Correlations and path analysis in components of fiber yield in cultivars of upland cotton

Abstract

This study evaluated the relative contribution of agronomic and technological components on the fiber yield in upland cotton cultivars. The experiment was carried out with 11 upland cotton cultivars in a completely randomized blocks design with three replications. Initially, we performed analysis of variance, with the F test at 5% probability for the effect of cultivar as fixed effects as well as block and environment effects as random. Then the values were ordered according to cluster test Scott-Knott, at 5% probability level. The significance of the null hypothesis that all possible canonical correlations are null was evaluated using the chi-square test. The correlations were estimated through the path analysis. By examining the canonical correlations there was dependence between the two groups of variables and therefore it is possible to promote changes in certain characteristics through the selection of others correlated. Plants of upland cotton with higher fiber yield were influenced by the decrease in average weight of the cotton boll. When there is a reduced fiber yield, there is also an increase in uniformity and strength thereof. The fiber resistance had negative indirect effects on the fiber uniformity and length.Key words: Gossypium hirsutum, fiber quality, agronomic traits.Correlações e análise de trilha em componentes da produtividade de fibra em cultivares de algodoeiro herbáceo ResumoObjetivou-se avaliar a contribuição relativa dos componentes agronômicos e tecnológicos da fibra na variável produtividade da fibra em cultivares de algodoeiro herbáceo. O experimento foi realizado com 11 cultivares de algodão herbáceo e o delineamento experimental utilizado foi o de blocos casualizados com três repetições. Inicialmente, realizou-se a análise de variância, com o teste F a 5% de probabilidade, considerando o efeito da cultivar como fixo e os efeitos de bloco e ambiente como aleatórios. Em seguida, os valores médios foram ordenados, segundo o teste de agrupamento Scott-Knott, a 5% de probabilidade. A significância da hipótese de nulidade em que todas as possíveis correlações canônicas são nulas foi avaliada utilizando-se o teste χ 2 . As correlações foram estimadas através da análise de trilha. Pelo estudo de correlações canônicas, há dependência entre os dois grupos de variáveis e, portanto, é possível promover alterações em determinadas caracterís-ticas através da seleção para outras correlacionadas. Plantas de algodão herbáceo com maior produtividade da fibra são influenciadas pela diminuição da massa média de capulhos. Quando há diminuição da produtividade da fibra, há também aumento na uniformidade e no comprimento. A resistência da fibra possui efeitos indiretos positivos sobre a uniformidade e o comprimento da fibra.Palavras-chave: Gossypium hirsutum, qualidade da fibra, características agronômicas.

<b>Interrelations between agronomic and technological fiber traits in upland cotton

“…This information is important for cotton breeding programs aimed at selecting genotypes with longer fiber length, since an indirect selection will improve other important traits for fiber processing. Similar results were observed by Ulloa (2006), Hoogerheide et al (2007), Araújo, Almeida, Bertini, Vidal Neto, and Bleicher (2012), Farias, Carvalho, Silva Filho, and Teodoro (2016 a and b) and Queiroz et al (2017b), which verifies the importance of selecting cotton genotypes with higher UHM.…”

A classification proposal for coefficients of variation in Eucalyptus experiments involving survival, growth and wood quality variables

“…The coefficient of variation (CV) has been used by researchers to describe the accuracy of their experiments (DinardoMiranda and Fracasso 2010; Araújo et al 2012;Granato et al 2014), since it gives a general indication of the variation levels using the standard deviation as a fraction of the mean (Arnhold andMilani 2011). Consequently, Pimentel-Gomes (1985) conducted a classification of the CVs obtained from agricultural studies, which were classified as low for values lower than 10%, moderate for values from 10 to 20%, high for values higher than 20 up to 30% and very high for values higher than 30%.…”

Impact of Mating System on Genetic Variability and Correlation Coeffeicents in Cotton

“…Kampli et al, 2002, reported high GCV and PCV for some yield characters. While Arauja et al, 2012, reported that the lowest GCV and PCV values were associated with fiber quality characters is due to the smaller number of genes influencing their responses.…”