• TABLE OF CONTENTS
HIDE
 Front Cover
 Table of Contents
 Introduction
 Purpose of study
 Performance of mechanical...
 Use of equipment, performance and...
 Number of machines and acres harvested...
 Performance rates and capacity...
 Variation in acres harvested per...
 Variation in amount of potatoes...
 Operating time lost and proportion...
 Harvested per hour
 Injuries to potatoes in harvesting...
 One-row direct harvesters
 Comparison of injuries in potatoes...
 Place where injuries occurred
 Injuries to potatoes when run through...
 Reduction of injuries
 Cost of harvesting and handling...
 Items included and method of calculating...
 The conventional system
 Per acre and per unit cost
 The completely mechanized...
 Per acre and per unit cost of harvesting...
 The partially mechanized syste...
 Comparison of cost of harvesting...
 Relation of total acres harvested...
 Relation of total hours harvester...
 Effect of variation in expected...
 Custom mechanical harvesting
 Problems of custom harvesting
 Summary and conclusions














Group Title: Bulletin / University of Florida. Agricultural Experiment Station ;
Title: An analysis of quality and cost of harvesting and handling potatoes with mechanical equipment /
CITATION THUMBNAILS PAGE IMAGE ZOOMABLE
Full Citation
STANDARD VIEW MARC VIEW
Permanent Link: http://ufdc.ufl.edu/UF00026747/00001
 Material Information
Title: An analysis of quality and cost of harvesting and handling potatoes with mechanical equipment /
Series Title: Bulletin / University of Florida. Agricultural Experiment Station ;
Physical Description: 72 p. : ill. ; 23 cm.
Language: English
Creator: Greene, R. E. L ( Robert Edward Lee ), 1910-
Kushman, Leaton J ( Leaton John ), 1919-
Spurlock, H. C
Publisher: University of Florida Agricultural Experiment Station
Place of Publication: Gainesville, Fla
Publication Date: 1959
Copyright Date: 1959
 Subjects
Subject: Potatoes -- Handling   ( lcsh )
Potatoes -- Harvesting -- Machinery   ( lcsh )
Potato industry -- Costs   ( lcsh )
Genre: government publication (state, provincial, terriorial, dependent)   ( marcgt )
non-fiction   ( marcgt )
 Notes
Statement of Responsibility: by R.E.L. Greene, L.J. Kushman and H.C. Spurlock.
General Note: Cover title.
General Note: "In cooperation with Agricultural Marketing Service, United States Department of Agriculture."
General Note: Originally presented as: Thesis (Ph. D.)--University of Florida.
 Record Information
Bibliographic ID: UF00026747
Volume ID: VID00001
Source Institution: University of Florida
Holding Location: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: ltuf - AEN7741
oclc - 18299416
alephbibnum - 000927038

Table of Contents
    Front Cover
        Page 1
    Table of Contents
        Page 2
    Introduction
        Page 3
    Purpose of study
        Page 4
    Performance of mechanical equipment
        Page 5
        Page 6
    Use of equipment, performance and rates of harvesting
        Page 7
    Number of machines and acres harvested mechanically in 1953 and 1954
        Page 8
        Page 9
    Performance rates and capacity of harvesters
        Page 10
    Variation in acres harvested per hour
        Page 11
        Page 12
        Page 13
    Variation in amount of potatoes harvested per hour
        Page 14
    Operating time lost and proportion due to various causes
        Page 15
        Page 16
    Harvested per hour
        Page 17
        Page 18
        Page 19
    Injuries to potatoes in harvesting and handling
        Page 20
    One-row direct harvesters
        Page 21
        Page 22
        Page 23
    Comparison of injuries in potatoes harvested mechanically and with conventional methods
        Page 24
        Page 25
        Page 26
        Page 27
    Place where injuries occurred
        Page 28
    Injuries to potatoes when run through bins
        Page 29
        Page 30
    Reduction of injuries
        Page 31
        Page 32
    Cost of harvesting and handling poataoes with different systems
        Page 33
    Items included and method of calculating cost
        Page 34
    The conventional system
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
    Per acre and per unit cost
        Page 40
        Page 41
        Page 42
    The completely mechanized system
        Page 43
        Page 44
        Page 45
        Page 46
    Per acre and per unit cost of harvesting and handling potatoes
        Page 47
        Page 48
        Page 49
    The partially mechanized system
        Page 50
        Page 51
        Page 52
        Page 53
    Comparison of cost of harvesting and handling potatoes with various systems
        Page 54
        Page 55
    Relation of total acres harvested per season and rate of harvesting per hour to cost per unit
        Page 56
        Page 57
        Page 58
        Page 59
        Page 60
    Relation of total hours harvester operated per season and rate of harvesting per hour to cost per unit
        Page 61
        Page 62
        Page 63
    Effect of variation in expected life and cost of equipment on per unit cost
        Page 64
        Page 65
    Custom mechanical harvesting
        Page 66
    Problems of custom harvesting
        Page 67
        Page 68
    Summary and conclusions
        Page 69
        Page 70
        Page 71
        Page 72
Full Text


Bulletin 612


October 1959


UNIVERSITY OF FLORIDA
AGRICULTURAL EXPERIMENT STATIONS
JOSEPH R. BECKENBACH, Director
GAINESVILLE, FLORIDA
In Cooperation with
Agricultural Marketing Service, United States Department of Agriculture





AN ANALYSIS OF QUALITY AND COST

OF HARVESTING AND HANDLING

POTATOES WITH MECHANICAL

EQUIPMENT


By
R. E. L. GREENE, L. J. KUSHMAN AND H. C. SPURLOCK
Agricultural Economist, Florida Agricultural Experiment Station, Gaines-
ville, Florida; Physiologist, Marketing Research Division, Agricultural Mar-
keting Service, United States Department of Agriculture; and Former
Research Assistant, Florida Agricultural Experiment Station, Gainesville,
Florida, respectively.

Fig. 1.-Two-row mechanical harvester digging and loading potatoes in bulk.









