Breeding for drought tolerance in maize populations under the moisture-stress conditions of Ethiopia

arid zones aridoculture breeding methods breeding value conservation de l'eau crop yield cubrimiento del suelo descendance drought resistance drought stress dry farming environmental factors espacement espaciamiento ethiopia etiopia facteur du milieu factores ambientales fitomejoramiento genotipos genotypes mulching paillage plant breeding plant population progenie progeny rendement des cultures rendimiento de cultivos seedbed preparation selection criteria spacing statistical methods variedades varieties water conservation zea mays zone aride