Optimization of the digestible dry matter yield from semi-exotic populations of maize

Semi-exotic populations of maize with late maturity can be obtained by crossing exotic germplasm with adapted inbred lines. Being very productive, these populations give an appropriate starting point for the development of long season forage maize suitable for mild weather zones. Criteria to be considered for the discrimination between semi-exotic populations regarding their production of digestible dry matter are discussed in base to preliminary results. Although the materials are intented for use as forage, maximization of ear yields still appears as a basis factor. For stover digestibility and/or cell wall and/or against NDF would be complementary aspects to be considered as a strategy for improving the nutritive quality of the plant. Although further research is needed, none of the criteria seem imcompatible with increases production and the choice of a trait depends strongly on the ease of recording it.This work has been done with a grant by CICYT, n. AGR89-0373Peer reviewe