Bulb Size Research Articles

Influence of paclobutrazol and bulb sizes on seed yield and yield attributing traits of onion (Allium cepa L) cv Taherpuri

Different doses of paclobutrazol (PBZ) and different bulb sizes of onion were evaluated to determine their effect on growth and seed production of onion. Onion variety ‘Taherpuri’ with three-bulb sizes – small, medium and large – was used. Four doses of PBZ were 0 (control), 20, 40, and 80 mg l−1. The two-factor experiment was laid out in a randomized complete block design with three replications. Application of PBZ significantly reduced the plant height, tillers per bulb, leaves per plant and length of scape. However, in other parameters such as the number of flowers, umbels per bulb, umbel diameter, 1000-seed weight and seed yield, there were no significant influences of PBZ concentrations used (p < 0.05). On the contrary, plant height, number of leaves per plant, length of scape, effective fruits per umbel, percentage of fruit set, and seed yield were positively influenced by different bulb sizes of onion. Higher values were obtained for the above-mentioned parameters from the larger-sized bulbs and values were decreased as the bulb sizes decreased. The maximum seed yield was recorded in plants grown from the large-sized mother bulb. The interaction between the PBZ doses and bulb sizes were also significant for some variables while it was not significant for others.

Effect of environmental factors and bulb mass on the invasive geophyte Oxalis pes-caprae development

Oxalis pes-caprae is an invasive pseudoannual plant that reproduces exclusively via offspring bulbs in the introduced range. It is most abundant in disturbed, fertile sites such as agricultural fields, but it is also found in undisturbed shrublands and shadier forest habitats. Oxalis infestation depends on long distance bulb dispersal (mainly anthropogenic) and on the ability of bulbs to grow and reproduce successfully. We conducted a greenhouse experiment to test the effects of parent bulb size on Oxalis growth and offspring production as a function of light availability (ambient and shade), planting depth (surface vs. 9 cm deep), and soil volume (full pots and pots with reduced soil volume). Oxalis grew and reproduced prolifically in all treatments. However, plant development and final offspring bulb production were sensitive to environmental conditions. Shading and reduced soil volume reduced maximum plant biomass relative to control and planting depth treatments, which produced either higher number of offspring bulbs (control) or larger offspring bulbs and higher total offspring bulb biomass (planting depth). Parent bulb size and vegetative reproductive organs had little effect on plant growth and offspring production. Our results are consistent with the lower abundance of Oxalis in undisturbed soils and shadier habitats in the field but indicate that even in these marginal habitats Oxalis can reproduce prolifically and contribute to further spread.

Morphological and Histochemical Study of the Nasal Cavity and Fused Olfactory Bulb of the Brown-Eared Bulbul,Hysipetes amaurotis

The brown-eared bulbul (Hysipetes amaurotis) is commonly found in Japan where it is regarded as a harmful bird that causes damage to agricultural products. Few studies have investigated the sensory apparatus of this bird, and consequently little is known of the sensory modalities it uses. Here we analyzed the anatomical and histological properties of the nasal cavity and olfactory bulb (OB) of the bulbul in order to investigate the functional level of olfaction in this species. Although both anterior and maxillary conchae were observed in the bulbul nasal cavity, there was no structure equivalent to the posterior concha. The OB located on the ventral side of the anterior extremity of the cerebrum and the ratio of olfactory bulb size to that of the cerebral hemisphere were very small. Interestingly, the left and right OBs were completely fused at the midline of the cerebrum. Furthermore, certain types of lectins that bind to the olfactory nerve of vertebrates with a well-developed sense of smell also bound positively to the olfactory nerve and glomerular layers of the bulbul OB. These findings suggest that the brown-eared bulbul has an anatomically and functionally less well developed sense of smell compared to other avian species. Although the molecular and developmental mechanisms underlying the fusion of the OB remain unknown, we suggest that the fused OB may offer a unique model for studying the evolution and development of the central olfactory nervous system in vertebrates.

