scholarly journals Número suficiente de repetições para análise de trilha em milho

2021 ◽  
Vol 43 ◽  
pp. e32
Author(s):  
Alberto Cargnelutti Filho ◽  
Marcos Toebe ◽  
Bruna Mendonça Alves ◽  
Ismael Mario Marcio Neu ◽  
Jéssica Andiara Kleinpaul

The number of replications is assumed to interfere in the estimates of the path analysis coefficients. Thus, the objective of this work was to determine the sufficient number of replications for the path analysis of traits in maize cultivars. An experiment was conducted with 15 maize cultivars in a complete randomized block design with nine replications, and seven variables were measured. Then, 511 data files (matrices) formed by all combinations of the nine replications were organized, in groups of 1, 2, 3, 4, 5, 6, 7, 8 and 9 replications. In each matrix, containing the averages of 15 cultivars for the seven variables, Pearson's linear correlation coefficients were estimated, the multicollinearity diagnostics and path analysis were performed and dispersion diagrams were constructed. The sufficient number of replications for the path analysis was determined from the parameter estimates of the quadratic response plateau model. With the replications number increases, the accuracy of the path analysis coefficient estimates improves, but the gains in accuracy gradually decrease. Six replications are sufficient to perform the path analysis of agronomic traits of maize cultivars and can be used as a reference for designing future experiments.

2019 ◽  
Vol 10 (1) ◽  
pp. 168-175
Author(s):  
Daniela Sarti Dvorjak ◽  
Sandra Helena Unêda-Trevisoli ◽  
Wallace De Sousa Leite ◽  
Alysson Jalles da Silva ◽  
Fabiana Mota da Silva ◽  
...  

Path analysis is an important study that slices the correlation coefficients between two variables to evaluate whether the relationship between them is of cause and effect. This study aimed to estimate the phenotypic and genotypic correlations between agronomic traits and perform a path analysis in order to identify variables for indirect selection aiming at a higher grain yield. Fourteen soybean F6 lines from the soybean breeding program of FCAV–UNESP, Jaboticabal, São Paulo, Brazil, were analyzed. The experimental design was a randomized block design with three replications. The agronomic traits plant height at maturity (PHM), first pod height (FPH), lodging (Ld), agronomic value (AV), number of pods per plant (NP), number of seeds per plant (NS), and grain yield (GY) were evaluated. Overall, the genotypic correlations were higher than their corresponding phenotypic correlations. The genotypic correlations between grain yield and the traits agronomic value, number of pods per plant, and number of seeds per plant were positive, significant, and of high magnitude. Path analysis showed that the trait number of seeds per plant had the highest direct effect on grain yield, while the trait number of pods per plant had the highest indirect effect through the number of seeds per plant on grain yield


2017 ◽  
Vol 39 (4) ◽  
Author(s):  
NICOLE TREVISANI ◽  
RITA CAROLINA DE MELO ◽  
MAURO PORTO COLLI ◽  
JEFFERSON LUÍS MEIRELLES COIMBRA ◽  
ALTAMIR FREDERICO GUIDOLIN

ABSTRACT Knowledge about associations between traits is fundamental for plant breeding, since indirect selection can accelerate the development of promising genotypes. This study assessed the magnitude of associations between agronomically important traits in fisális (Physalis peruviana L). The experiment was conducted in Lages, Santa Catarina, and the treatments consisted of six fisális populations. The experiment was arranged in a randomized block design, with two replications and seven plants per plot. The correlations between traits were estimated based on the Pearson correlation coefficients and partitioned into direct and indirect effects through path analysis. Fruit weight was positively correlated with number of seeds (0.874), equatorial fruit diameter (0.738) and polar fruit diameter (0.672). By path analysis, number of seeds was identified as the trait with the highest direct contribution to fruit weight. The high phenotypic correlations between the equatorial and polar fruit diameters with fruit weight were mainly due to the indirect effect via number of seeds (0.505 and 0.459). The selection for heavier fisális fruits was strongly influenced by number of seeds, i.e., this trait should be taken into account for selection.


