasing demand for food, climate change, and other human interventions are leading to significant increases in water consumption by the agricultural sector. This requires rationalizing the water used for the production of agricultural crops through improved irrigation management practices. Therefore, this study aimed to estimate the water footprint (WF) of onion (Allium cepa L.) and carrot (Daucus carota) crops using the CROPWAT model and the SSEB (Simplified Surface Energy Balance) algorithm. Experiments were carried out at two center-pivot irrigated fields belonging to Tawdeehiya Commercial Farms in the southeastern region of the Riyadh governorate, Saudi Arabia. Individual bands and vegetation indices (VIs) were retrieved from Sentinel-2 satellite data, including the normalized difference vegetation index (NDVI), soil adjusted vegetation index (SAVI), optimized soil adjusted vegetation index (OSAVI), renormalized difference vegetation index (RDVI), and enhanced vegetation index (EVI), and the land surface temperatures (LST) extracted from Landsat-8 data were used to estimate crop productivity (CP), crop water use (CWU) (i.e., evapotranspiration—ETa), and crop WF. Crop growth/phenology stages and georeferenced biophysical parameters were recorded during the growth period, and crop yield samples were collected randomly from predetermined sampling locations. It was found that the NIR band was appropriate for predicting onion yield (R2 = 0.68; p > F = 0.02) and carrot yield (R2 = 0.77; p > F = 0.02). The results also showed the feasibility of using the RDVI and EVI to estimate the yields of onion and carrot crops, with bias values of 15% and –17%, respectively. The CWU has also been successfully estimated using the SSEB algorithm, with an overall accuracy of 89%. The SSEB-estimated CWU was relatively high compared to the applied amounts by 10.6% (onions) and 12.6% (carrots). Finally, the crop WF was successfully estimated at 312 m3 t−1 and 230 m3 t−1 for carrots and onions, respectively, with an overall accuracy of 71.11%. The outcomes of this study can serve as a reference for crop irrigation management practices in the study region and areas with similar environmental conditions. [ABSTRACT FROM AUTHOR]

Onion is one of the most economically and nutritionally important vegetable crops in West Africa. Onions are very important for consumers due to the antioxidants and compounds they contain that may reduce inflammation, lower triglycerides and reduce cholesterol levels, resulting in lower risks of heart disease and blood clots. However, high-yielding varieties that are accessible to farmers remain scarce. The objective of the present study was to identify adapted onion genotypes for sustainable production in Northern Ghana and Southern Mali. Nine onion lines, including a check variety, were assessed for yield stability using a randomized complete block design. The trials were carried out in "technology parks" under the joint management of farmers and researchers. Onion bulb weight was recorded for each plot after harvest. Separate analyses of variances were performed for each location and season. Analysis of variance of combined locations, seasons and lines was performed to determine the most stable varieties using the line-superiority measure and ecovalence stability coefficients. Results indicated that the lines AVON1310 and AVON1325 were most stable for yield performance over locations and seasons (Wi = 2.20 and 11.60, respectively; Pi = 1.32 and 6.56, respectively). From the genotype main effects and genotype-by-environment interaction biplots, the best performing lines were AVON1310 (33.32 t.h−1), AVON1308 (28.81 t.h−1) and AVON1325 (31.68 t.h−1). The stability of these lines makes them potential candidates for commercial release in West Africa to contribute to sustainably intensifying onion production in the region. [ABSTRACT FROM AUTHOR]

Onion (Allium cepa L.) is an important bulb plant grown worldwide. Proper use of the agronomic practice has undoubtedly contributed to growing crop yields. The right level of any farming practice, like the distance between plants, plant density, date of planting, and time of harvest, can produce the wanted outcomes. Therefore, this research was piloted to evaluate the influence of plant spacing on the development of bulb harvest-related traits of onion varieties in Dambi Dollo University, Western Ethiopia, in 2021. Three onion varieties (Adama red, Monarch, Nafis) and four intra-row spaces (6 cm, 8 cm, 10 cm, and 12 cm) in factorial combinations were settled by a complete randomized block design which was simulated three times. The findings of the study indicate that all the factors related to crop growth and bulb yield of onion varieties were mainly influenced by different kinds and plant spacing. Conversely, the collaboration of these two factors did not affect all other factors, but the interaction of the two factors had a great effect on the days to maturity measured in this study. The highest plant height was registered on the onion planted at a distance of 10 cm (59.83 cm) and 12 cm (59.08 cm) distance between plants. The high commercial yields (34.44 t ha−1) and entire bulb yield (35.40 t ha−1) were found in the Nafis variety. The highest marketable yields (31.12 ha−1) and entire marketable yield (31.78 ha−1) were recorded on an onion plant planted 10 cm between plants. Therefore, in the research area, farmers can use a variety of Nafis and a 10 cm distance between plants to increase their onion production. [ABSTRACT FROM AUTHOR]

