Bulb Size Research Articles

Growth, Yield and Bulb Quality as Affected by Nitrogen Fertilization and Intra-row Spacing of Two Onion (Allium cepa L.) Cultivars

In response to the rising demand and escalating prices due to several internal demographic reasons in the last few years, interest in increasing productivity and bulb quality has been a major concern. The objective of this research was,therefore, to improve yield and quality of onion through determining more relevant and contemporary nitrogen and population density that cope with the changing production environment in Sudan. So an experiment to study the effect of threenitrogen fertilization levels (0, 120 and 240 kg N/ha.) and three population densities (intra-row spacing of 5, 10 and 15 Cm) on growth, yield and quality of two widely consumed cultivars [Kamlin and Texas Early Grano(TEG)] was carried out for twoseasons. Treatments were arranged in a split-split plot design with three replications; cultivars were randomized in the main plots, intra-row spacing in the sub-plots and nitrogen fertilization in the sub-sub plots. Results indicated that nitrogen applicationat the rate of 120 kg N/ha significantly increased vegetative growth, bulb size, total and marketable yields. Moreover, bolting percentage (a main quality defect) decreased with increasing nitrogen fertilization. Nitrogen fertilization had nosignificant effect on bulb shape, dry matter and TSS. Although high plant density (5cm intra-row spacing) reduced plant growth and increased bolting, it also increased total and marketable yields and reduced bulb splitting (a defect). CultivarTEG exceeded Kamlin in plant growth aspects and consequently average bulb weight, total and marketable yields; however, bulb splitting was also high. In conclusion, planting onion at 5cm intra-row spacing and applying 120 kg N/ha., significantly increased productivity and improved bulb quality in central Sudan.

Influence of PGPR, AM Fungi and Conventional Chemical Fertilizers Armament on Growth, Yield Quality, Nutrient’s translocations and Quercetin Content in Onion Crop Cultivated in Semi-Arid Region of India

The rhizosphere is the thin region of the soil that is directly affected by secretion from the roots and the microbes accompanying the soil, known as the root microbiome. The rhizosphere involving the pores of the soil includes many beneficial bacteria and other diverse microorganisms. The field experiment was conducted during the Kharif season at the Lasalgaon taluka of Nashik district farmers’ field, Maharashtra, India, to determine the influence of biofertilizers on onion. To study the effect of five combinations of biofertilizers compared with the recommended rate of chemical fertilizers on cash crop onion cv. Nashik Red. The treatments were control (100% RRF), Azotobacter + AM fungi, Azospirillum + AM fungi, Azotobacter + Azospirillum, Azotobacter + Azospirillum + AM fungi and Bio consortium (NPK) + Azospirillum + AM fungi. Height (64.24 ± 3.22 cm) and the number of leaves (13.58 ± 3.12) of the plant was maximum with the application of the consortium (NPK) + Azospirillum + AM fungi. The maximum leaf area (84.45 ± 2.44 cm2) was recorded in T6 and the minimum in T4 (82.45 ± 2.25). Different doses of onion plants inoculated with biofertilizers showed a significant increase in quality parameters such as neck thickness (1.12 ± 0.22cm), bulb diameter (14.45 ± 0.53cm), bulb size index (19.45 to ± 0.51 cm2), bulb weight (68.15 ± 2.27g), bulb length (6.21 to ± 1.48 cm), bulb scale (11.23 ± 1.23) was maximum in the consortium (NPK) + Azospirillum + AM fungi treated onion. Biofertilizers such as consortium treatments such as consortium (NPK) + Azospirillum + AM fungi resulted in a better morphological character, quality yield, TSS, starch, reduction sugar, quercetin contents among root colonization of mycorrhizae compared to the uninoculated control (100% RRF). The consortium (NPK) + Azospirillum + AM fungi and 100% RRF provided a maximum bulb length of 6.21 ± 1.48cm and 6.12 ± 1.59cm, respectively. The maximum number of scales per bulb (11.23 ± 1.23) was counted by the consortium (NPK) + Azospirillum + AM fungi. Plants treated with the consortium (NPK) + Azospirillum + AM fungi produced the maximum bulb weight (68.15 ± 2.27g) and the minimum (64.23 ± 2.39 g) in Azotobacter + Azospirillum. The maximum TSS (13.354 %) was noticed in T6 and the minimum in T3. The maximum percentage of starch (6.65%) and the highest percentage of reducing sugars (1.98%) were detected by Azotobacter + Azospirillum + AM fungi. Total pooled weight loss (%) up to 60 days was found to be minimal (11.87%) by Azotobacter + AM fungi followed by Azotobacter + Azospirillum (14.40%). The maximum colonization of mycorrhizae (79.9%) was recorded in the consortium (NPK) + Azospirillum + AM fungi and the minimum in the control (46.67%). It was therefore concluded that the combination of the consortium (NPK bioinoculum) + Azospirillum + AM fungi are improved for onion quality and productivity than the others in terms of sustainable production and environmental consideration.

