Bulb Weight Research Articles

Yield and Yield Components of Onion as Influenced by Intra-Row Spacing and Nitrogen Fertilizer Levels in Rift Valley, Ethiopia

Background and Objectives: Farmers currently employ nationally approved fertilizer rates and plant spacing when growing onions, but knowledge of plant population density and fertilizer rates that may produce the best bulb production for different cultivars and locations is limited. As a result, gardeners frequently use nonspecific plant population densities for various cultivars, resulting in sub-optimal bulb yields.
 Materials and Methods: A field experiment was conducted in 2019 from August to December to study the effects of intra-row plant spacing and levels of nitrogen on yield and quality of onion (Allium cepa L.) variety Nafis under irrigation.
 Results: The main effect of intra-row spacing on stand count and both nitrogen levels and intra-row spacing on plant height and the number of leaves per plant was observed. The interaction of nitrogen level and intra-row distance affected days to maturity, leaf length, leaf diameter, bulb diameter, mean bulb weight, marketable and unmarketable bulb yield, and all bulb size categories. Increased intra-row spacing to 10.5 cm and N rate of 82 kg ha-1 increased marketable and total bulb yield by approximately 3.14 and 3.21 t ha-1, respectively, spacing and decreased unmarketable bulb yield by 1.38 t ha-1.
 Conclusion: The use of 82 kg ha-1 N at the intra-row spacing of 10.5 cm was optimum for bulb production of onions. 82 kg ha-1 N at 10.5 cm intra-row spacing resulted in the highest net benefit.

Effects of Varieties and Different Environments on Growth and Yield Performance of Shallot (Allium cepa var. aggregatum)

Shallot (Allium cepa var. aggregatum) is one of the major cash crops produced in the Amhara region, including East Gojjam Zone, Ethiopia. However, the shallot is being out of production, and there are limited research efforts concerning the influence of the growing environment on shallot varieties. Thus, the objective of the study was to identify adaptable and high-yielding shallot varieties across different agroecologies/location in the East Gojjam Zone of Ethiopia. The experiment was conducted at three locations (Debre Markos, Wonka, and Yelam Gej) during 2019/20 and 2020/21 growing seasons. The study consists of four shallot varieties (Minjar, Huruta, Negelle, and local). The experiment was conducted in a randomized complete block design with three replications. Data on growth, yield, and yield component parameters were recorded and analyzed using SAS Computer Software version 9.0. The present results indicated that the highest plant height, leaf length, number of shoots per plant, number of bulblets per bulb, average bulb weight, total yield, and marketable yield per hectare were recorded from improved shallot varieties Minjar, Negelle, and Huruta. Thus, Minjar, Negelle, and Huruta were better performed for growth, yield, and yield components at all testing locations. Thus, Minjar, Negelle, and Huruta were found to be superior in yield and yield components at all testing locations and were thus suggested to be used by the growers in the study area. It would be advisable to evaluate the varieties in the participatory varietal trail for further dissemination of varieties to shallot growers in the study area.

Effect of nitrogen, phosphorus and potassium on the growth and yield performance of garlic (Allium sativum L.) in coastal zone of Bangladesh