Background: To evaluate the usefulness of fresh onion (Allium cepa L.) leaves, a food waste, as a new food resource, we characterized the taste characteristics, volatile compounds, sensory properties, and antioxidant activity of fresh onion leaves compared with those of Welsh onion (Allium fistulosum L.) (green leaf, small variety) leaves. Results: The total sugar (g/100 g), total organic acid (mg/100 g), and total free amino acid (mg/100 g) concentrations of fresh onion leaves were 2.12 ± 0.15, 730.02 ± 17.43, and 93.72 ± 7.17, respectively, and were significantly (p < 0.05) lower than those of Welsh onion leaves (2.38 ± 0.07, 907.23 ± 20.79, and 131.34 ± 10.22, respectively). In fresh onion leaves, dipropyl disulfide concentration was higher than five times that in Welsh onion leaves. Regarding the sensory properties of the boiled samples, the fresh onion leaves' color was less favorable than Welsh onion leaves (p < 0.05), and the taste and aroma were indifferent. The total oxygen radical absorbance capacity value (μmol Trolox equivalents/100 g) and 1,1-diphenyl-2-picrylhydrazyl free radical-scavenging activity (μmol Trolox equivalents/100 g) of fresh onion leaves were 805.78 ± 100.32 and 406.70 ± 63.64, respectively, and differed insignificantly compared with Welsh onion leaves (888.00 ± 112.61 and 382.98 ± 26.08, respectively). However, the total phenolic content (mg gallic acid equivalents/100 g) and quercetin concentration (mg/100 g) of fresh onion leaves were 36.53 ± 2.53 and 5.71 ± 0.11, respectively, and were significantly (p < 0.05) higher than those of Welsh onion leaves (25.07 ± 2.02 and 0.18 ± 0.02, respectively). Additionally, total vitamin C (23.36 ± 0.62 mg/100 g) and β-carotene (1529.32 ± 167.77 μg/100 g) concentrations in fresh onion leaves were similar to those rich vegetables. Conclusions: This is the first study to report fresh onion leaves' sensory properties and volatile compounds. Additionally, fresh onion leaves could be a new food resource, presenting an alternative to Welsh onion leaves and acting as an excellent dietary source of antioxidants, including quercetin, vitamin C, and β-carotene. [ABSTRACT FROM AUTHOR]

Onion (Allium cepa L.) bulbs produced in the Pacific Northwest of the United States in 2014 and 2015 had unusually high incidence of internal decay. This decay was not detectable externally, leading to marketing problems when bulbs were packed and shipped to markets. The onion growing seasons in 2014 and 2015 were unusually hot, suggesting a connection of heat stress to bulb internal decay. Field studies to investigate the effect of temperature on onion bulb internal decay and yield were conducted in 2016–18 with drip-irrigated onions at the Oregon State University, Malheur Experiment Station located in eastern Oregon. Two long-day onion cultivars were submitted to four cultural practice variations to affect soil and bulb temperatures: bare soil check, supplemental heat using electric heat cables, white kaolinite clay application to the bulb sides and soil surface, and wheat (Triticum aestivum L.) straw mulch. The treatments established significant midafternoon average bulb and soil surface temperature gradients in the following order of increasing temperature: straw mulch, kaolinite, check, and supplemental heat. Averaged over years and cultivars, straw-mulched onions had the highest yield of bulbs larger than 102 mm diameter. Averaged over years and cultivars, onions receiving supplemental heat had the lowest total and marketable yield with no difference among the other treatments. Straw mulched onions had higher total and marketable yield than the bare soil check treatment in 2017, the hottest year. Averaged over the 3 years and two cultivars, marketable yield and yield of bulbs larger than 102 mm diameter decreased with increasing midafternoon bulb temperatures. Kaolinite application did not increase bulb yield nor bulb size compared with the bare soil check. The incidence of internal bulb decay was low all 3 years. In 2017, onions receiving supplemental heat had the highest internal decay and the straw-mulched onions had among the lowest internal decay. There was little difference in the measured soil moisture among treatments. Straw mulching may attenuate the negative effects of excessive heat on yield and bulb internal quality for long day onion production. [ABSTRACT FROM AUTHOR]