Screening of Onion (Allium cepa L.) Genotypes for Waterlogging Tolerance.

Onion production is severely affected by waterlogging conditions, which are created due to heavy rainfall. Hence, the identification of waterlogging-tolerant onion genotypes is crucial for increasing onion production. In the present study, 100 distinct onion genotypes were screened for waterlogging tolerance under artificial conditions by using the phenotypic approach in the monsoon season of 2017. Based on plant survival and recovery and changes in bulb weight, we identified 19 tolerant, 27 intermediate tolerant, and 54 highly sensitive onion genotypes. The tolerant genotypes exhibited higher plant survival and better recovery and bulb size, whereas sensitive genotypes exhibited higher plant mortality, poor recovery, and small bulb size under waterlogging conditions. Furthermore, a subset of 12 contrasting genotypes was selected for field trials during monsoon seasons 2018 and 2019. Results revealed that considerable variation in the morphological, physiological, and yield characteristics were observed across the genotypes under stress conditions. Waterlogging-tolerant genotypes, namely, Acc. 1666, Acc. 1622, W-355, W-208, KH-M-2, and RGP-5, exhibited higher plant height, leaf number, leaf area, leaf length, chlorophyll content, membrane stability index (MSI), pyruvic acid, antioxidant content, and bulb yield than sensitive genotypes under stress conditions. Furthermore, the principal component analysis biplot revealed a strong association of leaf number, leaf area, chlorophyll content, MSI, and bulb yield with tolerant genotypes under stress conditions. The study indicates that the waterlogging-tolerant onion genotypes with promising stress-adaptive traits can be used in plant breeding programs for developing waterlogging-tolerant onion varieties.

Jasmonic acid biosynthetic genes TgLOX4 and TgLOX5 are involved in daughter bulb development in tulip (Tulipa gesneriana).

Tulip bulbs are modified underground stems that originate from axillary meristems of mother bulb scales. Hormones, including jasmonic acids (JAs), play key roles in the regulation of tulip bulb development. Here, we compared variations in daughter bulb development through transcriptomic profiling analysis and characterized the functions of JA biosynthesis-related genes during daughter bulb enlargement. The results showed that tulip cultivars exhibited contrasting bulb size variations. Transcriptomic analyses revealed that genes involved in plant hormones and development, including the two lipoxygenase genes TgLOX4 and TgLOX5, showed significant changes in expression following tulip bulb growth. Ectopic overexpression of TgLOX4 and TgLOX5 in Arabidopsis enhanced endogenous JA content, improved plant growth, and increased lateral root numbers. Silencing of these two genes in tulip repressed the growth of daughter bulbs. Furthermore, exogenous JA treatment promoted tulip bulb growth, whereas the JA biosynthesis inhibitor sodium diethyldithiocarbamate (DIECA) inhibited this process. This study offers supporting evidence for the involvement of tulip TgLOX4 and TgLOX5 in the regulation of daughter bulb growth and development.

