The objetive was to evaluate the growth of the young plants cultivated in greenhouse conditions under three levels water stress 25, 50 and 75% of the field capacity (cc) after two growth periods (30 and 60 days). The observed variables were: plant height, dry matter, biomass allocation and stomatal density. The three levels water stress, didn't exercise influence on root length. The relation between root and aerial shoot part for the treatment under 25% cc, was 2:1 approximately and under 50 and 75% cc, this relation was in the order of 1:1. The water stress reduced the height of the plants at 25% cc after 30 days. After 60 days, the values found were 22,60; 22,70 and 28,76cm at 25, 50 and 75% cc respectively. There was significant reduction in the leaf area and production of the dry matter at 25% cc after 30 and 60 days when compared at 50 and 75% cc. Higher root biomass allocation ocurred at 25%cc after 30 and 60 days. M. urundeuva is hypostomatic, with anomocytic stomats. Stomatal density varied between 372 and 524 stomats/mm².
aroeira; water stress; growth; biomass allocation; caatinga