Rapid somatic expansion causes the brain to lag behind: the case of the brain and behavior of New Zealand's Haast's Eagle (Harpagornis moorei)

ABSTRACT New Zealand's late Pleistocene and Holocene Haast's eagle (Harpagornis moorei) was the sole predator of the moa (Aves: Dinornithiformes) and the largest eagle so far described. Recent molecular evidence has hypothesised that it evolved from a much smaller Asian/Australian eagle within the past 1.8 my. Osteometry and high-resolution spiral computed tomography of skeletal remains of Haast's eagle were used to determine morphological and functionally significant characteristics of the central and peripheral nervous system and sensory apparatuses and to test these against hypotheses about behavior and evolution based on molecular and external morphology. Compared with other accipitrids, Haast's eagle had a proportionally low endocranial volume for its body weight. There was no anatomical evidence to support the significant use of olfaction by Haast's eagle, as the olfactory bulb size and cross-sectional area of the olfactory nerve foramen were no larger than would be expected for Accipitridae of this body weight. Both the size of the neural canal at the cervicothoracic junction and the brachial spinal quotient (ratio of neural canal area at cervicothoracic and caudal thoracic levels) were low, suggesting that the spinal cord at brachial levels was also small. These data are consistent with the hypothesis that Harpagornis had evolved to large size from a smaller ancestor and that the ancestors of Haast's eagle appear to have undergone rapid expansion of body size and elements of the hindlimb somatic nervous system at the expense of enlargement of the brain and visual, olfactory, and vestibular apparatuses.

New Insights Into the Brain, Braincase, and Ear Region of Tyrannosaurs (Dinosauria, Theropoda), with Implications for Sensory Organization and Behavior

The braincase region of tyrannosaurs was investigated to provide insights on anatomical attributes relevant to inferences of sensory biology and behavior. CT scanning focused on three specimens of Tyrannosaurus rex, a juvenile Gorgosaurus, and the controversial Cleveland skull (CMNH 7541). Analysis shows that the cerebral hemispheres were enlarged, but conflicting information on the optic lobes suggests that brain conformation was not fully avian. Previous estimates of olfactory bulb size for T. rex were much too large, but even the corrected sizes are relatively larger than other theropods, suggesting that odor detection was indeed of particular importance to tyrannosaurs. The inner ears show a number of coelurosaurian traits, such as elongate and rounded and rostral, lateral semicircular canals, and incipient twisting of the common crus, which we interpret to be related to enhanced reflexes coordinating rapid eye and head movements. The cochlea is elongate, which, coupled with the finding of extensive tympanic pneumaticity, supports the inference of behavioral emphasis of low-frequency sounds. Three main groups of sinuses pneumatized the braincase, and there are a number of perhaps systematically relevant differences. Orientation of the endosseous labyrinth reveals that alert head postures of T. rex and Gorgosaurus were somewhat depressed below the horizontal, but the Cleveland skull had a very strongly down-turned posture. It is concluded that tyrannosaur sensory biology is consistent with their predatory coelurosaurian heritage, with emphasis on relatively quick, coordinated eye and head movements, and probably sensitive low-frequency hearing; tyrannosaurs apomorphically enhanced their olfactory apparatus. The taxonomic status of the Cleveland skull remains unresolved.

Effect of bulb weight on the growth and flowering of Herbertia lahue subsp. lahue (Iridaceae)