Performance Evaluation of Onion Varieties at Biyo Awale Cluster in Diredawa Administration

Onion (<i>Allium cepa</i> L.) is an important crop worldwide. It is important in the daily Ethiopian diet. It is widely produced by small farmers and commercial growers throughout the year for local use and export market. No strong study has been conducted to evaluate the suitability of onion cultivation in Biyo Awale district of Diredawa. Hence, the present experiment was conducted to study the performance of improved varieties of onion for their suitability for cultivation in Biyo Awale district of Diredawa. The study was carried out during 2018-2019 cropping season to test the performance of onion varieties. Five high yielding onion varieties were planted in complete randomized block design experiment with three replications including local check at farmer’s field. The quantitative data on bulb yield, plant height, bulb size and number of leaves of onion varieties were collected. Harvesting was done and weighed when all onion varieties reach maturity (90% tops down). The results revealed that the tested onion varieties differ significantly for leaf length, leaf number, neck diameter, bulb diameter, average bulb weight and bulb yield. Among the varieties Bombay red and Melkam produced higher bulb yield (25.56 and 21.13 t ha^-1) and gave 140.68% and 98.96% yield advantage over local check varieties, respectively. Therefore, Bombay Red and Melkam varieties were recommended to the study area and similar agro-ecology.

Review on the effects of phosphorus on growth and yield of onion (Allium cepa L.)

Onions (Allium cepa L.) are biennial herbaceous plant of the family Alliaceous that are typically grown as annuals. Globally, onions were produced at nearly 35 millions tones per annuals. In Ethiopia, it is widely grown in the rift valley and lakes regions of the country. The objective of this seminar is to review the effects of different level of phosphorus on growth and yield of onion. Phosphorus fertilizer is one the most complex production in many tropical soils, owing to low native content and phosphorus immobilization with the soil. In onion, phosphorus deficiencies reduced root and leaf growth, bulb size and yield and also delay maturation. In the soil the amount of phosphorus is moderately low. Onion growth and yield can be enhanced by applying phosphorus. The use of optimum phosphorus fertilizer is one of the prominent to increase production. Still optimum rate of phosphorus fertilizer is not well identified. To optimize phosphorus availability through phosphorus addition, soil factors must be considered and research should be focused on the level of phosphorus on growth and yield of onion.

Responses of Garlic Quality and Yields to Various Types and Rates of Potassium Fertilizer Applications

Potassium (K) is a critical plant nutrient that determines quality in a myriad of crops and increases production yields. However, excessive application of various types of K fertilizers can decrease both the food quality and yields, which translates as economic losses and food safety issues. The objectives of this study were to 1) elucidate the impacts of different application rates of various K fertilizers on garlic, with the aim to identify the optimal and most economical K fertilizer dosage and 2) compare the effects of applying two common K fertilizers (KCl and K2SO4) on garlic, to determine the optimal combination. From 2018 to 2020, we utilized two distinct K-fertilized fields to conduct our experiments. The results revealed optimal KCl fertilization increased the biomass and vegetation index in garlic, and promoted the transfer of nitrogen, phosphorus, and potassium nutrients from the stem and leaf to bulb, thereby increasing bulb production. The application of KCl fertilizer increased the number of cloves, the diameters of the cloves and bulbs, and reduced variations in bulb size. In addition, the application of KCl fertilizer improved the nutritional quality (Vitamin C, soluble sugar, soluble protein, and allicin) of the garlic and reduced the accumulation of nitrate. However, excessive KCl fertilizer cause decreased yields, appearance traits, and nutritional quality. Applying the same rate of K fertilizer in the form of K2SO4 in isolation increased the garlic yield by only 0.1% to 22.5% when compared with KCl fertilizer. However, the results were not always significant. In this study, the highest yields, appearance traits, and nutritional quality were achieved with the ratio of K2SO4: KCl = 3:1. Consequently, to ensure the highest economic value (considering the market prices of K fertilizer, garlic sprouts, and bulbs), the authors recommend a K fertilizer rate of 252.5 kg·ha−1 K2O, with K2SO4 accounting for 61.6% for garlic production in field.

A Meta study on development of sub-irrigated container for onion crop

A low cost container made from recycled material with multi objectives like tower gardening, sub irrigation and self-composting techniques to provide the optimum controlled environment for growing a wide range of agricultural products has been synthesized. For evaluation of fabricated bucket container for sub irrigation, sandy clay and silty loam have been selected. The results of the study revealed that there was saving in area of about 65.89 percent. There is a saving of 54.4 percent of water applied to the soil for plant growth. The water that applied to the field can be utilized for growing double crop in the container. ANOVA test performed at 5% level of significance for the plant heights at 20 DAT and 40 DAT indicated that the highest average plant height 46 cm was recorded in treatment T1 followed by T2, T3 and T4. From this it is concluded that the height of onion plants was good in containers compared to fields. The highest yield of spring onion was recorded in T1 compared to others. The yield of spring onion in T1 was 157g. The growth of plants and bulb size was good in sub-irrigated container than in the fields.

