Influência da profundidade e pressão de compactação da semente no tempo de emergência de plântulas milho (Zea mays L.).

Abstract

The region of Campos Gerais, State of Paraná, stands among the largest corn producers in the country. Reaching such a high level was a consequence of the advent of No Tillage. Admitting that final crop yield is a result of the entire productive process, the importance of the planting process is brought to attention. The planting process is characterized by the horizontal and vertical distribution of seeds. This paper analyzed the effect of different pressure levels made by presswheels and of theoretic depths on the variables “real seed depth” and “emergence time”. Treatments consisted of five pressure adjustments and four seed depth adjustments. The planter was a Semeato® PS 8 with eight planting rows, with offset double-disk furrow openers and 60°-angle double presswheels. The compaction pressure had no influence on emergence time in more profound depths; in shallower depths, the emergence time decreased significantly with increasing pressure. The real seed depth increased in shallower theoretic depths, and decreased in more profound theoretic depths with increasing compaction pressure.