Lack of sufficient knowledge about the physical and mechanical properties of onion can result in higher waste during harvesting and post-harvesting. The objective of this work was to determine some physical and mechanical properties of onion cultivated in China. These properties include linear dimensions, mass, shape index, pull-out force, compression and shear forces. The mean longitudinal diameter of bulb (BLD), transverse diameter of bulb (BTD), bulb weight (BW), pull-out force of bulb (BPF), depth of the bulb buried in the soil (BSD), bulb shape index (BSI), diameter of cauloid (CD), circumferential distribution of root systems (RCD), longitudinal length of root systems (RLL) and weight of root systems (RW) were 78.1±9.6 mm, 89.6±10.1 mm, 333.0±101.7 g, 43.9±21.6 N, 35.7±8.7 mm, 1.2±0.1, 15.3±3.7 mm, 89.2±19.7 mm, 42.9±10.0 mm and 0.8±0.4 g. In the study of mechanical properties of onions, the maximum compression force (MCF) required for compression deformation 10 mm of bulb was 462.2 N, and the maximum shear failure force (MSF) required for shearing of cauloid was 113.8 N. The results of the research will be very useful in the design and optimization of harvest and postharvest machines with reduced waste and damage. [ABSTRACT FROM AUTHOR]

The current study sought to synthesize silver nanoparticles (AgNPs) from Amaryllis vittata (L.) leaf and bulb extracts in order to determine their biological significance and use the toxic plants for human health benefits. The formation of silver nanoparticles was detected by a change in color from whitish to brown for bulb-AgNPs and from light green to dark brown for leaf-AgNPs. For the optimization of silver nanoparticles, various experimental physicochemical parameters such as pH, temperature, and salt were determined. UV-vis spectroscopy, Fourier transform infrared spectroscopy, X-ray dispersion spectroscopy, scanning electron microscopy, and energy dispersion spectroscopy analysis were used to characterize nanoparticles. Despite the fact that flavonoids in plant extracts were implicated in the reduction and capping procedure, the prepared nanoparticles demonstrated maximum absorbency between 400 and 500 nm. SEM analysis confirmed the preparation of monodispersed spherical crystalline particles with fcc structure. The bioinspired nanoparticles were found to show effective insecticidal activity against Tribolium castaneum and phytotoxic activity against Lemna aequincotialis. In comparison to plant extracts alone, the tested fabricated nanoparticles showed significant potential to scavenge free radicals and relieve pain. Antibacterial testing against human pathogenic strains, i.e., Escherichia coli and Pseudomonas aureginosa, and antifungal testing against Aspergillus niger revealed the significant potential for microbe resistance using AgNPs. As a result of the findings, the tested silver nanoparticles demonstrated promising potential for developing new and effective pharmacological and agricultural medications. Furthermore, the effects of biogenic AgNPs on an in vitro culture of Solanum tuberosum L. plants were investigated, and the findings indicated that bulb-AgNPs and leaf-AgNPs produced biomass and induced antioxidants via their active constituents. As a result, bulb-AgNPs and leaf-AgNPs may be recommended for use in Solanum tuberosum L. tissue culture for biomass fabrication and metabolic induction. [ABSTRACT FROM AUTHOR]

The online version of the original article can be found at https://doi.org/10.1007/s10327-024-01168-2Correction: Journal of General Plant Pathologyhttps://doi.org/10.1007/s10327-024-01168-2In the sentence beginning "Throughout the experiment,..." in this article, the value "5.5" should have read "4.0". The original article has been updated.Publisher's NoteSpringer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.By Sachiko Shimizu and Motoaki TojoReported by Author; Author [Extracted from the article]

