Resumo

MENDEZ-NATERA, J. R.; MEDINA L., O. H.; FENDEL, J. E.  e  MERAZO, J. F.. Effect of several tillage methods and the form of urea placement on seed yield and its components of three sesame varieties (Sesamum indicum L.). Rev. Fac. Agron. [online]. 2002, vol.19, n.1, pp.34-47. ISSN 0378-7818.

The objective of this study was to determine the effect of four tillage methods and placement of urea on seed yields and its components in three sesame varieties. The experiment was carried out in a Ultisol sandy loam soil. Four tillage methods were used: Chisel: a pass of chisel-plow 30 days before sowing (DBS) and a pass of rotary cultivator 1 DBS; Harrow: three passes of harrow at 30, 15 and 1 DBS (conventional method); Minimum tillage: a pass of rotary cultivator 1 DBS; and Chisel + Harrow: a pass of chisel 30 DBS and three passes of harrow at 30, 15 and 1 DBS. Three sesame cultivars were sown: Glauca, Acarigua and Blanca and urea was applied (200 kg/ha) in two forms: banded into the soil and superficial. Urea placement did not affect seed yields and its components. Minimum tillage caused considerable losses of plants; on the other hand, three harrow passes caused a bigger emergence and lower plant mortality. The biggest seed yields were found in Glauca with Harrow, in Blanca with Chisel and in Acarigua with Harrow or Chisel. In Chisel + Harrow, the three cultivars had similar yields, but in Chisel and Minimum tillage, Blanca had greater yields in seeds and harrow, and Glauca had the greatest yields.

Palavras-chave : Tillage methods; urea placement; sesame; cultivars.