Bulb Crops Research Articles

Morphological, biochemical and molecular characterization of short-day tropical Indian garlic (Allium sativum L.)

Garlic, an asexually propagated bulbous crop, displays a wide diversity based on its morphological traits and biochemical compositions. This study investigated the genetic variability of Indian garlic through morphological, biochemical, and molecular markers. Twenty-nine genotypes along with three Allium species as outgroup were included in the present study. Observations were recorded on 14 quantitative traits, 17 qualitative traits, and 9 biochemical traits in fresh garlic. Significant variability was observed among genotypes for different characters. All the morphological and biochemical traits showed higher phenotypic coefficient of variation (PCV) than genotypic coefficient of variation (GCV) revealing the role of environment in trait expression. High to moderate heritability and genetic advance as percent mean were recorded for different traits except dry matter and Total Soluble Solids (TSS). Correlation analysis revealed the highest positive correlation between total yield, marketable yield, Ferric Reducing Antioxidant Potential (FRAP) and 2,2-diphenyl-1-picrylhyrazyl (DPPH). Cluster analysis differentiated all the genotypes into three major clusters based on morphological and biochemical traits. 214 Simple Sequence Repeats (SSRs) were screened and nine markers exhibited polymorphism. Cluster analysis using molecular markers revealed 4 distinct clusters. The observations from this study will help in the identification of diverse garlic germplasm for its efficient management and duplicate identification of germplasm resources.

In Situ and Ex Situ Conservation of Ornamental Geophytes in Poland

The protection of biological diversity in nature and in agriculture, including the production of ornamental crops, has become increasingly important in Poland as well as worldwide. The Convention on Biological Diversity, signed in 1992 at the Earth Summit of the UN in Rio de Janeiro and ratified by the Polish government in 1995, imposed new regulations related to the protection of nature and the genetic resources of cultivated crops in Poland. The conservation of the genera, varieties and cultivars of ornamental geophytes—a group of plants of great interest from a botanical and physiological, but also a horticultural point of view—takes place in situ (both in nature and in the places of cultivation) and through the establishment of ex situ gene banks and collections. The natural genetic resources of ornamental geophytes include species from the genera Allium, Fritillaria, Gladiolus, Iris, Leucojum, Lilium and Muscari, among others, and more than a dozen species are protected by law due to varying degrees of threats. Botanical gardens play an essential role in the conservation of endangered species. Their activities focus on genus monitoring, managing ex situ gene banks (including National Collections), developing propagation methods and carrying out their reintroduction. In order to protect the national genetic resources of cultivated plants, the National Centre for Plant Genetic Resources at the Plant Breeding and Acclimatisation Institute—National Research Institute, under the auspices of the Ministry of Agriculture and Rural Development, was established. Concerning ornamental geophytes, the National Centre coordinates two field collections of cultivars of the genera Gladiolus, Lilium, Narcissus and Tulipa, which are of great economic importance and have a long tradition of breeding in Poland. The first one is located at the National Institute of Horticultural Research in Skierniewice (central Poland), and the second one is at the Experimental Substation of Variety Testing in Lisewo (northern Poland). The history of tulip collections in Poland dates back to the 1960s. At that time, the first breeding work for this species began. The collection of bulbous crops in Skierniewice is currently one of the largest in Poland, with a total of 934 accessions. Most of them are tulips (522) and lilies (222). Other plants in the collection in Skierniewice are gladiolus and narcissus. The most valuable accessions are grown under special protection (tunnels with dense nets) to guard against insects and maintain a mild climate inside. The genetic resources of the ornamental bulb plant collection in Lisewo currently consist of 611 accessions, mainly tulips (358), daffodils (121) and gladioli (132). All bulbous crops in both collections (Skierniewice and Lisewo) are grown in accordance with all principles of agrotechnics (negative field selection, fertilisation, soil maintenance). A particularly important task of botanical gardens, universities, research institutes and the National Centre is leading research on the methods of storage for survival organs, in vitro cultures and cryopreservation. We have discovered that the various activities for the species conservation of ornamental geophytes require a great deal of constantly deepening knowledge and extraordinary measures, including frequent monitoring of the effects of the applied measures.