Potential yield of onion (Allium cepa L.) in semi-arid regions is reduced by abiotic (soil infertility, poor agronomic practices, and unbalanced fertilization) and biotic (use of low yielding varieties, insect pest, and diseases) challenges. Soil infertility causes up to 60% yield loss in onion. This study was undertaken to assess the influence of manure and phosphorus (P2O5) fertilizer levels on growth and bulb development of onion under semi-arid conditions. Manure at 30 or 60 kg/5 m2 or 0.24, 0.48 or 0.62 g/plant for phosphorus and treatments combined at each application rate were used. Application of phosphorus and manure at 0.24 to 0.48 g/plant and 30 kg/5 m2 plot, respectively, improved vegetative and bulb development and weight. A combination of 30 kg/5 plot manure and 0.48 g/plant phosphorus produced an economic benefit based on number and weight of marketable bulbs. Application of 0.24 to 0.31 t∙ha−1 of P2O5, increased number of unmarketable bulbs. 'Red Bombay' performed better than 'Red Mantle.' Individual or combination application of P2O5 at 0.12 to 0.31 t∙ha−1 and organic manure at 60 t∙ha−1 may produce adequate yield, and 'Red Bombay' maybe a better choice than 'Red Mantle' under semi-arid conditions. Application of manure and phosphorus improves vegetative and yield in onion cultivars. Use of 30 kg/5 m2 of manure and a combination of 30 kg/5 m2 and 0.48 g/plant manure and P2O5, respectively, appear to improve yield. [ABSTRACT FROM AUTHOR]

The present study was undertaken at the Agricultural Research Substation, Sumerpur-Pali to find out the effect of different fertilizer levels and crop geometry on kharif onion (Allium cepa L.) production. The experiment was laid out in split plot design with NPKS levels as main plot and crop geometry as subplot with three replications. Spacious crop geometry with highest dose of fertilizer (15 cm x 15 cm + 140 N: 80 P: 80 K: 40 S kg ha-1) produced maximum plant height (98.20 cm), leaves plant-1 (20), bulb polar diameter (79.34 mm), equatorial diameter (85.10 mm), bulb weight (137.44 g) and harvest index (51.30) with huge quantity of split/multiplier bulbs (6.54 t ha-1). Marketable yield (43.71 t ha-1), gross return (₹ 5.25 lakhs), net return (₹ 4.25 lakhs) and B: C ratio (4.25) were higher in the closer crop geometry (10 cm x 10 cm) with highest dose of fertilizer, whereas maximum biological yield (126.75 t ha-1) and total bulb yield (61.60 t ha-1) were reported in the closest spacing with highest dose of fertilizer (7.5 cm x 7.5 cm + 140 N: 80 P: 80 K: 40 S kg ha-1), which also produced the highest quantity (28.69 t ha-1) of unmarketable bulbs. It is concluded that for maximum production of better quality of kharif onion bulb, the seedlings should be planted at 10 cm x 10 cm spacing with the highest level of fertilizer dose (140 N: 80 P: 80 K: 40 S kg ha-1). [ABSTRACT FROM AUTHOR]

One of the most important problems during the implementation of any technology is to reduce labor costs, energy, and resource conservation while increasing the yield of cultivated crops and, as a result, reducing the cost of production. Despite a significant amount of scientific research devoted to the problem of energy and resource conservation in the cultivation and harvesting of agricultural crops and the development of mechanization tools that ensure the high-quality performance of technological operations, there remain issues that have not been fully resolved to date. In addition, not all the results of known theoretical and experimental studies can be directly applied to intensify the process of harvesting root crops since the quality indicators of marketable products depend on the type and technological parameters of the separating working bodies. This article presents the design of a rod elevator with an adjustable angle of inclination of the web, which reduces damage to commercial products of root crops and bulbs with maximum completeness of separation. A laboratory facility has been developed to substantiate the design and technological parameters of a separating system with an adjustable web inclination angle. Based on the results of theoretical and experimental studies, a machine for harvesting onions with an adjustable blade inclination angle has been developed, which provides an increase in the quality indicators of onion harvesting at optimal values of the parameters: (1) translational speed of movement of the rod elevator with an adjustable web inclination angle of 1.7 m/s with a 98.4% completeness of separation and 1.7% damage to the bulbs; (2) translational speed of the movement of the machine for harvesting root crops and onions 1.0 m/s with a 98.5% separation completeness and 1.1% damage to the bulbs; (3) digging depth of the digging plowshare equal to 0.02 m, with an onion heap separation completeness of more than 98% and product damage of less than 1.4%. The results of theoretical and experimental studies of a rod elevator to substantiate the design and technological parameters during its interaction with a heap of onion are presented. Basic design and technological parameters of the studied rod elevator are substantiated, namely, the distance S1 of the movement of the rod of the actuators, the angle a1 of the longitudinal inclination of the surface of the rod elevator relative to the horizon, and differential equations of motion of the onion-sowing pile element on the surface of the rod elevator with an adjustable angle of inclination of the web. [ABSTRACT FROM AUTHOR]

