Emergence and development of Russian wild ryegrass seedlings as influenced by seed source, seed mass, and seeding depth in an artificial medium

1995 ◽  
Vol 75 (1) ◽  
pp. 167-170 ◽  
Author(s):  
W. E. Limbach ◽  
C. A. Call
Keyword(s):  
Regression Models ◽  
Seedling Emergence ◽  
Seed Mass ◽  
Seed Source ◽  
Rooting Depth ◽  
Artificial Medium ◽  
Psathyrostachys Juncea ◽  
Seedling Biomass ◽  
Multiple Regression Models ◽  
Length Data

Seedling emergence, seedling biomass, and root lengths of Russian wild ryegrass seedlings were analyzed with respect to seed source, seed mass, seeding depth, and harvest. Multiple regression models containing these factors were statistically significant predictors of the log-transformed seedling biomass and root length data (DF = 9, Fbiomass = 1763.67, Froot = 949.33, and P < 0.0001 for both variables). The effects of seed mass, seeding depth, and harvest were significantly related to the dependent measures while the effect of seed source was not significant. Seedling emergence from suboptimal seeding depths was significantly greater for heavy seeds than for light seeds (χ = 14.076, DF = 7, P < 0.0001). Key words: Fritted clay, Psathyrostachys juncea (Fisch.) Nevski, rooting depth, Russian wild ryegrass, seed size, Syn-A, Vinall

Germination and seedling establishment in cashew (Anacardium occidentale L.): An interaction between seed size, relative growth rate and seedling biomass

2017 ◽  
Vol 45 (2) ◽  
pp. 110
Author(s):  
Babli Mog, J.D. Adiga M.G. Nayak and G.S. Mohana
Keyword(s):  
Leaf Area ◽  
Seed Size ◽  
Seedling Establishment ◽  
Seedling Survival ◽  
Seedling Emergence ◽  
Seed Mass ◽  
Germination Percentage ◽  
Mass Ratio ◽  
Unit Leaf ◽  
Seedling Biomass

<p>Seeds of cashew were used to determine the effect of seed mass (5.2 to 7.8 g) on germination, seedling emergence and growth<br />under nursery conditions. Germination percentage and germination time showed significant correlation with seed mass. Large<br />sized seeds had higher germination percentage (81.6%) and produced more vigorous seedlings. Per cent seedling emergence was<br />related to seed mass with large sized seeds exhibited faster emergence. Seed mass significantly affected seedling survival and<br />survival rate was high in seedlings arising from large sized seeds (62.9%). Seedling vigor expressed in terms of shoot and root<br />length, leaf number, leaf area and total dry matter was significantly affected by seed mass. Seedlings that emerged from large sized<br />seeds showed better growth and produced heavier seedlings as compared to medium sized seeds. RGR showed significant variation<br />(0.152 to 0.240 g g-1day-1) among two seed size classes positively correlated with seed mass, leaf area (LA), unit leaf rate per unit<br />leaf area (ULRM), root to shoot ratio (R/S) and root mass ratio (RMR) and negatively with stem mass ratio (SMR). The study<br />concluded that the seed mass and RGR have influence on seedling growth and success of seedling establishment in cashew.</p>

Adaptation of Pinuscontorta populations to heterogeneous environments in northern Idaho

1983 ◽  
Vol 13 (3) ◽  
pp. 405-411 ◽  
Author(s):  
G. E. Rehfeldt
Keyword(s):  
Genetic Variation ◽  
Multiple Regression ◽  
Regression Models ◽  
Leaf Length ◽  
Seed Source ◽  
Freezing Injury ◽  
Quadratic Model ◽  
Heterogeneous Environments ◽  
Multiple Regression Models ◽  
Northern Idaho

Genetic variation among 28 lodgepole pine (Pinuscontorta Dougl.) populations from northern Idaho was studied in three contrasting environments. Populations were located within 55 km of the Priest River Experimental Forest where 4-year-old seedlings were compared in environments at 750, 1200, and 1500 m elevation. Statistical analyses of six variables (4-year height, leaf length, freezing injury, multiple whorls, lammas growth, and adjusted height) detected differentiation among populations. Multiple regression models related adaptive differentiation to geographic and ecologic characteristics of the seed source. Elevation of the seed source, represented in a quadratic model, accounted for as much as 86% of the variance among populations. Results were used to estimate the limits and consequences of elevational transfers of seed.

scholarly journals 242 Effect of trucking distance on sale price of beef calf and feeder cattle lots sold through video auctions from 2010 through 2018

2020 ◽  
Vol 98 (Supplement_3) ◽  
pp. 10-11
Author(s):  
Esther D McCabe ◽  
Mike E King ◽  
Karol E Fike ◽  
Maggie J Smith ◽  
Glenn M Rogers ◽  
...  
Keyword(s):  
Multiple Regression ◽  
Regression Models ◽  
Average Weight ◽  
Sale Price ◽  
Feeder Cattle ◽  
A Value ◽  
Multiple Regression Models ◽  
Determine Effect