P. Morales, F. Schiappacasse, P. Penailillo, and P. Yanez. 2009. Effect of bulb weight on growth and fl owering of Herbertia lahue subsp. lahue (Iridaceae). Cien. Inv. Agr. 36(2):259266. Bulb weight or size is one of the critical factors affecting the vegetative growth and fl owering of bulbous species. This study assessed the effect of bulb weight on the growth and fl owering of Herbertia lahue subsp. lahue. This bulbous species, commonly known as “lahue,” has the potential to be used as an ornamental plant. Lahue bulbs were collected during their dormant period from Tregualemu (Region del Maule), grouped by weight categories and planted in Talca in an unheated polyethylene greenhouse. Phenology data, fl owering characteristics and the number of newly formed bulbs were recorded for one season. Plants emerged 2-3 weeks after planting and fl owered during the spring, between 8 and 9 months after planting. During fruit set, the leaves began their senescence process and reached dormancy during the summer. Lahue behaved as a typical geophyte adapted to a seasonal climate such as the Mediterranean climate of Central Chile. Bulbs weighing 0.35 g or more were able to fl ower. However, bulbs greater than 0.75 g produced more and better quality fl owers. The average multiplication rate of the bulbs was 1-1.13 bulblets per planted bulb, regardless of the bulb weight; there was no correlation between multiplication rate and bulb weight. This study demonstrated that it is possible to grow lahue as a pot plant or garden plant and that the size of the bulb will determine if fl owering can be achieved.

Effect of bulb size on selected morphological characteristics of seed stalks, seed yield and quality of onion (Allium cepa L.) seeds

Abstract In the years 2002 − 2004 research was carried out on the effect of onion (Allium cepa L.) ‘Wolska’ bulb size on selected morphological characteristics of seed stalks, seed yield and quality. Commercial bulbs (vernalised, one-year-old mother bulbs) were divided into three groups: small, medium and large, with diameters of 4.2-5.3 cm, 5.4-6.3 cm and 6.4-8.5 cm, respectively. Then, the bulbs of each group were planted in the field and grown routinely with the purpose of producing seeds. The following characters were measured on the seed stalks: number and height of seed stalks grown out from one bulb, the seed stalks’ diameter at the height of 10 cm above the ground, the diameter of the inflorescence, seed yield from a single stalk and from the entire plant, the weight of 1000 seeds, number of seeds in 1 g, length and width of the seeds, length and width of the embryos, and germination energy and capacity. Our experiments showed a significant influence of bulb size on the number of seed stalks and the inflorescence diameter. It was discovered that the big bulbs gave larger numbers of seed stalks than the seed stalks grown from the medium and small ones. Small bulbs gave seed stalks with smaller inflorescences than the medium and large ones. The bulb size had no effect on the seed stalk height or their diameter when measured at the level of 10 cm above the ground. The bulb size also did not affect seed yield per one seed stalk, but it did affect the seed yield obtained from the entire plant, which was bigger for plants grown from large bulbs in comparison with the small ones. The size of the bulbs had no effect on either the weight of 1000 seeds or the number of seeds in 1 g. It did not affect either the seed and embryo length and width or the seed germination energy and capacity.

Crucial role for Ser133-phosphorylated form of cyclic AMP-responsive element binding protein signaling in the differentiation and survival of neural progenitors under chronic cerebral hypoperfusion

Various stimuli, such as ischemia/hypoxia enhance newborn cell survival in the subventricular zone and their migration tangentially in chains toward the olfactory bulb. The present study assessed the fate of newborn neurons from subventricular zone to olfactory bulb under conditions of chronic cerebral hypoperfusion, and examined the role of cAMP-responsive element binding protein signaling on the survival of these neurons by using cilostazol, a potent inhibitor of type III phosphodiesterase. Rats underwent bilateral common carotid artery ligation. They were divided into sham-operated (n=70), vehicle- (n=70), and type III phosphodiesterase inhibitor–treated (n=70) groups. Immunohistochemically-stained section for 5-bromodeoxyuridine and a series of neuronal and glial markers were analyzed at days 7, 14, 21 and 28 after hypoperfusion. The reduction of olfactory bulb size gradually progressed in the vehicle group ( P<0.05), but not in the sham-operated and type III phosphodiesterase inhibitor-treated group. The subventricular zone of the vehicle-treated rats contained significantly larger numbers of newborn neuroblasts after hypoperfusion, compared with sham-operated rats ( P<0.05), but significantly lower numbers in the rostral migratory stream and olfactory bulb ( P<0.05). Treatment of rats with type III phosphodiesterase inhibitor increased the number of neuroblasts and enhanced the survival and differentiation of cells ( P<0.05). Phosphorylated cAMP-responsive element binding protein within neuroblasts was markedly decreased in the subventricular zone, rostral migratory stream, and olfactory bulb of vehicle-treated rats ( P<0.05), but treatment with type III phosphodiesterase inhibitor resulted in recovery of this expression throughout hypoperfusion, leading to enhanced neurogenesis ( P<0.05). These effects were abrogated by protein kinase A and C inhibitor. Our results indicated that cAMP-responsive element binding protein signaling is a key mediator of neurogenesis after prolonged hypoperfusion and provide the basis for new regenerative therapies for ischemic brain injury.

