Chondrilla juncea in Australia. 3. Seed maturity and other factors affecting germination and establishment

1970 ◽  
Vol 10 (42) ◽  
pp. 62 ◽  
Author(s):  
EG Cuthbertson
Keyword(s):  
Soil Type ◽  
Moisture Stress ◽  
Wagga Wagga ◽  
Factors Affecting ◽  
Rate Of Spread ◽  
South Wales ◽  
Short Period ◽  
The Relationship ◽  
Mature Seeds ◽  
Chondrilla Juncea

The relationship between seed colour and viability and also the effect of seed age, moisture stress, depth of seed burial, and soil type on the germination of skeleton weed (Chondrilla juncea L.) were studied at Wagga Wagga, New South Wales. As the developing seeds matured their colour changed from greenish-white through yellow to yellow-brown or olive-green. Some 25 per cent of the yellow seeds were capable of germination but then only for a short period after shedding. Fully coloured, mature seeds showed 80 to 90 per cent germination capacity and remained viable for two to three years when stored in open containers. A few samples were dormant for about 12 weeks but the majority germinated rapidly when ample moisture was available. Germination was delayed and decreased with increasing water stress. Soil type had no apparent effect on germination but emergence was inversely related to depth of planting. There was no emergence from below 13 mm (1/2 inch) in heavy clays or 38 mm (19 inches) in other soils. Surface sown seeds did not establish readily on compacted surfaces, emphasizing the importance of the cultivated fallow in increasing the rate of spread.

Chondrilla juncea L. in Australia. I. Some factors affecting flowering

1966 ◽  
Vol 17 (4) ◽  
pp. 457 ◽  
Author(s):  
EG Cuthbertson
Keyword(s):  
Dark Period ◽  
Critical Factor ◽  
Photoperiodic Response ◽  
Day Length ◽  
Floral Initiation ◽  
Factors Affecting ◽  
Two Stages ◽  
Relationship Of ◽  
The Relationship ◽  
Chondrilla Juncea

The interaction between day length and vernalization, and the influence of growth temperature on flowering, in Chondrilla juncea L. (skeleton weed) have been studied. Bolting and floral initiation in unvernalized plants were suppressed in a 9-hr photoperiod. Increasing the photoperiod beyond 12 hr resulted in progressively earlier bolting and floral initiation, the critical day length being slightly less than 12 hr. Interrupting a 16-hr dark period by 1 hr of low-intensity light near its centre caused some plants to flower. Prior vernalization further accelerated bolting and flowering and reduced the dependence on day length. Vernalization, however, was not an obligate requirement. Post-bolting development was favoured by high temperatures. It was concluded that flowering in skeleton weed occurred in two stages. The first or photo-inductive phase was controlled by at least two partial processes. These were vernalization and a photoperiodic response in which the length of the dark period was the critical factor. The relationship of the flowering processes to the distribution of skeleton weed in Australia is discussed briefly.

Factors influencing the soil-test calibration for Colwell P and wheat under winter-dominant rainfall

2020 ◽  
Vol 71 (2) ◽  
pp. 113
Author(s):  
Mark Conyers ◽  
Richard Bell ◽  
Michael Bell
Keyword(s):  
Soil Type ◽  
Wheat Yield ◽  
Sowing Date ◽  
Soil Test ◽  
Soil Tests ◽  
Factors Affecting ◽  
Soil P ◽  
Critical Range ◽  
South Wales ◽  
Dry Conditions

Critical ranges for soil tests are based on results that inevitably involve some broad variance around the fitted relationship. Some of the variation is related to field-based factors affecting crop response to nutrients in the soil and some to the efficiency of the soil-test extractant itself. Most attempts to improve soil tests focus on the extractant, whereas here, we explore the variation that could be accounted for by field-based factors in the soil-test calibration relationship between Colwell phosphorus (P) and wheat yield, using the Australian Better Fertiliser Decisions for Crops database—the biggest dataset available for this relationship. Calibrations developed from this dataset have been criticised, and so we aimed to explore factors accounting for more of the variation in the relationships for the dryland, winter-dominant rainfall region of southern New South Wales. As reported previously, soil type was shown to influence the critical range and r-value for the Colwell P soil-test calibration for P responses by wheat. We also identified a tendency for dry conditions, at sowing or during the season, to lower relative yields for a given soil-test value, indicating increased reliance on fertiliser P over soil P. A similar trend was evident for later sowing date, again suggesting an increased probability of crop P requirements being met from the fertiliser P. However, additional records need to be generated to establish definitively that early sowing or subsurface P reserves minimise response to fertiliser P. In general, factors that influence crop access to soil P will have an impact on response to fertiliser P. Although this analysis shows that it is possible to ‘tighten’ the response curve for Colwell P and wheat by restricting the data for a given soil type to ideal management and seasonal conditions, the ‘outliers’ that are excluded frequently reflect an important subset of environmental conditions encountered by wheat crops in dryland agriculture.

