Abstract

Soil cadmium (Cd) represents a problem in cocoa farms in Peru. The objective of this study was to evaluate the effect of the diversity of arbuscular mycorrhizal fungi (AMF) from different provinces of the Peruvian Amazon on cadmium uptake and cacao plant growth under nursery conditions. Germinated seeds were inoculated with different AMF species, at a rate of 1,500 spores, in substrates conformed by 1:2 sand and agricultural soil, with two levels of addition of Cd (0 and 5 mg . kg(-1)). The height of the plant and leaf area, and colonization and mycelium of AMF were evaluated; likewise, Cd levels were quantified in the soil and the stems of the cocoa seedlings. A completely randomized design with a bifactorial arrangement was used with eight treatments and eight replications per treatment, which were compared by ANOVA and mean separation by Tukey's test. The results indicate that the AMF species from the Mariscal Caceres province consortium promoted greater plant height and leaf area, while the species from the Lamas consortium presented a greater reduction of cadmium in soil and stems. Therefore, the diversity of AMF species associated with cocoa plants could be considered a potential tool to immobilize Cd and improve growth in cocoa plants.