CONTENTS
Page
IN TRODUCTION .................... ..... .. ....... ...... ........ ...... .. ......... 3
Purpose of Study ....................... .... ..... ............ .. .... ........... ........ .... 4
M ethod of Study ......................................--- ----------------... ............ ..--...------ 4
Performance of Mechanical Equipment ...............................----- 5
Physical Injuries --.---5----...........-...-..------5
Costs of Harvesting Potatoes ........-................ --------------- 7
USE OF EQUIPMENT, PERFORMANCE AND RATES OF HARVESTING --...........-- 7
Number of Machines and Acres Harvested Mechanically in 1953 and
1954 .........- ............................ ............------------- -- .--------. 8
Performance Rates and Capacity of Harvesters ................................--- 10
Variation in Acres Harvested per Hour ....-... .--.............--..-....... 11
Variation in Amount of Potatoes Harvested per Hour .................... 14
Factors Affecting Rate of Harvesting ....-.........-----........---.....------- 14
Operating Time Lost and Proportion Due to Various Causes .......... 15
Relation of Yield per Acre and Other Factors to Total Volume
Harvested per Hour .... -- -.. -----.............. 17
INJURIES TO POTATOES IN HARVESTING AND HANDLING ...........................----- 20
Amount and Type of Injury .~..................... --- --.....- 20
Bulk Loading and Hauling of Potatoes in Field Bags to the Pack-
inghouse ......--.. - ........... ---- -.......... --........---.-- -- 20
One-Row Direct H arvesters ............................ -.......... ..........-- -- 21
Direct Mechanical Harvesters and Handling in Bulk -...................... 21
Comparison of Injuries in Potatoes Harvested Mechanically and
with Conventional Methods ..-----... ...- -..... ........ ................... 24
Place Where Injuries Occurred --.--------..........-....--..----.....-.......- 28
Injuries to Potatoes When Run through Bins ..---------...............- 29
Reduction of Injuries ............... .......... .. ........ ------ ..----------. 31
COST OF HARVESTING AND HANDLING POTATOES WITH DIFFERENT SYSTEMS 33
Items Included and Method of Calculating Cost .................-... ............ 34
The Conventional System ................... ........ ............... .... ..... .......----- 35
Investment, Estimated Life and Cost of Operating Harvesting
Equipm ent ........................................ ............... --- ---- 35
Per Acre and Per Unit Cost ........................- ... .... ..... ........- 40
The Completely Mechanized System ................................--....... 43
Investment, Estimated Life and Cost of Operating Harvesting
Equipment --..- ....-- ...--- --....---- ... --.. --------... .......---- 43
Per Acre and Per Unit Cost of Harvesting and Handling Potatoes 47
The Partially Mechanized System ..................... . .................. 50
Cost of Harvesting Potatoes with a 1-Row Bagger Type Harvester 50
Cost of Bulk Handling of Potatoes in Field Bags .......................... 50
Comparison of Cost of Harvesting and Handling Potatoes with Vari-
ous Systems -...-......-..... ---..........-- .. -- --..--. --------- .... 54
FACTORS AFFECTING COST PER UNIT OF HARVESTING AND HANDLING PO-
TATOES .......-.............----------------. --- ------ .... ....------ -.. ---------. 54
Relation of Total Acres Harvested per Season and Rate of Harvesting
per H our to Cost per Unit .................... ..............-- .................. 56
Relation of Total Hours Harvester Operated per Season and Rate of
Harvesting per Hour to Cost per Unit ........................................ 61
Effect of Variation in Expected Life and Cost of Equipment on per
Unit Cost ....----.............. ....--- .---------.-- -------- -- -.. ........ 64
CUSTOM MECHANICAL HARVESTING ..............-...... ....... ................- 66
Extent of U se ........................... -.. .. .. -------- ....- - -........... 66
Problems of Custom Harvesting --.....-.....- .... .................... ............. 67
SUMMARY AND CONCLUSIONS ................---------- -- ---- --------------- ---------. 69








An Analysis of Quality and Cost of

Harvesting and Handling Potatoes with

Mechanical Equipment

By R. E. L. GREENE, L. J. KUSHMAN AND H. C. SPURLOCK

Harvesting and handling of potatoes require much human
labor. In recent years costs of harvesting have increased with
rising wage rates. Since wage rates have increased relative to
the cost of operating mechanical equipment, farmers have sought
to substitute mechanical for human power wherever possible.
The development of mechanical equipment, which reduces
substantially the amount of labor required to harvest and handle
potatoes, has occurred mainly since 1950. Harvesters were first
used in North Dakota and Idaho I and later moved into the South-
eastern states. Such equipment was first used commercially in
the Southeast to an appreciable extent in Alabama in 1952.1
Because a shift to mechanical harvesting will have a tremen-
dous impact on the potato industry in this area, potato growers
and packinghouse operators have asked such questions as:
What are the methods of harvesting and handling potatoes
mechanically?
What are some of the problems associated with these methods
of handling?
How does the quality of potatoes harvested with mechanical
equipment compare with the quality of potatoes harvested with
conventional methods?
What is the investment in a unit of mechanical equipment
and how does the cost of harvesting potatoes mechanically com-
pare with the conventional method?

1 This is the second in a series of reports. A report has been prepared
describing the various systems and equipment being used to harvest and
handle potatoes mechanically in the Southeast. See Equipment for Me-
chanical Harvesting and Handling of Potatoes in the Southeast. Bulletin
579, Florida Agricultural Experiment Station, November 1956.
Note.-This study was supported by funds provided by the Research and
Marketing Act of 1946 and State research funds. The work was begun as
a contributing project to Southern Regional Potato Marketing Research
Project SM-9.
Acknowledgments.-Much of the data in this manuscript was originally
in a dissertation presented by Hooper C. Spurlock to the Graduate Council
of the University of Florida in partial fulfillment of the requirements for
the degree of doctor of philosophy. The authors wish to express their ap-
preciation to potato growers, machinery manufacturers and owners and
managers of packinghouses without whose cooperation this study would
have been impossible.






Florida Agricultural Experiment Stations


Answers to these questions will determine the usefulness of
such equipment and the need for further development in this
field.
PURPOSE OF STUDY
To obtain some definite information on the questions listed
above, the Florida Agricultural Experiment Station, in coopera-
tion with the Biological Sciences Branch of the Agricultural
Marketing Service, U. S. Department of Agriculture, began a
regional research study in which special attention was given to
mechanical harvesting and handling of potatoes in Florida and
Alabama.2 The purpose of the work was to determine the effects
of mechanical harvesting of early Irish potatoes on harvesting
practices, quality, costs and organization of packinghouses. Some
experimental work was done on ways and means of decreasing
the amount of damage to potatoes harvested mechanically. At-
tention was given also to problems of increasing efficiency of
operation of mechanical equipment.
The equipment, problems of operation and suggestions for
improving the operation of mechanical equipment were described
earlier.3 This report deals with an analysis of quality and costs
of harvesting and handling potatoes mechanically.

METHOD OF STUDY
To obtain the data in this study, visits were made during the
1953 and 1954 harvesting seasons to areas in Florida and Ala-
bama where mechanical equipment was used. Observations were
made on methods and types of equipment used, how the equip-
ment operated and problems encountered. Data were obtained
on changes and adjustments made by manufacturers, farmers
and packinghouse operators to make the equipment operate more
satisfactorily. Records were obtained on the performance of
the equipment, the amount of physical injuries in potatoes har-
vested and handled mechanically and the costs of harvesting and
handling potatoes both with the conventional system and with
mechanical equipment.4

2 This work was part of a larger project entitled, "Improving Methods
and Practices in Harvesting, Handling and Packing Early Irish Potatoes."
3 Bulletin 579 (see footnote 1).
4 Systems for harvesting and handling potatoes, as used in the South-
east, may be classified into 3 groups: (1) conventional system (2) com-
pletely mechanized system and (3) partially mechanized system.
In the conventional system of harvesting, a 1- or 2-row tractor-drawn