Agricultural drought analyses for temperate Australia using a biophysical pasture model. 2. Relationship between rainfall and the start and end of predicted droughts

2008 ◽  
Vol 59 (11) ◽  
pp. 1061 ◽  
Author(s):  
G. M. Lodge ◽  
I. R. Johnson
Keyword(s):  
New South ◽  
Summer Rainfall ◽  
Growing Season ◽  
Agricultural Drought ◽  
Wagga Wagga ◽  
Climate Data ◽  
Winter Rainfall ◽  
Rainfall Occurrence ◽  
South Wales ◽  
The Relationship

This paper reports relationships between predicted soil water content (SWC) on the first day of the month (SWCFOM, mm of water) and previous monthly rainfall for 100 years of daily climate data (1905–2005) at four sites (Albany, Western Australia; Hamilton, Victoria; and Wagga Wagga and Barraba, New South Wales). Overall, predicted SWCFOM was correlated (P < 0.05) with rainfall in the previous one, two, or three months. However, the proportion of variation in SWCFOM that could be attributed to its regression on previous rainfall was variable and the relationship tended to improve when individual months were examined. At the three winter-rainfall sites (Albany, Hamilton, and Wagga Wagga), there was a reasonably good relationship between the start of a predicted drought and the end of the growing season and also between the end of a predicted drought and the occurrence of break-of-season. However, for the summer-rainfall dominant site at Barraba, rainfall occurrence was less seasonally defined and there was no clear relationship. While analysis of historical rainfall data for the months in which predicted agricultural droughts started or ended provided some useful insights, it was concluded that it would probably be more instructive to model SWC outcomes for a range of future rainfall scenarios and then examine their likelihood of occurrence using rainfall percentiles.

Chondrilla juncea in Australia. 4. Root morphology and regeneration from root fragments

1972 ◽  
Vol 12 (58) ◽  
pp. 528 ◽  
Author(s):  
EG Cuthbertson
Keyword(s):  
Root System ◽  
Soil Type ◽  
Vegetative Reproduction ◽  
Clay Content ◽  
Lateral Spread ◽  
Wagga Wagga ◽  
Regenerative Capacity ◽  
Shoot Bud ◽  
Shoot Production ◽  
Chondrilla Juncea

The morphology of the root system of Chondrilla juncea and its response to changes in soil type near Wagga Wagga, New South Wales, is described. The root system is described as consisting of vigorous long roots capable of vegetative reproduction at any depth and short roots, apparently without secondary thickening, of limited life span. The long root system consists of a simple tap root and a number of surface laterals, which increase in frequency and extent of lateral spread as soil clay content decreases. The relationship between plant age, growth stage, and depth of origin, as well as depth of planting and soil type, on shoot production from root fragments also was studied. Root fragments from depths to 80 cm and more did not differ appreciably in regenerative capacity. But, whereas shoot buds formed on some seedling roots two to four weeks after germination, all such roots formed buds five weeks after germination. Soil type and depth of planting did not affect shoot production from root fragments per s e, but establishment of new plants fell as depth of planting increased. A comparison of vegetative and reproductive plant roots of similar age showed that regenerative capacity was minimal during the reproductive growth phase. The inhibition of shoot bud formation on the roots, however, was confined to the proximal 40 cm. It is suggested that weed control operations are likely to be more effective when carried out shortly after stem initiation than at other times.

The number of employed as a macroeconomic indicator of working time dynamics

2020 ◽  
Vol 16 (5) ◽  
pp. 935-945
Author(s):  
I.A. Zaikova
Keyword(s):  
Comparative Analysis ◽  
Manufacturing Sector ◽  
Working Hours ◽  
Working Time ◽  
Labor Costs ◽  
Factors Affecting ◽  
Time Dynamics ◽  
Developed Economies ◽  
The Relationship ◽  
Macroeconomic Indicator