Effect of NPS and Zinc Fertilizer Rates on Growth and Yield of Onion (Allium cepa L.) at Shewa Robit, North Shewa, Ethiopia

Onions, a crucial bulb crop cultivated globally, including in Ethiopia, face significant production challenges. These constraints encompass poor soil fertility, inappropriate fertilizer usage, limited availability of improved varieties, disease and insect pests, and the high costs associated with commercial fertilizers. Among these limitations, improper fertilizer application amounts and types play a pivotal role in restricting onion production. To address this, a field experiment was conducted during the 2020-2021 cropping season in the Shewa Robit district of the North Shewa zone. The study assessed the impact of NPS and Zn fertilizer rates on onion growth and yield. The treatments included four NPS fertilizer rates (0, 121, 242, and 363 kg/ha) and four levels of ZnSO4 (0, 0.25, 0.5, and 0.75% w/v). The experiment was laid out as a randomized complete block design in a factorial arrangement and replicated three times. The results demonstrated that the interaction effect of NPS and Zn fertilizers significantly influenced various onion parameters, including days to maturity, plant height, leaf length, marketable bulb yield, unmarketable bulb yield, and total bulb yield. The application of NPS at a rate of 242 kg/ha and 0.75% ZnSO4 led to the highest plant height (65.20 cm), leaf length (51.93 cm), marketable bulb yield (34.87 t/ha), and total bulb yield (35.04 t/ha). In addition, this treatment combination yielded the highest net benefit (908,628.89 ETB/ha) with an acceptable MRR (313.64%) compared to other treatments. Hence, it can be recommended for economical production of onion in the study area and areas with similar agroecologies.

Influence of genetic and environmental factors on incidence of bolting in short day onions

Bolting is the premature flowering malady in bulb crop of onion cultivation. It has detrimental effects on bulb quality and market value. This research aimed to investigate the relationship between genetic predisposition and environmental conditions in relation to bolting in different onion genotypes and hybrids. Findings revealed that, the divergent patterns between the regions of Bengaluru and Bagalkot indicate that weather differences in geographical locations play a significant role in influencing the bolting tendencies of onions. The rabi season exhibited the highest bolting rate (15.09%), surpassing the kharif (0.21%) and summer (1.53%) seasons, emphasizing the role of seasonality in triggering bolting. Interestingly, even under identical environmental conditions, yellow onions demonstrated higher bolting percentage compared to red and white onions, suggesting the presence of genetic variation. This variation could be attributed to disparities in the presence and expression levels of the bolting genes. Collectively, these results highlight the combined influence of genetic and environmental factors, as well as their interactions on onion bolting tendencies.

A Review of the Prospective Effects of Spacing and Varieties on Onion Yield and Yield Components (Allium cepa L.) in Ethiopia.

Onion (Allium cepa L.) is the most important commercial vegetable crop widely grown throughout the world. It is also an important bulb crop in Ethiopia. However, its production and productivity are restricted by different factors, including biotic and abiotic stresses. This review investigates the potential impacts of spacing and varieties on onion yield and yield components in Ethiopia. Countries around the world are producing onion for its nutritional value, medicinal properties, minerals, proteins, and carbohydrates. In terms of production, onion ranks second only after tomatoes. The average onion yield in Ethiopia is estimated to be 8.8 tons/ha, while in the world, it is approximately 19.7 tons/ha. Inappropriate spacing and inadequate onion varieties are some of the limitations widely described for yield variation in Ethiopia. Thus, to control the size, shape, and yield of onion bulbs, spacing determination and variety improvement are some of the techniques currently employed in Ethiopia. Adama red, Bombay red, and red creole are some of the known varieties in the country, and the intrarow spacings for Adama red and Bombay red are reported to be 4 cm and 6 cm, respectively. Different spacing between onion plants affects how much they produce and other factors such as size and quality, depending on the variety. It is important to assess whether changing spacing makes sense from both a farming and economic standpoint, alongside considering other agricultural methods.

