Onion Varieties Research Articles

Participatory Demonstration and Evaluation of Onion Varieties in Lume and Dugda Woredas, East Shewa Zone of Oromia Regional State, Ethiopia

Onion ( Allium cepa L.) is one of the most important vegetable crops grown in Ethiopia as well as in the study area. The crop is produced as a cash crop and it is widely used to increase the taste of the different types of food. The research activity was carried out to show the performance of recently released onion varieties (Nafis and Nasik red) along with the check (Bombay red) with their recommended agronomic recommendations through on-farm demonstration and evaluation under farmers' management and resources. Dugda woreda and Lume Woreda were purposively selected based on their onion production potentials from east Shewa zone. From each Woreda randomly one kebele was selected, Shinbi-Gamo kebele from Dugda woreda and Shera-Gibandiba from Lume woreda. Twenty-four farmers were selected, twelve farmers per woreda, for hosting the demonstrations. All the data collected from the demonstration fields and farmers were analyzed through simple descriptive statistics and preference ranking tool. The mean yield obtained from the demonstration field for each variety were 167.72 qt/ha (Nafis), 161.56 qt/ha (Nasik red) and 149.8 qt/ha (Bombay red) in Dugda woreda. In Lume woreda, the mean yield of the varieties was 320.39 qt/ha (Nafis) 257.39 qt/ha (Nasik red) and 257.39 qt/ha (Bombay red). Nafis variety shows better yield performance than the other two varieties in both woredas. The farmer's preference, further showed that Nafis variety was the best one or superior to the others by its high yielding ability, bulb size, and market preference. Therefore, agricultural research and woreda offices of agriculture should take the lead to further popularize the selected varieties in their respective mandate areas to boost production and productivity of the onion. Keywords: Demonstration, East Shewa Zone, Evaluation, Onion DOI : 10.7176/JNSR/9-17-06 Publication date :September 30 th 2019

Convective drying of yellow discarded onion (Angaco INTA): Modelling of moisture loss kinetics and effect on phenolic compounds

The Angaco INTA onion variety is the most cultivated and its production, mostly is destined for export. Due to their high-quality standards of these markets, many onions are discarded. The drying process seems to be a promising solution that not only give added value to this product, but also extend shelf life. In this work, the influence of convective drying process, at 60 and 70 °C, on the kinetic behavior, antioxidant activity, phenolic and flavonoid contents of discarded onion slices were investigated. Considering that, the Angaco INTA onion is a variety genetically developed to have shorter cultivation times in this region; the phenolic compounds content in this onion variety, the drying kinetics and its influence on this content have never been studied. In this study, the phenolic compounds contributions to dehydrated product quality was evaluated, observing that the convective drying increased the total soluble phenolic and flavonoid contents and antioxidant properties for both temperatures, being highest at 70 °C. The rehydration ratios were similar to the slices dried at 60 and 70 °C. Several models were used for describing the obtained drying curve equation of onion slices, being the Midilli’s model the one that presented the best fit. Ficks’s model of water diffusion fitted all experimental data with acceptable correlation coefficients. Considering the achieved findings, 70 °C is the optimum temperature to produce the dehydrated Angaco INTA onion.

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Effect of Quercetin Rich Onion Extracts on Bacterial Quorum Sensing.

