More on comparing means, the analysis of variance and the F-test

2018 ◽  
pp. 143-150
Author(s):  
D.G. Rees
Keyword(s):  
Analysis Of Variance ◽  
F Test

scholarly journals Tolerance of Annual Winter Species to Protoporfirinogen Oxidase Inhibiting Herbicides (Protox)

2018 ◽  
Vol 36 (0) ◽  
Author(s):  
C. ALVES ◽  
L. GALON ◽  
R.R. KAIZER ◽  
F.L. WINTER ◽  
C.M. HOLZ ◽  
...  
Keyword(s):  
Leaf Area ◽  
Plant Species ◽  
Analysis Of Variance ◽  
Dry Matter ◽  
Stem Diameter ◽  
F Test ◽  
Tolerant Species ◽  
Randomized Design ◽  
Completely Randomized Design ◽  
Linear Regressions

ABSTRACT: The use of plant species for the phytoremediation of soils contaminated with herbicides is an alternative that has been emphasized to minimize the effects of the persistence of agrochemicals in the environment. The objective of this study was to evaluate the tolerance potential of winter species in soils contaminated with sulfentrazone and fomesafen. The experiment was in a completely randomized design with four replications. Doses of fomesafen (0.0, 0.125, 0.250, and 0.5 kg ha-1) and sulfentrazone (0.0, 0.3, 0.6 and 1.2 kg ha-1) were applied during the pre-emergence of phytoremediate species (black oat, vetch, birdsfood trefoil, radish and lupin). Forty five days after the emergence of the species, the phytotoxicity (%), leaf area (cm2), stalk and/or stem diameter (mm), height (cm) and dry matter (g) variables of the plants were evaluated. Data were submitted to analysis of variance by F test; when significant, linear or non linear regressions were applied to evaluate the effect of herbicide doses on the studied species. Birdsfood trefoil was the less tolerant species to fomesafen and sulfentrazone. Black oat was less affected by the application of fomesafen doses, but it was highly susceptible to sulfentrazone. Radish presented tolerance only up to the fomesafen dose of 0.25 kg ha-1; as for sulfentrazone, the species showed tolerance. The most tolerant species to fomesafen and sulfentrazone, regardless of the dose, was the lupine, which is a possible alternative for the phytoremediation of soils contaminated with these herbicides.

scholarly journals Effect of Applied Treatments on Growth Performance of three Cultivated Medicinal Plants of Kaski District, Nepal

2014 ◽  
Vol 2 (1) ◽  
pp. 31-40
Author(s):  
YP Timilsina ◽  
YP Tripathee
Keyword(s):  
Medicinal Plants ◽  
Growth Performance ◽  
Analysis Of Variance ◽  
Interdisciplinary Studies ◽  
F Test ◽  
Average Growth ◽  
Growth Performances ◽  
Open Treatment ◽  
Natural Climate

This research explores the growth performance of three potential medicinal plants namely, Bajradanti (Potentilla flugens), Chutro (Breberisaristata), and Timur (Xanthoxylumarmatum) cultivated at nursery of Institute of Forestry with the application of tunnel, shaded and open beds treatment each with 4.0 m x 1.0 m size and constant supportive facilities of manure, irrigation and care. From the measurement of ten months growth performance, B. Aristata and X. armatum showed their better growth in open bed than shed and tunnel beds, unlike P. Flugens showed better performance in shed bed. The average growth performances per month of P. fulgens and X. armatum vary significantly with respect to applied treatments (p<0.05) but converse in the case of B. aristata when using parametric F- test based on one way analysis of variance. Determined contribution of open treatment for growth performance per month in the species indicates that natural climate is tolerable as well as favorable for thorny types of medicinal plants than that of others. DOI: http://dx.doi.org/10.3126/ctbijis.v2i1.10811 Crossing the Border: International Journal of Interdisciplinary Studies Vol.2(1) 2014: 31-40

