CORN HYBRID SEED PRODUCTION OF MALE FERTILE AND MALE STERILE ISOGENIC LINES AND ITS RESPONSE TO FERTILIZER AND PLANT DENSITY

Abstract

Research results concerning comparisons between cytoplasmic male sterile and male fertile versions of corn (Zea mays L.) lines were not found in refereed literature produced in México. The objective of this study was to evaluate two fertilizer rates (200-100-00 and 160-60- 00, kg ha^-1 of NPK) and two plant densities (83 000 and 62 500 plants/ha) on hybrid seed yield and seed quality of four male sterile and four male fertile isogenic corn lines. A field experiment was established in the Tecamac Experimental Research Station in the State of México, under a complete randomized blocks design with a split plot treatments arrangement and three replications. The experimental plot was isolated from neighbored corn plantings and surrounded by a restorer line. Therefore, seed from eight types of hybrids was obtained: four from male fertile plants and four from the male sterile versions. Ear and seed yield, seed yield components and seed quality (using the standard germination test) were evaluated. Statistical differences among hybrids and hybrids versions (male sterile or detossald) were found for all yield and yield components traits. Seed yield and physical seed quality of the hybrids formed with male sterile lines were higher than those hybrids obtained from male fertile plants and detasseled. Seed germination was not affected by any treatment.