The experiment was carried out at Agricultural Research Field, Noakhali Science and Technology University, Noakhali, Bangladesh during the period from November 2021 to March 2022, to observe the effect of nitrogen (N), phosphorus (P) and potassium (k) fertilizer on growth and yield of garlic (Allium sativum L. V: BINA Roshun-1). The experiment was laid out in a Randomized Complete Block Design (RCBD) comprising four treatments with three replications. The treatments were T0 (no NPK), T1 (NPK 70-70-100 kg ha-1), T2 (NPK 100-100-140 kg ha-1), T3 (NPK 130-130-180 kg ha-1), and here, N = Nitrogen, P=P2O5, K= K2O respectively. Data were recorded from harvesting stages of plant growth on the plant height, number of leaves per plant, leaf length, number of roots per plant, bulb diameter, bulb length, number of cloves per plant, whole weight of plant, fresh weight of bulb and fresh bulb yield per hectare. All the recorded parameters were statistically significant (p<0.01). The highest plant height (69.57 cm) was recorded from T3 (NPK 130-130-180 kg ha-1) whereas the lowest plant height (51.40 cm) was obtained from the control T0 (no NPK). The maximum number of leaves per plant (9.97), leaf length (38.10 cm), number of roots per plant (90.83), bulb length (3.30 cm), bulb diameter (3.80 cm), number of cloves per plant (28.97), whole weight of plant (65.07 g), fresh weight of bulb (42.50 g) and fresh bulb yield per hectare (2.83 t/ha) was found in treatment T3 (NPK 130-130-180 kg ha-1) whereas lowest data recorded from control T0 (no NPK). Observing the results, it can be stated that application of NPK fertilizer @ N 130 kg ha-1, P2O5 130 kg ha-1 and K2O 180 kg ha-1 for garlic cultivation gave better growth and yield in the coastal zone of Bangladesh. Res. Agric. Livest. Fish. 10(1): 53-60

Survival Rate, Disease Incidence, and Yield of Shallots by Seed Priming and Application of Tithonia Compost Enriched with Gliocladium virens

This study aimed to evaluate the effects of seed priming with Moringa leaf extract (MLE) and the application of Tithonia compost enriched with Gliocladium virens on survival rate, disease incidence, and yield components of shallot. This research was carried out from September to December 2022 at the Teaching Farm, Faculty of Agriculture, Hasanuddin University. The study was conducted with a factorial design of two factors with three replications. The first factor was seed priming, consisting of unprimed hydropriming, 12.5% MLE, 25% MLE, and 37.5% MLE. The second factor is the dose of compost, composed of 0 t/ha, 5 t/ha, 10 t/ha, and 15 t/ha. All data were evaluated using analysis of variance (ANOVA) and Tukey’s multiple means comparison to determine statistical differences between treatments at the 95% confidence level. The results showed that seed priming with MLE and Tithonia compost enriched with Gliocladium virens affected the percentage of surviving seedlings after transplanting. Alone, seed priming with MLE at a concentration of 37.5% and application of Tithonia compost at a dose of 15 t/ha had the best effect on the number of bulbs per plant, bulb weight, bulb diameter and bulb production. Furthermore, adding Tithonia compost enriched with Gliocladium virens reduced the incidence of Fusarium wilt. As a result, the use of MLE as a priming agent and the addition of Tithonia compost enriched with Gliocladium virens is recommended.

Combined Application of Azolla and Inorganic Potassium Fertilizer Influence the Growth, Yield and Storability of Onion in Alluvial Soil

ABSTRACT Azolla (Azolla pinnata R. Br.) is an aquatic fern that supplies potassium (K) and other plant nutrients with their use and organic matter after decomposition in the soil to improve soil quality. Alluvial soils are deficient in available K due to intensive cropping systems, the use of high-yield varieties (HYVs), and improper fertilizer application. With high demand for K fertilizers and complete dependence on imports in India have affected its availability and cost. Azolla can be an alternative option for a source of K nutrients. Keeping this fact in view, the present study was formulated to understand the effect of K applied through Azolla and inorganic K fertilizer on the growth, yield, and storability of onion (Allium cepa L.). An incubation study was carried out to examine the K dynamics as influenced by levels and sources of K. Results showed that the use of Azolla along with mineral K fertilizer (NPK1/2 + K1/2 through mulching of Azolla and NP+ K1/2 through green manuring (GM) of Azolla + K1/2 through mulching of Azolla) has increased the water-soluble K (WS-K) and available K (Av-K) from 0 to 35 days of incubation (DI) and further decreased thereafter up to 105 DI. Azolla-based K application showed the availability of more K in the soil throughout the incubation period as compared to inorganic sources alone. The highest exchangeable K (Ex-K) was recorded in soil treated with Azolla similar to WS-K and Av-K. A field experiment was also conducted on the onion crop at the Bihar Agricultural College research farm, Sabour. The findings suggest that the maximum bulb weight (32.8 g bulb−1) and bulb yield (12.5 t ha−1) were recorded in the treatment NPK+ K1/2 through mulching of Azolla in two splits increased by 33% and 43%, respectively. Treatments applied with the full dose of recommended inorganic K alone resulted in 14% less bulb yield than the treatment combined with the full dose of recommended mineral K through inorganic fertilizer and half dose of recommended K supplied through Azolla mulching. The results also indicated that Azolla-based K application resulted in higher nutrient uptake, soil available nutrient status, and better storability in onion than conventional mineral K fertilization. Overall, the study concludes that Azolla may maintain K availability by increasing the amount of Ex-K and ensuring constant availability of the nutrient during the entire growth period.