Quorum sensing (QS) regulates bacterial gene expression and studies suggest quercetin, a flavonol found in onion, as a QS inhibitor. There are no studies showing the anti-QS activity of plants containing quercetin in its native glycosylated forms. This study aimed to evaluate the antimicrobial and anti-QS potential of organic extracts of onion varieties and its representative phenolic compounds quercetin aglycone and quercetin 3-β-D-glucoside in the QS model bacteria Chromobacterium violaceum ATCC 12472, Pseudomonas aeruginosa PAO1, and Serratia marcescens MG1. Three phenolic extracts were obtained: red onion extract in methanol acidified with 2.5% acetic acid (RO-1), white onion extract in methanol (WO-1) and white onion extract in methanol ammonium (WO-2). Quercetin 4-O-glucoside and quercetin 3,4-O-diglucoside were identified as the predominant compounds in both onion varieties using HPLC-DAD and LC-ESI-MS/MS. However, quercetin aglycone, cyanidin 3-O-glucoside and quercetin glycoside were identified only in RO-1. The three extracts showed minimum inhibitory concentration (MIC) values equal to or above 125 μg/ml of dried extract. Violacein production was significantly reduced by RO-1 and quercetin aglycone, but not by quercetin 3-β-D-glucoside. Motility in P. aeruginosa PAO1 was inhibited by RO-1, while WO-2 inhibited S. marcescens MG1 motility only in high concentration. Quercetin aglycone and quercetin 3-β-D-glucoside were effective at inhibiting motility in P. aeruginosa PAO1 and S. marcescens MG1. Surprisingly, biofilm formation was not affected by any extracts or the quercetins tested at sub-MIC concentrations. In silico studies suggested a better interaction and placement of quercetin aglycone in the structures of the CviR protein of C. violaceum ATCC 12472 than the glycosylated compound which corroborates the better inhibitory effect of the former over violacein production. On the other hand, the two quercetins were well placed in the AHLs binding pockets of the LasR protein of P. aeruginosa PAO1. Overall onion extracts and quercetin presented antimicrobial activity, and interference on QS regulated production of violacein and swarming motility.

Study of Four Onion Varieties Drying Kinetics in an Oven and a Solar Greenhouse

Onion production (Allium cepa L.) in Senegal reached 390 000 tons in 2016. Due to post-harvest losses, annual demand (150 000 and 250 000 tons) is being met through imports. This work consists in proposing a drying process at a lower cost to overcome this dependence and preserve the quality of the product. The optimization of local onion varieties drying in an oven and in solar greenhouse, as well as the physicochemical characterization of the products were carried out. The moisture of fresh onion bulb varies between 85.56 ± 0.60 and 89.13 ± 0.69 (%). To obtain a moisture £ 8.89 ± 0.16 (%) ensuring stability, the optimal drying conditions in the oven are 60° C / 6H (Galmi Violet) and 7H (Safari, Gandiol F1 and Orient F1). Under these conditions, the content of polyphenols in g equivalent of gallic acid / 100 g db increases (0.111 ± 0.0040 to 0.312 ± 0.0041 before drying, 0.546 g ± 0.0117 to 0.837 ± 0.0091 after drying). Optimum solar drying in a greenhouse is obtained between temperatures of 35 to 65° C / 8H-9H. From a perspective of sustainable development, the perspective is the modeling of drying kinetics in a solar greenhouse.

Management of Onion Thrips [Thrips tabaci Lind. (Thysanoptera: Thripidae)] on Onion Using Eco-Friendly Cultural Practices and Varieties of Onion in Central Zone of Tigray, Ethiopia

Onion thrips, Thrips tabaci (Thysanoptera: Thripidae) is a major insect pest constraining onion production in the Central Zone of Tigray. Therefore, field experiment was conducted at Axum Agricultural Research from November 2015 to April 2016 to manage onion thrips using multiple techniques. The experiment was laid out in a randomized complete block design (RCBD) with split plot arrangement and replicated three times. Onion varieties Bombay Red and Nasik Red were used as main plot treatments and intercropping onion with one or two other vegetables including, cabbage, carrot and lettuce, as subplot treatments. Treating onion with the insecticide lambda-cyhalothrin (Karate) 5% EC and untreated sole onion were included as standard and control checks. Results showed that intercropping onion with cabbage, onion with cabbage + carrot and onion with cabbage + lettuce significantly reduced T. tabaci population by 58.47, 63.81 and 50.51%, respectively at higher infestations. Similarly, intercropping onion with cabbage, onion with cabbage + carrot and onion with lettuce + carrot showed a better effect in reducing thrips damage severity by 23.37, 23.09 and 17.66%, respectively, at higher infestations. Predatory thrips were observed on onion intercrops except the Karate 5% EC treated check. The highest marketable onion yield (35.52 t/ha) was obtained from onion intercropped with carrot and lettuce, though not significantly different from the untreated check. The lowest (23.54 t/ha) was obtained from onion intercropped with cabbage + lettuce. However, onion intercropped with lettuce gave the highest gross income (307344 ETB/ha). The lowest gross income was recorded from the insecticide treated plot (194583 ETB/ha). The study clearly showed that intercropping onion with other vegetables reduced the number of onion thrips and their damage on onion in the central zone of Tigray and hence can form an integral component in the integrated management of thrips on onion.