Harvesting and Handling Potatoes Mechanically


Performance of Mechanical Equipment.-To obtain data on
performance, all operators of mechanical harvesters were visited
at the end of the 1953 season and asked to estimate their average
rate of harvesting. During the 1954 season a special effort was
made to obtain data on the average rate of harvesting and varia-
tions in rates under different conditions. For selected periods,
supervised daily records were kept on the operation of a number
of different machines. Detailed data were recorded on total
hours operated, acres and volume harvested, yield per acre, time
loss due to various causes, number and size of loads hauled and
size of operating crews. Also, an estimate was made of length
of rows, weeds and vines in the fields, and other relevant infor-
mation.
Data on performance were analyzed to show the average
rate and factors affecting the rate of harvesting. Several makes
of equipment and methods of harvesting were observed. Each
was widely different, so the data were treated separately. In
the presentation, completely mechanized direct-type harvesters
are designated as Makes A, B and C; completely mechanized
indirect types as Makes E and F; and one-row bagger type as
Make G. Major emphasis is given to Makes B and G, since these
harvesters were used the most.
Physical Injuries.-Samples of potatoes were collected at
selected points during the harvesting and handling process and
examined to determine the amount of physical damage sustained
and placed where damage occurred. Usually 3 to 6 samples of


digger is used to dig the potatoes and drop them back on the ground. They
are then picked up by hand and placed in field containers-boxes or bags.
The potatoes are hauled from the field to the packinghouse on flat bed
trucks. They are loaded and unloaded manually. When the term "conven-
tional digging," "usual digging," or "in the usual manner" is used in this
report, it means harvesting and handling potatoes by the conventional
system.
In complete mechanization, both the harvesting and handling are mech-
anized. Mechanical equipment is used to dig the potatoes and load them
in bulk in special bodies mounted on trucks or trailers. In direct harvest-
ing, digging and loading are accomplished with a machine in 1 operation.
In indirect harvesting, the potatoes are first dug with a conventional digger
and placed in a window by means of a windrowing attachment. A machine
is then used to pick them up out of the window and load them in bulk.
Partial mechanization refers to the use of mechanical equipment for
only a part of the harvesting operations and the use of conventional meth-
ods for the remainder. That is, the potatoes may be dug with a harvester
that places them in field containers, which are then handled manually in
the field and at the packinghouse in the usual way. On the other hand,
the potatoes may be dug and picked up in the usual way. They may then
be loaded in bulk in the field by means of a field loader to be hauled to the
packinghouse.






Florida Agricultural Experiment Stations


about 30 pounds each were collected, but the number varied
from 1 to 12 and the size from 25 to 60 pounds, depending on the
variation in amount of damage to be measured.
The place of sampling varied. For direct mechanical har-
vesters, samples were usually collected from the end of the bulk
loader just as the potatoes were placed in the bulk bodies, from
the end of the conveyor in the bulk trucks as they were unloaded
and off the washer in the packinghouse. The latter point was
selected as it was a common point for all methods. The samples
gave a measure of total damage in digging, loading, unloading
and placing the potatoes on the washer.
After the samples were collected, the potatoes were washed,
if this had not already been done, and examined for physical
injuries. In 1953, before the potatoes in each sample were ex-
amined, they were divided into 3 size classifications according
to diameter: (1) less than 17/8 inches, (2) 17/8 inches to 3 inches
and (3) over 3 inches. The potatoes were not sized in 1954 5.
Three classes of injuries were recorded, (1) cuts (as by the dig-
ger blade), (2) major injuries (injuries of sufficient extent that
the potatoes probably would not meet U. S. No. 1 grade require-
ments) and (3) minor injuries (non-grade defects).6 Potatoes
were classed as injured if moisture could be squeezed from the
suspected area of injury. All data were recorded by weight and
converted to percentages on that basis.
In the study, care was taken to obtain samples as representa-
tive as possible and not to add injuries during the collection and
later examination of the potatoes. It was difficult to obtain
paired comparisons between different equipment or methods,
as they were nearly always used in different fields and by differ-
ent growers. Instead of making direct comparisons, samples
were taken at various times and under different conditions in
order to establish an average for the various situations.
The data on physical injuries were summarized to show a
comparison of the amount of damage in potatoes harvested with
different types of equipment and the amount of damage at vari-
5 The potatoes were not sized in 1954 because it was found there was
a close relationship between size and amount of injury. However, in the
same year and for potatoes of the same variety, the proportion of potatoes
in identical size groups did not vary greatly. Variation in amount of in-
juries in samples was not due to variation in size of potatoes.
6 Major injury was damage which could not be removed without a loss
of over 5 percent of the total weight of the potato. Minor injury was dam-
age that could be removed with a loss of less than 5 percent of the weight
of the potato.






Harvesting and Handling Potatoes Mechanically


ous points in the harvesting and handling process. A compari-
son was made also of the variation in damage occurring in differ-
ent packinghouses according to the adequacy with which each
was set up to receive potatoes hauled in bulk.
Costs of Harvesting Potatoes.-The operators of mechanical
equipment were interviewed at the end of the 1953 and 1954
seasons. Data were obtained on number of acres harvested,
costs of operating the equipment and other pertinent informa-
tion.
Data were obtained also from growers using the conventional
system of harvesting to compare costs for the various meth-
ods. Data were obtained from 30 growers in Alabama for the
1953 season. Data were obtained in Florida for the 1954 season
from 6 growers in the Fort Myers area, 26 growers in Dade
County and 39 growers in the Hastings area. In collecting data
in each area on cost of harvesting by the conventional method,
an effort was made to select operators representative of the vari-
ous size growers. The data for Alabama were adjusted to the
1954 season by applying 1954 cost rates.
The data on cost were analyzed to determine the cost of har-
vesting and handling potatoes per acre harvested and per 100-
pound packed bag. This was done for the different harvesting
systems studied. Costs of harvesting and handling included all
costs from vine killing, if done, until the potatoes were placed
on the washer in the packinghouse. The total cost to this point
was selected for comparison, as it was common to all methods
of harvesting and handling. Cost per unit for the conventional
system was based on a normal yield per acre. For mechanical
equipment, cost per unit was based on the average yield for the
years the records were taken. The farmers had not had enough
experience with mechanical equipment to estimate its perform-
ance under normal conditions.

USE OF EQUIPMENT, PERFORMANCE AND
RATES OF HARVESTING
Data on performance, rates of harvesting and capacity of
mechanical equipment are needed to determine the amount of
potatoes that can be harvested in a given period and the volume
a unit of equipment can supply a packinghouse. Performance
must be measured not only by the acres or amount harvested
but also by the degree to which vines, weeds, clods and trash are






8 Florida Agricultural Experiment Stations

eliminated from the potatoes before they are loaded in bulk or
placed in small containers.

NUMBER OF MACHINES AND ACRES HARVESTED MECHANICALLY
IN 1953 AND 1954

During the 1953 season 6 farmer-built mechanical harvesters
were operated in Florida. In the Fort Myers area about 700
acres of potatoes were harvested by 3 2-row machines that placed
the potatoes in field boxes (Table 1). About 300 acres were har-
vested on a custom basis by 1 manufacturer who operated 2
2-row direct harvesters to demonstrate his equipment. Three 1-
row direct harvesters that placed the potatoes in field bags were
used to harvest 125 acres in the Hastings area. Two farmers
used bulk handling equipment to handle about 500 acres of po-
tatoes from the field to the packinghouse.

TABLE 1.-NUMBER OF MECHANICAL HARVESTERS AND ACRES OF POTATOES
HARVESTED, ALABAMA AND FLORIDA, 1953 AND 1954 SEASONS.