Comparative assessment of different nutrient sources on growth, yield and nutrient uptake by onion (Allium cepa L.)

The present study was carried out on onion cv. Nasik Red in a randomized block design with three replications. The experiment comprised of nine treatments of different nutrient sources including organic manures and inorganic fertilizers. The effects of organic manures (farmyard manure, vermicompost and jeevamrut) alone and in conjugation with inorganic fertilizers on growth, nutrient uptake and yield of onion were studied. Integrated use of inorganic fertilizers and organic manure significantly influenced plant growth, yield and nutrient uptake by crop. The results showed that highest number (7.4) and length of leaves (36.6 cm), bulb size (19 cm2), NPK uptake (122.5, 16.7 and 67.4 kg ha−1, respectively) and biological yield (441.9 q ha−1) was recorded under T2 i.e., RDF + FYM @ 250 q ha−1. Increment in biological yield under T2 was 69.2% over control. Our results could provide a better understanding of the importance of inorganic fertilizers plus organic manure in maintaining soil fertility and thus enhancing nutrient uptake and crop production.

Determination of carbohydrate accumulation and plant growth dynamics in snowdrop (Galanthus elwesii Hook.) response to moisture levels in different substrates

In terms of botany, geophytes are known by their own survival strategy due to have a swollen storage organs. Snowdrops (Galanthus, 20 spp.; Amaryllidaceae) are important type of wild-sourced ornamental bulb genus in all geophyte species. Also, have a great deal of potential for use on landscape designs. Whereas, not much study has been done regarding the growth dynamics of snowdrops at harsh environmental conditions. This experiment was conducted to evaluate the effects of abiotic stress conditions on the performance of snowdrop (Galanthus elwesii Hook.) in soiless culture. Substrates and moisture were the variables. Peat + perlite and cocopeat were used as a substrate in pots. Moisture levels were applied; ML1, ML2 (well-watered and moderately tolerant treatments), ML3 (moderate stress) and ML4 (severe stress). Moisture had a statistically significant effect (P &lt; 0.05) on circumference size, height and weight of the snowdrop bulbs. Plant height and carbohydrate accumulation were also affected by moisture levels in different substrates. The correlation between total carbohydrate (r = 0.95) and starch (r = 0.98) were positively determined. The reduced sugar, total sugar, starch and total carbohydrate values were increased by the severe stress treatment (ML4).

Unilateral Choanal Atresia: Indications of Long-Term Olfactory Deficits and Volumetric Brain Changes Postsurgically

Background: Very few studies have investigated whether unilateral choanal atresia is associated with permanent olfactory deficits. Objective: This study aimed to evaluate the olfactory performance of patients with unilateral choanal atresia postsurgically. Methods: Three patients with unilateral atresia were examined in terms of olfactory performance with the Sniffin’ Sticks test (odor identification, threshold, and discrimination), size of the olfactory bulb, and volumetric brain changes. Results: All patients demonstrated significantly lower olfactory performance in terms of odor threshold on the same side with the choanal atresia. Grey matter reductions were found ipsilaterally in the hippocampus. Conclusions: This pilot study indicates that persistent olfactory deficits and volumetric brain changes are present in patients with unilateral choanal atresia.