Preventing bolting in onion (Allium cepa L.) bulb crop; effect of transplanting date and seedling age

Preventing bolting in onion (Allium cepa L.) bulb crop; effect of transplanting date and seedling age

Effect of edible dyes on value addition and post-harvest life of tuberose spikes

Tuberose is one of the most imperative bulbous crops with white fragrant florets, used for loose as well as cut flowers. All the commercial varieties have white colour flower only which is limiting factor in its popularity and marketing. By using edible dyes this issue may be solved for getting higher price in market as well as consumers satisfaction. An investigation was carried out to study the effect of food dyes on value addition and post harvest life of cut spikes of tuberose cv. Local Double in completely randomized design with factorial concept consisting thirty-six treatment combinations and one absolute control. Different treatments of food dyes and immersion time considerably induced colour in tuberose spikes without affecting postharvest life. The results revealed that 4% lemon yellow food dye with one hour immersion of tuberose cut spikes was found best in improving vase life (6.02 days), floret diameter (3.29 cm), opening of florets (49.66%) and visual appearance with minimum physiological loss in weight (16.91 % and 34.04 % at second and fourth day, respectively). Tinted tuberose cut spikes aids higher net return than white flowers, which will benefit farmers in fetching good prices.

Screening of onion (Allium cepa) genotypes to find out novel resistant source against purple blotch (Alternaria porri)

Purple blotch caused by Alternaria porri (Ellis) Cif., 1930 causes huge losses to bulb crop and seed crop of onion (Allium cepa L.). This is a major disease affecting successful onion production in majority of the onion growing areas. To identify resistant source against purple blotch, 34 onion genotypes with good marketable yield based on field evaluation trial in 2017 and allied species Pusa Soumya were screened under protected conditions during kharif, 2018 at insect proof net house facility of ICAR-Indian Agricultural Research Institute, New Delhi. The pure culture of Alternaria porri, isolated from infected leaf samples of onion crop raised under natural epiphytotic conditions during kharif, 2017. Highest change of disease severity index was observed between 1–2 weeks post inoculation (WPI) while highest disease severity index was recorded at 5 WPI suggesting that preventive measures must be employed as soon as disease symptoms appear in the field. The disease severity index ranged from 0.10–33.33 at 1 WPI, which increased to 9.33–89.33 at 5 WPI. The cultivated allied species Pusa Soumya was identified as novel resistance source with DSI value less than 10.0% at 5 WPI. Four genotypes exhibited moderately susceptible reaction, while 20 genotypes were susceptible and 10 genotypes were highly susceptible. The area under disease progress curve (AUDPC) value ranged from 22.33–240.17. Pusa Soumya had the lowest value and among onion lines Arka Kirtiman was found promising. Three onion genotypes had low relative AUDPC value and can effectively be utilized in resistance breeding programme. The average daily temperature between 20–25°C and relative humidity above 75% was found ideal for disease development.

Evaluating the Influence of Water Scarcity on the Host Response of Garlic to the Stem and Bulb Nematode Ditylenchus dipsaci.

Ditylenchus dipsaci is a plant-parasitic nematode with a great economic impact on bulbous crops, including garlic (Allium sativum L.), and is distributed worldwide, particularly in the Mediterranean region. Traditionally, garlic was a rainfed crop in Spain, but irrigated areas have increased during the last few decades. However, the expected climatic conditions, with longer and more intense droughts, will make it necessary to reduce the water supply to garlic crops. This poses the urgent need to select garlic cultivars more tolerant to water scarcity and that are also more resistant to plant pathogenic organisms. The aim of this work was to analyze the influence of water stress on the host response of garlic plants to D. dipsaci. The specific objectives were to evaluate the level of nematode infestation in plants from four garlic genotypes treated with a reduced irrigation regime and compare them with those of control plants not subjected to water stress. The observed results were correlated with changes in the bulb and root development, as well as in the physiological parameters (total chlorophyll concentration and proline accumulation). The effects were different depending on whether the plants were subjected to water stress before or after nematode inoculation, as well as whether the water stress was continuous or discontinuous. Garlic inter-cultivar variability also affected the obtained results.