Item Alabama Florida
1953 1 1954 1953 | 1954

Number of harvesters in use:
Direct ...................... ..... .... 8* 12 4** 6
Indirect ............ .......................... 6 4 it
1-row .........................-- ..-- ..---- - 3 11
Acres of potatoes harvested
mechanically:
Direct .-..-- ................................... 995 1,121 1,000t 1,335
Indirect ............... ....... ..-----........... 1,055 634 40
1-row machines ............................ - 125 522

Total ....................................... I 2,050 1,755 1,125 1,897

Acres dug with conventional
diggers and bulk handled ...... 321 500 746
Total harvested acres of com-
mercial potatoes ............... 31,800 19,700 40,700 31,700
Percent of commercial crop
harvested mechanically ........ 6.5 9.0 2.8 6.0

Two machines were operated as custom harvesters.
** Two machines were operated as custom harvesters and 2 as direct harvesters to place
the potatoes in field boxes.
t This machines was operated on rental basis as a demonstration machine.
t 700 acres were dug direct and placed in field boxes.

In Alabama during the 1953 season 6 farmer-owned 2-row
direct harvesters and 6 1-row indirect harvesters were operated.






Harvesting and Handling Potatoes Mechanically


One company also operated several direct 2-row machines on a
custom or purchase contract basis. Mechanical equipment was
used to harvest 2,050 acres of potatoes, or about 6.5 percent of
the commercial crop.
There was a considerable increase in the use of mechanical
equipment in Florida during the 1954 season. Commercially-
built harvesters were operated in Fort Myers and Hastings areas.
Four farmer-owned and 2 custom operated 2-row direct har-
vesters that loaded the potatoes in bulk harvested 1,335 acres.
Eleven farmer-built 1-row machines that placed the potatoes in
bags were used to harvest 522 acres in the Hastings area. In
addition, potatoes on 746 acres were dug with conventional dig-
gers, picked up by hand and then field loaded and hauled in bulk
trucks to the packinghouse.
During the 1954 season in Alabama 16 mechanical harvesters
were used to harvest 1,755 acres of potatoes. Field loaders and
bulk trucks were used to handle 321 acres of conventionally dug
potatoes from the field to the packinghouse. Two hundred ninety
five less acres of potatoes were harvested mechanically in 1954
than in 1953. The drop was due to a decrease in size of the crop,
as the proportion of the commercial crop harvested mechanically
increased from 6.5 to 9.0 percent.
Since 1954 the use of mechanical harvesting and handling
equipment has increased rapidly in Florida, especially in the
Hastings area. In 1956 approximately 15 1-row and 20 or more
2-row harvesters operated in the area. Observations during the
1957 season indicated that the use of mechanical harvesters more
than doubled, with about 35 1-row and 50 2-row machines being
used. These 85 machines probably harvested from 1/4 to 1/:
of all potatoes in the area. Mechanical equipment was used ex-
tensively also in the Fort Myers-Immokalee area in 1957, but no
estimate is available on the amount of potatoes harvested. Me-
chanical equipment has not been used in other potato areas in
Florida.
The use of mechanical equipment has decreased in Alabama
since 1954. A factor in the decrease, no doubt, has been a series
of unfavorable crop years which made it difficult to use the equip-
ment. Also, a majority of growers in Alabama hauled their
potatoes to packinghouses operated on a custom basis. This
makes it difficult to operate mechanical harvesters to full ca-
pacity, for often the bulk trucks have to wait at the packing-
house to unload. Under such circumstances, cost of harvesting






Florida Agricultural Experiment Stations


may be increased rather than decreased when a grower uses a
mechanical harvester.

PERFORMANCE RATES AND CAPACITY OF HARVESTERS
Records were obtained for the 1953 season for all farmers
who operated mechanical harvesters in Alabama. These data
showed that the average rate of harvesting varied from 0.60
to 1.33 acres and averaged 0.70 acre per hour of operation (Table
2). The estimated yield for the 7 farm units studied was 144
packed hundredweights equivalent 7 per acre. This compared
with an estimated normal yield of 121 hundredweights per acre.
From the daily records kept on performance of equipment in
1954, it was possible to calculate percent of operating time idle
and acres and amount of potatoes harvested per total and net
hours of operation. Since the farmer is usually interested in
the amount of potatoes harvested in a given period, including
the time lost for repairs or otherwise, the data on rates of per-
formance refer to amount harvested per total hour unless other-
wise indicated.
In Alabama records were kept with two operators using Make
A harvesters and five using Make B harvesters. Operators of
Make A equipment harvested an average of 0.61 acre per hour
on potatoes that yielded 170 hundredweights per acre (Table 3).
Farmers using Make B equipment harvested an average of 0.82
acre per hour, but their yield averaged only 124 hundredweights
per acre. Percent of operating time lost due to waiting for
trucks, breakdowns and so forth averaged 15 percent for Make A
harvesters and 6 percent for Make B harvesters.
In the Hastings, Florida area, records were obtained for 4
operators using Make B type harvesters. Rate of harvesting
ranged from 0.58 to 0.90 acre and averaged 0.70 acre per hour.
Twelve percent of the total hours observed was lost due to
breakdowns and waiting for trucks. Records were also obtained
from 4 operators who used the Make G 1-row bagger harvester.
These men operated 11 harvesters. The data for all harvesters
for each operator was averaged since the machines were operated
as a unit. The rate of harvesting for each operator ranged from
0.30 to 0.37 acre and averaged 0.32 acre per hour. Only 5 per-
cent of the operating time was lost.

7 Hereafter, when the term "hundredweight" is used it means a 100-
pound equivalent packed bag of potatoes unless otherwise stated.







Harvesting and Handling Potatoes Mechanically


TABLE 2.-RATES OF PERFORMANCE FOR MECHANICAL HARVESTERS USED ON
7 FARM UNITS IN ALABAMA IN 1953.

Farm Unit Number
Item
1 2 3 4 5 6 7*

Mechanical harvester:
Number ...... .......................... 1 1 2 1 1 1 3
Hopper type boxes:
Number ....... .. .......... ...... 3 3 4 3 4 4 12
Acres in potatoes ........ ....... 110 119 300 115 190 500 500
Acres harvested mechanically ......110 119 200 115 190 350 500
Acres harvested per machine ..... 110 119 100 115 190 ** 167
Yield per acre: (100-lb. equiva-
lent packed bags)
1953 yield ............ 141 169 141 123 105 101 227
Normal yieldt ................ .......... 136 123 88 123 105 101 171
Average hours machine
operated per day .................. 10 9 10 8 9 10 9
Amount harvested per machine
per hour under average con-
ditions Acres .................... .70 .67 .60 .75 .78 .80 1.33
100-lb. equivalent packed bags 98 113 84 92 82 82 302

All potatoes on this farm were white varieties grown for making potato chips. They
were handled with less care than potatoes packed for table stock.
** On this farm, 50 acres were harvested with a mechanical harvester on a custom basis.
The machine owned by the farmer was used to harvest 300 acres.
t Yield expected under average weather and crop conditions.

In Florida and Alabama amount harvested for 2-row ma-
chines varied from 55 to 185 acres during the 1954 season. The
average number of acres harvested per machine was 99 in Ala-
bama and 145 in Florida. An average of 51 acres was harvested
with the 1-row machines in the Hastings area.
Variation in Acres Harvested per Hour.-There was a con-
siderable variation in both number of acres and amount of pota-
toes harvested per hour of operation among the different op-
erators and also for the same operator on different days. In
Alabama sufficient records were not obtained for the Make A
harvester to show variations. Records were obtained for 24
harvester days for operators using Make B harvesters. Acres
of potatoes harvested per hour ranged from less than 0.75 on 7
days to 0.90 acre or more on 10 days (Table 4). Yield per acre
averaged 142 hundredweights on the days when acres harvested
per hour was lowest and 116 hundredweights on days when rate
of harvesting was highest.