Performance Evaluation of Onion Varieties at Biyo Awale Cluster in Diredawa Administration

Onion (Allium cepa L.) is an important crop worldwide. It is important in the daily Ethiopian diet. It is widely produced by small farmers and commercial growers throughout the year for local use and export market. No strong study has been conducted to evaluate the suitability of onion cultivation in Biyo Awale district of Diredawa. Hence, the present experiment was conducted to study the performance of improved varieties of onion for their suitability for cultivation in Biyo Awale district of Diredawa. The study was carried out during 2018-2019 cropping season to test the performance of onion varieties. Five high yielding onion varieties were planted in complete randomized block design experiment with three replications including local check at farmer’s field. The quantitative data on bulb yield, plant height, bulb size and number of leaves of onion varieties were collected. Harvesting was done and weighed when all onion varieties reach maturity (90% tops down). The results revealed that the tested onion varieties differ significantly for leaf length, leaf number, neck diameter, bulb diameter, average bulb weight and bulb yield. Among the varieties Bombay red and Melkam produced higher bulb yield (25.56 and 21.13 t ha -1 ) and gave 140.68% and 98.96% yield advantage over local check varieties, respectively. Therefore, Bombay Red and Melkam varieties were recommended to the study area and similar agro-ecology. Keywords: Bulb yield, Onion, Varieties DOI: 10.7176/ALST/90-01 Publication date: November 30 th 2021

Design, Analysis and Development of Digging and Roller Chain Conveying System for Self-Propelled Onion Harvester

Abstract: The history of Agriculture in India dates back to Indus Valley Civilisation. India ranks second worldwide in farm outputs. As of 2018, agriculture employed more than 50% of the Indian workforce and contributed 17–18% to the country's GDP. India has the largest net cropped area, followed by the US and China, yet mechanization in farming is comparatively low compared to developed countries. The lack of technological development and unaffordability of new and competent machines for the average farmer are the few of the reasons for this encumbrance. The development of the onion harvester intends that it will provide a reliable and affordable alternative to traditional farming practices. The digging and conveying systems are the integrated part of the onion harvester. The design of the blade and conveyor is made by using CATIA V5 and analysis of the parts are done using ANSYS Workbench. During design and analysis, severe factors are considered such as preventing the damage to onion bulbs, size of bulbs, soil condition, onion leaves at a predetermined height and roots of the crops to penetrate. This paper is intended to discuss the results of the design and analysis of the digging and conveying systems under the guidelines of the SAE TIFAN rulebook [1]. Keywords: Onion Harvester, Blade Design, Conveyor Design, FEA Analysis.

Seed bulb size influences the effects of exogenous brassinolide on yield and quality of Pinellia ternata.

In recent years, natural Pinellia ternata populations of have gradually been exhausted, while the cultivated yield has been limited due to lack of research and uncertain climate condition. Therefore, it is necessary to explore methods of improving yield and quality in P. ternata using brassinolide (BR) treatments and choice of a suitable seed bulb size. This article reports the effects of BR and two seed bulb sizes (diameter: 0.5-1.0 cm and 1.0-1.5 cm) on active and nutrient components and antioxidant activity in P. ternata. The experiment included six levels of BR (0, 0.05, 0.10, 0.50, 1.00 and 2.00 mg l-1 ). The tuber yield of the two seed bulb sizes and bulbil yield of small seed bulbs increased 5.67%, 22.66% and 69.23% by day 105 after 0.50 mg l-1 BR treatment, compared with the control. On day 105, only 0.05 mg l-1 BR increased scores in principal components analysis (PCA) in tubers of small seed bulbs by 167.29%, and 0.05 and 0.50 mg l-1 BR increased PCA score in bulbils of large seed bulbs by 145.66% and 252.97%, respectively, compared with the control. Significant BR × seed bulb size interactions were found on yield and quality of P. ternata. The results indicate that BR effects on yield and quality of tubers and bulbils of P. ternata are not only related to BR concentration but also to seed bulb size.

Response of vegetative and fruit growth to the soil volume wetted by irrigation in a super-high-density olive orchard

