Competitive Interaction ofAxonopus compressusandAsystasia gangeticaunder Contrasting Sunlight Intensity

Abstract

Axonopus compressusis one of the native soft grass species in oil palm in Malaysia which can be used as a cover crop. The competitive ability ofA. compressusto overcomeA. gangeticawas studied using multiple-density, multiple-proportion replacements series under a glasshouse and full sunlight conditions in a poly bag for 10 weeks.A. compressusproduced more dry weight and leaf area when competing againstA. gangeticathan in monoculture at both densities in the full sunlight and at high density in the shade. Moreover, the relative yield and relative crowding coefficients also indicatedA. compressusis a stronger competitor thanA. gangeticaat both densities in the full sunlight and high density in the shade. It seemed thatA. gangeticaplants in the shade did not compete with each other and were more competitive againstA. compressusas could influenceA. compressusheight in the shade. It is concluded that although suppression ofA. gangeticabyA. compressusoccurred under full sunlight, irrespective of plant density, this ability reduced under shade asA. compressusdensity decreased. The result suggests thatA. compressusin high density could be considered as a candidate for cover crops under oil palm canopy.