BASIC SPRAYING EQUIPMENT:

 Herbicide tank with by-pass return for agitation.
 Foot or line strainer.
 Pump (Nylon roller or vane pump of about 6 gpm generally satisfactory
 and economical).
 Pressure regulator and gauge.
 Quick-acting shut-off valve.
 Hose and fittings (one-half inch satisfactory).
 Nozzles (fan-type).

 For most herbicide spraying in crops pressures in the range 20 to 40
psi are satisfactory and herbicides should be applied in about 25 to gO 'pa of
water. Any combination of tractor speed and nozzle tips to accomplish these
pressures and deliveries should be effective. Generally, spray drift is mini-
mized by low pressures and the larger nozzles which deliver coarse spray.


CALIBRATION: GENERAL PROCEDURE:

 Initial calibration of a spray outfit may be accomplished easily by
the following procedure.

 1. Adjust nozzles, spraying pressure and tractor speed as they are to
be operated in the field.

 2. Fill herbicide tank completely withwa'ter.

 3. With tractor operating as in number (1) above, spray water over a
measured course of several hundred yards in a fitted field.

 4. Determine amount of water required to refill tank to replace that
sprayed over measured course.

 5. Calculate area sprayed: Width of bands or boom spread-times
distance.

 6. From 4 and 5 calculate quantity of water applied per acre.

 7. Rate of application per acre can be decreased by: using smaller
nozzle tips, less pressure or faster tractor speed.

 8. Rate of application per acre can be increased by: larger nozzle
tips, higher pressures or slower tractor speed.

 9. When calibration is completed add desired quantity of herbicide
per acre to amount of water applied per acre by the spray unit.