In most fruit tree orchards under localised irrigation, only a fraction of the rhizosphere is wetted by irrigation. As this may reduce growth and production, such that there is a demand for information on the optimum number and location of emitters. In a mature ‘Arbequina’ olive orchard with 1667 trees ha-1, we analysed the impact of applying the same amount of water with one vs. two drip irrigation pipes (laterals) per tree row. We had trees under full irrigation, for which irrigation supplies amounted to 80–100% of the crop water needs (ETc), and two deficit irrigation treatments supplying ca. 40% of ETc. We used the HYDRUS 2D/3D (v. 1.11) model to simulate the shape and volume of the fraction of the rhizosphere wetted by irrigation (irrigation bulbs), as well as drainage and soil evaporation. For both full irrigation and deficit irrigation, differences in the soil volume and the soil surface wetted by irrigation were not sufficient to affect drainage and soil evaporation. The greatest values of root length density and root surface per unit volume were found in trees under deficit irrigation with two laterals, and the lowest in fully irrigated trees with one lateral. This, however, was counterbalanced by both the greater size of the irrigation bulbs and the greater soil water contents in the bulbs of the fully irrigated trees, such that water uptake was not enhanced by the second lateral. For 2 consecutive years we found no impact of irrigating with one or two laterals per tree row on water potential and stomatal conductance, shoot and fruit growth, leaf area and production, either for full irrigation or deficit irrigation conditions. Therefore, our findings suggest no benefits of irrigating super high density olive orchards with two laterals instead of one.

Digest: New insight into sensory trade-off in phyllostomid bats.

Do the relative size of the olfactory bulb, cochlea, and orbit correlate with diet in phyllostomid bats? Hall et al. (2021) found that the degree of frugivory is positively correlated with the relative size of the olfactory bulb and the orbit. The degree of animalivory is negatively correlated with the relative size of the olfactory bulb and the orbit. Finally, the degree of nectarivory is negatively correlated with the relative size of the cochlea.

Composition and Dose of Ameliorant Against C/N Ratio, Soil pH, Plant Phosphate Content on Potato Plants

This article aims to study the addition of ameliorant material in the soil to increase fertility rates, especially for potato plants grown at the height of 750 m above sea level. The experiments were conducted on medium plains 750 m above sea level in the Jatinangor area, Indonesia, with land type Incepticol. The composition of ameliorant consists of Cattle manure, biochar from coconut shells, and dolomite. The seeds of the potatoes used are relatively good varietal when cultivated in a medium plain. The design of the environment used is the group’s random draft repeated three times, the treatment design consists of K0: control; K1: Cattle manure 10 Mg ha-1; K2: Cattle manure 20 Mg ha-1; K3: Cattle manure 8 Mg ha-1, dolomite 1 Mg ha-1, 1 Mg ha-1 biochar; K4: Cattle manure 16 Mg ha-1, dolomite 2 Mg ha-1, 2-Mg biochar ha-1, K5: Cattle manure 8 Mg ha-1, dolomite 2 Mg ha-1; K6: Cattle manure 16 Mg ha-1, dolomite 4 Mg ha-1; K7: Cattle manure 8 Mg ha-1, biochar 2 Mg ha-1; K8: Cattle manure 16 Mg ha-1, biochar 4 Mg ha-1. Results showed that the composition and dose of ameliorant could increase the value of soil pH but have not improved the C/N ratio and absorption of phosphorus plants. The best result was obtained from the composition treatment of 16 Mg ha-1 Cattle manure, 2 Mg ha-1 dolomite, and 2 Mg ha-1 biochar. Soil pH is capable of increased by 16.83%, and the size of the potato bulbs of Class L (450-550 mm) amounted to 35, 11%, size M (350-450 mm) by 25.89%, and size S (200-350 mm) amounting to 34.37% when compared with controls.

Composition and dose of ameliorant against C/N ratio, soil PH, plant phosphate content on potato plants

This article aims to learn the addition of ameliorant material on the ground so as to increase the level of soil fertility especially for the potato plants that are buenabled on the medium plains. The experiments were conducted on medium plains with a height of 750 m above sea level in Jatinangor area, Indonesia with land type Incepticol. The composition of ameliorant consists of chicken manure, coconut shells and dolomite biochar. The seeds of the potatoes used are relatively good varietal when cultivated in a medium plain. The design of the environment used is the group's random draft repeated 3 times, the treatment design consists of K 0 : control; K 1 : Cattle manure 10 ton ha -1 ; K 2 : Cattle manure 20 ton ha -1 ; K 3 : Cattle manure 8 tons ha -1 , dolomite 1 ton ha -1 , 1 ton ha -1 biochar; K 4 : Cattle manure 16 tons ha -1 , dolomite 2 ton ha -1 , 2 ton biochar ha -1 , K 5 : Cattle manure 8 tons ha -1 , dolomite 2 ton ha -1 ; K 6 : Cattle manure 16 ton ha -1 , dolomite 4 ton ha -1 ; K 7 : Cattle manure 8 tons ha -1 , biochar 2 ton ha -1 ; K 8 : Cattle manure 16 ton ha -1 , biochar 4 ton ha -1 . Results showed that the composition and dose of ameliorant able to increase the value of soil pH, but have not been able to improve the C/N ratio and absorption of phosphorus plants. Best result obtained from the treatment of Cattle manure composition 16 ton ha-1, dolomite 2 ton ha-1, 2 ton ha-1 biochar. Soil pH is capable of increased by 16.83% and the size of the potato bulbs of Class L (450-550 mm) amounted to 35, 11%, size M (350-450 mm) by 25.89% and size S (200-350 mm) amounting to 34.37% when compared with controls

