The development of new irrigation equipments and the improvement of the already existent, as the microsprinkler, demand to evaluate the hydraulic characteristics as well as the appropriate installation in the field conditions to obtain higher indexes of the water distribution uniformity. This work had the objective to obtain the discharge x pressure equation, the manufacturing variation coefficient - CVf and the discharge variation coefficient - CVq, water distribution uniformity for different overlap degrees of the microsprinkler of the modulate group, orange nozzle, new and used, installed in the upside-down at 1.20 m above laboratory ground. The increase of the spacing among microsprinkler and lateral reduced the uniformity indexes for all of the pressures for the new and the used microsprinkler. The high jet concentration occurred in the range from 0.0 to 1.0 m of the support rod of the new and used microsprinkler. The wetted area by the used microsprinkler was smaller than the new one.
seedling; trickle irrigation; greenhouse
