Effect of As concentration in the irrigation water on the concentration of P
(g kg−1) in the roots (A) and leaves (B) of lettuce plants (Lactuca sativa L.) inoculated
with Trichoderma harzianum T22 or Trichoderma atroviride P1. As 0, As 5 and As 10
refer to As concentrations of 0, 5 and 10 mg L−1 in the irrigation solution. Black,
white and grid bars refer, respectively, to no Trichoderma, T. harzianum T22 and T.
atroviride P1 treatment. Bars represent mean values at least four different replicates
± SD (n = 4); those followed by the same letter are not significantly different
by Tukey’s test at the 5% level.