The influence of land management and date of planting on physical properties of Safid e Pai-saye onion (Allium cepa L.)

Onion botanically named Allium cepa L. is a major crop of Alliaceae family. It is one of the largest commercially grown vegetables in the world including Afghanistan. This crop originated from Afghanistan and large number of its wild varieties are observed in the country. Local variety named Safid e Paisaye was selected for this investigation due to its capacity of longer storage and higher demand in the market. Very less research efforts are made to improve its bulb quality and share in the market. This investigation is carried out at Kabul university agriculture research farm in coordination with Amity University Uttar Pradesh, to study the effect of land management and planting date on bulb physical properties of onion. The parameters studied in this investigation include bulb width (cm), length (cm), thickness (cm), geometric mean diameter, arithmetic mean diameter, shape index, sphericity, roundness, ellipsoid ratio, frontal surface, cross sectional area, total area, number of scales, equatorial firmness (Kg/cm2) and polar firmness (Kg/cm2). The data is collected using required tools and was analyzed using R statistical analysis software. The results showed significant effect of planting date on physical properties of onion bulb. The first planting date (10th May) recorded the largest bulb width (6.95 cm), length (4.42 cm), thickness (6.75 cm), geometric mean diameter (5.91 cm), arithmetic mean diameter (6.04 cm), frontal surface (24.26 cm2), cross sectional area (28.84 cm2) and total area (110.63 cm2). The same planting date recorded the lowest values for bulb shape index (0.64) and sphericity (0.85). Land management practices did not have significant effect on physical properties of onion bulb. None of the studied factors had significant effect on bulb roundness, ellipsoid ratio, number of scales, equatorial firmness and polar firmness. Conclusions: early planting of Safid e Paisaye onion seedlings can increase bulb size and improve bulb physical characteristics. This also helps to maintain the flat and round shape of onion bulb. Land preparation method and plough depth do not have significant influence on physical properties of onion bulb.

Scaling and Structural Properties of Juvenile Bull Kelp (Nereocystis luetkeana).

SynopsisBull kelp (Nereocystis luetkeana), the only canopy-forming kelp in the Salish Sea, provides primary production in the nearshore subtidal environment and serves as an important habitat for economically and ecologically important species. An annual species, each year juvenile bull kelp sporophytes must grow from the hydrodynamically more benign benthos to the water column, where they experience substantial drag at the surface. Because of the differences in morphology and ecology across life stages, and the fact that previous work has focused mainly on adult bull kelp, we tested whether morphology and structural properties change with stipe length, investigating scaling of both juvenile (stipe length < 40 cm) and mature (stipe length > 40 cm) kelp, and testing how juvenile stipes fail. Juvenile bull kelp grow proportionally (isometric growth) when young, but lengthen more quickly than would be predicted by bulb size (negative allometry) at maturity. Based on our data, the predicted breakpoint between isometric and allometric growth occurred at about 33 cm, likely approximately one to two weeks of growth. Cross-sectional area of the stipe, force to failure, work to failure, and stiffness (Young's modulus) all grow more slowly than would be predicted based on length, while maximum stress and toughness increase more quickly than predicted. There is no change in extensibility over the size range we tested, suggesting that this material property does not change with stipe length. The differences in biomechanics between juvenile and adult kelp are likely a response to the varied hydrodynamic environments experienced during the annual life cycle, which highlights the importance of studying organisms across life stages.