Although the majority of horticultural crops are mycorrhiza-dependent, the role of arbuscular mycorrhizal (AM) inoculation in plant production has been neglected in high-input agriculture. Field application of a commercial inoculum mix of Glomus spp. was tested in spice pepper (Capsicum annuum L. var. longum), cv. Szegedi, cultivation. With polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP), differences in small subunit ribosomal RNA genes were used to characterize groups of arbuscular mycorrhizal fungi (AMF) with respect to effects of mycorrhizal inoculation on an indigenous AMF population. The AMF inoculant was able to establish in the rhizosphere of pepper plants and mycorrhizal inoculation increased yield of spice pepper by more than 65% compared with the non-treated control plants. Having relatively high root colonization in the control, non-inoculated treatment indicated high presence of indigenous populations of AMF in the field soil. Although the inoculation affected structure of the resident AM fungal community, it did not influence the composition of AMF associated with pepper roots significantly.

Rooted cuttings of geranium were grown with and without a slow release fertilizer and inoculated or not with a commercial inoculum containing AM fungi. After six weeks plants were transplanted into larger containers and one-half of the plants were inoculated with AM. Inoculation increased pelargonium growth along with nitrogen, phosphorous and potassium concentrations in shoot than caused a slight decrease in shoot growth and enhanced N concentration. Colony forming units of total fungi and bacteria in the rhizosphere were not influenced by AM;  although RFLP profiles of DNA isolated from bacteria living in rhizosphere showed a more diverse community in AM-inoculated than non-inoculated plants at low nutrient supply. Our results suggest that mycorrhizal inoculation not only has an effect on plant growth and uptake of elements but it also influences directly or indirectly the bacterial community of the rhizosphere.

The aim of this study was to test the use of commercially available arbuscular mycorrhiza (AM) inoculant Symbivit, a mixture of six species of Glomus spp., in spice pepper field cultivation. The inoculants containing arbuscular mycorrhizal fungi (AMF) was able to establish a symbiosis in the rhizosphere of pepper plants and mycorrhizal inoculation increased fresh and dry weights of shoots of spice pepper cv. Szegedi and only fresh weight of Kalocsai type. There were no significant differences in the root weights due to treatment only in fresh weight of Kalocsai pepper type. Treated plants of both variants exhibited an increase in cumulative crop production compared with control non-treated plants and the growth response of pepper was higher for var. Szegedi than var. Kalocsai. Mycorrhizal inoculation had a great positive effect on external hyphal length of AMF also showing differences in that between Kalocsai and Szegedi variants. The root colonization showed seasonality by treated and non-treated plants. The lowest degree of colonization was observed in June in general and colonization percent increased during vegetative development and there was a slight decrease at harvesting. In conclusion, it can be stated that inoculation with Symbivit containing mycorrhizal fungi could be an integral part of spice pepper production.