SOME FACTORS AFFECTING ARTIFICIAL CURING OF ONION BULBS AND ITS EFFECTS ON THE STORABILITY

This research aimed to study some factors affecting the artificial curing of onion bulbs and its effects on the storability of bulbs in terms of (total soluble solids TSS and onion storage losses) comparing with the conventional curing method in Egypt. The study also aimed to determine the influence of different levels of maturity stages (harvesting time), about of 20, 30, 40% and 50 % tops down and bulb sizes (large, medium and small) on the change in the bulbs moisture content and the time required for complete curing. The obtained results showed that, during field curing, the bulbs moisture content decreased gradually from initial moisture of 87-90 % ±0.5% (w.b) to a final level of 81.5 % ±0.5% (w.b) after 16 day (384 h). At maturity stages of 20, 30, 40, and 50 % of tops down, the results revealed that, curing of onion bulbs artificially can reduce the required time of curing by about 68.8, 71.9, 75 and 81.3 % for large size of bulbs, and by 71.9, 75, 78 and 81.3 for medium and small size of bulbs, compared with traditional curing method of bulbs (control treatment). The results also showed that artificial curing of bulbs at 20, 30, 40, and 50% of tops down, may save the time required for curing bulbs comparing to traditional curing method of onion bulbs, that in turn increase the available time for preparing the land of the next crop (maize, rice and cotton crops; and other summer vegetable crops) by about 13, 13.5, 14 and 15 day when curing large size of bulbs, while it save about 13.5, 14, 14.5 and 15 day when curing medium and small size of bulbs. The storability of onion bulbs improved with about of 12.73 % for bulbs harvested at 40 and 50 % tops down, while it was 12.44 % for bulbs harvested at 30 % tops down comparing with traditional curing.

A Resistance Reduction Study of a Trimaran using Waterline Parabolization

Waterline parabolization or addition of side bulbs about the ship's midbody can significantly reduce the wave-making resistance of a vessel [Calisal, S. M., Goren, O., and Danisman, D. B., 2002 Resistance reduction by increased beam for displacement-type ships, Journal of Ship Research, 46, 3, 208–213]. These side bulbs are designed to create a wave pattern that interacts with the ship wave system of the hull at the desired speed range. This concept was first successfully tested on a coaster tanker and then extended to the UBC series hull, a series typical of Canadian West Coast fishing vessels. Systematic tow tank experiments revealed that while parabolization decreases the total resistance, the form factor suffered an increase. An integral boundary layer solver and a 2D RANS solver both showed that the increase in viscous resistance was mainly caused by an increase in form drag or viscous pressure drag. The parabolization concept was subsequently extended to a high-speed NPL trimaran to determine whether resistance reduction using parabolic side bulbs could be achieved for a very slender multihull vessel. A Rankine source panel method was used to predict the wave-making characteristics of the trimaran, and an integral boundary layer solver and a RANS solver were used to calculate the viscous drag. A parametric study, varying the size and location of bulbs, was first performed on the center hull to design the side bulb. The study was then extended to the trimaran to evaluate the additional wave interactions caused by the outriggers. Experimental model tests validated the numerically predicted wave interactions, as well as the change in viscous drag. Based on the numerical work, a modified NPL trimaran hull form was designed that reduced the total resistance of the vessel by up to 6% in the design speed range and providing critical additional engine or accommodation space.

