Fig. 4

Effect of inoculation with R. irregularis on grain yield in field-grown rice plants. Rice plants (Loto and Gines) were grown in Ebro Delta (May–October 2016). For each variety, three independent plots (1 to 3) were designed for each condition (mycorrhizal: Ri, colored in green; non-mycorrhizal: -, colored in black) (see Additional file 2: Figure S2 for the experimental design). Grain yield parameters were measured. Twelve plants per condition in each parcel were analyzed and pooled. a Grain yield (grams) per plant. b Number of panicles in each plant. c Number of grains per panicle. d Grain weight. Measurements were done for 100 grains from plants from each variety and condition. Error bars represent the standard deviation for each condition