Advancing Agricultural Predictions: A Deep Learning Approach to Estimating Bulb Weight Using Neural Prophet Model

A deep learning methodology was utilized to predict the bulb weights of garlic and onions in the Jeolla Province of Korea. The Korea Rural Economic Institute (KREI) operates the Outlook & Agricultural Statistics Information System (OASIS) platform, which provides actual measurements of garlic and onions. We trained the Neural Prophet (NP) lagged time-series model using this data. The NP model effectively handles lagged variables and their covariates by inserting a hidden layer. Our results indicate that the NP model performed with around 5% mean absolute error in predicting bulb weights, with a gap of 3.3 g and 4.7 g with average weights of 63.7 g and 129.9 g for garlic and onions, respectively. This experimental research was based on only three years of measurement data. Hence, the gap between observed and predicted data can be reduced by accumulating more measurement data in the future.

Agronomic responses of four garlic genotypes in two different locations

Agronomic performance of garlic is speculated strongly affected by genotype ´ environment interaction, however, interaction evaluation is rarely studied in Indonesia. This research aimed to study the agronomic response of four garlic varieties in two different locations. The research was conducted from April to December 2021 using Lumbu Putih, Lumbu Hijau, Lumbu Kuning, and Tawangmangu Baru genotypes grown in two locations, i.e., Lembang (1250 m asl) and Ciwidey (1200 m asl), Bandung, West Java using randomized complete block design with three replications. Results showed that genotypes ´ locations interaction was found for traits: plant height, pseudo-stem stem diameter, number of stomata, weight, and diameter of fresh and dried bulbs. Chlorophyll content (SPAD value) depends on genotype, height of fresh bulbs and percentage of weight loss depending on location, while number of leaves was independently affected by genotype and location. Lumbu Kuning produced the highest average fresh weight with considerable differences in both locations (Lembang: 52.01 g, Ciwidey: 31.87 g) and also had the highest weight of dry bulb when planted in Lembang (24.65 g). Pearson's correlation showed that the strongest positive correlation (r=0.91) was found between the weight of the fresh bulb and pseudo-stem diameter when garlic genotypes were planted in Ciwidey. The present study implies the importance to select suitable genotypes for a particular location.
 Keywords: genotype, environment, interaction, SPAD value, stomata, weight loss

Influences of Seedling Age and Variety on the Growth and Bulb Yield of Onion in Northwest Ethiopia

