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V. Developments in Spraying and Dusting Equipment

V. Developments in Spraying and Dusting Equipment

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were manufactured during each of the intervening years. In 1947 one

buyers’ guide listed only five manufacturers of tractor-mounted powertake-off sprayers, but a hundred manufacturers were listed in 1957.

The airplane is considered an agricultural machine for applying spray

and dust materials, since an estimated 5000 planes treat over 60 million

acres annually for pest control, A U. S. Department of Agriculture

(1958~)report on the pesticide situation for 1957-1958 stated: “The

acreage treated by aircraft for pest control in California rose from 296,059

in 1946 to 5,611,000 in 1956, with the area in 1956 almost twice that in

1951.” The U. S. Department of Commerce (1957) gives a breakdown

of aviation application uses for agriculture. The U. S. Department of

Agriculture (1958d) also gives a selected list of references on aircraft

in agriculture.

Much progress has been made in the manufacture of spray equipment for both ground machines and aircraft by the use of better materials and manufacturing techniques. Improved nozzles, pumps, valves,

as well as longer-lasting tanks and lines, have come about by the use of

higher-grade metals or newly developed synthetic materials. For instance,

as many as six different types of stainless steel are used in the manufacture of present-day spray equipment. Detailed discussion of the use and

development of spray and dusting equipment is given by Smith (1955)

and Bainer et al. (1955).

Considerable work has been done on the effect of particle and droplet

size when using different chemicals for various purposes. However, researchers are still working for a method to control droplet size and to

produce sprays with a large percentage of droplets in a narrow range

of sizes. Other problems concern methods of increasing the percentage

of material which actually sticks to the plant stem and leaf surfaces, and

ways of measuring these amounts quickly and accurately.

A new photographic and electronic counting method of measuring

spray droplet size has been reported by Farnham (1958) to be a hundred times faster than presently used methods. Brittain et al. (1955)

discuss a relatively simple method of evaluating the deposit on plants,

and Kromer (1949) relates the engineering challenge of spray application. Black (1956) reports on the corrosion and abrasion effects of pesticides on application equipment.


Sprayers for field crops are primarily of three types-tractor-mounted,

tractor-trailed, and high-clearance self-propelled. Orchard sprayers are

generally classified as high pressure or blower (mist) types. Recent developments have been the increased use of self-propelled sprayers for



ficld crops and blower (mist) typc sprayers for orchards. The introduction of blower (mist) sprayers for use on field crops, primarily vegetable

crops, has been for disease control.

Williamson ( 1958) discusses recent increased use of self-propelled

high-clearance sprayers in cotton, Black et al. (1954) describe the de-

FIG. 8. New m i s t blower sprayer maneuverable for spraying in any direction.

(Courtesy Food Machinery and Chemical COT.)



velopment of a high-clearance, self-propelled sprayer for sweet corn.

These sprayers have recently been equipped with attachments such a s

topping devices for cutting tops from crops, flame cultivators for use

in flaming rank-growing cotton for weed control, and granular insecticide distributors for corn borer control.

The new development of blower-type sprayers, sometimes referred

to as air-blast or mist-concentrate sprayers, is significant and their use

is rapidly expanding. These sprayers use less water, thereby applying

more concentrated spray while also obtaining equal or better coverage

than hydraulic sprayers using large volumes of water. The use of this

type sprayer for row crops and vegetables is discussed by J. D. Wilson

( 1956) (Fig. 8 ) .

Recent developments and methodology in the use of airplanes for

forest and row-crop spraying are discussed by Isler and Thornton (1955),

Young et al. (1957), Chamberlin et aZ. (1955), U. S . Department of

Agriculture ( 1954), and Anonymous ( 1956~).

Helicopters are being used to a small but increasing extent. Their

use is limited to spraying of high-value specialty crops, such as cranberries, which are difficult to get to with either ground equipment or

winged-type aircraft.



Although the use of dusting equipment has rapidly declined owing

to increased use of sprays in the past decade, there has been some improvement in application equipment. This is particularly true with respect to modification of dusting equipment for use of granules.

Improved hopper and metering equipment design has resulted in more

uniform distribution of dust across the swath for both ground machines

and aircraft. For aircraft, an additional small airfoil has been closely

coupled to numerous discharge points to aid in promoting rapid spreading of the materials. This new equipment dispenses liquid, dust, or

granules with only minor adjustments being necessary for dispensing

the different types of materials.

VI. Developments in Harvesting Equipment

Quality changes through improved design and manufacturing processes have produced harvesting machines which do a better job in less

time, last longer, and require less labor for operation. The number of

machines has increased, although the number of farms has decreased.

During the period 1950 through 1958, the number of grain combines

increased by 46 per cent, corn pickers by 63 per cent, pickup balers by



201 per cent, and field forage harvesters by 215 per cent. Percentage

increase of machines on specialized crops is even greater, depending

upon the number needed and the degree of success in perfecting the

equipment. The harvesting of specialized crops is rapidly changing from

hand to mechanical methods. Scarcity of labor and tightening of the

economic situation is expediting this change-over.

Increase of mechanized harvesting contributed primarily to the 21

per cent reduction in man-hours used on farms in the past ten years.

There has been very little reduction in man-hours used for those crops

in which the harvesting has not been mechanized.

The general trend has been toward harvesting equipment that can

be operated by one man with the least expenditure of his energy. The

trend in design is toward more automatic operation, increased use of

hydraulic systems, V-belt drives, self-aligning prepacked bearings, and

lighter materials for construction where possible. Less vibration is experienced owing to better balancing of moving parts. The use of large

harvester-mounted bulk bins unloaded by gravity dumping or auger

conveyors is becoming standard practice.

There is a trend toward larger self-propelled machines for the bigger

farms. Smaller machines are being designed to mount on tractors or

other power units which can accommodate several types of equipment.

Harvesting machines are being designed to operate under a wider range

of crops and cropping conditions.




Forage crop production of over 100 million tons (excluding that used

for silage) constitutes approximately one-fifth of all harvested crop acreage in the United States. S t r i d e r and Phillips (1956) report that while

only 29 per cent of all hay was baled in 1944, 73 per cent was baled in

1954. This trend was due primarily to the introduction of automatic-tie

pickup balers, reduction of storage space requirements, and ease of handling as compared with loose hay. Chopped hay for curing and dehydration increased from approximately 2 to 7 per cent during the same

period. Long, loose hay has steadily declined during these same years

to a low of 20 per cent in 1954.

Although hay crops in general have a relatively low cash value per

acre, much progress has been made in equipment for mechanizing the

crop. Improvements in hay crushers have decreased the hazard of crop

loss under changing weather conditions. Automatic one-man-operated

balers with a second man loading the trailer has been a common practice

for the past ten years. Recently, one-man hay balers have been designed

to kick or throw the bale into the trailer, thereby eliminating one man

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V. Developments in Spraying and Dusting Equipment

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