Susceptibility to Stemphylium vesicarium of asparagus, onion, pear, and rye in Canada

Diseases caused by Stemphylium vesicarium are an increasing problem in the major asparagus and onion production regions of eastern and central Canada. Replicated and repeated controlled environment and field trials were conducted in Ontario to assess the disease reaction of asparagus and onion cultivars to determine if isolates from one crop can cross-infect other hosts, to assess the variation of disease symptoms among cultivars of onion and of asparagus, and to assess the ability of the pathogen to survive in a non-host species. All of the varieties of asparagus and onion assessed were susceptible to infection by S. vesicarium. There were small differences in susceptibility among varieties and in aggressiveness among isolates. These differences were not strongly associated with host crop. Onion cultivars that developed higher numbers of lesions often had lower levels of leaf dieback and vice versa. This indicated that resistance to infection was independent of susceptibility to development of dieback symptoms. In asparagus, infection on spears was not consistently correlated with severity on ferns. All isolates from asparagus and onion produced typical symptoms on wounded, but not unwounded, pear fruit. Finally, the pathogen was shown to colonize and sporulate on necrotic leaves of autumn rye, which is often used as a cover crop in asparagus fields. Stemphylium vesicarium can cross-infect asparagus and onion.

Variability, heritability and trait association studies for bulb and antioxidant traits in onion (Allium cepa) varieties

Onion (Allium cepa L.) is one of the most important vegetable having year round demand and consumed fresh, cooked or processed. It occupies maximum area under vegetables in India. The consumption of onion has been associated with many health benefits. The genetic improvement work mainly focused on improving yield and there has been little effort on improving quality traits. Therefore, information on variability, heritability and trait association of phytochemicals content, antioxidant activity and bulb traits are lacking. The present study was conducted to bridge the gap and generate information on these aspects. A total of eight quality traits and four bulb traits were analyzed in 22 onion genotypes of five different skin colour. The genotypes were procured from diverse geographic region. The total soluble solids content (TSS), pungency, total phenol, flavonoids content, and antioxidant activities as estimated through CUPRAC and FRAP in the onion varieties varied from 10.13-16.65 °Brix, 4.67-12.28 μmol Pyruvic acid/g FW, 740.67-1145.33 μg Gallic acid equivalent/ml, 31.67 - 465.0 μg Quercetin equivalent/ml, 2.23 - 5.14 μmol Trolox/g and 1.60-4.63 μmole Trolox/g, respectively. There was less difference between phenotypic and genotypic components of variance for pungency, total phenols, antioxidant activity and juice recovery, suggesting greater role of genotype in the expression of quality traits and better scope of improvement for these traits. The high heritability estimates (>75%) for bulb diameter, total phenols, flavonoids, pungency and antioxidant activity, and higher value of genotypic correlation co-efficient over phenotypic co-efficient supports greater role of genotype in the expression of quality traits. The high estimate of heritability and comparatively, low estimate of genetic advance and genetic gain suggest the role of both additive and non-additive gene action. Thus hybridization and selection would be the best strategy to improve quality traits in Indian onion genotypes. Future breeding attempt to develop onion varieties with higher health benefits should focus on medium sized varieties without compromising on yield.

