Fig. 4
Effects of the VOCs produced by Trichoderma atroviride LZ42 on the root growth of tomato seedlings in modified root Y-tube olfactometers. a Tomato seedlings grown in the root Y-tube olfactometers for 14 days. b Percentages of tomato primary roots growing in the control arm or the LZ42 arm 14 days after sowing. Control versus control was used as a negative control. N indicates the number of root olfactometer replicates. Choices of primary roots were analysed with binomial tests (H0 = 0.50). Asterisk indicates pairwise differences between the control and LZ42 choices. c Length of the primary root. d Total root dry weight of the primary root. Asterisks (*) in the figure indicate significant differences derived from two-sample comparisons (P = 0.05)