Evaluation of maize top crosses under two nitrogen levels

Fernando Lisboa Guedes,Gustavo Andrade Cardoso,João Cândido De Souza,Matheus Costa Dos Reis,Emiliano Fernandes Nassau Costa,Hugo Junqueira Ematné

doi:10.1590/s1413-70542011000600011

Fernando Lisboa Guedes, Gustavo Andrade Cardoso + Show 4 more

Open Access

https://doi.org/10.1590/s1413-70542011000600011

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Abstract

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.

Highlights

IntroductionThere 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
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

Summary

Introduction

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 noticeable in relation to consumption of fertilizers, especially nitrogenous ones. It is necessary to obtain plants that use nitrogen efficiently (N) and respond well to nitrogen that has been applied. This breeding strategy helps to increase the sustainability of the system, since N is a nutrient that most increases the cost of production (GERNER; HARRIS, 1993; DANGL et al, 2000), and reduces the environmental impact of excessive use of nitrogen in successive plantings

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