Abstract The objective was to determine effect of trucking distance on sale price of beef calf and feeder cattle lots sold through Superior Livestock Video Auctions from 2010 through 2018. Data analyzed were collected from 211 livestock video auctions. There were 42,043 beef calf lots and 19,680 feeder cattle lots used in these analyses. Six states (Colorado, Iowa, Kansas, Nebraska, Oklahoma, and Texas) of delivery comprised 70% of calf lots and 83% of feeder cattle lots and were used in these analyses. All lot characteristics that could be accurately quantified or categorized were used to develop multiple regression models that evaluated effects of independent factors using backwards selection. A value of P &lt; 0.05 was used to maintain a factor in the final models. Based upon reported state of origin and state of delivery, lots were categorized into one of the following trucking distance categories: 1) Within-State, 2) Short-Haul, 3) Medium-Haul, and 4) Long-Haul. Average weight and number of calves in lots analyzed was 259.2 ± 38.4 kg BW and 100.6 ± 74.3 head, respectively. Average weight and number of feeder cattle in lots analyzed was 358.4 ± 34.3 kg BW and 110.6 ± 104.1 head, respectively. Beef calf lots hauled Within-State sold for more ($169.24/45.36 kg; P &lt; 0.0001) than other trucking distance categories (Table 1). Long-Haul calf lots sold for the lowest (P &lt; 0.0001) price ($166.70/45.36 kg). Within-State and Short-Haul feeder cattle lots sold for the greatest (P &lt; 0.0001) price ($149.96 and $149.81/45.36 kg, respectively; Table 2). Long-Haul feeder cattle lots sold for the lowest (P &lt; 0.0001) price, $148.43/45.36 kg. These results indicate there is a price advantage for lots expected to be hauled shorter distances, likely because of cost and risk associated with transportation.

scholarly journals Characterization of Ultra-Thin Diamond-Like Carbon Films by SEM/EDX

Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 729
Author(s):  
Chanida Puttichaem ◽  
Guilherme P. Souza ◽  
Kurt C. Ruthe ◽  
Kittipong Chainok
Keyword(s):  
Regression Models ◽  
Hard Disk Drives ◽  
Carbon Films ◽  
Diamond Like Carbon ◽  
Disk Drives ◽  
Cross Sectional ◽  
Protective Films ◽  
High Throughput Method ◽  
Multiple Regression Models

A novel, high throughput method to characterize the chemistry of ultra-thin diamond-like carbon films is discussed. The method uses surface sensitive SEM/EDX to provide substrate-specific, semi-quantitative silicon nitride/DLC stack composition of protective films extensively used in the hard disk drives industry and at Angstrom-level. SEM/EDX output is correlated to TEM to provide direct, gauge-capable film thickness information using multiple regression models that make predictions based on film constituents. The best model uses the N/Si ratio in the films, instead of separate Si and N contributions. Topography of substrate/film after undergoing wear is correlatively and compositionally described based on chemical changes detected via the SEM/EDX method without the need for tedious cross-sectional workflows. Wear track regions of the substrate have a film depleted of carbon, as well as Si and N in the most severe cases, also revealing iron oxide formation. Analysis of film composition variations around industry-level thicknesses reveals a complex interplay between oxygen, silicon and nitrogen, which has been reflected mathematically in the regression models, as well as used to provide valuable insights into the as-deposited physics of the film.

Seasonal cycles in germination and seedling emergence of summer and winter populations of catchweed bedstraw (Galium aparine) and wild mustard (Brassica kaber)

Weed Science ◽  
2006 ◽  
Vol 54 (1) ◽  
pp. 114-120 ◽  
Author(s):  
Husrev Mennan ◽  
Mathieu Ngouajio
Keyword(s):  
Soil Depth ◽  
Cropping Systems ◽  
Seedling Emergence ◽  
Seed Mass ◽  
Soil Surface ◽  
Burial Depth ◽  
Galium Aparine ◽  
Wild Mustard ◽  
Seed Population ◽  
Brassica Kaber

Catchweed bedstraw and wild mustard each produce two populations per year: a winter population (WP) in June, and a summer population (SP) in September. Experiments were conducted to determine whether the WP and SP differ in seed mass and seasonal germination. Seeds of both weeds were buried at 0, 5, 10, and 20 cm in cultivated fields, and retrieved at monthly intervals for 24 mo for germination tests in the laboratory. Additionally, seedling emergence from seeds buried at 0, 5, and 10 cm in the field was evaluated for 1 yr. Seeds from the WP were heavier than those from the SP for both species. Germination of exhumed seeds was affected by burial depth and by seed population. It was highest for seeds that remained on the soil surface and declined with increasing depth of burial. The WP of catchweed bedstraw produced two germination peaks per year, whereas the SP and all populations of wild mustard had only one peak. The WP of both weeds germinated earlier than the SP. Seedling emergence for both species in the field was greater for the WP than for the SP. Increasing soil depth reduced seedling emergence of both the WP and SP of wild mustard and affected only the WP of catchweed bedstraw. We conclude that the WP and SP of catchweed bedstraw and wild mustard seeds used in this study differed in seed mass, seasonal germination, and seedling emergence. The ability of a WP to produce large seeds that germinate early and have two germination peaks per year could make these populations a serious problem in cropping systems.

