MOMENTO DE COSECHA Y TEMPERATURA DE SECADO: ¿Cómo afectan el vigor de la semilla de maíz?

JUAN SANTIAGO MARTIREN; DIEGO BATLLA

Congreso; IX Congreso Nacional de Maíz; 2010

To avoid non-uniform plant stands under early planting dates, it is essential to have high vigor seed lots. Harvest time and drying temperature are factors that can affect the quality (vigor) of hybrid corn seed. The objective of the present work was to evaluate the effect of harvest time and drying temperature on corn seed vigor. Final germination and emergence percentage, were evaluated for seeds harvested between 42 and 16% seed moisture content and dried at constant temperatures of 35, 40, 45 and 50ºC, and at alternating temperatures of 35/45, 35/50 and 40/50ºC. Harvested seeds, both pre and post physiological maturity (PM), achieved high percentages of germination and emergence when dried at 35°C. However, seeds dried at 50°C reached high germination and emergence percentages only when harvested post PM. Similar trends were observed for seeds dried at temperatures between 35 and 50ºC, and those dried at alternating temperatures. Obtained results suggest the existence of a “critical point” around the time of PM where seeds seem to acquire tolerance to be desiccated at “high temperatures”, and that the acquisitions of this tolerance take place in a short period between 41 and 33% seed moisture content. These findings have important implications for hybrid corn seed production, showing that decision on harvest time and drying temperature could be an important key to improve seed quality.