In experimental work with perennial weeds it is often desirable to apply large gallonages of solution from a boom plot sprayer. Moreover, since tillage is frequently a counterpart of the control procedure the sprayer must be constructed to withstand rough usage on cloddy land. The sprayer illustrated in Figure 1 can deliver from 2 to 100 gallons of solution per acre in proper spray pattern through standard nozzles. Being light and strong, it can be pushed comparatively easily across uneven surfaces.

Overall weight of the sprayer is 150 pounds. Rate of travel is gauged by a speedometer indicating zero to 10 mph. Pressure is supplied by a quickly replaceable air pressure tank and the liquid is held in a 2-gallon pressure container. Dosage rate is determined by speed of travel and size of nozzle orifice tip. Because of the large capacity of the liquid flow system from tank to nozzle, loss of pressure is slight even when heavy gallonages of solution are applied. All parts of the system are of copper or brass except the solution tank which is of galvanized iron. However, since the outlet from tank to tubing is at the center of a dished bottom, drainage is good. Pet-cocks at each end of the boom permit thorough flushing. The boom can be set from a 6-inch to a 60-inch height and the angle of nozzle to the ground, adjusted over 20°. A supporting leg is provided at the rear of the frame to keep the sprayer upright when not in use. Air-pressure and speedometer gauges and the spray control valve are mounted directly in front of the operator. When applying 100 gallons of spray per acre, the 2-gallon solution tank permits coverage of 100 feet. Width of spray pattern is 8.5 feet.