Onion production is reliant on synthetic chemical inputs such as fertilizer and pesticides to ensure its profitability. In the Great Lakes region (USA), onion thrips (Thrips tabaci) and a complex of bacterial pathogens that cause bulb rot disease threaten the sustainability of onion production. The potential exists for reducing T. tabaci infestations and bulb rot disease incidence in onions by decreasing the amounts of fertilizer applied at planting and the insecticide applied to foliage during the season. In a three-year study that included 20 New York commercial onion fields, the impact of synthetic fertilizer (no fertilizer, half rate, and full rate) and insecticide use (action threshold-based application program and weekly application program) on T. tabaci populations and bulb rot disease incidence was examined. Results indicated that the amount of fertilizer applied to an onion at planting had no impact on T. tabaci population levels, bulb rot disease incidence, or onion bulb size and yield. In contrast, insecticide use had the greatest impact on reducing T. tabaci densities. Both the action threshold-based program and weekly spray program reduced T. tabaci infestation levels below the economic injury level, but the action threshold program averaged 2.3 fewer applications per season. The insecticide program had no effect on bulb rot incidence, bulb size, or yield. We conclude that synthetic fertilizer and insecticide inputs can be reduced substantially without compromising onion bulb yields, and this should lead to greater profits and a reduction of chemicals in the environment. [ABSTRACT FROM AUTHOR]

In order to obtain high yield components and good competitive indices of fennel and onion, different intercropping systems (sole crop of each components, 1:1, 1:2, 2:1 and 2:2 of fennel: onion, respectively) under different potassium fertilizer levels (0.0, 24 and 48 kg K2O/feddan) were used. A field experiment was carried out at Experimental Farm (Ghazala Farm), Faculty of Agriculture, Zagazig University, Egypt during the consecutive seasons of 2019/2020 and 2020/2021. The achieved results revealed that, intercropping systems significantly decreased fruit and bulb yield per feddan of fennel and onion, respectively, compared to sole crop of each one. Data obtained clearly that, rate of 24 as well as 48 kg of potassium level/ feddan gave increased of yield components of each fennel or onion plants. Furthermore, aggressivity and competitive ratio values indicated that fennel component were the dominant, whereas onion was the dominated one in different intercropping systems. The highest value of land utilization efficiency percentage (128.91 and 137.67 as well as 136.86 and 135.10) were obtained when fennel intercropped with onion at 2: 1 as well as 2: 2 systems under fertilization level of 24 K2O/feddan in 1st and 2nd seasons, respectively. Therefore, the intercropping systems of 2:1 and 2: 2 raised yield advantage over the sole crop per unit area as revealed by the highest total land equivalent ratio (LER), area time equivalent ratio (ATER) and land utilization efficiency (LUE%). [ABSTRACT FROM AUTHOR]