Nutrient content and yield in relation to top breakover in onion developed from greenhouse‐grown transplants

AbstractBACKGROUND: Onions (Allium cepa L.) generally are harvested based on percentage of tops broken over. Since plant metabolism changes over time, percentage of tops broken over may be used to determine a harvest time to deliver marketable bulbs with the best nutrient content.RESULTS: The cultivars Candy and Texas Grano 1015 Y were harvested at 10%, 20%, 30%, 40% and 50% breakover in 2006 and 2007. Larger and heavier bulbs were produced by Candy and in 2006, the year with near‐normal precipitation. There was little difference in bulb size and weight due to percent breakover. Contents of chemical moieties in bulbs were affected by year, with the majority of values being higher in 2006, and there were either no differences due to cultivar, or where differences were found nitrate‐N, phosphate and sulfate contents were lower in Candy. Soluble solids content was lower in 2006 and higher in Candy. Content of nitrogen and phosphorous in a Kjeldahl digest, nitrate‐N, phosphate, potassium and sulfate were either linearly or quadratically distributed over percent breakover. Nitrite‐N, calcium, magnesium, sodium and soluble solids were randomly distributed over percent breakover. Bulb size and weight did not change from the 20% breakover point, and most of the chemical moieties analyzed, with the exception of nitrate‐ and nitrite‐N values, were highest below the 30% breakover.CONCLUSION: Harvest occurring soon after breakover begins could be beneficial in terms of nutrient content without loss of bulb size or weight. Copyright © 2009 Society of Chemical Industry

Olfactory sensitivity for alkylpyrazines—a comparative study in CD‐1 mice and spider monkeys

Using a conditioning paradigm, the olfactory sensitivity of four CD-1 mice for six alkylpyrazines was investigated. With all six stimuli, the animals discriminated concentrations <or=0.1 ppm (parts per million) from the odorless solvent, and with three of the six stimuli the animals were even able to detect concentrations <or=0.1 ppb (parts per billion). Four spider monkeys tested in parallel were found to detect five of the same six stimuli at concentrations <1 ppm and with one stimulus they were able to discriminate concentrations <1 ppb from the solvent. The results showed CD-1 mice to be more sensitive than spider monkeys with five of the six alkylpyrazines tested. There was a significant positive correlation between sensitivity and the number of alkyl groups attached to the pyrazine (Pyr) ring in both species. A comparison of the detection thresholds obtained here to those obtained in human subjects suggests that neither the number of functional olfactory receptor genes nor the absolute or the relative size of the olfactory bulbs reliably predict a species' olfactory sensitivity. These threshold data may provide useful information for the choice of adequate stimulus concentrations in electrophysiological or imaging studies of the olfactory system or investigations of the discriminative abilities of mice and spider monkeys.

Yield Performance of Four Onion (&lt;i&gt;Allium Cepa&lt;/i&gt; L.) Varieties Compared with the Local Variety under Open Field Conditions at Anse Boileau, Seychelles

A field experiment was conducted from April to September, 2005 and 2006 planting seasons at the Vegetable Evaluation and Research Station Farm located at Anse Boileau, Seychelles to evaluate the yield performance of four onion varieties, ‘Onion Orient\', ‘Lucy 15205\', ‘CAL 606\', and ‘Red Creole-2\' against the commonly grown variety ‘Red Creole-1\' under field conditions. The experiment consisted of five treatments laid out in a randomized complete block design with four replications. The results obtained showed that while variety ‘Onion Orient\' was the earliest to maturity, variety ‘CAL 606\' recorded the highest number of leaves, bulb size, biological bulb weight, economic bulb weight, dry bulb weight and best yield which were significantly (P≤0.05) increased by 34.6 %, 23.9 %, 16.8 %, 28.6 %, 35.0 % and 33.9 % respectively in 2005 and 40.0 %, 25.1 %, 10.9 %, 23.6 %, 30.0 % and 28.9 % respectively in 2006 compared to those obtained from the regular variety ‘Red Creole-1\'. Similarly, the yield produced from varieties ‘Onion Orient\', ‘Lucy 15205\' and ‘Red Creole-2\' was significantly (P≤0.05) increased by 9.8 %, 15.1 % and 28.8 % respectively in 2005 and 5.36 %, 6.19 % and 25.6 % respectively in 2006 compared to that obtained from ‘Red Creole-1\'. The yield of ‘CAL 606\' was the greatest, followed by ‘Red Creole-2\', ‘Lucy 15205\', ‘Onion Orient\' and ‘Red Creole-1\' respectively. The implication of this study, showed that variety ‘CAL 606\' performed best and could therefore be recommended as a potential replacement for the popular variety ‘Red Creole-1\' in Seychelles. Keywords : onion varieties, yield Journal of Science & Technology (Ghana) Vol. 28 (3) 2008: pp. 28-33

