TY  - PRO
AU  - Banziger,M.
AU  - Edmeades,G.O.|Banziger,M.|Mickelson,H.R.|Peña-Valdivia,C.B.
AU  - Lafitte,H.R.
ED  - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico DF (Mexico)
TI  - Breeding for N-stressed environments:  How useful are low-N selection environments and secondary traits?
SN  - 968-6923-93-4
U1  - 633.153 
PY  - 1997///
CY  - Mexico, DF (Mexico)
PB  - CIMMYT
KW  - Climatic factors
KW  - Flowering
KW  - Genotype environment interaction
KW  - AGROVOC
KW  - Nitrogen content
KW  - Selection
KW  - Zea mays
KW  - Plant breeding
KW  - CIMMYT
N2  - The present study examines (i) to what extent alpha (0,1) lattice designs and secondary traits improve selection efficiency under low N, and (ii) whether selection under high N is an efficient approach for increasing grain yields under low N. Grain yield and the secondary traits anthesis-silking interval (ASI), number of ears per plant, leaf chlorophyll concentration and leaf senescence of 19 maize trials grown under low N and 14 under high N conditions were analyzed. Broad-sense heritabilities of traits, genetic correlations between environments and traits and predicted response to selection were calculated. The results indicate that (i) alpha (0,1) lattice designs and secondary traits can considerably increase the efficiency of selection for grain yield in maize breeding programs targeting low N environments, and that (ii) if the N stress present in the target environment leads to a yield reduction greater than about 40%, a breeding program should include low N selection environments in order to maximize selection gains for that target environment
ER  -