Effects of arbuscular mycorrhizal fungi on Gazania rigens pot plant cultivation in a Mediterranean environment

Abstract

Herbaceous plants used in island beds and borders need to be rapid growing, high performing and maintaining good visual quality during the growing season. Arbuscular mycorrhizal (AM) fungi application is acquiring interest for its beneficial effects on ornamental bedding plants. Gazania rigens is a herbaceous ornamental plant grown for its large daisy-like flowers. The species thrives in the coastal areas of the Mediterranean region, particularly in the mild climate of southern Italy and Sicily, where performs well in summer bedding schemes in sea side gardens even in dry and windy conditions. The aim of this study was to evaluate the effect of inoculation with Rhizophagus irregularis on several ornamental parameters of Gazania rigens. Prior to transplanting, three-months-old plants received a mycorrhizal inoculum carrying 40 spores g-1 of Rhizophagus irregularis. Inoculum was applied at a rate of 10 g plant-1. The AM application significantly increased number of flowers per clump by 100% and number of flowers per plant by 124.0%. Rhizophagus irregularis also positively influenced number of leaves per plant, plant height, and roots dry weight. Our findings indicated that mycorrhizal inoculation with R. irregularis may be beneficial to nursery growers wishing to produce high quality gazania for spring-summer bedding plant schemes.