PRODUCTIVITY AND QUALITY OF SEEDS IN CORN LINES AND HYBRIDS (Zea mays L.) FOR THE TRANSITION ZONE "EL BAJIO-VALLES ALTOS" OF MEXICO 1

Abstract

Several important characters for corn seed product ion were analized using three four-way experimental hybrids anda double-cross hybrid, produced by the National lnstitute of Agricultura! Research (INIA). Component inbreds and single crosses were also included. All these materials were grown in 7 environments located in the regions of Valles Altos, El Bajío and the transition zone between the first two regions (1700 to 2200 m.a.s.l .). From the obtained results it was concluded that: both seed size and yield should be considered together to assess the maximum productivity of commercial seed in inbreds and single crosses; evaluation of seed qual ity permitted the identification of the best parents and their most appropiate environments for seed production; each genotype should be seed-increased in its optimum environment as determined by yield, seed size and healthiness, as well as the flowering time when producing single or doublecrosses.