Florida Agricultural Experiment Stations


TABLE 3.-ACRES AND HUNDREDWEIGHTS EQUIVALENT HARVESTED WITH
MECHANICAL HARVESTERS PER TOTAL AND NET HOURS OF OPERATION AND
PERCENT OF OPERATING TIME LOST, BY OPERATORS, ALABAMA AND HAST-
INGS AREA, FLORIDA, 1954.


Acres Harvested
per


I
Total Net
Hour Hour


(Acres) (Acres)


Hundredweights
Harvested per


Total Net
Hour Hour


Yield
per
Acre


(Num- (Num- (100-lb.
ber) ber) bag)


Percent-
Total age of
Hours Operat-
Ob- ing
served I Time
I Lost*


(Num- (Per-
ber) cent)


Baldwin County, Alabama, Make A Mechanical Harvesters


1 ........... 0.59 0.62
2 ............ 0.61 0.76


Total or
average 0.61 I 0.72


Baldwin County, Alabama, Make B Mechanical Harvesters


0.57 0.60
0.80 0.83
0.84 1.07
0.93 0.97
1.04 1.04



0.82 0.87


80 85 141
94 97 118
109 140 130
120 126 130
64 64 61



101 108 124


Hastings Area, Florida, Make B Mechanical Harvesters**


Total or
average 0.70


Hastings Area, Florida, Make


G Mechanical Harvesters


1 .......... 0.30 1 0.32 62
4 .... ... 0.30 0.32 59
3 ............ 0.31 0.36 75
2 ........... 0.37 0.37 56


Total or
average 0.32 0.34 63


67


208 114
191 116
241 120 1
150 119



196 469


* Time lost due to breakdowns, waiting for trucks, etc.
** Includes Sebago potatoes only.


Operator
Number


148
89



104


154
109



123


248
144



170


19
54



73


4
1 -.........
3 ............
5 ............
2 ............


Total or
average


5.3
3.1
22.0
4.9
0.0



5.8


0.63
0.81
0.87
1.02



0.80


94
139
188
184



137


103
164
224
209



157


8.6
15.2
15.9
12.1


,


1







Harvesting and Handling Potatoes Mechanically


TABLE 4.-VARIATION IN ACRES OF POTATOES HARVESTED PER HOUR WITH
MECHANICAL HARVESTERS, QUANTITY HARVESTED, YIELD PER ACRE AND
PROPORTION OF OPERATING TIME LOST, ALABAMA AND HASTINGS AREA,
FLORIDA, 1954.

Average Rate of
Number Harvesting Yield Proportion
Acres of per Hour per of
Harvested Obser- I Hundred- Acre Operating
per Hour vations I weights (cwt) Time Lost
Acres I Equiva- (percent)
lent
Baldwin County, Alabama, Make B Mechanical Harvesters

Less than 0.75 .... 7 0.58 82 142 4.7
0.75-0.89 ............ 7 0.81 102 127 9.5
0.90 or more ........ 10 0.98 114 116 3.7

Total or ]
average ................ 24 0.82 101 124 | 5.8
Hastings Area, Florida, Make B Mechanical Harvesters

Less than 0.70 .... 14 0.56 98 174 11.3
0.70-0.79 .......... 13 0.74 163 221 13.5
0.80 or more ........ 8 0.89 167 189 12.6

I I
Total or
average ............. 35 0.70 137 197 12.3

Hastings Area, Florida, Make G Mechanical Harvesters

Less than 0.30 .... 17 0.25 60 251 7.3
0.30-0.39 ............ 25 0.34 64 187 4.6
0.40 or more ........ 6 0.43 68 159 *

Total or
average ................ 48 0.32 63 196 5.1
Less than 0.05 percent.

Records in the Hastings area included 35 days for 4 operators
using Make B harvesters. During these observations acres har-
vested per hour was less than 0.70 on 14 days, 0.70 to 0.79 on 13
days and 0.80 acre or more on only 8 days. The low average of
0.56 acre per hour was due to reduced speed and poor operating
efficiency. Stumps (common in the new ground areas), excessive
amounts of weeds and grass, short head lands and narrow beds
were some of the factors that contributed to the low acreage har-
vested. Loss of operating time averaged 12.4 percent, but there
was little variation with acres harvested per hour.






Florida Agricultural Experiment Stations


Data were obtained for 48 harvester operating days for Make
G 1-row machines in the Hastings area. During the time ob-
served less than 0.30 acre were harvested on 17 days and 0.40
acre or more on only 6 days. Acres harvested per hour varied
inversely with yield per acre. The amount of potatoes harvested
with this type of machine is limited by the capacity of the work-
ers to bag the potatoes. On days when acres harvested per hour
were least, the number of bags harvested per hour averaged
only 60. This compared with 68 bags on the days when the num-
ber of acres harvested per hour was largest.
Variation in Amount of Potatoes Harvested per Hour.-In
considering rate of harvesting for mechanical equipment, the
volume harvested rather than the number of acres is the most
significant figure. The amount harvested per hour will vary
with the number of acres harvested unless there is a variation
in yield per acre. The speed of harvesting may be varied with
yield. However, fields with high yields usually are in better
condition and contain less weeds and grass than fields with low
yields. Therefore, the speed of operating the harvester may in-
crease even as yield increases, thus resulting in an even larger
increase in volume harvested.
The average rate of harvesting for Make B harvesters in
Alabama was 101 hundredweights per hour (Table 5). However,
amount harvested varied from 78 hundredweights with the low-
est rate of harvesting to 124 hundredweights on the days with
the highest rate of harvesting. The average rate of harvesting
for harvester B in the Hastings area digging Sebago potatoes
varied from 91 hundredweights per hour on days when the rate
was lowest to 192 hundredweights on days when the rate was
highest. As the rate of harvesting increased, acres harvested
per hour increased, even though yield per acre was also higher.
Records for the 1-row machines showed that rates of harvest-
ing per hour varied from an average of 49 hundredweights for
the low group to 80 for the high group and averaged 63 hundred-
weights for all groups. As the amount harvested per hour in-
creased there was very little variation in acres harvested per
hour but yield per acre was higher.

FACTORS AFFECTING RATE OF HARVESTING
Some of the principal items that affected the volume of po-
tatoes havested per hour were yield per acre, weeds and grass in
the fields, short rows, difficulty in turning at the end of the rows,








Harvesting and Handling Potatoes Mechanically


poor traction and loss of operating time due to mechanical break-
downs, delays in unloading the bulk trucks at the packinghouses
and other factors.

TABLE 5.-VARIATION IN AMOUNT OF POTATOES HARVESTED PER HouR WITH
MECHANICAL HARVESTERS, ACRES HARVESTED, YIELD PER ACRE AND PRO-
PORTION OF OPERATING TIME LOST, ALABAMA AND HASTINGS AREA,
FLORIDA, 1954.


