Adaptabilidade e estabilidade de cultivares de milho para diferentes safras, espaçamentos e populações de plantas
Data
2013-02-28
Autores
Guimarães, Aparecida Antunes [UNESP]
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O cultivo de cultivares detentoras de boas características agroindustriais representa, na prática, uma das tecnologias que mais contribuem para a melhoria dos níveis de rendimento da cultura, devido aos custos relativamente baixos quando comparada com os demais itens que compõem o sistema produtivo do milho. Diante deste cenário, faz-se necessário avaliar a adaptabilidade e a estabilidade fenotípica, a fim de obter informações que proporcionem identificar cultivares estáveis e de adaptabilidade ampla ou específica para determinados ambientes. Com esse objetivo foram avaliadas cinco cultivares de milho em 20 ambientes compostos pela combinação de duas safras x dois espaçamentos x cinco populações de plantas. Os experimentos foram conduzidos na segunda safra em 2009 e na primeira safra em 2010/11, na área experimental da Fazenda de Ensino, Pesquisa e Extensão da UNESP - Câmpus de Ilha Solteira. Os tratamentos (híbridos x populações de plantas) foram dispostos em blocos ao acaso, em esquema fatorial 5x5, com quatro repetições, sendo repetidos nas combinações safras x espaçamentos (considerados experimentos diferentes). Foram utilizadas as cultivares híbridas XB 6010, XB 9003, XB 6012, XB 7253 e AG 9010 e as populações de 50.000, 60.000, 70.000, 80.000 e 90.000 plantas ha-1. Foram realizadas análises de estabilidade e adaptabilidade pelos métodos da regressão bissegmentada e AMMI (Additive Main Effects and Multiplicative Interaction Analysis). Houve interação entre os híbridos e ambientes em relação ao florescimento feminino e o híbrido AG 9010 foi o mais precoce e estável para este caráter, mantendo o tempo de florescimento praticamente inalterado em todos os ambientes, embora com média de rendimento baixa. Para acamamento/quebramento de colmo não houve significância da interação...
The cultivation of cultivars possessing good characteristics of agribusiness is, in practice, one of the technologies which most contribute to the improvement of crop yield due to the relatively low cost when compared with the other items that make up the corn production system. Given this scenario, it is necessary to evaluate the adaptability and phenotypic stability in order to obtain information to identify cultivars that provide stable and wide or specific adaptability. With this objective were evaluated five corn hybrids in 20 environments, composed by the combination of two growing seasons, two spacing and five plant populations. The experiments were conducted in the second season in 2009 and the first season in 2010/11, at the experimental farm of São Paulo State University - Campus of Ilha Solteira, Brazil. Treatments (cultivars x plant populations) were arranged in randomized block in 5x5 factorial designs with four replications being repeated in season crop x spacings combinations (considered different experiments). Were used the hybrid cultivars XB 6010, XB 9003, XB 6012, XB 7253 and AG 9010 and populations of 50,000, 60,000, 70,000, 80,000 and 90,000 plants ha-1. Analyzes were performed of stability and adaptability by the methods of bi-segmented regression and AMMI (Additive Main Effects and Multiplicative Interaction Analysis). There was interaction between hybrids and environments in relation to female flowering and hybrid AG 9010 was the earliest and most stable for this trait, keeping time of flowering nearly unchanged in all environments, although with low average yield. For lodging/breaking stem the interaction was not significant, indicating similar behavior of the hybrids front environmental variation. To yield, hybrid XB6010 was the less responsive of the evaluated group, but with good behavior in unfavorable... (Complete abstract click electronic access below)
The cultivation of cultivars possessing good characteristics of agribusiness is, in practice, one of the technologies which most contribute to the improvement of crop yield due to the relatively low cost when compared with the other items that make up the corn production system. Given this scenario, it is necessary to evaluate the adaptability and phenotypic stability in order to obtain information to identify cultivars that provide stable and wide or specific adaptability. With this objective were evaluated five corn hybrids in 20 environments, composed by the combination of two growing seasons, two spacing and five plant populations. The experiments were conducted in the second season in 2009 and the first season in 2010/11, at the experimental farm of São Paulo State University - Campus of Ilha Solteira, Brazil. Treatments (cultivars x plant populations) were arranged in randomized block in 5x5 factorial designs with four replications being repeated in season crop x spacings combinations (considered different experiments). Were used the hybrid cultivars XB 6010, XB 9003, XB 6012, XB 7253 and AG 9010 and populations of 50,000, 60,000, 70,000, 80,000 and 90,000 plants ha-1. Analyzes were performed of stability and adaptability by the methods of bi-segmented regression and AMMI (Additive Main Effects and Multiplicative Interaction Analysis). There was interaction between hybrids and environments in relation to female flowering and hybrid AG 9010 was the earliest and most stable for this trait, keeping time of flowering nearly unchanged in all environments, although with low average yield. For lodging/breaking stem the interaction was not significant, indicating similar behavior of the hybrids front environmental variation. To yield, hybrid XB6010 was the less responsive of the evaluated group, but with good behavior in unfavorable... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Milho - Cultivares, Milho - Espaçamento, Plantas - Melhoramento genetico, Corn
Como citar
GUIMARÃES, Aparecida Antunes. Adaptabilidade e estabilidade de cultivares de milho para diferentes safras, espaçamentos e populações de plantas. 2013. 66 f. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Engenharia de Ilha Solteira, 2013.