Onion is one of the major cash crops and helps improve the livelihoods of smallholder farmers. Although genetically and morphologically different, seedlings of all released onion varieties are transplanted at the ages ranging from 40 to 50 days, which contributes to the low level of productivity in Ethiopia. Therefore, a field experiment was conducted at the research site of Fogera National Research and Training Center during the 2019/20 irrigation season with the objective of identifying the optimum seedling age for improved onion productivity in Northwest Ethiopia. The treatments consisted of three varieties (Adama red, Bombay red, and Nasik red) and four seedling ages (30, 40, 50, and 60 days) of onion, which were laid down in 3 × 4 factorial arrangement using randomized complete block design with three replications. Growth and yield parameters of onion were collected based on the standard procedures and analyzed using SAS version 9.6. The results revealed that both variety and seedling age significantly ( P < 0.001 ) influenced plant height, leaf number, bulb diameter, fresh bulb weight, and marketable bulb yield, while their interaction effect did not influence these parameters. Days to maturity was significantly ( P < 0.001 ) affected by main as well as by the interaction effects of variety and seedling age. Younger seedling took longer time to mature, while older seedlings matured relatively early. The seedlings of Bombay red variety at 60 days age gave the earliest maturity days (105.33 days) compared to the other combinations. The highest plant height (50.18 cm), leaf number (12.00), bulb diameter (53.47 mm), bulb weight (84.39 g), and marketable bulb yield (29.97 t/ha) were recorded from Bombay red variety where the marketable yield recorded from Nasik red was statistically similar with that of Bombay red variety. Seedlings with 60 days old performed best in terms of all the tested growth and yield parameters including the highest marketability (32.03 t/ha). Accordingly, 60 days old seedlings and Bombay red and Nasik red varieties can be used to increase the productivity of onion in the study area and areas with similar agroecology.

Vermicompost Application on Shallot (Allium cepa, L.)

Vermicompost is an organic fertilizer containing essential macro and micronutrients for plant growth. This study aimed to determine the dose and time of vermicompost application to the shallot. The study was carried out at an altitude of 1054 meters above sea level in Air Duku Village, Selupu Rejang District, Rejang Lebong Regency, Bengkulu Province. A Split Plot Design with three replications was used in the study. The main plot was the time of vermicompost application, which was ten days before and during planting. Sub-plots were vermicompost doses of 0, 10, 20, 30, and 40 tons/ha. Vermicompost applied ten days before planting at a 40 ton/ha resulted in the tallest shallot shoot (36.60 cm) and the highest number of leaves (28.20). Vermicompost applied ten days before planting produced more shallot bulbs (4.46 bulbs), larger bulb diameter (19.18 mm), heavier bulb weight per clump (4.75 g), and heavier bulb weight per m2 (837.73 g) than vermicompost applied at planting. Vermicompost at a dose of 40 tons/ha resulted in 5.80 bulbs per plant, 18.96 mm bulb diameter, 4.63 g bulb weight per clump, and 1022.25 g bulb weight per m2, higher than the lower dose. Therefore, vermicompost could benefit as a source of plant nutrients, comparable to synthetic fertilizers in shallot production.

Growth and Yield of Shallots at various Plant Spacing in Ultisol Dry Land

Plant spacing was one method that could be used to boost plant populations. In order to increase shallot (Allium ascalonicum L.) production and productivity on less-than-ideal ground, such as dry land in Jambi. This study aimed to examine the effects of various plant spacing on the growth and yield of shallots and to obtain plant spacing that provides the best shallot growth and yield. This research was conducted at the Teaching and Research Farm, Faculty of Agriculture, University of Jambi. The design used a Randomized Block Design (RBD) consisting of four treatments with six replications. The treated plant spacing was:10 cm x 10 cm; 15 cm x 15 cm; 15 cm x 20 cm; and 20 cm x 20 cm. Various plant spacing affected the shallot growth and yield, and a plant spacing of 15 cm x 15 cm provided better growth and yield compared to any other plant spacing, with the number of leaves per plant, the weight of bulbs per clump, and the weight per bulb of 22, 49, 49.84, and 13.94 g successively.