Quantity
Harvested


Number
of


Average R
Harvest
per Ho


r Hour i Obser- Hundred-
redweights) vations weights I
Equiva-
I _lent |
Baldwin County, Alabama, Make


ate of
ing
ur


Acres


Yield
per
Acre
(cwt)


Propor-
tion of
Operating
Time Lost
(percent)


B Mechanical Harvesters


Less than 90 ........ 9 78 0.69 113 4.0
90- 109 ............... 7 99 0.79 125 9.0
110 or more .......... 8 124 0.99 131 5.0


Total or
Average ................ 24 101 0.82 124 5.8

Hastings Area, Florida, Make B Mechanical Harvesters

Less than 120 ...... 13 91 0.59 155 10.7
120- 169 .............. 13 150 0.72 208 13.7
170 or more .......... 9 192 0.84 229 13.3


Total or
Average .......... .. 35 137 0.70 197 12.3

Hastings Area, Florida, Make G Mechanical Harvesters


Less than 55 ........
55- 69 .................
70 or more ..........


Total or
Average ................


49 0.32 152 2.5
59 0.31 193 6.0
80 0.34 237 6.8


48


0.32


196


Operating Time Lost and Proportion Due to Various Causes.
-Operating delays were of 2 kinds: delays resulting in the dig-
ging equipment being inactive for only a few minutes, such as a
short pause to free a digger chain or conveyor elevator of potato
vines or roots, and those ranging from a few minutes to an hour
or more due to such things as mechanical breakdowns and wait-


per
(hundi







Florida Agricultural Experiment Stations


ing for bulk trucks. Mechanical breakdowns included chain
breaks, broken axles, clutches and so forth.
The causes of work stoppages were grouped as mechanical,
waiting for bulk trucks, rain, lack of laborers, flat tires and mis-
cellaneous. Make G 1-row harvesters with only 5.1 percent of
the operating time lost had the least inactive time for all har-
vesters (Table 6). Of the total time lost for this make of har-
vester, about 2/3 was due to mechanical breakdown and 1/6 to
shortage of labor. No time was lost waiting for trucks, for these
machines were not dependent upon trucks for continuous har-
vesting. Since the potatoes were placed in field bags for hauling
to the packinghouse, the bags were set off on the ground, to be
hauled later if a truck was not available, and the digging con-
tinued.

TABLE 6.-OPERATING TIME LOST AND PROPORTION DUE TO VARIOUS CAUSES,
BALDWIN COUNTY, ALABAMA, AND HASTINGS AREA, FLORIDA, 1954.

Baldwin County, Hastings Area,
Alabama Florida
Item Make A Make B Make B Make G
Harvest- Harvest- Harvest- Harvest-
ers ers ers ers

Total hours observed ........ 73 197 309 468
Hours equipment idle ........ 11 11 38 24
Percent of operating time
idle ........................... 15.0 5.8 12.3 5.1
Proportion of idle time
due to:
Mechanical:
Chains ....................... 49.1 10.9 17.2 24.7
Other .............................. 44.2** 26.3 21.1 38.9
Waiting for trucks .......... 6.7 43.8 40.1 -
Rain .................................. 10.2 10.8
Labor ................................. 19.0 .9 16.7
Miscellaneous t ................ 7.2 4.7
Flat tires .......................... - 3.3 4.2

Total .............................. 100.0 100.0 100.0 100.0

Both drive and conveyor chains.
** Primarily 1 major breakdown.
t Mostly due to equipment stuck in ditches.

Time lost averaged 12.3 percent of the total operating time
for the Make B harvesters in the Hastings area but only 5.8
percent in Alabama. In each area slightly more than 2/5 of the
time lost was due to waiting for trucks and slightly less than
this amount to mechanical breakdowns. For the Make A har-







Harvesting and Handling Potatoes Mechanically


vesters in Alabama, about 93 percent of the lost operating time
was due almost entirely to mechanical breakdowns.
For the hours operated, Make B harvesters in Alabama lost
only about 1/ as much time as Make A and less than half as much
as Make B in Florida. When this study was made, farmers in
Alabama had had more experience in operating mechanical har-
vesters than farmers in the Hastings area. As a result, they
probably had learned how to avoid some of the difficulties in op-
erating mechanical equipment.
Relation of Yield per Acre and Other Factors to Total Volume
Harvested per Hour.-Yield per acre is one of the most important
factors affecting volume of potatoes harvested per hour when
harvested with mechanical equipment and hauled in bulk. The
effect, however, of yield on rate of harvesting varies, depending
on amount of weeds and grass in the field. For the Make B har-
vesters in the Hastings area the average rate of harvesting in-
creased from 90 to 178 hundredweights per hour as average yield
per acre increased from 147 to 233 hundredweights. In Alabama,
rate of harvesting increased from 80 to 107 hundredweights per
hour as yield per acre increased from 97 to 145 hundredweights.
In the case of the Make G 1-row harvester at Hastings, Flor-
ida, volume harvested per hour increased as yield increased up
to about 240 bags per acre. The limiting factor on this machine
was the amount of potatoes that could be bagged per hour. If
yield per acre was high, the speed of the machine was reduced
so only the volume the baggers could handle was delivered.
These data indicate that the maximum capacity of this machine
is 60 to 70 hundredweights per hour.
The relationship between yield and rate of harvesting is ex-
pressed in another way in Table 8. In this table rate of harvest-
ing is shown in terms of volume per net hour of operation to
eliminate differences due to variation in amount of time the
harvesters were not operating. There was a high correlation
between yield and volume harvested for Make A harvesters
operated in Alabama and Make B and G harvesters in Florida.
There was no significant correlation between yield per acre and
volume harvested per hour for Make B harvesters in Alabama.
The correlation coefficients in Table 8 also show the effects
of weeds, grass and clods in the field on rate of harvesting and
also the relation among several factors. Potatoes harvested
with Make A harvesters in Alabama and Make B in Florida had
fewer weeds and clods in fields with high yields than in fields







Florida Agricultural Experiment Stations


with low yields. However, fields of potatoes with high yields
harvested with Make B harvesters in Alabama and Make G in
the Hastings area contained more weeds than those with low
yields.

TABLE 7.-RELATION OF YIELD PER ACRE TO ACRES AND VOLUME OF POTA-
TOES HARVESTED PER HOUR, BALDWIN COUNTY, ALABAMA AND HASTINGS
AREA, FLORIDA, 1954.

Num- Average Rate of Rating Propor-
Yield per ber Average Harvesting for tion of
Acre of I Yield per Hour Trash, Operat-
(hundred- I Ob- per Hundred- Vines ing
weights) serva- Acre weights and Time
tions (cwt) Equiva- Acres Clods* Lost
Silent (percent)
Baldwin County, Alabama, Make B Mechanical Harvesters
1 I I
Less than
120 ......... 6 97 80 0.96 38 4.5
120-134 .... 10 126 100 0.80 51 9.2
135 or more 8 145 107 0.74 57 2.5

Total or
average ...... 24 124 101 0.82 50 5.8

Hastings Area, Florida, Make B Mechanical Harvesters

Less than
185 .......... 11 147 90 0.62 50 8.7
185-209 .... 11 195 137 0.70 35 13.5
210 or more 13 233 178 0.76 20 14.5

Total or
average ...... 35 197 137 0.70 34 12.3

Hastings Area, Florida, Make G Mechanical Harvesters

Less than
185 .......... 18 143 52 0.36 21 2.7
185-239 .... 15 210 72 0.34 22 3.3
240 or more 15 263 68 0.26 39 9.7


Total or
average .... 48 196 63 0.32 26 5.1

Amount of vines, clods and weeds in the fields was rated from 0 to 100.

