Germination Biology Of <i>Mariacus longibracteatus</i> Cherm And <i>Oryza barthii</i> A. Chev.

Abstract

The germination biology of two most abundant and frequent weeds of lowland rice in Edo state was studied. The two species varied in their temperature requirements for germination: the optimum temperature for the germination of M. longibracteatus 40^oC while O. barthii was 32^oC. M. longibracteatus did not germinate at temperatures below 25^oC but O. barthii germinated at 20^oC. Optimum seedling emergence was recorded at a depth of 0.5cm in M. longibracteatus whereas O. barthii emerged most at depths of 2.0 and 3.0cm. Both species showed controlled seed germination as a survival mechanism. Simulated moisture stress and hydrogen ion activity adversely affected the germination of seeds of both species indicating high sensitivity to moisture stress and solute concentrations. Treatments that would increase the soil pH would limit the spread of both species.

Key Words: Germination biology, weeds, lowland rice

Global Journal of Agricultural Sciences Vol.3(1&2) 2004: 15-18