Subject. The working time of workers at any stage of economic development is a value reflecting the level of labor productivity. Any progress in productivity contributes to changes in the volume of labor costs and the number of employed. Depending on the relationship between the total volume of labor costs and the number of employed, the duration of working time per one worker may change (it may increase, decrease, or remain unchanged). Objectives. The study aims to confirm the importance of such a macroeconomic indicator as the number of employed in varying working hours. Methods. The study rests on the comparative analysis of countries with developed economies based on some indicators like dynamics of the working time fund, dynamics of the number of employed, average number of hours worked during the year per employee, etc. The analyzed timespan is 25 years (from 1991 to 2016). Results. The comparative analysis revealed that in the non-production sphere and the economy as a whole the macroeconomic determinants correlate so that the length of working time per worker reduces. When considering the analysis results for the manufacturing sector, no single trend was identified. Conclusions. One of the key factors affecting the change in working hours is the number of employed. The relationship between the working time fund and the number of employed directly determines the dynamics of working time per worker.

Examination of Conditions for the Determination of Carbamate Pesticides in Soils

1992 ◽  
Vol 57 (8) ◽  
pp. 1632-1638 ◽  
Author(s):  
Věra Tatarkovičová ◽  
Zdeněk Stránský
Keyword(s):  
Activated Carbon ◽  
Solvent Extraction ◽  
Soil Type ◽  
Extraction Procedure ◽  
Purification Procedure ◽  
Factors Affecting ◽  
Carbamate Pesticides ◽  
Rp Hplc ◽  
Extracting Solvent

The procedure for the determination of carbamate pesticides in soil was optimized. The following factors affecting the final results were investigated: extracting solvent, extraction procedure, extract purification procedure, and soil type. Triple extraction with acetone and purification of the extract on a two-stage purification column containing an activated carbon-silica gel 1+1 mixture were found optimal. The extracts after treatment were analyzed by RP-HPLC with UV detection. The method developed allows carbamate pesticides in soil to be determined at concentrations in excess of 30 μg kg-1.

scholarly journals The Mediating Effect of Marital Intimacy on the Relationship between Spouse-Related Stress and Prenatal Depression in Pregnant Couples: An Actor–Partner Interdependent Model Test

2021 ◽  
Vol 18 (2) ◽  
pp. 487
Author(s):  
Miyoung Lee ◽  
Yeon-Suk Kim ◽  
Mi-Kyoung Lee
Keyword(s):  
Mediating Effect ◽  
Prenatal Depression ◽  
Mediating Effects ◽  
Factors Affecting ◽  
Marital Intimacy ◽  
Paternal Factors ◽  
Two Cities ◽  
Related Stress ◽  
The Relationship ◽  
Structured Questionnaire

Prenatal depression is an important factor in predicting postpartum depression. Most studies have assessed factors affecting prenatal depression by focusing on pregnant wives. However, the emotional and psychological aspects of both expectant parents need to be considered. Therefore, the purpose of this study was to examine the effect of spouse-related stress in expectant couples on prenatal depression and investigate the mediating effects of marital intimacy on this relationship. A total of 120 expectant couples from two cities in Korea at more than 15 weeks of completed pregnancy participated in the study. Using a structured questionnaire, we assessed the general characteristics of the participants, spouse-related stress, prenatal depression, and marital intimacy. The results revealed that four actor effects and one partner effect were significant. Marital intimacy and prenatal depression among expectant parents were affected by spouse-related stress. Moreover, spouse-related stress in the husbands completely mediated marital intimacy in pregnant wives, demonstrating partner effects on prenatal depression in pregnant wives. Therefore, it was observed that paternal factors affect prenatal depression in pregnant wives. This warrants the inclusion of husbands in marital interventions and strategies to improve marital intimacy in pregnant wives.

scholarly journals A Quantitative Analysis of Factors Influencing Organic Matter Concentration in the Topsoil of Black Soil in Northeast China Based on Spatial Heterogeneous Patterns

2021 ◽  
Vol 10 (5) ◽  
pp. 348
Author(s):  
Zhenbo Du ◽  
Bingbo Gao ◽  
Cong Ou ◽  
Zhenrong Du ◽  
Jianyu Yang ◽  
...  
Keyword(s):  
Land Use ◽  
Organic Matter ◽  
Soil Erosion ◽  
Soil Type ◽  
Northeast China ◽  
Black Soil ◽  
Factors Affecting ◽  
Soil Zone ◽  
Rainfed Farming ◽  
Study Results

