APPLYING 2,4-D


 An application of 1 pound of 2,4-D acid equivalent per acre is generally
sufficient for controlling water hyacinths. This quantity of 2,4-D can be
mixed and applied in quantities of water varying from 2 to 150 gallons per
acre depending upon the method of application. The volume, or "bulk" of
the actual spraying solution, is only important in its relation to thorough,
uniform coverage. Using ordinary farm type spraying equipment from 50 to
100 gallons of solution will usually be needed to cover 1 acre. The labels
on commercial lots of 2,4-D amines usually show the number of pounds of
2,4-D acid equivalent contained in 1 gallon of the liquid. For example,
where the strength is 4 pounds of acid equivalent per gallon, which is a
common commercial formulation, 1 quart of the liquid should be applied
with suitable spray equipment to cover 1 acre regardless of the quantity
of water required.

 Satisfactory application can be made with a variety of spraying
equipment ranging from knapsack type to large capacity power units, The
type selected will vary with the degree of infestation, the size of the
area to be treated, and the ruggedness of the banks and growth adjacent
to the canal or pond. Relatively inexpensive sprayers suitable for
applying sprays under low pressure up to 100 psi. are available
commercially and consist essentially of a rotary pump, pressure regulator,
suction hose, and boom and nozzles, or discharge hose and adjustable-spray
hand gun. If higher pressure 300 to 600 psi. is needed for reaching
remote weeds, then a somewhat more expensive plunger-type pump and high
pressure fittings are required. Both type units are usually powered by
light weight, air-cooled, gasoline engines.

 It is best to work at low pressures and with a coarse spray, where
 feasible, to reduce danger of spray drift. The higher the pressure used
 the smaller the spray droplet size, and an extremely fine mist can be
 easily carried by wind and harm sensitive crops in the vicinity. For
 example, an 0.0008-inch-diameter spray particle, when released from a
 height of 10 feet, reportedly, can drift a distance of about mile in a
 3 mph. wind; whereas, droplets half this size can travel approximately
 1 mile.

 Sprays can be distributed most uniformly using a boom with flat
 spray nozzles, or a boomless cluster of nozzles such as the "Boomjet" or
 "Broadjet" which operate at pressures of 60 psi. or less and produce a
 flat spray which gives uniform and complete coverage. These methods are
 preferable where conditions allow the use of such equipment. However,
 most agencies engaged in hyacinth control in south Florida use the
 orchard type hand gun with an adjustable spray pattern because it is more
 adaptable to the variety of conditions encountered.

 The usual method' of application is spraying from a boat. However,
 in many cases it may be best to mount the spraying equipment on a truck
 and spray from the bank.

 In calibrating the spray equipment and in calculating quantities it
 will be helpful to remember that there are 43,560 sq. ft. in 1 acre and
 also that a strip 8 feet wide, one mile long, is approximately 1 acre.