Effects of arbuscular mycorrhizae Glomus iranicum var. tenuihypharum on strawberry fruit yield and quality

Mycorrhizal fungi are symbiotic organisms able to support ecosystem services and bring benefits to crop production by supplying a set of functions. The application of arbuscular mycorrhizal fungi (AMF) could be a suitable option to improve nutrient uptake and yield. AMF support plant nutrition by absorbing and translocating mineral nutrients beyond the depletion zones of plant rhizosphere. Aim of this work was to test the efficacy of an AMF, Glomus iranicum var. tenuihypharum, in open field conditions (Forlì, Italy; 44°09'57”N; 12°04'33”E) on two June-bearing strawberry (Fragaria × ananassa Duch.) cultivars, 'Brilla' (B) and 'Sibilla' (S). In a randomized block design, the effects of G. iranicum on biomass partitioning, yield, fruit size, total soluble solids, titratable acidity, flesh firmness, skin resistance, and fruit color of cold-stored plants were evaluated. Mycorrhizal colonization intensity (M%) in root samples was also determined, as this can be affected by environmental conditions. Preliminary results showed that M% in B and S strawberry inoculated plants was significantly higher compared to control plants. Inoculated plants showed increased plant growth: in January 2019 branch crown number of AFM strawberry plants was 21% (B) to 33% (S) higher as compared to control plants, and dry matter accumulation increased significantly. The treatments in B and S increased both total (+2.9 and +10.6%, respectively) and marketable yield, and improved fruit skin resistance, thus allowing a longer shelf life. Fruit color in inoculated plants showed higher lightness value (L*), with a brighter red tonality. AFM inoculum application seems to be a fruitful option to increase sustainability of open field strawberry production.