Strategies for mycorrhizal inoculation of six annual bedding plant species

We inoculated six common annual bedding plant species with the vesicular-ar buscular mycorrhizal fungus Glomus intraradices Schenck & Smith using two f ertilizer P concentrations (3 or 15 mu g . mL(-1)) and three inoculation ti mings (inoculation at sowing, at transplanting, or at both times). The plan t species used were: Salvia splendens F. Sellow ex Roem. & Schult. cv. Fire cracker Rose; Impatiens walleriana Hook. f,cv. Sun and Shade Royal Red; Tag etes patula L. cv. Girls Golden; Petunia x hybrida Hort. Vilm.-Andr. cv. Fr eedom Blue; Coleus x hybridus Voss, cv, Jazz Salmon; and Viola x wittrockia na Gems. cv. Majestic Giant White. In general, Coleus, Petunia, and Viola w ere colonized more than were Impatiens, Tagetes, and Salvia. Inoculation at sowing required less inoculum than either of the other methods. Moreover, it was generally as effective in promoting colonization as double inoculati on, and was often more effective than inoculation at transplanting. Mycorrh izal colonization was significantly reduced by the higher P concentration. The use of Myconate(R), a water-soluble form of the flavonoid formononetin, significantly stimulated colonization in Salvia.