Accurate estimation of the nutrient requirements of Chinese onion is essential to increase its nutrient utilization efficiency and yield. In this study, the yield and nutrient uptake data were collected from major Chinese onion growing regions during 2001 to 2018, and the relationship between Chinese onion yield and nutrient uptake was evaluated using the Quantitative Evaluation of the Fertility of Tropical Soils (QUEFTS) model. The QUEFTS model predicted the linear-parabolic platform curve of the balanced nutrient uptake of Chinese onion and estimated the demand of nitrogen (N), phosphorus (P), and potassium (K) for the potential target yields ranging from 40 t/ha to 120 t/ha. The nutrients required for the target yield increased linearly before reaching 60% to 70% of the potential yield. Nutrient requirements for producing 1 t of Chinese onion were 1.91 kg N--0.28 kg P--1.71 kg K. The corresponding nutrient internal efficiency (IE, yield per unit nutrient uptake) was 524.6 kg/kg, 3585.7 kg/kg, and 584.3 kg/kg for N, P and K, respectively. Subsequently, a nutrition decision-making software, Nutrient Expert (NE), for the Chinese onion was developed based on the improved QUEFTS model. Field verification studies for NE fertilizer recommendation were conducted in multiple Chinese onion growing plots for 2 consecutive years. Results showed that the QUEFTS model can be used to accurately estimate the nutrient requirements for Chinese onion within a defined range of target yield. [ABSTRACT FROM AUTHOR]

Soil health decreases and residual pesticides increase due to the application of inorganic fertilizers and pesticides continuously during the cultivation of crops. The effect of 12 hours or 24 hours soil submersion and chicken litters or zeolite application before planting on residual pesticides in soil and bulbs of shallots (Allium ascalonicum L.) are studied. Samples of soils and bulbs have proceeded after shallot cultivation conducted in Brebes, Indonesia. Then organophosphate residues in the samples are analyzed using gas chromatography in the Laboratory of the Indonesian Agricultural Environment Research Institute, Bogor. The data are compared to the standard of maximum residue levels (MRL) of pesticides in agricultural products. Results show that residual pesticides in treated soils are below the detection limit of the GC equipment, except malathion is detected with values ranging from 0.039-0.050 ppm. However, residual organophosphate pesticides in the bulbs are mainly below the maximum residue levels. The only exception is chlorpyrifos which has a value above the maximum residue levels of pesticides (0.076 ppm). Farmers should be educated in integrated pest management and applying synthetic pesticides as the last option for controlling pests and diseases. [ABSTRACT FROM AUTHOR]

Two field experiments were conducted during the two successive winter seasons 2019/2020 and 2020/2021 at the Faculty of Agriculture Azhar University Farm, Assiut Governorate, Egypt, to study the effect of foliar spraying with different concentrations of algae extract and nitrogen fertilizer rates on growth, yield and quality of onion plants. The results proved that algae spraying led to an increase in the growth, productivity and quality of onions grown in loamy soil in Upper Egypt. The highest yield was obtained by foliar spraying of algae at a concentration of 4.0 g l–1 . In addition to fertilizing the soil with 90 kg nitrogen / fed., spraying onion plants after 30 and 45 days of cultivation with algae extract at a concentration of 4.0 g l–1 led to an increase in the total yield by (16.21 and 20.74%.) and the weight of the onion (22.69 and 27) and the onion and onion diameter (16.20 and 19.02%) compared to the control treatment in the first and second seasons, respectively. In addition, despite the superiority of the soil fertilization treatment at a rate of 120 kg per fed., the improvement rates were not significant. Therefore, the mineral fertilization treatment at a rate of 90 kg per fed., with algae spraying is considered the best economically. [ABSTRACT FROM AUTHOR]

During this study, 21 garlic genotypes consisted of ten clones of Egyptian cultivar, nine clones of Chinese cultivar, as well as their original populations were evaluated to estimate the extent of improvement in four yield component traits after six cycles of clonal selection. Also, simple phenotypic correlation among these traits and their relationship with yield. Besides estimating linear and quadratic responses (simple and multiple regression); to clarify the relationship between yield and the four studied characteristics. This research has been conducted at the Research farm of Faculty of Agriculture in “Abies” area of Alexandria University, Egypt, for 2020/2021 during the winter season, in a randomized complete block design with three replications. The studied traits were included bulb weight, cloves weight per bulb, average clove weight, cloves number per bulb, and yield per plot. T-test in group reflected a significant improvement in the four yield components traits, whether in the improved clones of Egyptian or Chinese cultivar. The results illustrated, also, that yield per plot showed a highly significant positive correlation with bulb weight, cloves weight per bulb, and average clove weight. Stepwise regression indicated that more than 98% of the variation in yield is explained by bulb weight, average clove weight, and cloves number per bulb. Thus, high yield of garlic plants can be obtained by selecting breeding materials with these aforementioned three variables. [ABSTRACT FROM AUTHOR]

