Fig. 3.

Root water potentials of V. corymbosum plants grown in a split-pot system with one wet side (open symbols) and one dry side (filled symbols). Water potentials were determined over the night-time for fine roots (root orders 1–4) under dry (filled squares) and wet (open squares) conditions, medium roots (orders 5–7) under dry conditions (filled circles), and coarse roots (orders 8 and higher) under dry conditions (filled inverted triangles). Initiation of the nocturnal period is indicated by (↓Noc) and the irrigation event by (↓i). Error bars represent one standard error of the mean (n=5). Statistical differences were found among root orders under dry conditions (P=0.010), over time (P=0.008) and the interaction of wet versus dry of fine roots and time (P=0.003). Lower case letters that differ between root orders (filled symbols) indicate a significant difference (P <0.05) and capital letters that differ between fine roots under dry (filled squares) and wet (open squares) conditions indicate a significant difference (P <0.05).