Fig 1. The response index (RI) values of methanol extracts with five concentrations from the first (S1), second (S2) and third (S3) stubbles of six alfalfa varieties to the germination rate of green foxtail.

Each data point is the mean ± standard deviation (SD) of three replicates. Different capital (or lowercase) letters in the same variety mean significant differences (P < 0.05) among the three stubbles (or five concentrations). The symbol of “*” represents significant differences between the treatments of stubble (S), concentration (C), and their interactions (S × C). Levels of significance are indicated as: “*” means P < 0.05, “**” means P < 0.01, “***” means P < 0.001, the same below.