Caracterización morfológica de poblaciones de arroz maleza, en el distrito de riego del río Zulia, norte de Santander, Colombia

rice weeds (wr) dramatically reduces both yield and quality paddy milled rice, and also reduces farm value. the objective of this study was to characterize some populations of wr at zulia river irrigation district, norte de santander department, colombia. the experiment consisted of 22 wr and three rice varieties (oryzica-1, oryzica-3 and fedearroz-50). a randomized block design with three replications was utilized and 21 attributes of plants and seeds were evaluated. regarding to plant type, results showed that 50% of wr had intermediate growth habit, 36.40% good tillering, 45.45% moderate lodging and 31.80% moderate grain shattering; 77.27% of wr had similar or shorter plant height than rice varieties (112.30 - 87.30 cm), and 54% of them had flowering time comparable to rice varieties 65.71 to 79 days after cultivated field. as regards as grains: 45.45% of wr were long grain type like fedearroz 50; 95.45% of them with apex of the lemma and pale angle between 0-10°, similar to fedearroz 50. all wr grains had lemma and pale pubescent and high variation of paddy grain sizes (7,13-10,15 mm); 63.64% had awn of various sizes. 50% of am had grain caryopsides length rated as medium grain, like fedearroz 50 and oryzica 1 (5.6 to 6.5 mm). 73% of wr grains had red pericarp and 54% had brown lemma and pale. these results suggest that wr might had been introgressed in cultivated rice probably due to hybridization