2020 ◽  
Vol 19 ◽  
pp. 14
Author(s):  
ALBERTO ​CARGNELUTTI FILHO ◽  
MARCOS TOEBE

The objective of this work was to determine the sufficient number of replicates for estimation of dissimilarity measures among maize cultivars. Data of five variables were used, which were evaluated in an experiment with 15 maize cultivars, in randomized block design with nine replicates. A number of 511 data files were formed, being 9, 36, 84, 126, 126, 84, 36, 9, and 1 obtained, respectively from 1, 2, 3, 4, 5, 6, 7, 8, and 9 replicates. Three dissimilarity matrices were determined between i and i’ cultivars containing, respectively, Euclidean, Manhattan, and Chebyshev distances. For each of the 105 distances between cultivars, in each dissimilarity measure, the power function was adjusted for the coefficient of variation of the (dependent variable) as a function of the number of replicates (independent variable), totaling 315 equations. For each equation, the abscissa axis value (Xs, sufficient number of replicates) was determined, corresponding to the maximum curvature point. With the increase of the number of replicates, there is an improvement in the accuracy of the estimates of dissimilarity measures among maize cultivars, however, the gains in precision decrease gradually. Six replicates are sufficient to estimate the dissimilarity measures among maize cultivars expressed by the Euclidean, Manhattan, and Chebyshev distances.


2019 ◽  
Vol 13 (1) ◽  
Author(s):  
Maria Inês Diel ◽  
Débora Turchetto Zamban ◽  
Tiago Olivoto ◽  
Dionatan Ketzer Krysczun ◽  
Marcos Vinícius Marques Pinheiro ◽  
...  

The objective of this study was to identify and estimate the relationships between production component variables and fruit yields in tomatoes. This experiment was conducted in a randomized block design with a 2×3×3 factorial arrangement, with two tomato hybrids (Netuno and San Vito), three doses of boron (H3BO3 - 0, 2, 4 g pit1)  and three calcium floral applications (no application; application every 7 days; and application every 14 days), totaling 18 treatments with four replications and 20 plants per plot. Pearson correlation coefficients were estimated between the measured variables and, after that, those with greater significance were selected for productivity with the Stepwise method and verification of multicollinearity using the number of condition and inflation factor of the variance. The correlations of the selected variables were decomposed into direct and indirect effects on fruit productivity with path analysis. There was a strong correlation between the variables, excluding the variables height, diameter and average mass of the fruits. Thus, there were cause and effect relationships between the independent variable total mass of the fruits and the principal variable total fruit yield. The variables diameter and total number of fruits did not contribute to an increased tomato production.


2015 ◽  
Vol 28 (3) ◽  
pp. 230-238 ◽  
Author(s):  
PHILIPE LIMA DE AMORIM ◽  
JANAINA AZEVEDO MARTUSCELLO ◽  
JOSÉ TEODORICO DE ARAÚJO FILHO ◽  
DANIEL DE NORONHA FIGUEIREDO VIEIRA DA CUNHA ◽  
LIANA JANK

ABSTRACT: Cultivars of the genus Nopalea are known in Brazil for being tolerant to cochineal carmine attacks, thus making the cultivation of this genus a promising alternative for mitigating the negative effects of this insect on the production of biomass. With the objectives of characterizing morphologically spineless forage cactus varieties and identify morphological characteristics that may be the focus in spineless forage cactus breeding programs, an experiment was conducted in a completely randomized block design with 11 treatments and four replications. The variety Alagoas showed the highest values of weight, area and volume of cladodes. The varieties Negro Michoacan F7 and V7, Tamazunchale V12 showed the highest values of the cladode area index, the total volume of cladodes and total fresh mass production. The varieties Negro Michoacan V7 and F7 presented the highest water use efficiency and dry mass yield. Cladode volume showed the highest correlation coefficients with the fresh weight of cladodes. Aiming the release of varieties for biomass production, varieties Negro Michoacan F7, V7 and Tamazunchale V12 may substitute the Miúda variety. The number and cladode area index may be used as criteria for selection of superior varieties in breeding programs.