Mapping genetic variation and seed zones for Bromus carinatus in the Blue Mountains of eastern Oregon, USAIn this article, mention of companies or trade names does not constitute an endorsement of any product or procedure.

Botany ◽  
2010 ◽  
Vol 88 (8) ◽  
pp. 725-736 ◽  
Author(s):  
R. C. Johnson ◽  
Vicky J. Erickson ◽  
Nancy L. Mandel ◽  
J. Bradley St Clair ◽  
Kenneth W. Vance-Borland
Keyword(s):  
Environmental Variables ◽  
Regression Models ◽  
Plant Traits ◽  
Seed Source ◽  
Maximum Temperature ◽  
Blue Mountains ◽  
Seed Transfer ◽  
Bromus Carinatus ◽  
Seed Zones ◽  
Transfer Zones

Seed transfer zones ensure that germplasm selected for restoration is suitable and sustainable in diverse environments. In this study, seed zones were developed for mountain brome ( Bromus carinatus Hook. & Arn.) in the Blue Mountains of northeastern Oregon and adjoining Washington. Plants from 148 Blue Mountain seed source locations were evaluated in common-garden studies at two contrasting test sites. Data on phenology, morphology, and production were collected over two growing seasons. Plant traits varied significantly and were frequently correlated with annual precipitation and annual maximum temperature at seed source locations (P < 0.05). Plants from warmer locations generally had higher dry matter production, longer leaves, wider crowns, denser foliage, and greater plant height than those from cooler locations. Regression models of environmental variables with the first two principal components (PC 1 and PC 2) explained 46% and 40% of the total variation, respectively. Maps of PC 1 and PC 2 generally corresponded to elevation, temperature, and precipitation gradients. The regression models developed from PC 1 and PC 2 and environmental variables were used to map seed transfer zones. These maps will be useful in selecting mountain brome seed sources for habitat restoration in the Blue Mountains.

Multiple regression models for predicting total daily pollen concentration in Cartagena

Grana ◽  
2005 ◽  
Vol 44 (2) ◽  
pp. 108-114 ◽  
Author(s):  
José Manuel Angosto ◽  
Stella Moreno‐Grau ◽  
Javier Bayo ◽  
Belén Elvira‐Rendueles
Keyword(s):  
Multiple Regression ◽  
Regression Models ◽  
Pollen Concentration ◽  
Multiple Regression Models ◽  
Daily Pollen Concentration

The Effects of Prepaid Metering Systems on Customer Satisfaction in Niger State, Nigeria

2021 ◽  
Vol 2 (2) ◽  
Author(s):  
Ayooluwa Femi Aribisala ◽  
Musa Mohammed
Keyword(s):  
Customer Satisfaction ◽  
Regression Models ◽  
Response Rate ◽  
Spearman Correlation ◽  
Electricity Use ◽  
Customer Care ◽  
Level Of Satisfaction ◽  
Multiple Regression Models ◽  
The Relationship ◽  
Structured Questionnaire

Energy consumers in Nigeria have long complained about Distribution Companies' unfair billing practices, exorbitant monthly electricity bills resulting from meter estimation rather than accurate meter reading and calculation based on uninterrupted electricity use. The objectives of the study were to establish the relationship between the prepaid metering system and customer satisfaction; and to evaluate the level of satisfaction with respect to the usage of the prepaid metering system in Niger State, Nigeria. In carrying out the study, the structured questionnaire was administered to 393 randomly chosen respondents drawn from prepaid meter users, out of which 344 responded generating a response rate of 87.5%. The data derived were subjected to spearman correlation and multiple regression models. The major findings from the study showed a significant, moderate and positive relationship between the prepaid metering system and customer satisfaction. Additionally, three significant predictors, Affordability, Availability and Flexibility with p < .01 are statistically significant. Further findings from descriptive statistics revealed that users had the highest level of satisfaction with the privacy they had as a result of no meter readers and no accumulated. The study concluded that there exist a positive and beneficial link between the prepaid metering system and customer satisfaction. The study therefore recommends the provision of a smart metering system, good customer care units and a marketing campaign for better knowledge of the prepaid metering system.

scholarly journals New Algorithms for L1 Norm Regression

2019 ◽  
Vol 1 (1) ◽  
pp. 1-18
Author(s):  
Bijan Bidabad
Keyword(s):  
Linear Regression ◽  
Regression Models ◽  
Simple Linear Regression ◽  
L1 Norm ◽  
Median Problem ◽  
Regression Parameters ◽  
Multiple Regression Models ◽  
Weighted Median ◽  
Weighted Median Problem ◽  
New Algorithms

In this paper, we propose four algorithms for L1 norm computation of regression parameters, where two of them are more efficient for simple and multiple regression models.  However, we start with restricted simple linear regression and corresponding derivation and computation of the weighted median problem. In this respect, a computing function is coded.  With discussion on the m parameters model, we continue to expand the algorithm to include unrestricted simple linear regression, and two crude and efficient algorithms are proposed. The procedures are then generalized to the m parameters model by presenting two new algorithms, where the algorithm 4 is selected as more efficient. Various properties of these algorithms are discussed.

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