Resumen

ESPINOSA-CALDERON, Alejandro et al. Effect of haversting dates, productivity and seed size on two maize hybrids seed vigour. Agric. Téc. Méx [online]. 2009, vol.35, n.2, pp.169-177. ISSN 0568-2517.

Seedling vigor is an important trait for seed quality, particularly when sowing and soil bed preparation are not optimal. The aim of this research was to determine the effect of five harvest dates and two seed sizes on the seed vigor of two corn hybrids adapted to high valleys of Mexico (2 200 to 2 600 masl), Puma 1075 and Puma 1076, seed from similar growth cycle and year. The research consisted of two phases, the first was carried out during the spring-summer season in 2004, in which the hybrids seed was increased and where harvest took place at five different dates. The seed was benefited and stored. In the second phase, during the spring-summer of 2006 an experiment was conducted to determine the vigor of the different seed samples produced in 2004. The experiment was conducted under a completely randomized block design and data were taken for: rate of emergency, plumule length, longitude of radicle, fresh weight of plumule, fresh weight of root, dry weight of plumule and root dry weight. There were highly significant differences (p<0.01) in the interaction between genotype and seed size for the variables fresh weight of plumule and fresh weight of root, but no for other variables. For many traits no differences were observed between genotypes, size seed, as well as their interaction, which may be due to the fact that the two hybrids, have similarities since they have a parent in common. Another factor could be due to the fact that the depth of planting , soil type and moisture conditions utilized were favorable and therefore there was none adverse factor to elicit differences in seed vigor.

Palabras llave : Zea mays L.; harvest date; quality and size of seed; vigor.