Agronomía Tropical (2001) 51, 501-517
Aída Ortiz Domínguez and Laura González (2001)
Estudio preliminar del banco de semillas de malezas del suelo de algunas zonas arroceras de Calabozo, Guárico
[Preliminary study of weed seed hanks of certain soils of rice areas of Calabozo, Guárico]
Agronomía Tropical 51 (4), 501-517
Abstract: The incidence of weed seed banks in soils of rice producing farms of Calabozo (State Guárico) was evaluated during the wet season of 1999. A sampling of conglomerates (zone) was used. Nine out 19 conglomerates were chosen. lnside of each conglomerate a random selection of 10% of farms was done, and 10% of total sowed area was sample (765 ha, 16 farmers and 760 samples analyzed). The sampling method used was the double diagonal taking 10 points per lot. Samples were taken with a large drill with diameter of 8 cm and depth of 14 cm. Two methodologies to estimate weed seed banks in soils were used: separation of seeds by method of Malonne modified in this study and emergence of seedlings by Forcella (1997). Data were analyzed using the descriptive statistics. Results showed that when the method of separating seeds was used, the zones with more than 10% incidence of weed diasporas were: Lecherito, Uverito, El Pálito and Uverote, whereas with the method of emergence seedlings, the zones Carretera Nacional, Uverote and Lecherito showed more than 14% of incidence. When species were quantified by both methods, the most frequent weeds were: Limnocharis flava, Cyperus ferax, Ludwigia spp., Fimbristylis littoralis, Echinochloa colona and Limnocharis flava, which suggest certain species have more viability of seeds and/or less dormancy. The information obtained related to weed species frequent in seed banks soils in calabozo-Guárico, contributed to the adaptation of more practical and economic method for local condititons. The volume of soil used (958 cm3) was not adequate to detect red rice.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
(original language: Spanish)
Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
surveys/sampling/distribution
Pest and/or beneficial records:
| Beneficial | Pest/Disease/Weed | Crop/Product | Country | Quarant.
|
|---|---|---|---|---|
| Echinochloa colona (weed) | Rice (Oryza) | Venezuela | ||
| Fimbristylis littoralis (weed) | Rice (Oryza) | Venezuela | ||
| Ludwigia (weeds) | Rice (Oryza) | Venezuela | ||
| Limnocharis flava (weed) | Rice (Oryza) | Venezuela | ||
| Cyperus odoratus (weed) | Rice (Oryza) | Venezuela |