Optimum rate of NPS fertilizer for economical production of irrigated onion (Allium cepa L) in Dembyia District of Amhara Region, Ethiopia

Onion is one of the most important vegetable crops grown under irrigation in Amhara Region. Application of fertilizer is an important input to increase yields of vegetables including onion where its rate mostly depends on the fertility status of the particular soil. The present study was initiated with the objective to identify the optimum rate of the newly introduced NPS fertilizer for maximum bulb yield of onion under irrigated smallholder farming system. The study was conducted in Dembyia District during the 2014/2015 irrigation season. Twelve NPS fertilizer rates were laid down on Randomized Complete Block Design (RCBD) with three replications to identify the optimum rates of NPS where maximum yield of Adama Red onion variety can be obtained. The results of the experiment revealed that most of the growth and yield parameters of onion were significantly affected by NPS fertilizer. The longest plant height (60.1 cm) was recorded when N:P2O5:S was applied at the rate of 73.5:92:16.95 kg ha-1, respectively. The longest (51.1cm) and widest (1.44 cm) onion leaves were recorded on plants where N:P2O5:S was applied with 136.5:119.6:22 kg ha-1. Onion plants supplied with 105:119.6:22 kg ha-1 N:P2O5:S fertilizer rate gave the highest mean bulb weight (198.8 g), marketable yield (20.8 ha-1) and total bulb yield (21.4 t ha-1). Similarly, onion plants supplied with 105:119.6:22 kg ha-1 N:P2O5:S fertilizer rate recorded the highest marginal rate of return followed by those onion plants supplied with 105: 92:16.95 kg ha-1. Onion plants which were not supplied with NPS fertilizer showed generally lower growth and yield parameters. Application of NPS fertilizer at the rate of 105:119.6:22: kg ha-1 N:P2O5:S can be recommended for economical production of onion in the study area.

Correction to Higher Antioxidant Activity, Total Flavonols, and Specific Quercetin Glucosides in Two Different Onion ( Allium cepa L.) Varieties Grown under Organic Production: Results from a 6-Year Field Study.

We carried out a 6-year study to assess the effect of conventional, organic, and mixed cultivation practices on bioactive compounds (flavonoids, anthocyanins) and antioxidant capacity in onion. Total flavonoids, total anthocyanins, individual flavonols, individual anthocyanins, and antioxidant activity were measured in two varieties (‘Hyskin’ and ‘Red Baron’) grown in a long-term split-plot factorial systems comparison trial. This is the first report of repeated measurements of bioactive content over an extensive time period in a single crop type within the same trial. Antioxidant activity (DPPH and FRAP), total flavonol content, and levels of Q 3,4′ D and Q 3 G were higher in both varieties under fully organic compared to fully conventional management. Total flavonoids were higher in ‘Red Baron’ and when onions were grown under organic soil treatment. Differences were primarily due to different soil management practices used in organic agriculture rather than pesticide/ herbicide application.

THE BULBOUS FORMS OF INTERSPECIFIC HYBRIDS OF ALLIUM, THEIR CREATION AND EVALUATION

The paper presents the stages of creating bulbous forms between A. cepa L. and A. Vavilovii Pop. et Vved. through hybridization, in vitro embryo culture, backrossing, inbreeding and cross-breeding. As object of research were considered inbred progeny I 1-5 from BC 1-2 F 5 combinations of crossing of A. cepa x A. Vavilovii. The parent species A. cepa L. of the onion variety Odintsovets was the standard. In plants of the first year of vegetation studied signs: the color of dry scales of the bulb, the weight of the bulb, the index of the bulb shape and the number of leaves. Phytopathological assessment of onion plants for resistance to downy mildew (peronosporosis) was carried out. In the progeny of interspecies hybrids plants were aligned on the color of the bulb (yellow and brownish). The average weight of the bulb varied from 33.5 to 92.3 g in generations I 1-5 from ВС 1 , and in generations I 1-5 from ВС 2 it varied from 22.1 to 93.6 g. plants of bulbous forms had a flat bulb (I=0.6-0.7). Only plants from the progeny I3 and I5 from BC 2 formed rounded-flat bulbs (I=0,8-0,9). The number of leaves in bulbous plants in the progeny varied on average from 5.3 to 7.1 PCs. The score of peronosporosis was low and medium (0.5-1.0). Was selected form of inbred progenies of I 1-5 from BC 1-2 with a dense bulb is flat and round-flat shape, which combined a relatively high resistance to downy mildew with a mature bulb is capable of storing.