Application of Data Mining with K-Nearest Neighbors Algorithm for Shallot Price Prediction

Shallots are an important and widely consumed bulb crop in Indonesia, both for medicinal and culinary purposes. However, shallot yield is substantially affected by its supply, often leading to significant price fluctuations that greatly impact consumers and producers, especially farmers. Farmers who cannot accurately predict shallot prices often incur losses when selling to shallot distributors. If this problem is not resolved, it may discourage farmers from cultivating shallots. Therefore, a prediction system is needed to forecast shallot prices in the future, thus helping farmers make the right decisions. This research uses the K-Nearest Neighbors (KNN) algorithm for shallot price prediction. KNN classifies data into specific categories based on the closest distance to a set of k patterns for each category, using the Euclidean distance formula to calculate the distance. The dataset consists of 303 entries with five features: farmer price, seller price, retail price, seed price, and yield. The test results of the Shallot Price Prediction System in North Sumatra Province, Indonesia, using the K-Nearest Neighbors Algorithm, showed the best performance when using 80% training data and 20% testing data, with a value of k=2, resulting in a Mean Absolute Error (MAE) of 25,786 and a Mean Squared Error (MSE) of 72. This system empowers farmers to predict the future price of shallots before selling their crops to distributors.

Biorational Approaches for Purple Blotch Disease of Garlic (Allium sativum L.) Incited by Alternaria porri (Ellis) Cif

Garlic (Allium sativum L.) is the second most important bulb crop after onion. It is a major spice crop. Garlic is attacked by many diseases, one of which is Purple blotch. This study was aimed to determine the effect of botanicals and bio-agent on purple blotch disease of garlic caused by Alternaria porri. The research work was undertaken at Central Research Farm (CRF) Sam Higginbottom University of Agriculture, Technology and Sciences, SHUATS, Naini, Prayagraj during Rabi in 2022-23. A randomized block design with eight treatments was employed including T0 (Control - untreated) , T1 ( Azoxystrobin @0.1% as treated check), T2 (Trichoderma harzianum @10g/litre) , T3 (Lantana camara leaf extract @10%), T4 (Azadirachta indica leaf extract @10%), T5 (Henna leaf extract @2% + Licorice root extract @2% + Rosemary leaf extract @2% ), T6 (Licorice root extract @10%) and T7 (Neem cake @50g/m2). The treatments led to significant decrease in purple blotch severity in garlic.The results revealed that among the treatments, T7 showed minimum disease intensity (4.33, 18.74 and 26.35%) at 30, 60 and 90 days after sowing (DAS) respectively; while maximum disease intensity was recorded in T0 (10.42, 25.52 and 34.68%). T7 also recorded maximum plant height (24.02, 34.01 and 45.71cm) at 30, 60 and 90 DAS, respectively and highest yield of 4.46t/ha. Maximum number of leaves were recorded with T3 (5.53, 7.5 and 9.4) at 30, 60 and 90 DAS respectively. Fungicide usage is increasing day by day that can lead to negative effect on human and soil health in the long run, so there is need to find effective and economic alternatives preferably some bio-agents and botanicals.

Advancements in Lily Viruses Management: Challenges and Solutions in Elimination and Detection

Lilies are important crops that are commonly used as cut flowers (Lilium spp.) and edible bulb crops (Lilium davidii var. unicolor). However, virus infections can significantly impact the quantity and quality of lily production. Various methods have been developed to eliminate viruses in lilies, including in vitro culture and virus detection techniques. Meristem culture is the most effective method, which can be combined with other techniques such as thermotherapy and chemotherapy. Nonetheless, virus elimination is affected by several factors, including cultivar, explants used, virus type, and duration of treatments. Efficient diagnostic methods, such as serological and molecular techniques, have been developed to detect viral infections in lilies, including enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcriptase polymerase chain reaction (real-time RT-PCR). However, cross-contamination and multiple-virus contamination can lead to unreliable results, and more sophisticated protocols and systems have been developed to address these issues. The objective of this review is to provide a comprehensive overview of the development of lily virus eradication, detection strategies, challenges, and solutions associated with these procedures, and how more sophisticated approaches such as multiplex RT-PCR, indirect ELISA (ID-ELISA), immunocapture RT-PCR (IC-RT-PCR), and immunochromatographic test strips (ICSs) can alleviate some of these setbacks.

