Effect of soil solution phosphorus on seedling growth of the pejibaye palm in an oxisol1

Two experiments were undertaken to determine the effect of mycorrhizal inoculation and soil solution phosphorus (P) concentration on the growth of pejibaye (Bactris gasipaes, Palmae) seedling progenies from two Amazonian populations in a Hawaiian Oxisol. Mycorrhizal colonization and effectiveness were insignificant, perhaps because of residual fumigant toxicity and apparent water stress. Soil solution P concentration had highly significant effects on seedling leaf number, leaf area, plant biomass, anthracnose damage to leaves, and growth and physiological parameters in both experiments. Genotype effects were significant in the experiment involving progenies from two different populations, but not in the experiment involving two progenies from the same population. Native soil solution P concentration in this Oxisol was insufficient for acceptable pejibaye growth, while 0.2 mg/L soil P gave very good growth.