Patterns of post-fire flowering and fruiting in Chlorogalum pomeridianum var. pomeridianum (DC.) Kunth in southern California chaparral

For many geophytes living in Mediterranean ecosystems, the passage of fire can produce bursts of flowering, seed production, vegetative growth, and seedling recruitment. In the present study, we investigated patterns of flowering and fruit production of the chaparral geophyte Chlorogalum pomeridianum (common soap plant) at two sites: one burned in a prescribed fire and one in nearby unburned chaparral. Both sites burned in a wildfire 2 years later, and we continued monitoring marked plants for an additional 6 years, enabling us to observe the effects of recent reburning on reproduction and growth. We found that flowering was stimulated by fire but was not strictly fire-dependent. There was a positive relationship between bulb size and leaf area, as well as between these two characteristics and flower and fruit production. Flower stalk initiation occurred when plants reached a minimum leaf area of ~1000 cm2, indicating that a minimum bulb size must be reached before reproductive effort is initiated. Direct herbivory of flowering stalks reduced fruiting and leaf herbivory indirectly prevented the initiation of flowering stalks. In the first several years after fire, flower and fruit production could be explained by resource matching but in subsequent years, resource matching was replaced by resource switching.

Molecular and biochemical identification of alien chromosome additions in shallot (Allium cepa L. Aggregatum group) carrying extra chromosome(s) of bunching onion (A. fistulosum L.)

To develop the bunching onion (Allium fistulosum L.; genomes, FF) chromosome-specific genetic markers for identifying extra chromosomes, eight shallot (A. cepa L. Aggregatum group; genomes, AA)--A. fistulosum monosomic addition plants (AA+nF) and 62 shallot--A. fistulosum single-alien deletion plants (AAF-nF) were analyzed by 23 different chromosome-specific genetic markers of shallot. The eight monosomic addition plants consisted of one AA+2F, two AA+6F, and five AA+8F. Of the 62 single-alien deletion plants, 60 could be identified as six different single-alien deletion lines (AAF-1F, -3F, -4F, -6F, -7F, and -8F) out of the eight possible types. Several single-alien deletion lines were classified on the basis of leaf and bulb characteristics. AAF-8F had the largest number of expanded leaves of five deletion plants. AAF-7F grew most vigorously, as expressed by its long leaf blade and biggest bulb size. AAF-4F had very small bulbs. AAF-7F and AAF-8F had different bulbs from those of shallot as well as other types of single-alien deletion lines in skin and outer scale color. Regarding the sugar content of the bulb tissues, the single-alien deletion lines showed higher fructan content than shallot. Moreover, shallot could not produce fructan with degree of polymerization (DP) 12 or higher, although the single-alien deletion lines showed DP 20 or higher. The content of S-alk(en)yl-L-cysteine sulfoxide (ACSO) in the single-alien deletion lines was significantly lower than that in shallot. These results indicated that chromosomes from A. fistulosum might carry anonymous factors to increase the highly polymerized fructan production and inhibit the synthesis of ACSO in shallot bulbs. Accordingly, alien chromosomes from A. fistulosum in shallot would contribute to modify the quality of shallot bulbs.