Correlation and path analysis studies in onion (Allium cepa) genotypes

The present study was carried out at the experimental farm of the Department of Vegetable Sciences, Dr. YashwantSingh Parmar University of Horticulture and Forestry, Nauni, Solan, Himachal Pradesh during the winter (rabi) season of 2019–20 and 2020–21 to study the genetic variability, correlation and path studies in 30 different genotypes of the onion (Allium cepa L.) crop. All genotypes reflected a wide and significant spectrum of variability for all the traits under study. Genotypes UHF-ONI-13, UHF-ONI-15 and UHF-ONI-16 outperformed other genotypes in terms of yield and other critical horticultural characteristics. The magnitude of phenotypic coefficient of variation was higher than the genotypic coefficient of variation for all the characters. The phenotypic and genotypic coefficients of variability were high for doubles/deformed bulbs, moderate for leaf length, plant height, average bulb weight, bulb yield per plot and per hectare. High heritability along with high to moderate genetic gain was observed for doubles/deformed bulbs, leaf length, plant height, average bulb weight, bulb yield per plot and bulb yield per hectare, which suggested that improvement can be achieved through simple selection. Bulb yield had significant and positive correlation with average bulb weight, equatorial diameter, plant height, polar diameter, days to harvest and days to 50% neck fall. Path analysis showed that bulb weight, equatorial diameter, bulb shape index, neck thickness, total soluble solids, plant height and leaf length had a positive direct effect on bulb yield.

Application of Petrovita Liquid Fertilizer on the Growth and Yield of Shallot Plants (Allium Ascalonicum L.)

Red onion (Allium ascalonicum L.) is a kitchen spice used almost every day by Indonesian people, not to mention small restaurants to large restaurants. The purpose of this study was to determine the application of Petrovita Liquid Fertilizer to the growth and yield of shallot plants. This research research was conducted in 2019 within six months of the year starting from a method using a randomized block design (RBD) consisting of six doses of Petrovita Liquid Fertilizer, with three replications and two sample plants. Use of Liquid Petrovita at doses Z0 = no fertilizer/control, Z1 = 1 ml/l/plant, Z2 = 2 ml/l/plant, Z3 = 3 ml/l/plant, Z4= 4 ml/l/plant, and Z5 = 5 ml/l/plant. Observations consisted of plant length, number of leaves, fresh weight of plants, the weight of plant tubers, and number of plant tubers. The results showed that the dose of Petrovita Liquid Fertilizer Significantly affected all observation variables, namely plant length, number of leaves, number of bulbs, fresh weight of plants and wet weight of shallot bulbs. The treatment of Petrovita Liquid Fertilizer dose of 5 ml per liter of water showed the highest growth and yield with a yield of 30.16 cm plant length, 46.00 leaves, 68.33 grams of wet plant weight, 49.00 grams of tuber weight, and the number of tubers per plant 10.00 although statistically not significantly different from the Petrovita Fertilizer Liquid fertilizer treatment using a dose of 1 ml per liter of water with a plant length of 29.00 cm, number of leaves 34.83, plant wet weight 58.16 gram, tuber weight per plant 38.56 grams and the number of tubers planted were 8.16.

Performance valuation of onion (Allium cepa L.) genotypes under different levels of salinity for the development of cultivars suitable for saline regions.

Abiotic stress, especially salt stress, is one of the major barriers to crop production worldwide. Crops like onion that belong to the glycophytic group are more sensitive to salinity stress. A huge study regarding the influence of salinity stress on the growth and development of crops has already been done and is still ongoing. One of the major targets of the research is to develop genotypes that have enhanced performance under stress environments. The world needs more of these types of genotypes to combat the ever-growing salt-stressed soils. Therefore, a number of germplasm were studied during the 2019-2020 and 2020-2021 seasons under different salt concentrations to identify tolerant genotypes as well as to study the plants' responses at different growth stages against elevated salinity levels. A 2-year study was conducted where germination potential was evaluated in the first year and carried out in petri dish culture of seeds, followed by plastic pot culture for plant establishment and bulb development evaluation during the second year. Four different saline water solutions having different salt concentrations (0, 8, 10, and 12 dS m-1) were applied to the petri dishes and pots as the source of water for plants in both seasons. Results indicated that a significant reduction in plants' performance occurs under higher salinity levels. Salt concentration had an adverse impact on germination, leaf development and growth, the height of plants, bulb size and shape, and the bulb weight of onion. All the growth phases of onion are sensitive to elevated concentrations. Variable performances were observed in the genotypes under stress conditions, and a few genotypes (Ac Bog 409, Ac Bog 414, Ac Bog 424, Ac Bog 430, Ac Bog 417, Ac Bog 419, Ac Bog 420, Ac Bog 422, and Ac Bog 425) having some sort of tolerance to salt stress were identified, which might be recommended for mass production. Tolerance indices could successfully be applied in selecting the salt-tolerant genotypes. Thus, the present findings and the identified genotypes could be further utilized in salt stress improvement research on onion.