The presence or absence of weeds and grass largely explains
the difference in acres harvested per hour for the Make B har-







Harvesting and Handling Potatoes Mechanically


vesters as yield per acre increased. In the Hastings, Florida,
area the number of acres harvested per hour was highest in the
fields with the highest yields, but in Alabama the reverse was
true (Table 7). Even with an increased yield it was possible to
operate the harvesters at higher rates of speed, even though
more potatoes were handled because of the decrease in amount
of weeds and grass. As the amount of weeds and grass increased
in Alabama the rate of harvesting was reduced because of more
difficult digging conditions.

TABLE 8.-CORRELATION BETWEEN YIELD PER ACRE AND VOLUME OF POTA-
TOES HARVESTED WITH MECHANICAL HARVESTERS PER NET HOUR OF
OPERATION AND RELATIONSHIP AMONG SELECTED FACTORS, BALDWIN
COUNTY, ALABAMA, AND HASTINGS AREA, FLORIDA, 1954.


Selected Factors
Correlated


Yield per acre and amount
harvested per net hour .........
Weeds, grass, clods and amount
harvested per net hour ........
Pickers on harvester and
amount harvested per net
h ou r ............................................
Amount harvested per net hour
and trash in loads ..................
Vines, weeds, clods, etc., and
yield per acre .........................
Pickers on harvester and
yield per acre ................ .........
Trash in loads and yield
per acre .............-........... ...... ..
Pickers on harvester and
vines, weeds and clods ..........
Vines, weeds, clods, etc.,
and trash in loads -...-...........
Pickers on harvester and
trash in loads ..........................

Significant at the .01 percent level.
** Significant at the .02 percent level.
t Significant at the .05 percent level.


Alabama Florida

Make A Make B Make B | Make G


.840* .284 .826* .655*

-.709** .118 -.575* .460*

-.181 .636* -.117 .142

-.476 .245 -.441* -.267

-.638t .481t -.480* .399*
-.508 -.145 1 -.118 -.073


-.364

-.007

.797*

-.188


-.351
.097

.537*

-.637*


-.438
-.069

-.234

.359**


In Florida more operating time was lost on days when yields
were high than on days when they were low. This was due in
part to a shortage of bulk trucks because the potatoes were being
harvested faster than they could be handled at the packinghouse.
The amount of extraneous material was not an important
factor in decreasing the correlation between yield per acre of
potatoes and rate of harvesting with Make G 1-row harvesters.
This machine had a vine eliminator so that extraneous material






Florida Agricultural Experiment Stations


caused little, if any, difficulty. Apparently, a limited maximum
speed was the primary cause of the lower rate of harvesting
with the Make G harvesters where yields were high.
The coefficients in Table 8 also show that the amount of
weeds, grass and other material in the bulk loads was greater
as the amount of this material increased in the fields. This was
to be expected, as the number of pickers on the machines were
not varied a great deal. When digging conditions were bad, it
was impossible to separate all of the extraneous material from
the potatoes. These data emphasize the importance of good
yields and clean fields for the most economical operation of
mechanical harvesters.

INJURIES TO POTATOES IN HARVESTING
AND HANDLING
To be considered satisfactory, harvesting and handling of
potatoes must not only be economical but also must not injure
the potatoes excessively. Injuries not only affect appearance
but cause waste, increase paring losses and often pave the way
for decay. Major injuries may be scored as grade defects. The
importance of keeping injuries to a minimum cannot be over-
emphasized, since they are usually the most common defects
on potatoes.
AMOUNT AND TYPE OF INJURY
Many factors affected the amount of injuries in potatoes
harvested with mechanical equipment. Some of the more im-
portant were variety, maturity, condition of the field, type of
equipment (including modification), care with which the equip-
ment was operated and type of facilities at the packinghouse
for receiving potatoes hauled in bulk. Although data on injuries
were collected for the 1953 and 1954 seasons, major emphasis in
this report is given to the data collected in 1954, since the results
for the 2 seasons were somewhat similar 8. In a few instances
the 1954 data are supplemented with some collected in 1955 as
a part of another phase of this work.
Bulk Loading and Hauling of Potatoes in Field Bags to the
Packinghouse.-From the standpoint of injuries, using a field
loader and bulk trucks to handle potatoes picked up and placed

8 See mimeograph report Mechanical Harvesting and Bulk Handling of
Potatoes in Florida and Alabama, by R. E. L. Greene, L. J. Kushman, J. S.
Norton and H. C. Spurlock, Florida Agricultural Experiment Station, Agri-
cultural Economics Series No. 54-10. January 1954.






Harvesting and Handling Potatoes Mechanically


in field bags was very satisfactory. Samples were collected from
field bags of potatoes before they were loaded in bulk trucks and
off the conveyor in the packinghouse after the potatoes were un-
loaded. An average of 3 tests with fairly mature Sebago po-
tatoes at Hastings showed only 0.2 percent major damage and
1.7 percent minor damage was added to the potatoes in loading
with the field loader and hauling in bulk trucks (Table 9). An
average of 2 tests for Bliss Triumph potatoes similarly handled
in Alabama showed an increase of only 0.2 percent of major
damage and 4.2 percent of minor damage.
One farmer in Alabama dug his potatoes with a conventional
digger but hauled about half of the crop in field bags and the rest
was field loaded and hauled in bulk. Samples collected from the
washer at the packinghouse on 3 different days showed slightly
less injuries in the potatoes field loaded and hauled in bulk (Table
10). Damage would have been even less if the rods on the con-
veyor of the field loader had been covered with rubber and the
arrangement at the packinghouse more satisfactory for unload-
ing potatoes hauled in bulk.
One-row Direct Harvesters.-Samples of potatoes dug and
placed in field bags with Make G 1-row harvesters were collected
off the washer in the packinghouses. These potatoes were hauled
to the packinghouses in the usual way. An average for 7 samples
of Sebago potatoes from 3 packinghouses in the Hastings area
in 1954 showed 1.3 pounds of major damage and 14.5 pounds of
minor damage per 100 pounds of field-run potatoes; an average
of 2 samples for the same method of handling in 1955 showed
0.9 pound major damage and 7.9 pounds of minor damage (Ta-
ble 11).
Damage for the 1-row machines in 1954 was probably higher
than usual, since some of the samples were collected early in the
digging season when potatoes injured easily and the operators
were just learning to use the equipment.
Direct Mechanical Harvesters and Handling in Bulk.-Since
the use of mechanical equipment was more widespread in 1954
and 1955 and farmers had had more experience with its use, the
data for the latter 2 years are presented to show amount of in-
juries to potatoes when harvested and handled in bulk. Samples
for 3 makes of direct harvesters in the Hastings area digging
Sebago potatoes averaged slightly less than 10 pounds of dam-
aged potatoes per 100 pounds, of which a little more than %3.
was minor damage (Table 12). In red potatoes in Alabama,







Florida Agricultural Experiment Stations


TABLE 9.-AMOUNT OF INJURIES TO POTATOES AT END OF PICKING UP AND
AFTER LOADING AND UNLOADING WITH BULK EQUIPMENT, HASTINGS,
FLORIDA, 1953 AND ALABAMA, 1954.