Black soil is fertile, abundant with organic matter (OM) and is exceptional for farming. The black soil zone in northeast China is the third-largest black soil zone globally and produces a quarter of China’s commodity grain. However, the soil organic matter (SOM) in this zone is declining, and the quality of cultivated land is falling off rapidly due to overexploitation and unsustainable management practices. To help develop an integrated protection strategy for black soil, this study aimed to identify the primary factors contributing to SOM degradation. The geographic detector, which can detect both linear and nonlinear relationships and the interactions based on spatial heterogeneous patterns, was used to quantitatively analyze the natural and anthropogenic factors affecting SOM concentration in northeast China. In descending order, the nine factors affecting SOM are temperature, gross domestic product (GDP), elevation, population, soil type, precipitation, soil erosion, land use, and geomorphology. The influence of all factors is significant, and the interaction of any two factors enhances their impact. The SOM concentration decreases with increased temperature, population, soil erosion, elevation and terrain undulation. SOM rises with increased precipitation, initially decreases with increasing GDP but then increases, and varies by soil type and land use. Conclusions about detailed impacts are presented in this paper. For example, wind erosion has a more significant effect than water erosion, and irrigated land has a lower SOM content than dry land. Based on the study results, protection measures, including conservation tillage, farmland shelterbelts, cross-slope ridges, terraces, and rainfed farming are recommended. The conversion of high-quality farmland to non-farm uses should be prohibited.

scholarly journals Comparison of the sensitivity of Western blotting between PVDF and NC membranes

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yufang Xiang ◽  
Yuanyuan Zheng ◽  
Shaobo Liu ◽  
Gang Liu ◽  
Zhi Li ◽  
...  
Keyword(s):  
Western Blotting ◽  
Polyvinylidene Fluoride ◽  
Staining Intensity ◽  
Detection Sensitivity ◽  
Key Factors ◽  
Post Translational Modifications ◽  
Factors Affecting ◽  
Molecular Weights ◽  
Direct Blue ◽  
The Relationship

AbstractWestern blotting (WB) is one of the most widely used techniques to identify proteins as well as post translational modifications of proteins. The selection of electroblotted membrane is one of the key factors affecting the detection sensitivity of the protein which is transferred from gel to membrane in WB. The most common used membranes are polyvinylidene fluoride (PVDF) and nitrocellulose (NC) membranes. Which membrane of these two is more suitable for WB has not been reported so far. Here, by incubating proteins which were transferred to PVDF or NC membranes with a series of antibodies and different types of lectins, we investigated the relationship between the binding ability of these two membranes to proteins or glycoproteins and the molecular weight of the target protein. The antibody re-probed ability of the two membranes was also explored. Moreover, we verified the above results by directly incubating proteins having different molecular weights onto PVDF or NC membranes. Bound proteins were stained with direct blue-71, and the staining intensity was quantitated by scanning and densitometry.

scholarly journals The Influence of Pre-Procedural Imaging and Cystic Duct Cholangiography on Endoscopic Transpapillary Gallbladder Drainage in Acute Cholecystitis

Diagnostics ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1286
Author(s):  
Junya Sato ◽  
Kazunari Nakahara ◽  
Yosuke Michikawa ◽  
Ryo Morita ◽  
Keigo Suetani ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Acute Cholecystitis ◽  
Cystic Duct ◽  
Magnetic Resonance Cholangiopancreatography ◽  
Procedure Time ◽  
Technical Success ◽  
Factors Affecting ◽  
Gallbladder Drainage ◽  
Procedural Evaluation ◽  
The Relationship

Endoscopic transpapillary gallbladder drainage (ETGBD) for acute cholecystitis is challenging. We evaluated the influence of pre-procedural imaging and cystic duct cholangiography on ETGBD. Patients who underwent ETGBD for acute cholecystitis were retrospectively examined. The rate of gallbladder contrast on cholangiography, the accuracy of cystic duct direction and location by computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP), and the relationship between pre-procedural imaging and the technical success of ETGBD were investigated. A total of 145 patients were enrolled in this study. Gallbladder contrast on cholangiography was observed in 29 patients. The accuracy of cystic duct direction and location (proximal or distal, right or left, and cranial or caudal) by CT were, respectively, 79%, 60%, and 58% by CT and 68%, 55%, and 58% by MRCP. Patients showing gallbladder contrast on cholangiography underwent ETGBD with a significantly shorter procedure time and a lower rate of cystic duct injury. No other factors affecting procedure time, technical success, and cystic duct injury were identified. Pre-procedural evaluation of cystic duct direction and location by CT or MRCP was difficult in patients with acute cholecystitis. Patients who showed gallbladder contrast on cholangiography showed a shorter procedure time and a lower rate of cystic duct injury.

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