Effect of transplanting dates, cultivars and zinc on yield and economics of onion in semi-arid conditions in Rajasthan

Delayed transplanting and insufficient nutrient application are the major factors responsible for reducedonion yield. Proper planting time is critical for getting optimal bulb yield. Selection of right cultivar is one of themost important variables in getting higher growth and yield attributes for a particular agro-climatic condition. Anexperiment was conducted to determine the effect of transplanting date, cultivar and zinc application method onyield, yield attributes and economics of onion. Results were found to be significant for all the yield attributes,yield and economics of onion. Transplanting on 01st January significantly increased the average bulb weight(81.10 g), equatorial diameter (5.58 cm), polar diameter (4.52 cm), total bulb yield (387.42 q/ha), net return (Rs367963/ha) and B:C ratio (3.84) in a pooled analysis. Among the cultivars, significantly higher average bulbweight (79.37 g), equatorial diameter (5.48 cm), polar diameter (4.42 cm), total bulb yield (387.95 q/ha), net return(Rs 368680/ha) and B:C ratio (3.83) were recorded in Bhima Shakti. In zinc application methods, significantlyhigher average bulb weight (79.68 g), equatorial diameter (5.50 cm), polar diameter (4.42 cm), total bulb yield(386.67 q/ha), net return (Rs 364973/ha) and B:C ratio (3.78) were recorded with foliar spray of zinc sulphate @0.5 per cent at 30 & 45 DAT. The reduced neck thickness (0.70, 0.73 & 0.72 cm) was recorded on 01st Januarytransplanting, Bhima Shakti cultivar and foliar spray of zinc sulphate @ 0.5 per cent at 30 & 45 DAT, respectively.

Characterization and Evaluation of Lilium In Bangladesh

Thirty-seven genotypes of Lilium were collected and evaluated under Lilium shade at floriculture Division, Horticulture Research Centre, Bangladesh Agricultural Research Institute, Gazipur during 2017-21 to characterize different species of Lilium available in Bangladesh and collected from abroad. Notable variations in different qualitative and quantitative parameters were observed among the 37 genotypes under study. Among them, 31 genotypes were found suitable for cut flowers and six (06) suitable for pot culture. The longest stalk and rachis (94.3 cm and 36.0 cm, respectively) were produced by the genotype Lil-036. The maximum number of florets per stick (10.5) was produced by BARI Lilium-1. The maximum vase life was observed in Lil-007 and BARI Lilium-2 (11.0 days), whereas the minimum in Lil-022 and Lil-026 (5.0 days). The heaviest and the largest bulbs were produced by the genotype Lil-036 (72.4 g) and (6.6 cm) respectively. Considering the length of stalk and rachis, number of florets per stick, duration of vase life, average bulb weight, the genotypes, Lil-018, Lil-021, Lil-034, Lil-035 and Lil-036 were selected for further evaluation.
 Bangladesh J. Agril. Res. 47(1): 39-50, March 2022

Effects of microbial biostimulants (Trichoderma album and Bacillus megaterium) on growth, quality attributes, and yield of onion under field conditions

