The feasibility of pre-emergenge herbicide application for upland rice by CDA 250 spray method was studied. The herbicide used was pen dimethalin at 0,0; 1,5; 2,0; 2,5 and 3,0 1/ha of comercial 50% E.C. formulation. Conventional spraying was carried out using 110C3 flat fan nozzles applying 200 1/ha of spray volume CDA250 was applied by rotary atomizers (Micromax) spraying twc volume rates: 50 1/ha and 27 1/ha. The results pointed out that: a)- CDA 250 spray method was equivalent to the conventional spray method in the control of weeds and crop yield; b) - for Micromax nozzles applying commercial 50 E.C. formulation of pendimethalin at 0,48 /min of nozzle feed rate, the distance between nozzles should be 1,75 m and at 0,96 1/min feed rate this distance shoud be 1,90 m; c)- CDA 250, applying 27 1/ha presents large logistic advantages.
CDA 250; rotary atomizer; spray; pendimethalin