Parametric Alternatives to the Analysis of Variance

1982 ◽  
Vol 7 (3) ◽  
pp. 207-214 ◽  
Author(s):  
Jennifer J. Clinch ◽  
H. J. Keselman
Keyword(s):  
Monte Carlo ◽  
Analysis Of Variance ◽  
Monte Carlo Methods ◽  
Type I Error ◽  
Type I ◽  
Test Statistic ◽  
F Test ◽  
Assumption Violations ◽  
Mean Equality

The ANOVA, Welch, and Brown and Forsyth tests for mean equality were compared using Monte Carlo methods. The tests’ rates of Type I error and power were examined when populations were non-normal, variances were heterogeneous, and group sizes were unequal. The ANOVA F test was most affected by the assumption violations. The test proposed by Brown and Forsyth appeared, on the average, to be the “best” test statistic for testing an omnibus hypothesis of mean equality.

scholarly journals Control of Dichelops melacanthus with insecticides associated with sulphur applied in different times in corn

2017 ◽  
Vol 10 (1) ◽  
pp. 67
Author(s):  
J. C. Guerreiro ◽  
G. B. Silva ◽  
A. P. Azevedo ◽  
R. R. Espessato ◽  
A. T. Padovan ◽  
...  
Keyword(s):  
Experimental Design ◽  
Analysis Of Variance ◽  
Initial Phase ◽  
Stink Bug ◽  
Stink Bugs ◽  
F Test ◽  
Visual Evaluation ◽  
Corn Crop ◽  
Important Pest

The stink bug Dichelops melacanthus has become an important pest for corn crop and it has been causing several losses even in the initial phase of the crop. The objective of the experiment was the evaluation of effectiveness of the insecticides on the control of D. melacanthus in corn by adding of sulfur or not, in different control times. In order to evaluate the effect of the insecticide by adding or not sulfur on the control of D. melacanthus, 17 treatments with 4 different insecticides (with and without sulfur, in two different control times plus control) were used to get the results. The experimental design used was the randomized blocks, with four repetitions. The evaluation of effectiveness on stink bugs control was gotten by visual evaluation of the symptoms at 6, 13 and 20 days after emergence (DAE). Analysis of variance by F test (Anova) was done and the averages compared through Scott-knott test (p≤0,05). The pulverization of insecticides was more effective when it was done 4 (DAE), reducing the symptoms and injuries occasioned by the stink bug D. melacanthus and the mortality of damaged plants. The insecticide bifentrina+carbosulfano showed the higher effectiveness on stink bug control. To conclude, the use of sulfur associated to insecticides did not present a significant effect.

On the Non-Null Distribution of Anova F-Ratio in One Way Unbalanced Random Model

1987 ◽  
Vol 36 (1-2) ◽  
pp. 57-62 ◽  
Author(s):  
B. Singh
Keyword(s):  
Analysis Of Variance ◽  
Laguerre Polynomial ◽  
Null Distribution ◽  
Random Model ◽  
F Test ◽  
Practical Applications ◽  
Power Of The Test

Expressions for the non-null distribution of analysis of variance F-ratio and the power of F-test in the unbalanced one-way random model have been obtained. The exact values of power of the test have been worked out, numerically, and compared with those obtained by using ( i) the Laguerre polynomial and (ii) the two moments approximations. The computed results reveal that the two moments approximation, for the non-null distribution of F-ratio, is quite good and there is no need for the Laguerre polynomial approimation, which is computationally very tedious for practical applications.

Testing Micropreference Structures

1979 ◽  
Vol 16 (2) ◽  
pp. 247-257 ◽  
Author(s):  
Gordon G. Bechtel ◽  
P. J. O'connor
Keyword(s):  
Analysis Of Variance ◽  
Market Segment ◽  
Brand Preference ◽  
F Test ◽  
Variance Method ◽  
Data Analyses ◽  
Perceptual Structure

An analysis of variance method for scaling brand preference within a single consumer or market segment of consumers is described. This framework is used in developing a test for the accountability of preference in terms of mediating perceptual attributes. Unlike previous approaches, the method provides an F-test for a particular multiattribute structure individual by individual or segment by segment. These microtests are illustrated in two data analyses: intraindividual tests on an exogenous perceptual structure and intrasegment assessment of structures that are endogenous to each of the several segments.

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