Resumen

MARTINEZ DE CARRILLO, Mirna  y  W., Pedro Alfonso. MOST IMPORTANT WEED SPECIES IN VEGETABLE CROP PLANTINGS AT QUÍBOR VALLEY, LARA STATE, VENEZUELA. Bioagro [online]. 2003, vol.15, n.2, pp.91-96. ISSN 1316-3361.

The objective of this research was to determine the most common weed species in the onion and tomato-green pepper plantation systems at Quíbor valley, Lara State, Venezuela. To estimate the dominance of weeds, plots of 0.5 hectares were selected in each of 15 farms where five random samplings using a 1x1 m square were performed. Weeds were collected and identified. Thirty weed species belonging to families were identified, 30% Poaceae, 10% Asteraceae, 10 % Malvaceae, 6.67% Chenopodiaceae, 6.67 Cyparaceae and the remaining families in 3.33% each one, Amaranthaceae, Boraginaceae, Commelinaceae, Cucurbitaceae, Euphorbiaceae, Fabaceae, Portulacaceae, Scrophulariaceae, Solanaceae, Sterculiacea, Verbenaceae. In the onion system, from 26 weeds recorded, 66% were broadleaf, and 34% narrowleaf (19% Poaceae and 15% Cyparaceae) being dominant Eclipta alba (23.64%), followed Ciperus rotundus (14.75%), Portulaca oleracea (10.73%), Walteria americana (8.02%), Leptochloa uninervia (7.62%) y Chloris polydactyla (7.34%). In the tomato-pepper system among the 28 weeds recorded, 70 % were broadleaf and 30% narrowleaf (16% Poaceae and 14% Cyparaceae), being the most common Amaranthus spp. (31.53%), C. rotundus (13.57 %), P. oleracea (7.83%) and Sida sp. (7.58%).

Palabras clave : Weed taxonomy; vegetable crops; Lara State.