Evaluation of maize top crosses under two nitrogen levels

• Autor(a) principal: Guedes, Fernando Lisboa
• Data de Publicação: 2011
• Outros Autores: Souza, João Cândido de, Costa, Emiliano Fernandes Nassau, Reis, Matheus Costa dos, Cardoso, Gustavo Andrade, Ematné, Hugo Junqueira
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFLA
• Texto Completo: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1413-70542011000600011; http://repositorio.ufla.br/jspui/handle/1/7477
• topic: Genetic breeding; Zea mays; S0:1 progenies; Tester; Abiotic stress; Melhoramento genético; Progênies S0:1; Testadores; Estresse abiótico

Maize crops in Brazil have a wide diversity of management systems. There is a large contingent of family agriculture, which uses little or no agricultural inputs, compared to the rural enterprise which uses the most modern production systems. This difference in the management systems is particularly noticeable in relation to consumption of fertilizers, especially nitrogenous ones. Therefore it is necessary to obtain plants with efficient nitrogen (N) use that also respond to applied nitrogen. Thus, the aim of the study was to evaluate the performance of S0:1 progenies, in top crosses, under two nitrogen levels and select the best ones based on responsiveness and efficiency. Sixty seven S0:1 progenies from populations of single cross hybrids were crossed with two testers (T1 - single cross hybrid; T2 - population per se). A hundred and thirty four hybrid progenies plus ten controls were evaluated in two field trials with different levels of nitrogen (one with average levels - 50 kg ha-1 of N - and the other with low levels of nitrogen - 25 kg ha-1 of N) in a 12 x 12 triple lattice design. It is possible to identify and to select progenies from commercial single cross hybrids that are efficient and responsive to nitrogen application. The non-additive effect was as important as the additive effect for grain yield under different nitrogen levels.