Molecular cloning, characterization and promoter analysis of LbgCWIN1 and its expression profiles in response to exogenous sucrose during in vitro bulblet initiation in lily

Lily (Lilium spp.) is an important ornamental flower, which is mainly propagated by bulbs. Cell wall invertases (CWINs), which catalyze the irreversibly conversion of sucrose into glucose and fructose in the extracellular space, are key enzymes participating in sucrose allocation in higher plants. Previous studies have shown that CWINs play an essential role in bulblet initiation process in bulbous crops, but the underlying molecular mechanism remains unclear. Here, a CWIN gene of Lilium brownii var. giganteum (Lbg) was identified and amplified from genomic DNA. Quantitative RT-PCR assays revealed that the expression level of LbgCWIN1 was highly upregulated exactly when the endogenous starch degraded in non-sucrose medium during in vitro bulblet initiation in Lbg. Phylogenetic relationship, motif, and domain analysis of LbgCWIN1 protein and CWINs in other plant species showed that all sequences of these CWIN proteins were highly conserved. The promoter sequence of LbgCWIN1 possessed a number of alpha-amylase-, phytohormone-, light- and stress-responsive cis-elements. Meanwhile, β-glucuronidase (GUS) assay showed that the 459 bp upstream fragment from the translational start site displayed maximal promoter activity. These results revealed that LbgCWIN1 might function in the process of in vitro bulblet initiation and be in the response to degradation of endogenous starch.

Exogenous Application of Growth Regulators Improves the Growth and Quality of Dahlia variabilis L.

Dahlia (Dahlia variabilis L.), a bulb crop sold as cut flower, garden ornamental/potted plant, becomes a popular cut flower in the world. This experiment was designed to study the effects of foliar applied gibberellic acid, zinc, ascorbic acid, and thiamine on the growth and flower attributes of dahlia. The study was conducted under greenhouse conditions at the Floriculture Research Area, University of Agriculture, Faisalabad, Pakistan. There were thirteen treatment with three levels each; gibberellic acid, zinc sulphate, ascorbic acid, and thiamine. First, foliar application was done at vegetative stage (after 45 d of transplantation) and second, at the flowering stage. Application of gibberellic acid at 100 ppm significantly improved plant height (92.67 cm). Application of zinc at 0.50% produced the maximum number of flowers (28.47), diameter of flower (100.19 mm), and fresh weight of flower (11.16 g). Foliar application of thiamine increased nutrient accumulation in leaves of dahlia. The nitrogen contents (4.43 %) increased to maximum in response to treatment comprising ascorbic acid, whereas phosphorus content (1.41 mg g-1) and potassium contents (19.45 mg g-1) were at maximum in response to thiamine. The highest chlorophyll a (4.37 mg g-1) and b (2.04 mg g-1) contents were recorded in treatment comprising thiamine at 150 ppm. The highest carbohydrate contents (35.14%) were recorded in zinc application response. Application of thiamine significantly reduced the days of flowering and flower diameter. Overall, it can be recommended that application of thiamine at 150 ppm is more responsive to improve the growth and quality of dahlia flower as compared to gibberellic acid, zinc, and ascorbic acid.

Effective Induction of Fertile Gametes in Oriental × Trumpet (OT) Lily by High Temperatures.

Lily is a very important bulb crop, and interspecific distant hybridization is a crucial method of lily breeding. However, F1 interspecific hybrids tend to be highly sterile due to low levels of genetic homozygosity. This can be addressed by meiotic polyploidization, which has the advantage of reducing breeding time and being able to promote genetic recombination resulting in many variant progenies. High temperatures have been proven to induce 2n gametes via hindering a spindle formation in several plants, but little has been reported in lilies. In the present study, after observing the correlation between the development of the pollen mother cells (PMCs) and the length of the buds, 28-31 mm long buds were selected as the experimental material, which were at the stage of prophase I-metaphase I. Individual buds were induced at different temperatures (40 °C, 42 °C, and 44 °C) and durations (4 h and 6 h) using self-made multiwire heating equipment, and successfully induced fertile male gametes.. The best results were achieved with treatment of 42 °C for 4 h, reaching a maximum fertile pollen induction rate of 36.64%, while bud mortality was 40%. Two chemicals, colchicine and oryzalin, were also used by injection, and only the treatment with oryzalin obtained fertile gametes, with the highest fertile gamete rate of 15.39% at a concentration of 0.005%, while the bud mortality was 36.67%. This suggests that high temperatures have a superior effect on lily 2n gamete induction. In addition, the pollen obtained from the 6 h induction of high temperature was significantly larger than that from the 4 h induction, with an average diameter of 138.64 μm and 107.88 μm, respectively, 2.35 and 1.84 times wider than haploid pollen. The fertile pollen was crossed with four cultivars and two species, and a total of 267 embryonic seeds were obtained, with the highest embryonic rate of 4.52% in OT lily 'Mister Cas' as the parent, which had a germination rate of 26.27%. This suggests that the method of high-temperature induction for fertile gametes probably has important significance for ploidy and distant hybrid breeding in lilies.

