Resumen

ORTIZ DOMINGUEZ, Aída. Efectos de periodos de interferencia del arroz rojo sobre el rendimiento y sus componentes en las variedades de arroz zeta 15 y FONAIAP 2000¹. Agronomía Trop. [online]. 2005, vol.55, n.1, pp.7-34. ISSN 0002-192X.

The red rice is a weed very difficult to be controled in farms cultivated with rice, Oryza sativa L., due to their kindred. This affinity probably is used by the red rice to degrade the herbicide applies to control grasses in this crop. In this research we evaluate the effect of different periods of interference of red rice in the yield, and in the components of yield (number panicles per m-2, number of grain per panicle-1, % of fertility, and weight of 1000 grains), of the the varieties of rice ZETA 15 and FONAIAP 2000. The experiments was carried out in the dry season of the years 2000 and 2001, in the Municipio Anzoátegui, of Cojedes State. The experiment was a split-block-design with three blocks, where the factor A was the varieties of rice ZETA 15, and FONAIAP 2000, and the factor B were the periods de interference 0, 15, 30, 45, 60, and 130 days after emergence (dae). We carried out the analysis of variance, and applied the Duncan Multiply Range test (5%) to evaluate differences among means. The results shown that the red rice produced a negative interference in yield and their components (number panicles m-2, grain panicle-1 and weight of 1000 grains (only year 2001) in both varieties. The yield was reduced in 46 and 35% in ZETA 15 and 53 y 38% in FONAIAP 2000, for the treatments with interference of 130 dde, while the impact was higher, between 71 and 72% for ZETA 15 and 72 and 85% for FONAIAP 2000, when the varieties were alone, in each case for the years 2000 and 2001 respectively. We observec that to a larger periods of interference of red rice, there is a larger reduction in yield of rice. The total relative yield (TRY) was 0.30-0.36 in ZETA 15 and 0.25 - 0.24 in FONAIAP 2000, for the years 2000 and 2001 respectively, showing that there is an antagonistic relationship between rice varieties and red rice.

Palabras clave : Red rice; rice varieties; periods of interference.