Microbial biostimulants (MBs) promote plant growth and stress tolerance in a sustainable manner. However, precise field trials of MBs are required in natural setting with a range of crop varieties to harness the benefits of biostimulants on crop yield improvement. This study investigated the effects of two MBs, Trichoderma album and Bacillus megaterium, on an onion cultivar's growth, nutritional qualities, antioxidant properties, and yield potentials under field conditions for two successive years. Before transplantation, onion bulbs were gelatin-coated with 2.0 and 4.0 g L−1 of each of the MB. Results revealed that MBs-pretreated onion plants exhibited better growth indices, photosynthetic pigment contents, and yield-attributing features like bulb weight than control plants. Nutraceutical analysis demonstrated that T. album-pretreated (by 2.0 g L−1) onion cultivar enhanced the level of K+ (by 105.79%), Ca2+ (by 37.77%), proline (by 34.21%), and total free amino acids (by 144.58%) in bulb tissues over the control plants. Intriguingly, the pretreatment with both T. album and B. megaterium (by 2.0 g L−1) increased the levels of total soluble carbohydrates (by 19.10 and 84.02%), as well as antioxidant properties, including increased activities of superoxide dismutase (by 58.52 and 31.34%), catalase (by 164.71 and 232%), ascorbate peroxidase (by 175.35 and 212.69%), and glutathione-S-transferase (by 31.99 and 9.34%) and improved the contents of ascorbic acid (by 19.1 and 44.05%), glutathione (by 6.22 and 33.82%), and total flavonoids (by 171.98 and 56.24%, respectively) in the bulb tissues than control plants. Although both MBs promoted the growth and nutraceutical qualities of onion bulbs, T. album pretreatment showed better effects than that of B. megaterium in the field settings. Based on the morphophysiological attributes and biochemical properties, a low dose (2.0 g L−1) was more effective than a high dose (4.0 g L−1) of T. album in promoting onion growth. Overall, the current research findings imply that T. album might be a potential MB in improving growth and quality attributes, and hence the productivity of onion cultivars under field circumstances.

Onions Selected for Reduced Symptom Expression of Iris Yellow Spot Have Higher Photosynthetic Rates

Bulb onion (Allium cepa L.) is an economically valuable vegetable crop in the United States. Onion production is threatened by onion thrips, which are the vector for Iris yellow spot virus, which is the causal agent of Iris yellow spot (IYS). New Mexico State University (NMSU) breeding lines 12-236, 12-238, 12-243, and 12-337 have exhibited fewer IYS disease symptoms in the field; however, little is known about the effects of the disease on the photosynthesis rate (Pn). We hypothesized that these NMSU breeding lines would have a higher Pn than IYS-susceptible cultivars Rumba and Stockton Early Yellow. To test this hypothesis, a field study was conducted for 3 years at NMSU, and Pn was measured five times throughout each season at 2-week intervals. During bulb development and maturation, which occurred at 10 and 12 weeks after transplanting, all NMSU breeding lines exhibited a higher Pn when compared with that of an IYS-susceptible cultivar. Pn was highest at the end of the vegetative growth stage and decreased as bulbs approached maturation for all cultivars. Additionally, a high Pn at 10 and 12 weeks after transplanting coincided with high bulb weight at harvest. NMSU breeding lines have increased Pn compared with that of IYS-susceptible cultivars and resulted in larger and more marketable bulbs. These results indicate that maintaining Pn may be related to reduced IYS symptom expression of onion.

Evaluation the Effect of Fungicides, Micronutrients and Botanicals on Purple Blotch Complex of Onion in Bangladesh