2017 ◽  
Vol 38 (4) ◽  
pp. 1715 ◽  
Author(s):  
Sara Regina Silvestrin Rovaris ◽  
Pedro Mário de Araújo ◽  
Deoclécio Domingos Garbuglio ◽  
Cleber Vinicius Guiaretta de Azevedo ◽  
Cássio Egídio Cavenaghi Prete

The characterization of maize landraces is extremely important in breeding programs for use of these genotypes as sources of genetic variability. The objective of this study was to quantitatively characterize 28 populations of maize landraces from the state of Paraná using the estimates of the effects of varieties and heterosis parents and the general combining ability, thereby assessing the main agronomic traits. In the crop of 2008/09, 56 inter-varietal hybrids, obtained through a topcross, 28 populations of maize landraces and three check varieties were evaluated for female flowering (FF), plant height (PH), ear height (EH) and grain mass (GY). The treatments were evaluated in a randomized block design, with two replications, at three Paraná State locations: the Experimental Center of the Agronomic Institute of Paraná in Londrina (IAPAR) and the experimental units of Pato Branco and Ponta Grossa. The data were submitted to an analysis of variance, considering a fixed model for genotypes and a random model for environments; the averages grouped by the Scott-Knott test, along with intersections of topcrosses, were analyzed according to a readapted model proposed by Oliveira et al. (1997). According to estimates of the parental effects, the GI 133 population showed the most promising estimates for all characteristics. The GI 088 and GI 173 populations stood out with promising estimates of the effects of heterosis. The conclusion is that the populations GI 133 and GI 173 may be indicated for recurrent selection programs or participation in obtaining composites.


2021 ◽  
pp. 55-66
Author(s):  
Mulyati Mulyati ◽  
Baharuddin AB ◽  
R Sri Tejo Wulan

The use of inorganic fertilizers has an important role in increasing plant growth and production. But it also causes various problems such as decreasing soil organic matter, soil acidity, soil degradation, nutrient imbalance and increasing environmental pollution. Therefore, it needs to be balanced with the provision of organic fertilizers. A field experiment was conducted to study the effect of application of various doses of inorganic and organic fertilizers on N, P, K nutrient uptake and maize plant growth. The experimental design used was a randomized block design arranged in a factorial manner consisting of two factors. The first factor is the dose of inorganic fertilizer (A): 0, 150 and 300 kg ha-1 phonska and the second factor is organic fertilizer plus (P): 0, 10, 20 tons ha-1. The two factors were combined and each treatment combination was repeated three times. The data obtained were analyzed by analysis of variance at the 5% level of significance. The results showed that there was no interaction between the application of inorganic and organic fertilizers on the growth and nutrient uptake of N, P and K. However, the application of inorganic and organic fertilizers had a significant effect on all tested agronomic traits except for plant height. Nutrient uptake of N, P and K also increased significantly due to the application of inorganic and organic fertilizers. The balance of inorganic and organic fertilizer application increases the availability of nutrients as well as the uptake of N, P, and K nutrients by maize plants.


2011 ◽  
Vol 29 (4) ◽  
pp. 531-536 ◽  
Author(s):  
Angela Kwiatkowski ◽  
Edmar Clemente ◽  
Carlos Alberto Scapim

