Effect of planting density on growth and biomass yields of two dukung anak species, Phyllanthus debilis and Phyllanthus urinaria, grown on alluvial soil

A study was conducted to determine the effect of planting density, through manipulation of interplant distance and number of rows per bed, on growth and biomass yields of two species of dukung anak (Phyllanthus debilis and Phyllanthus urinaria) grown on alluvial soil at two locations. The fresh and dried biomass yields per hectare of the two species of dukung anak were significantly different, with the biomass yields of P. urinaria consistently higher than P. debilis at both locations. The lower plant height of P. urinaria than P. debilis was compensated by higher number of branches per plant that contributed significantly to higher yield for P. urinaria. The average drying ratio was 3.9 for both species of dukung anak at both locations. Closer interplant distance and higher number of plant rows per bed also consistently increased the fresh and dried biomass yields per hectare. The highest fresh and dried biomass yields for both species were obtained at interplant distance of 30 em with two rows per bed, which gave a population of 55,554 plants per hectare.