INDICATIVE TRAITS OF ALUMINUM SENSIBILITY IN RICE - I - GROWTH IN NUTRIENT SOLUTION

In this experiment, it was evaluated the sensibility of several rice ( Oryza sativa L.) plant traits (leaf area, LA; root area, RA; maximum r oot length, RL; maximum leaf length, LL; root number, RN; root dry wei ght, RDW; shoot dry weight, SDW) at different Al levels (0, 10, 20 e 3 0 mg L-1) in nutrient solution, aiming to establish a sequential respo nse order Trait values were represented by averaged values of 20 genot ypes. Twenty days old seedlings were transferred to nutrient solution at pH 4.0 and arranged in a random design with four replications. Resu lts were expressed as relative yield (RY%); Regression equations were fitted according to an exponential model between RY values (except for RN RY which did not show any response) and Al added levels. Sensibili ty order was deduced by paired t-test comparisons from b coefficients. It was concluded that RA RY resulted the most sensible indicator, clo sely followed by LA RY and RL RY. On the other extreme, LL RY resulted the least sensible trit while RDW RY and SDW RY showed intermediate s ensibility.