Of the seventeen onion varieties evaluated for assessment of variability in mean performance, variances, heritability and genetic advance, (L-883 and Bhima Shweta) were most promising genotypes in respect of gross and marketable bulb yield, minimum number of bolters, rotten and multi-centred bulbs, bulb weight, equatorial bulb diameter, total soluble solids, number of leaves per plant and earliness in maturity. High values of genetic and phenotypic for gross and marketable bulb yield, average bulb weight, days to 70% neck fall and plant height indicated more opportunity of selection for these traits. High genetic advance as percentage of mean coupled with high heritability was observed for gross and marketable bulb yield and average bulb weight. Therefore, significant improvement could be expected through selection for these traits. [ABSTRACT FROM AUTHOR]

Enhancing the food production for the growing world population has needed application of highly sustainable and efficient inputs to produce more food per unit of land. Hence, Tamil Nadu Agricultural University (TNAU), Coimbatore, Tamil Nadu has produced Water soluble fertilizers (WSF) in its maiden attempt and it is necessary to optimize on different crops. Small onion is one of the most important vegetables in the Indian diet and it has high demand but low productivity. To enhance crop productivity and quality of small onions, the application of TNAU-WSF was taken up. A field experiment was laid out in a Randomized block design (RBD) incorporating 8 treatments comprising of application of RDF at100% NPK as TNAU WSF, soil test based application of 75%, 100%, 125% NPK ha-1 as TNAU-WSF with soil application of sulphur (S) and foliar spray of TNAU Liquid multi micronutrient (LMM) and without S and TNAU LMM and absolute control. Each treatment was replicated thrice with onion (CO 4). Soil test based application of 125% NPK ha-1 as TNAU-WSF with sulphur (S) and TNAU LMM recorded significantly higher in plant height (54.01 cm), the number of leaves per bulb (8.56), leaf greenness (67.5 SPAD), root length (5.42 cm), polar bulb diameter (4.38 cm), equatorial bulb diameter (2.72 cm) fresh bulb weight (74.21 g), bulb yield (1751 t ha-1) and quality attributes like total soluble solids (TSS) (14.78 °Brix), ascorbic acid content (15.34 mg 100 g-1), pyruvic acid content (2.27 µmol g-1). However, soil test based application of 100% NPK ha-1 as TNAU-WSF was found to be an ideal rate to attain the economic target yield of the onion crop. [ABSTRACT FROM AUTHOR]

Genetic variability is the fundamental requirement for any plant breeding program to develop a superior cultivar. This study aimed to estimate the genetic variability and determine the correlation between the various quantitative characteristics of garlic accessions. The experiment was carried out in the Ezo-Otte area of the Chencha district in the Gamo highlands of southern Ethiopia and 28 garlic accessions were evaluated in a Randomized Complete Block Design with three replicates. Various morphological descriptors were measured to evaluate the variability and correlation coefficients. The analysis of variance showed a highly significant variation for all characters, which indicates greater variability in the accession. High and moderate heritability in broad sense estimates were obtained for the majority of the traits examined. Days to maturity (28.09), bulb weight (22.33), and bulb diameter (equatorial) (21.33) showed higher genetic advance. The maximum value of the genetic progress as a percentage of the mean was observed in bulb yield, clove weight, bulb diameter (equatorial), and number of leaves. In addition, bulb diameter (equatorial), clove weight, bulb weight, and plant height were observed to be highly hereditary coupled with high genetic advance as a percentage of the mean, suggesting that they can be improved by direct selection. Coefficient analysis has shown that maximum attention should be paid to bulb diameter (equatorial), the number of cloves, bulb diameter (equatorial), bulb weight, plant height, and leaf length, as these traits also correlate positively and significantly with bulb yield. [ABSTRACT FROM AUTHOR]