Evaluation of different varieties of onion in Nimar region of Madhya Pradesh

Onion varieties were evaluated for adaptability to the climatic conditions in India. It is used both raw and mature bulb stage as vegetable and spice. Three varieties of onion were planted under a Complete Randomized Block Design at farmer field. Successful onion production depends on the selection of varieties that are adapted to different climatic conditions imposed by specific environment. The quantitative data on yield of onion varieties and farmers perception on the varieties were collected. All the varieties were harvested at their maturity (80% top down) and then graded and weighted. The results revealed that highest plant height (cm) was reported from onion variety Agrifound light red (60.51cm) and lowest by NHRDF Red-3(57.88cm) . Similarly onion variety registered maximum number of leaves NHRDF Red-3 (10.28) and the lowest by Agrifound light red (9.99). Maximum weight of bulb (82.91g) and total yield of bulb (356.0) quintal/hectare was exhibited by var. Bhima Shakti with minimum days taken maturity (126.60) and minimum per cent incidence of bolting (1.66 %). The cultivar Bhima Shakti and NHRDF Red-3 performed well for the Nimar region of Madhya Pradesh in Rabi season.

PENAMPILAN PERTUMBUHAN DAN PRODUKSI LIMA VARIETAS BAWANG MERAH ( Allium ascalonicum ) DI KALIMANTAN BARAT

Introduction of high yielding varieties of red onion (Allium ascalonicum) is an effort that can be done to increase red onion production in West Kalimantan. This research aims to introduce new varieties that can adaptive for the conditions of the land in West Kalimantan in order to obtain location-specific varieties as well as to accelerate the deployment of red onion Agency for Agricultural Research and Development. The research was conducted from May to July 2014 at the Visitor BPTP Plots of West Kalimantan. Research using randomized block design with four replications. The varieties used are Katumi, Bima, Mentes, Pikatan and Manjung. Variables observed included: height of plant (cm), number of tillers (clumps), number of leaves (strands), bulbs diameter (mm), weight bulbs (g), production (tons / ha). The results showed that of the five varieties of onion were tested superior results achieved ranged from 6.11 to 9.37 tons / ha. The Varieties Bima and Katumi to give the highest production of 9.37 tons / ha and 9.09 tons / ha. Both of these varieties are recommended for development in West Kalimantan.

СОЗДАНИЕ ПЕРСПЕКТИВНЫХ ЛИНИЙ ЛУКА РЕПЧАТОГО ПРИ ВОССТАНОВЛЕНИИ СОРТА «СТРИГУНОВСКИЙ МЕСТНЫЙ»

СОЗДАНИЕ ПЕРСПЕКТИВНЫХ ЛИНИЙ ЛУКА РЕПЧАТОГО ПРИ ВОССТАНОВЛЕНИИ СОРТА «СТРИГУНОВСКИЙ МЕСТНЫЙ»

Expression analysis and association of bulbing to FLOWERING LOCUS T (FT) gene in short day onion (Allium cepa L.)

The present study was carried out with the objective of studying the expression of FLOWERING LOCUS T (FT) genes responsible for bulbing in onion. Six AcFT genes were used for expression studies at prebulbing (45 DAT), bulbing (60 DAT) and post bulbing (75 DAT) stage. Two varieties viz., Brown Spanish (long day) and Pusa Riddhi (short day) were used. It was observed that out of the reported six AcFT primers, four were able to amplify. Two new primers exhibiting amplification of AcFT1 and AcFT6 are reported. In short day onion variety, Pusa Riddhi, expression of five out of six genes studied (AcFT1, AcFT3, AcFT4, AcFT5 and AcFT6) were highest at the bulbing stage (60 DAT) suggesting their role in bulbing. In long day variety, Brown Spanish, expression of all the six genes except AcFT1 was very low at bulbing stage (60 DAT). This signifies that specific photoperiod conditions for gene expression were not achieved under Delhi conditions in long day onion. More studies towards understanding of the genes need to be addressed to understand the basic molecular process of bulbing in short day onion.

