Resumen

PARRA, José G; GARCIA, Andrés A; POLEO, Carmen J  y  FUENTES, Lilian M. Reproductive aspects and rodent community damages on direct grown rice in the Guarico river irrigation system. Agronomía Trop. [online]. 2012, vol.62, n.1-4, pp.163-170. ISSN 0002-192X.

Reproductive aspects and rodent community damages were evaluated on a direct sowing rice plot cultivated in the Guarico river in the irrigation system system during dry season 2009-2010. One hundred paited traps suplemented with Cucurbita maxima were used and placed at 10 m for two consecutive nights. Captured specimens were weighed, identifying the species and sex. The number of embryos in pregnant females and the position of testes in males were recorded. Damage assessment was determined on a 1.4 ha plot, 10 samples were selected using a square timber 0.5 x 0.5 m, and the number of healthy and damaged plants were counted. One hundred and sixty two specimens were captured: Zygodontomys brevicauda (n=102), Sigmodon alstoni (n=27), Oligoryzomys sp. (n=25) and Holochilus sciureus (n=8). Catches results were: 105 males and 57 females, with a sex rratio 1.8 ♂: ♀ 1, which is not different from 1: 1 (P = 0.05). Thirty four percent females (n=17) was pregnant and 84.7% males (n=89) showed scrotal testes. The highest capture rate (18%) was observed 40 days after sowing (DAS). The level of damage varied by crop stage (P = 0.0004) was greater at 76 DDS, when populations of H. sciureus were found. Further studies are required to determine the effect of direct sowing system on rodent community and its economic impact.

Palabras clave : rice; Zygodontomys brevicauda; Sigmodon alstoni; Oligoryzomys sp; Holochilus sciureus; direct sowing.