Table 3.

Frequency of apical root hair structures.

Sample	Density of root hairs with apical structures (number mm−1)	Percentage of root hairs with apical structures (out of all root hairs) (%)
Kruskal-Wallis test	H = 41.61	H = 35.10
	p < 0.001	p < 0.001
young seedlings (n = 30)	16.6 ± 3.0 a	35.8 ± 2.9 a
established seedlings (n = 30)	10.8 ± 2.0 a	36.3 ± 4.6 a
silty substrate (n = 30)	3.3 ± 1.0 b	16.3 ± 3.6 b
sandy substrate (n = 30)	1.7 ± 0.7 b	10.1 ± 3.1 b

Mean values of density of root hairs with the distinctive apical structures and fraction of root hairs with the apical structures ± SE are given. Differences between the samples were evaluated using the Kruskal-Wallis test and grouped according to the post hoc Nemenyi test (different letters indicate significantly different groups). For more details see Materials and Methods.