Efecto de la cobertura de rastrojos en la germinación del arroz (Oryza sativa L.) y principales malezas asociadas

Agronomía Mesoamericana 01/2005; DOI: 10.15517/am.v16i1.5182
Source: DOAJ

ABSTRACT Efecto de la cobertura de rastrojos en la germinacióndel arroz (Oryza sativaL.) y principales malezas asociadas. Para determinar el grado de interferencia causado por distintas cantidades de rastrojos de arroz (Oryza sativaL.) sobrela emergencia de arroz y malezas asociadas al cultivo, en el2003 se realizaron tres experimentos simultáneos en la hacienda el Pelón de la Bajura, Guanacaste, Costa Rica. Se aplicaron nueve tratamientos (0 a 9 t/ha) de coberturas con rastrojosde la variedad de arroz CR 1113 para medir los efectos en laemergencia del arroz y malezas. Las malezas asociadas incluyen las más frecuentes en agroecosistemas arroceros inundados: Oryza sativa, Echinochloa colona, Cyperusspp., Fim-bristylisspp., Ludwigiaspp. y Heteranthera limosa. En losprimeros dos experimentos se determinaron relaciones inversas entre el grado de cobertura y la densidad de plántulas demalezas emergidas (R2>0,89), y entre el grado de cobertura yel porcentaje de germinación del arroz (R2=0,86), respectivamente. Usando coberturas con rastrojos de frijol (Phaseolusvulgaris) en el tercer experimento, no se observó efecto supresor en la germinación del arroz, probablemente debido a supronta descomposición. Aunque la germinación del arroz nose afectó aún a las intensidades más altas de rastrojos evaluadas, conviene realizar pruebas similares a largo plazo para determinar posibles efectos debidos a la descomposición de residuos, alelopatía y acarreo de herbicidas después de variosciclos consecutivos del cultivo de arroz.

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