Biochemical, antioxidant properties and antimicrobial activity of different onion varieties in the Mediterranean area

Onion (Allium cepa L.) is a very important vegetable crop cultivated worldwide. The bulb is a major source of phytochemicals useful for human health and rich in sulphur compounds responsible for their typical odour and flavour. In this study, we investigated the volatile compounds and biochemical properties besides the antimicrobial activity of onion Montoro and Alife varieties, and of two ecotypes of Vatolla variety (spinning top and tapered shape), cropped in the southern Mediterranean area (Italy). For all investigated onions, the organosulphur compounds, mainly di- and trisulfides, are the most abundant compounds. Alife variety showed higher polyphenols amount (8.2 GAE mg/g dw) with respect to the lowest one (3.9 GAE mg/dw g) in spinning top Vatolla, as well as an higher antioxidant activity (42.37 µmol TE/g dw) about two-fold higher than those detected in the other varieties. All the onions showed low pungency level, confirming their popular classification as a sweet onion. The total content of soluble sugars ranged from 461 to 624 mg/g dw; malic acid was the major organic acid in Alife and Montoro varieties instead for both Vatolla ecotypes citric acid was the most abundant ones. The biochemical characterization highlighted the three onion varieties as a good source of bioactive compounds. The antimicrobial activity of the onion extracts pointed out an effective action against three Gram-positive species (B. cereus, L. innocua, S. aureus) and P. aeruginosa; consequently, they could represent a new source of natural antimicrobial agents.

Influence of host plants on biological parameters of Thrips tabaci

Influence of host plants: cabbage, garlic and two varieties of onion, Poona Red Desi and Onion Gawran were studied on the biological parameters of Thrips tabaci. Significant differences were found in total developmental time between the host plants with total mean of 17.54 days and the total life span of 45.23 days. Oviposition period was 24.2 days on cabbage compared to 18.6 days on garlic, while 23.3 days on Pusa Red Desi. The highest fecundity (80.4 eggs) was observed on cabbage and 58 eggs were obtained when reared on garlic. Longevity was reduced to 23 days on garlic compared to 30 days on cabbage and Poona Red Desi. However, non-significant difference was found in the finite rate of increase and intrinsic rate of increase among host plants. Mean generation time was significantly highest on cabbage (28.79 days), while 23.86 days on garlic. Net reproductive rate was non-significant on cabbage and PDR but significantly differed on Onion, Gawran and garlic. Significant differences were found in I instar, pre-pupal and pupal morphometric. These variations in life table traits imply that the host plants certainly affected the biological parameters of T. tabaci which will be helpful in the management of thrips on onion crop.

Evaluation of Mineral Profile and Selected Component of Improved Onion (<i>Allium cepa</i> L.) Varieties in Ethiopia

Because of its significant ingredient in various dishes, medicinal property, nutritional worth and energy value, red onions (Allium cepa L.) impart numerous health benefits to users. The purpose of this research was to determine mineral composition and selected physicochemical properties of different red onion (Allium cepa L.) varieties grown at same field management condition in Ethiopia as well as comparative study among varieties and between study varieties and standard reference. All field and laboratory data was analyzed using statics 10.0 soft ware and the result of both macro and micro nutrient mineral content in the onion bulbs revealed significant difference among the varieties at (P<0.05). Comparative study was conducted to investigate the mineral composition between studied improved varieties and standard reference and the result showed that Ethiopian onion cultivars were high in Na (147.75 – 189.05ppm), K (10219 – 11013ppm) and Ca (1223.2 – 1566.9ppm, Mg (609.07 – 703.56ppm), TP (2609.7 – 3055.8ppm), S (456.40 – 540.34ppm), Cu (2.179 – 2.47) and Fe (48.353 – 61.43ppm) content than standard (40.0, 1460, 230, 100, 1642.3, 168.0, 0.403 and 21.0ppm respectively) but low in Mn (9.55 – 14.457), Zn (14.84 – 22.483) and B (4.81 – 6.02ppm) than standard (12.9, 17.0, 6.10ppm) respectively). The result of soil data for both macro and micronutrient were low in the studied area.

Growth and yield of onion (Allium cepa L.) varieties as influenced by planting time under poplar based agroforestry system

Growth and yield of onion (<i>Allium cepa</i> L.) varieties as influenced by planting time under poplar based agroforestry system