Avian olfactory receptor gene repertoires: evidence for a well-developed sense of smell in birds?

Among vertebrates, the sense of smell is mediated by olfactory receptors (ORs) expressed in sensory neurons within the olfactory epithelium. Comparative genomic studies suggest that the olfactory acuity of mammalian species correlates positively with both the total number and the proportion of functional OR genes encoded in their genomes. In contrast to mammals, avian olfaction is poorly understood, with birds widely regarded as relying primarily on visual and auditory inputs. Here, we show that in nine bird species from seven orders (blue tit, Cyanistes caeruleus; black coucal, Centropus grillii; brown kiwi, Apteryx australis; canary, Serinus canaria; galah, Eolophus roseicapillus; red jungle fowl, Gallus gallus; kakapo, Strigops habroptilus; mallard, Anas platyrhynchos; snow petrel, Pagodroma nivea), the majority of amplified OR sequences are predicted to be from potentially functional genes. This finding is somewhat surprising as one previous report suggested that the majority of OR genes in an avian (red jungle fowl) genomic sequence are non-functional pseudogenes. We also show that it is not the estimated proportion of potentially functional OR genes, but rather the estimated total number of OR genes that correlates positively with relative olfactory bulb size, an anatomical correlate of olfactory capability. We further demonstrate that all the nine bird genomes examined encode OR genes belonging to a large gene clade, termed γ-c, the expansion of which appears to be a shared characteristic of class Aves. In summary, our findings suggest that olfaction in birds may be a more important sense than generally believed.

Homology of the “ethmoid complex” of tyrannosaurids and its implications for the reconstruction of the olfactory apparatus of non-avian theropods

ABSTRACT The “ethmoid complex” is an enigmatic element of the anterior portion of the braincase first described in Tyrannosaurus rex in 1912, which has since been recognized in many non-avian theropods. Because the “ethmoid complex” is a landmark for the reconstruction of the olfactory apparatus of non-avian theropods, we clarify the homology of this structure among archosaurs. The “ethmoid complex” consists of a trough-shaped element that is attached to an anteriorly-located median septum capped by a dorsal plate. Based on anatomical comparisons with the olfactory region of extant birds and crocodylians, the components of the “ethmoid complex” are shown to have cartilaginous or osteological homologues among extant archosaurs: the trough is homologous to the anterior portion of the planum supraseptale of crocodylians and embryonic birds, whereas the median septum and overlying dorsal plate are homologous to the avian mesethmoid and to the nasal septum and tectum nasi of crocodylians. Based on the location and ossification of olfactory region structures in non-avian theropods, the most appropriate terms for elements of the “ethmoid complex” are the sphenethmoid for the trough and the mesethmoid for the median septum and dorsal plate. The olfactory bulbs of nonavian theropods were housed within the sphenethmoid, which restricted the maximum size of the olfactory bulbs to a size smaller than the cerebral hemispheres.

Impact of Corn Gluten Meal Applications on Spring-Transplanted Onion Injury and Yields