Despite the favorable climatic conditions of the region for onion growing, due to significant plowing of foothills (up to 80%) and low productivity, which does not exceed 1.3 t/ha-1.5 t/ha of fodder units, they do not fully perform their fodder production and environmental function. Ago Peculiarities of cereal agrophytocenosis formation when growing on sod-podzolic soil of Precarpathians depending on doses and NPK ratios of mineral fertilizers have been studied is relevant today. Perennial cereal grass was formed from Phléum praténse, Lolium pratense and Bromus inermis, which is kept in agrocenosis at sufficient level with a sprout density of 1440 pcs/ m² -2726 pcs/m², share of sown crops 64%-95% and linear growth in the first moving on nitrogen-free backgrounds 31 cm-100 cmFertilizers had a different effect on the density and transformation of a sown cereal grass, especially by the years of its usage. With the application of N25 grass height increases by 1.3, and N50 by 1.7 times. In the third year of usage, agrophytocenosis, which is formed from a mixture of cereal grasses, is transformed into a grouping with a predominance of Bromus inermis, the share of which increases with the nitrogen dose increase. [ABSTRACT FROM AUTHOR]

The relative abundance of the reproductive types of Thrips tabaci Lindeman was occasionally surveyed by collecting female adults from the foliage of commercially grown Welsh onions, onions, and cabbages at various locations in Kyoto Prefecture between 2016 and 2018. Arrhenotokous females were found at 39 of the 46 surveyed sites and coexisted with thelytokous females at 26 sites, of which the arrhenotokous composition was higher than that of thelytokous at 19 sites. The arrhenotokous type was dominant in Kyoto City and Kumiyama Town, and thelytokous females were found to be dominant in the areas north of Fukuchiyama City. In cabbage, only arrhenotokous females were observed. The seasonal composition of T. tabaci reproductive types was additionally surveyed in Welsh onion plants grown in greenhouses in Kameoka City, Kyoto Prefecture, between November 2016 and June 2019. Thelytokous females were dominant between November 2016 and March 2017 and arrhenotokous females dominated between April 2017 and March 2018, except for January 2018. After May 2018, the thelytokous type dominated again. [ABSTRACT FROM AUTHOR]

The onion has great economic importance, since it is among the five most produced vegetables in Brazil. The objective of this work was to evaluate the effect of summer cover crops or corn cultivation on onion yield in minimum cultivation system under edaphoclimatic conditions in Lontras-SC. The following summer crops in the 2019/2020 crop were evaluated in the off-season of the onion crop: sunn hemp; consortium of millet; millet+sun hemp; corn for grain production. Summer crops were cultivated from December 2019 to March/April 2020 without fertilizer application, managing them with mowing at the end of their cycle. The onion crop was cultivated between July and November 2020. The straw of the predecessor crops, corn grain yield and onion yield were evaluated. The average straw mass of cover crops was 14.5 t. ha-1 and corn was 5.4 t. ha-1. The total yield of onion bulbs ranged from 22.0 to 26.6 ton-1, being lower when cultivated after corn and higher after millet. It is concluded that the use of millet as a predecessor crop allows greater total and commercial yield of onion bulbs. [ABSTRACT FROM AUTHOR]

A field experiment was conducted on 2019 growing season to evaluate effects of different rates of nitrogen, phosphorus, and sulfur on growth and yield of garlic under supplemental irrigation. A local variety, Tuma, was used and treated with six rates of NPS (T1 (0 : 0 : 0 kg/ha NPS) (control), T2 (19 : 38 : 7 kg/ha NPS), T3 (28.5 : 57 : 10.5 kg/ha NPS), T4 (47.5 : 76 : 14 kg/ha NPS), T5 (47.5 : 95 : 17.5 kg/ha NPS), and T6 (57 : 114 : 21 kg/ha NPS)). The experiment was laid out in randomized complete block design and replicated three times. Data were collected for days to 50% emergence, plant height, leaf number, leaf length, bulb weight, and total bulb yield. SAS version 9.2 was used to analyze the data. Means were separated using Fisher's test at 5% level of significance. All parameters were significantly P < 0.05 affected by the rates of NPS. The early days to 50% emergence (16) was recorded from T6 (57 : 114 : 21 kg/ha NPS), whereas the late days to 50% emergence was recorded from the control treatment (T1). Significantly highest leaf length (41.51 cm), leaf number (13.63), plant height (61.19 cm), bulb weight (39.44 g), and total bulb yield (14.91 ton ha−1) were recorded from T6 (57 : 114 : 21 kg/ha NPS). Therefore, from the result of this study, it can be concluded that the maximum total bulb yield of garlic was obtained with the application of 57 : 114 : 21 kg/ha NPS rate. [ABSTRACT FROM AUTHOR]