Avaliação De Características Da Fibra De Genótipos De Algodoeiro Cultivados Em Sistemas Adensado E Convencional

Abstract

O presente experimento foi conduzido com o objetivo de avaliar três genótipos de algodoeiro, cultivados em sistemas ultra-adensado, adensado e convencional, em relação a diferentes características de fibra. O ensaio foi conduzido de dezembro/2008 a junho/2009, no delineamento em blocos casualizados (DBC) com parcelas subdivididas (SPLIT PLOT), no esquema 3x3 e com 4 repetições, sendo que as parcelas constituíram-se dos espaçamentos (E) 0,90 m, 0,76 m e 0,38 m, e as subparcelas pelos genótipos (G): NUOPAL, DP 90 B e DP OPAL, mantendo uma população de 135.000 plantas por hectare para todos os tratamentos. As parcelas com espaçamento 0,76 m e 0,90 m foram constituídas de quatro linhas, já as parcelas com 0,38 m por seis linhas, todas com 15 m de comprimento subdivididas em três subparcelas com 5 m cada. Na área útil de cada subparcela retirou-se de forma aleatória uma amostra de 20 capulhos, que foram enviadas para o laboratório e analisadas pelo equipamento HVI. Os dados obtidos foram submetidos à análise de variância e as médias comparadas pelo teste de Tukey a 5% de probabilidade. Pelos resultados observou-se que o espaçamento entre linhas não interferiu nas características de qualidade de fibra dos genótipos analisados.

Agronomic and technical fibers traits in elite genotypes of cotton herbaceous

“…There were significant difference (p<0.05) among cotton genotypes for all traits, allowing to infer about the existence of genetic variability among genotypes (Table 1). Similar results were obtained in other studies with the cotton crop (Carvalho et al, 2015a, b;Jerônimo et al, 2014;Araújo et al, 2013;Martins et al, 2012;Freitas et al, 2007). It is noteworthy that there was no genotype × environment interaction, indicating linearity among environments and the occurrence of similar response of genotypes compared to the environmental effects.…”

“…We noted in Table 3 that for the degree of yellowing (DY), which indicates the degree of pigmentation of colour, all the tested genotypes obtained values acceptable by the textile industry (DY ≤ 8.48). It is worth mentioning that the average values obtained for the technological properties of fiber and yield cotton in seed are higher than those obtained in other studies with cotton genotypes (Jerônimo et al, 2014;Araújo et al, 2013;Martins et al, 2012;Freitas et al, 2007). This, in general, shows that the genetic breeding program from Embrapa Algodão has created genotypes according to the pattern required by Means followed by different letters in the columns differ by Skott-Knott test at 5% probability.…”

Correlations and path analysis among agronomic and technological traits of upland cotton

“…The results obtained are similar to those obtained in other studies of cotton crop (Freitas et al, 2007;Silva et al, 2011;Martins et al, 2012;Araújo et al, 2013;Jerônimo et al, 2014;Carvalho et al, 2015a,b). Table 1.…”

“…This is because selection based on one trait may result in changes in other important agronomic traits as well. This occurs because these correlations do not determine the relative importance of direct and indirect effects of the traits that comprise grain yield (Lynch and Walsh, 1998).…”

Genetic gains in agronomic and technological traits of elite cotton genotypes

“…These results allow to infer about the existence of genetic variability in the population, which is a favorable indicative for the improvement of the traits. Coefficient of variation (CVe) was less than 20% for all evaluated traits, similar to those obtained in other studies with the cotton crop (Freitas et al 2007;Martins et al 2012;Araújo et al 2013;Jerônimo et al 2014;Carvalho et al 2015a, b). There was no significant GxE interaction for any trait, which indicates similar expression of the genes that control these traits in the three environments.…”