Research to determine the relative benefits among alternative herbicides for weed control in onions (Allium cepa L.) should focus on weed control efficacy, and the impact of herbicides on crop injury, and the resulting weed competition on crop yields. Herbicide injury and weed competition can produce disproportionate reductions in onion yields as a result of onion's slow growth rate, short height, non-branching plant structure, low leaf area, and shallow root system. Field research was conducted in 2002 and 2003 in southeast Oklahoma (Lane, OK) to determine crop safety and yield response of selected pre-emergent synthetic herbicides and corn gluten meal (CGM) on spring-transplanted onion, cv. Hybrid Yellow Granex PRR, production. There were 21 treatments [12 synthetic herbicide treatments, five CGM applications, a full-season weed-free (hand-weeded) treatment, a full-season weedy-check, a partial-season weed-free (weed-free for the first half of the growing season by handweeding, then the weeds were allowed to grow), and a weedy-check without onions]. Synthetic herbicide treatments included pendimethalin applications at 0.5, 1.0, and 1.5 kg·ha−1 ai, oxyfluorfen at 0.1, 0.2, and 0.3 kg·ha−1 ai, and also tank-mixed at these three levels. In addition, the highest rate of each herbi-cide-pendimethalin (1.5 kg·ha−1 ai), oxyfluorfen (0.3 kg·ha−1 ai), and the tank mix of pendimethalin (1.5 kg·ha−1 ai) plus oxyfluorfen (0.3 kg·ha−1 ai)-were applied and kept weed-free by hand to determine the crop safety of these herbicides. CGM was applied at 1,000,2,000,3,000, and 4,000 kg·ha−1. A weed-free (hand-weeded) treatment was also combined with the highest CGM rate (4,000 kg·ha−1) to determine the effect of the CGM on crop injury and growth. Visual crop injury ratings were collected at 3, 5, 10, 20, and 30 days after planting, along with yields of marketable bulbs segregated by size. No phytotoxic symptoms or yield reductions were observed due to the synthetic herbicides or CGM applications. These compounds provided sufficient crop safety when applied at the rates studied. Increased weed competition caused a shift in bulb size distribution across the four bulb categories (colossal, large, medium, and small), resulting in a decreased number of colossal and large bulbs and an increase in small bulbs. Although the synthetic herbicides and CGM provided crop safety, and to some extent early weed control, reductions in crop yields as a result of weed competition demonstrated the need to include supplemental weed control with post-emergence herbicides or other weed control methods to produce maximum onion yields.

MODEL TESTS ON VERTICAL BEARING PERFORMANCE OF ENLARGED BASE BULB OF BURIED NODULAR PILES

A series of vertical load tests are performed on model piles with enlarged base bulb embedded in a medium dense sand filled in a soil chamber of 1000mm diameter. The model pile used is a nodular pile consisting of 114mm diameter double steel tubes with two nodes around the outer tube. The effects of the size and shape of the base bulb are investigated to find the behavior of the vertical load transfer and the fracture patter of the base bulbs. Detail measurement of strain gauges on the pile shaft show that the load share by parts of the pile varies with the increase of the settlement. The fracture pattern of the bulbs excavated after load tests explains well the measured load settlement characteristics.

Farklı Soğan Kesme Yöntemlerinin Fritillaria persica L.'nın Bazı Özellikleri Üzerine Etkisi

Fritillaria persica L. Türkiye’den üretimi yapılarak ihraç edilen türlerden birisi olup, vejetatif veya generatif yolla çoğaltılabilmektedir. Generatif çoğaltmada soğanların ihraç edilebilir boya gelmesi için 4-6 yıl gerekirken; vejetatif çoğaltmada ise çoğalma süresi daha kısa olmaktadır. Bu araştırma 2003-2005 yıllarında Ankara Üniversitesi Ziraat Fakültesi Tarla Bitkileri Bölümü Deneme Tarlasında yürütülmüştür. Denemede, bir bıçak yardımıyla, soğanın tamamı kesilmeksizin farklı kesme şekilleri ile hazırlanan, a) kontrol (kesilmemiş), b) alt kısmından ortasına kadar dikey olarak kesilmiş, c) üst kısmından orta kısmına kadar dikey kesilmiş, d) taban kısmı daire şeklinde derince çizilmiş ve e) alt taban kısmı oyularak çıkartılmış Fritillaria persica L. soğanları kullanılmıştır. Soğanlar 30x30 cm sıra arası ve sıra üzeri mesafe olacak şekilde 3 sıra halinde ve her sırada 7’şer soğan olacak şekilde tesadüf blokları deneme desenine göre 3 tekrarlamalı olarak dikilmişlerdir. Denemede bitki boyu, çiçeklenme oranı, çiçek salkım uzunluğu, meyve bağlama oranı, meyve sayısı, bitki başına soğan sayısı ve soğan verimi gibi karakterler ölçülmüştür. Soğan kesme yöntemlerinin bitki başına soğan sayısına ve soğan verimine etkili olduğu bulunmuştur.