Large-scale population structure and genetic architecture of agronomic traits of garlic.

Garlic, an asexually propagated crop, is the second important bulb crop after the onion and is used as a vegetable and medicinal plant. Abundant and diverse garlic resources have been formed over thousands of years of cultivation. However, genome variation, population structure and genetic architecture of garlic agronomic traits were still not well elucidated. Here, 1 100 258 single nucleotide polymorphisms (SNPs) were identified using genotyping-by-sequencing in 606 garlic accessions collected from 43 countries. Population structure, principal component and phylogenetic analysis showed that these accessions were divided into five subpopulations. Twenty agronomic traits, including above-ground growth traits, bulb-related and bolt-related traits in two consecutive years were implemented in a genome-wide association study. In total, 542 SNPs were associated with these agronomic traits, among which 188 SNPs were repeatedly associated with more than two traits. One SNP (chr6: 1896135972) was repeatedly associated with ten traits. These associated SNPs were located within or near 858 genes, 56 of which were transcription factors. Interestingly, one non-synonymous SNP (Chr4: 166524085) in ribosomal protein S5 was repeatedly associated with above-ground growth and bulb-related traits. Additionally, gene ontology enrichment analysis of candidate genes for genomic selection regions between complete-bolting and non-bolting accessions showed that these genes were significantly enriched in 'vegetative to reproductive phase transition of meristem', 'shoot system development', 'reproductive process', etc. These results provide valuable information for the reliable and efficient selection of candidate genes to achieve garlic genetic improvement and superior varieties.

Collision simulation of potato tubers for mechanized harvesting

AbstractThe economic losses caused by collision damages during mechanical potato harvesting are significant. In this study, the simulation analysis method was used to investigate the factors affecting these mechanical damages. Taking the typical early maturing potato variety Zaodabai as an example, our test results indicated that its elastic modulus is 3.148 MPa, Poisson's ratio is 0.45, and biological yield stress is 1.183 MPa. An accurate three‐dimensional potato model was created using reverse engineering technology. On this basis, the effects of drop height, collision mode, and collision material on the mechanical potato damage were investigated using finite element analysis. The results indicated that the potato damage characteristics become more evident as the drop height increased. Analyzing the collision mode of mechanized potato harvesting revealed that the potato damage degree is the lowest in the double‐rod long axis collision mode. The collision damage degree between a potato and four common collision materials was determined from highest to lowest as follows: 65 Mn rod, 65 Mn rubber‐coated rod, potato, and soil. This research provides a data basis and reference for the design and development of potato harvester equipment, particularly for low‐damage potato harvesters.Practical applicationsAs the fourth largest food crop in the world, potatoes have high economic value and are of great importance for food security. Collision damage in mechanized harvesting seriously reduces the quality and value of potatoes and causes large economic losses. Therefore, we aim to clarify the key factors affecting collision damage in mechanized harvesting. The influence of motion mode, collision height, collision method, and collision material on potato damage characteristics was investigated through simulation experiments. This study provides a data basis and reference methods for developing key components of high‐performance and low‐damage potato harvesters and serves as a reference for researching damage characteristics of other tuber, root, and bulb crops.

