Anthurium growth responses to phosphate fertilisation and inoculation with an arbuscular mycorrhizal fungus

We evaluated the effects of inoculation with an arbuscular mycorrhizal fungus (AMF) and phosphate fertilisation on the growth of commercial anthurium (Anthurium andraeanum Linden ex Andre, 'Eidibel') plantlets in a greenhouse experiment. We subjected the plantlets to the following treatments in a 3 x 4 factorial design: three AMF inoculation treatments [i.e., non-inoculated (NM) plantlets, or plantlets inoculated with Glomus intraradices Schenck & Smith (GI) or G. etunicatum Becker & Gerd. (GE)] and four rates of P fertiliser (5, 10, 15, or 30 mg l(-1)). Inoculation with G. intraradices or G. etunicatum promoted plantlet growth at all rates of P application, except 30 mg l(-1), with average dry weights (DWs) of 0.68 +/- 0.19 g in NM, 1.08 +/- 0.44 g in GI-inoculated, and 1.32 +/- 0.51 g in GE-inoculated plantlets. Inoculation with either AMF also increased shoot DWs, leaf areas, and shoot P concentrations. Increasing the rate of P application decreased the efficiency of symbiosis (ES; measured as the relative increase in DW) in GI-inoculated plantlets (ranging from 63.9% to 27.8%, with an average of 51.6%), but both the lowest and the highest rates of P application resulted in relatively high ES values (61.0% and 61.4%, respectively; ranging from 43.8% to 61.4% with an average of 55.6%) in GE-inoculated plantlets. Our results demonstrate that inoculation with either AMP significantly increased shoot P concentrations in A. andraeanum plantlets, which may reduce the need for the application of P fertiliser during greenhouse production.