Field research was conducted in the central research farm of Sher-e-Bangla Agricultural University (SAU), during the period from October 2020 to March 2021. The experiment was a layout with RCBD design to evaluate the effect of selected fungicides (Indofil, Mancer, and Ridomil Gold), micronutrients (Zinc, Boron, and Magnesium), and botanicals (neem and eucalyptus leave extract) on purple blotch complex of onion. Data were collected on percent disease incidence and percent disease index, the number of leaves per plant, leaf length, bulb diameter, bulb weight (fresh and dry), and yield. The local cultivar Faridpuri was used as a tested variety. Among the selected fungicides, Ridomil Gold gave a better result than other fungicides in controlling the percent disease incidence (52.67%) and percent disease index (49.00%) with the highest number of yield qualities per plant. In addition to this, the highest bulb diameter (18.23 cm), single bulb weight (47.98 g), fresh weight (3.16 Kg/plot), and dry weight (2.88Kg/plot) were also obtained in Ridomil Gold treated plots. This treatment also gave better yield performance (9.60 t ha-1) followed by Indofil (8.20 t ha-1) and Mancer (7.90 t ha-1), and increased yield by 54.34% over the control treatment. From the study, it was also found that among the micronutrients, boron gave more satisfactory results than botanicals.

Seedling Performance, Growth and Yield of Onion Sown by Direct Seeding in Tropical Riparian Soil

The objective of this study was to obtain a seed-origin onion (Allium cepa L.) that was able to grow in the tropical riparian soil. Research designed with non-experimental. Two cultivars were studied, namely Sanren and Lokananta. Onion seeds were planted directly without transplanting, there were three plots (4 m x 1.6 m x 0.3 m) and three germination testplot (1 m x 1.6 m x 0.3 m). Soil tillage, spacing/ population, fertilization, plant maintenance and pest-diseases control in accordance with the recommendations. Research result obtained Sanren had higher germination (94.40%) and vigor index (60.60) then Lokananta. The growth of two onion cultivars showed good performance because there was no transplanting. Almost all the the variables for seedlings, vegetative organs and bulbs were significantly different between two cultivars. From the boxplot test, it was found that the data were of symmetry for Sanren (number stems, dry weight of leaves, and dry weight of bulb), and the Lokananta cultivar (vigor index, number of stems, number of bulbs, plant height and leaf dry weight). There was a significant correlation for Sanren (plant height with bulbs weight and number of roots), and Lokananta cultivars (number of roots with number of stems and leaf dry weight). Fresh bulbs weight per clump from Sanren (46.71 g) and Lokananta (17.84 g).

Exogenous Growth Regulators and Water Stress Enhance Long-Term Storage Quality Characteristics of Onion

Exogenous growth regulators (GRs) play a crucial role in alleviating water stress and sustaining crop yields in water-stressed areas. However, their effects on onions post-harvest quality, particularly post-monsoon onion—often preferred for long-term storage—were never studied. Therefore, this led us to investigate the interaction between water stress and GRs on the physiochemical and functional quality attributes of onions during long-term storage (9 months, at 25 ± 1 °C and 65 ± 5% RH). Onion crop was raised under four water stress levels i.e., 1.00–0.85, 0.84–0.70, 0.69–0.40, and 0.39–0.10 IW: CPE, designated as no, low, medium, and severe water stress, respectively, using a line source sprinkler system (LSS). GR treatments include potassium nitrate (PN, 15 g L−1), sodium benzoate (SB, 100 mg L−1), thio-urea (TU, 450 ppm), and gibberellic acid (GA, 25 ppm). Results reveal that the significant temporal changes in the dry matter, rehydration ratio, total soluble sugar (TSS), protein, and total phenolics content (TP) of the onion bulbs during storage, indicate the cumulative impact of the treatments on overall physicochemical status. Water stress increased onion biochemical attributes, especially pyruvic acid content, superoxide dismutase (SOD), and peroxidase (POD) activity. Storage quality of onions progressively decreased with the increase in storage period. Stressed onions, especially those produced under severe water stress condition, showed high weight losses, presenting poor keeping quality. However, application of GRs, especially SB, TU, and PN, reduced bulb weight losses together with maintaining slightly better bulb physicochemical properties, thereby improving the overall storage quality, particularly with a moderate level of water stress (0.69–0.40 IW:CPE). The exogenous application of GRs with moderate water stress is suggested as a key strategy in improving the keeping quality of onion bulbs and ensuring its availability during the lean season.