Resumo

ESPINOZA, Y  e  GUTIERREZ, R. Agronomic characterization of Azolla accessions from Venezuela. Rev. Fac. Agron. [online]. 2006, vol.23, n.2, pp.135-150. ISSN 0378-7818.

Ten samplings were done from 1991-1993, with the aim of identifying and evaluating the agronomical productivity in the native Azolla, due to the importance of the Azolla-anabaena symbiosis as a way to fix nitrogen and its potential use as biofertilizer. Assents were kept in greenhouse conditions once were collected. A total of 67 assents were collected in all the sampled regions, and a 50% were found in Apure, Guárico and Portuguesa cities. 29 assents were identified using morphological and anatomical characteristics of the plant and of the reproductive organs. Of the 43% identified assents, 35% belong to Azolla filiculoides, 9% to A microphylla and the rest (57%) could not be determined. The productivity of the collection was from 250-1340 kg MS.ha^-1 and from 13 - 40 kg N.ha^-1. FONAIAP assents 1, 16, 22, 24, 31, 54 and 57 were identified as the most promissory in reason of the fixation rate of nitrogen, relative growth rate and duplication time of the biomass to be used as biofertilizer or as animal supplement. However, FONAIAP assent 10 that belongs to the A. microphylla was the most efficient in the use of phosphorus.

Palavras-chave : Azolla; biofertilizer; nitrogen fixation; growing rate; doubling time; phosphorous.