Índice de seleção para cultivares de milho com dupla aptidão: minimilho e milho verde

Abstract

ResumoEste trabalho teve por objetivo a elaboração de um índice que permita a seleção acurada de cultivares de milho com aptidão tanto para a produção de minimilho quanto para de milho verde. Os experimentos foram realizados no ano agrícola de 2002/2003 com dez cultivares comerciais de milho em dois experimentos. O primeiro quanto ao rendimento de minimilho e o segundo quanto ao de milho verde, delineados em blocos ao acaso com três repetições. A importância relativa dos caracteres estudados foi estimada por meio do método dos componentes principais e o agrupamento destes foi realizado pela análise de fatores. O seguinte índice foi obtido: I = 0,031 NEM + 0,013 MEM + 0,207 NEV + 0,243 MEV -0,16 AP -0,058 MFP, em que, NEM, MEM, NEV, MEV, AP e MFP são o número e a massa de espigas empalhadas de minimilho e de milho verde, altura de planta e massa de pendão fresca respectivamente. Esse índice indicou que híbridos triplos DKB 350, AG 8080 e AG 6690 e o duplo DKB 747 revelaram os melhores desempenhos para as produções de minimilho e de milho verde.Palavras-chave: componentes principais, análise de fatores, Zea mays L. Selection index of maize cultivars with twice fitness: baby corn and green corn AbstractThis study aimed to propose an index for allowing accurate selection of corn hybrids for producing both baby corn and green corn. The experiments were carried out during the 2002/2003 growing season and ten commercial corn cultivars were evaluated in two experiments, the first for evaluating the yield of baby corn and the second for the yield of green corn. Both experiments were designed in randomized blocks, with three replications. The relative importance of traits was estimated by the principal components method and the cluster analysis was carried out. The following index was obtained: I = 0.031 NEM + 0.013 MEM + 0.207 NEV + 0.243 MEV -0.16 AP -0.058 MFP, being considered the variables: number and mass of husked ears for baby corn (NEM and MEM) and green corn (NEV and MEV), plant height (AP) and the fresh mass of tassel (MFP). This index indicated that the three-way cross hybrids DKB 350, AG 8080 and AG 6690 and the double-cross hybrids DKB 747 have the best performances for the production of baby corn and green corn.

Diallel analysis of popcorn lines and hybrids for baby corn production

“…The coefficients of variation (Table 2) for EL and ED were similar to those reported by Rodrigues and Silva (2002). The coefficient of variation for EY was similar to that observed by DoVale et al (2011), when evaluating 10 commercial maize cultivars suited for baby corn production. Other authors such as Resende and Duarte (2007), using the selection accuracy as parameter for assessing the quality of experiments of cultivar evaluation.…”

“…Among the genotypes for grain production, some are possibly better-suited than others for baby corn production. The identification of these cultivars would allow their recommendation to farmers or their use as parents in breeding programs (DoVale et al 2011).…”

Porta-enxertos alternativos para cultivo de laranja Valência na região sudoeste do estado de São Paulo

“…Índices semelhantes baseados em características fenotípicas, já foram utilizados para seleções em outras culturas (Dovale et al, 2011;Ferreira et al, 2005).…”

Index selection of tropical maize genotypes for nitrogen use efficiency

“…To select the best genotypes for each condition, the weighted coefficients of the characters were calculated from the scores obtained for each factor, as suggested by Cruz et al (2012) and Dovale et al (2011). For both high and low N availability, Factor 1 yielded the most useful indices, as it assigned higher weights to characters with greater importance for NUE, in addition to discriminating between the genotypes.…”

“…Analysis of the relative importance of the studied characters -estimated using the method of principal components, factor analysis and by developing selection indices -were performed as described by Dovale et al (2011). All analyses were performed using the genetics and statistics software program GENES (Cruz, 2013).…”