Efficient Elimination of Viruses from Garlic Using a Combination of Shoot Meristem Culture, Thermotherapy, and Chemical Treatment

Garlic (Allium sativum L.) is a clonally propagated bulbous crop and can be infected by several viruses under field conditions. A virus complex reduces garlic yield and deteriorates the quality of the produce. In the present study, we aimed to eliminate Onion yellow dwarf virus (OYDV), Garlic common latent virus (GCLV), Shallot latent virus (SLV), and Allexiviruses from the infected crop using combination of meristem culture, thermotherapy, and chemotherapy. In this study, seven different treatments, namely shoot meristem culture, thermotherapy direct culture, chemotherapy direct culture, chemotherapy + meristem culture, thermotherapy + meristem culture, thermotherapy + chemotherapy direct culture, and thermotherapy + chemotherapy + meristem culture (TCMC), were used. Multiplex polymerase chain reaction (PCR) was employed to detect virus elimination, which revealed the percentage of virus-free plants was between 65 and 100%, 55 and 100%, and 13 and 100% in the case of GCLV, SLV, and OYDV, respectively. The in vitro regeneration efficiency was between 66.06 and 98.98%. However, the elimination of Allexiviruses could not be achieved. TCMC was the most effective treatment for eliminating GCLV, SLV, and OYDV from garlic, with 66.06% plant regeneration efficiency. The viral titre of the Allexivirus under all the treatments was monitored using real-time PCR, and the lowest viral load was observed in the TCMC treatment. The present study is the first to report the complete removal of GCLV, SLV, and OYDV from Indian red garlic with the application of thermotherapy coupled with chemotherapy and shoot meristem culture.

Effect of Growth promoters and Micronutrients on Performance of Onion under Hill Zone of Karnataka

Onion (Allium cepa) is one of the commercial bulb crops cultivated throughout India. Onion has huge demand for its edible bulb and the productivity is to be increased. An experiment was conducted to investigate the influence of growth promoters and micronutrients in bulb yield of onion cv. Bhima Shakti during 2021-22 at experimental block of College of Horticulture, Mudigere under hilly conditions. The experiment was laid out in Randomised block design with eleven treatments and three replications. The treatments consist of growth promoters (GA3 and NAA) applied at 75 ppm, 100 ppm, 125 ppm and micronutrients (ZnSO4 and Boron) applied at 0.25% and 0.50%. Growth promoters and micronutrients made a significant impact on growth and bulb yield of onion. The obtained results showed that plant height (74.52 cm) was significantly higher in T6-GA3@125 ppm at 105 days after transplanting (DAT). Maximum leaf girth (3.23 cm) at 105 DAT, days for maturity (125 days), bulb yield (34.50t/ha) and bulb volume (96.35 cc) were recorded significantly in T5-GA3@100 ppm. The application of gibberellic acid at the concentration of 100 ppm was effective for obtaining higher bulb yield.

Effect of Age of Seedling on Bolting and Yield of Rabi Onion Cv. NHRDF Red-3

Onion is one of the most important bulb crops of the Nalanda district. The trial is conducted to reduce the bolting percentage and improve the yield by transplanting onion seedlings at the proper age. Farmers are usually transplanting 75 to 80 days old seedlings in the Nalanda district. In this trail, farmers transplanted 60 days and 55 days old seedlings for consecutive two the financial year 2018-2019 and 2019-2020. The best result was obtained in the case of transplanting 55-day-old seedlings. The maximum bulb weight was 58.86 gm, the minimum bolting percentage was 1.98%, maximum yield 324.63 q/ha with the highest B:C ratio of 02.08 was recorded in the Year 2018-2019 in the case of 55 days of seedlings. A similar result was obtained in the year 2019-2020 as the highest bulb weight was 61.01 gm, the least bolting percentage was 1.98%, maximum yield was 325.25q/ha with the highest B:C ratio of 2.10 as compared to transplanting of 60 days old seedlings and farmers practice. In the case of farmers' practice, the average bulb weight was 57.45gm with a bolting percentage of 6.74%, the yield is 297.28 q/ha with B: C ratio of 1.77 in Years 2018-19, and 57.66 gm of bulb weight, 6.53% of bolting,296.56 q/ha of yield with B: C ratio of 1.76.