In Brazil, the greengrocery market of sweet corn has been expanding along the country. In contrast, there have been few agri-industries canning sweet corn (Zea mays) because of the lack of cultivars with agronomic characteristics proper to industrial purposes. The purpose of this study was to evaluate the general combining ability (GCA) of seven inbred lines of sweet corn, and the specific combining ability (SCA) of their hybrid combinations based on their agronomic traits, and the chemical composition of the grain. In the growing season 2006/2007, twenty-one single hybrids were evaluated in the Iguatemi Research Station, Maringá County, Northwestern Paraná, in Brazil using a complete randomized block design with four replications. Data were subjected to the analysis of variance and the genotypes were clustered by the Scott-Knott test. We estimated the GCA and SCA effects using the Griffing's method IV with the fixed model for plant height (PH), height of ear (EH), dehusked ears yield (DEY), reducing (RS) and total sugars (TS), starch (ST), proteins (PTN), ether extract (EE) and fibers (FB). The inbred line L4, which was originated from the 'Doce de Cuba', had the best GCA for crop yield and grain quality and therefore should be used in the next hybrid combinations. The hybrids L4xL5 and L3xL7 were the most promising with regard to crop yield and grain quality.


2020 ◽  
Vol 41 (1) ◽  
pp. 73
Author(s):  
Augusto Sousa Miranda ◽  
Felipe Nogueira Domingues ◽  
Bruno Spacek Godoy ◽  
Aníbal Coutinho do Rêgo ◽  
Cristian Faturi ◽  
...  

Sugarcane crops are grown in almost all regions of Brazil, in various types of soil and under the influence of different climate conditions, which results in diverse production environments as climate factors directly influence the yield and technological quality of a sugarcane crop. The present study evaluated the agronomic and technological characteristics of sugarcane cultivars grown in Af climate conditions. The agronomic traits (natural matter production and the number, length, and diameter of stalks) and technological attributes (Brix, purity, Pol, reducing sugars, total reducing sugars, moisture, and fiber content) of three sugarcane cultivars, IACSP93-6006, RB83-5486, and SP79-1011, were determined in a three-year experiment with a randomized block design using four blocks and two repetitions per block. The cultivars IACSP93-6006 and SP79-1011 exhibited superior agronomic traits compared to RB83-5486, showing better adaptation to the soil and climate conditions of the study area. However, the technological attributes, which were below the minimum standard levels required by the sugar and ethanol industry, were not statistically different among the studied cultivars. The abundant rainfall and high temperatures, characteristics of an Af climate, were not favorable for sucrose accumulation in the IACSP93-6006, RB83-5486, and SP79-1011 cultivars. Therefore, despite the high yield, sugarcane intended for industrial purposes should not be grown under Af climate conditions, owing to the insufficient technological parameters.


2016 ◽  
Vol 46 (10) ◽  
pp. 1737-1742
Author(s):  
Josana Andreia Langner ◽  
Nereu Augusto Streck ◽  
Genei Antonio Dalmago ◽  
Lia Rejane Silveira Reiniger ◽  
Angelica Durigon ◽  
...  

ABSTRACT: The objective of this study was to determine the maximum development rates for the phases of emergence, vegetative and reproductive, and to test the performance of the Wang and Engel (WE) model for simulating the development of landrace and improved maize cultivars sown on different dates. Model calibration was with data collected from a field experiment with a sowing date on December 13, 2014, and the model was tested with independent data from experiments with five sowing dates (August 20 and November 4, 2013, February 3 and August 15, 2014, and January 7, 2015) in Santa Maria, RS. The experiment was a complete randomized block design with four replicates. The dates of emergence (EM), silking (R1), and physiological maturity (R6) of two landraces ('Cinquentinha' and 'Bico de ouro') and two improved maize cultivars ('BRS Planalto' and 'AS 1573PRO') were recorded. Maximum daily developmental rates varied among cultivars from 0.2400 to 0.3411 d-1 for the emergence phase, from 0.0213 to 0.0234 d-1 for the vegetative phase, and from 0.0254 to 0.0298 d-1 for the reproductive phase. The WE model adequately estimated the developmental stages of landraces and improved maize cultivars with a mean error of 3.7 days. The cardinal temperatures used in the WE model were appropriate to estimate the developmental stages of landraces and improved maize cultivars.


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