Pounds of Injured Potatoes per 100 Pounds
of Field-Run Potatoes
IAt the End of
Extent of Injury Loading and Increase
At the End of Unloading in
Picking up with Bulk Injuries
Equipment
Sebago Potatoes, Hastings, Florida *


Minor injury .................... I
M ajor injury ........................

T otal ..............................

Digger cuts and
crushed potatoes ..............

Total damage .............
Bliss Triumph


Minor injury ................
Major injury ................

Total ...................

Digger cuts and
crushed potatoes .........

Total damage ........


3.5 5.2
1.6 1.8

5.1 7.0


0.6 1.0

5.7 8.0
Potatoes, Alabama **

22.1 26.3
1.2 | 1.4

23.3 27.7


0.9 0.2

24.2 27.9


S 4.2
S 0.2

4.4


1 -0.7t

3.7


* Average of 3 samplings.
** Average of 2 samplings. 1 from each of 2 growers.
t Negative value due to sampling error.


TABLE 10.-COMPARISON OF INJURIES IN BLISS TRIUMPH POTATOES DUG
WITH A CONVENTIONAL DIGGER WHEN HAULED TO THE PACKINGHOUSE IN
FIELD BAGS OR FIELD LOADED AND HAULED IN BULK, ALABAMA, 1954.*

Pounds of Injured Potatoes per 100
Pounds of Field-Run Potatoes
Extent of Injury Hauled in Field Field Loaded and
Bags Hauled in Bulk

M inor injury ................................ I 29.8 29.0
Major injury .............................. | 3.5 2.7

Total .............. .... ... 33.3 31.7


Digger cuts and
crushed potatoes ...................... 1.3

Total damage ...................... 34.6
An average of 3 samplings on 3 different days-all san
in the packinghouse.


nples


1.0

32.7
collected off the washer







Harvesting and Handling Potatoes Mechanically 23

TABLE 11.-AMOUNT OF INJURIES IN SEBAGO POTATOES DUG AND BAGGED
WITH ONE-ROW MAKE G MECHANICAL HARVESTERS AND HAULED TO
PACKINGHOUSE IN FIELD BAGS, HASTINGS AREA, FLORIDA, 1954 AND 1955.

Pounds of Injured Potatoes per 100
Extent of Injury Pounds of Field-Run Potatoes

1954" 1955**

M inor injury .............................. 14.5 7.9
M ajor injury ................................ 1.3 0.9


Total ..................................... 15.8 8.8


Digger cuts and
crushed potatoes ............... 0.8 0.8


Total damage ...................... 16.6 9.6
*Average of 7 samplings from 3 houses.
Average of 2 samplings from 1 house.


TABLE 12.-AMOUNT OF INJURIES IN POTATOES HARVESTED WITH DIFFERENT
MAKES OF MECHANICAL HARVESTERS AND HAULED IN BULK TRUCKS,
HASTINGS AREA, FLORIDA, 1954 AND 1955 AND BALDWIN COUNTY, ALA-
BAMA, 1954.

Pounds of Injured Potatoes per 100 Pounds
I of Field-Run Potatoes *
Extent of Hastings area Alabama
Injury 1954 1955 1954
SMake B Make B I Make C Make D Make A Make B

Minor injury .... 8.8 6.7 5.4 8.5 39.9 | 38.8
Major injury .... 1.8 1.1 0.7 1.0 7.8 9.5


Total .......... 10.6 7.8 6.1 9.5 47.7 48.3


Digger cuts
and crushed
potatoes ........ 0.7


Total
damage ._ 11.3


Pounds of pota-
toes examined 3234

Packinghouses
sampled ........ 5

*All samples collected from


0.5 1.6 1.2 .3 2.5



8.3 7.7 10.7 48.0 50.8


726


3

the washer


1077 1094


1 1

the packinghouse.


I


I






Florida Agricultural Experiment Stations


damage was considerably higher; about 48 of each 100 pounds
of field-run potatoes contained minor or major damage.
As indicated earlier, many things influenced the amount of
damage. Even with the same type of equipment, injuries varied
from day to day, field to field and packinghouse to packinghouse.
Samples of Pontiac potatoes collected in 1 packinghouse in Dade
County in 1953 showed a range in total injuries from 13 to 34
pounds per 100 pounds of field-run potatoes (Table 13).
It was observed in 1954 that inadequate receiving equipment
often resulted in excessive damage in unloading potatoes. Dam-
age in Sebago potatoes at Hastings ranged from a low of 3.1
pounds per 100 pounds of field-run potatoes in 1 house with
good receiving facilities to 21 pounds in a house with poor re-
ceiving facilities (Table 14). The mechanical equipment was
very carefully operated in the packinghouse with the low amount
of injuries.
In Alabama the amount of potatoes injured ranged from 43
pounds per 100 pounds at 1 packinghouse to 59 pounds at an-
other. Although injuries were high in mechanically harvested
potatoes, the amount was about the same as that in potatoes
dug and handled in the conventional way.

COMPARISON OF INJURIES IN POTATOES HARVESTED
MECHANICALLY AND WITH CONVENTIONAL METHODS
Growers and packers are particularly concerned with the
relative number of injuries to potatoes by mechanical harvest-
ing and bulk handling as compared to conventional methods.
This comparison was difficult to obtain because the 2 methods
were nearly always used in different fields and the potatoes
packed in different packinghouses. In Dade County in 1953,
samples of Pontiac potatoes harvested by each of the 2 methods
were obtained on 3 days from the same field or comparable fields.
The proportion of potatoes showing injuries was 17.5 percent for
those harvested mechanically and 15.6 for those handled in the
conventional way (Table 15). Mechanical harvesters have not
been successful in this area partly because of the nature of the
clods on the marl soil.
A more general comparison was obtained in 1953 in Baldwin
County, Alabama, for Bliss Triumph potatoes dug in the same
general area. Samples collected showed potatoes harvested and
handled in bulk contained about the same or slightly more in-
juries than those conventionally dug and handled in field bags







Harvesting and Handling Potatoes Mechanically


TABLE 13.-VARIATION IN AMOUNT AND TYPE OF INJURIES TO PONTIAC
POTATOES HARVESTED WITH MECHANICAL HARVESTER B AND HANDLED IN
BULK TRUCKS, DADE COUNTY, FLORIDA, FEBRUARY 25-MARCH 14, 1953*.


Date



February 25
March 22 ...
3
3
4
10


Average ...........


Percent of total


Pounds of Potatoes
Field-Run Po


Min
Injul


or
ries


9.2
13.5
19.1
20.1
16.9
18.0
15.8
23.2
12.4
20.8


16.9


79.7


Major
Injuries

2.7
4.1
2.4
3.0
1.8
4.5
2.7
8.2
2.1
3.4


3.5


16.5


per 100 Pounds of
tatoes with
Digger
Cuts Total


1.0
0.3
0.3
0.4
0.0
1.3
2.4
2.3
0.0
0.0


0.8


3.8


100.0


All samples collected from the washer in the packinghouse.


TABLE 14.-VARIATION BY PACKINGHOUSES IN AMOUNT OF INJURIES IN
POTATOES HARVESTED WITH MECHANICAL HARVESTERS AND HAULED IN
BULK, HASTINGS AREA, FLORIDA AND BALDWIN COUNTY, ALABAMA, 1954.


Arrangement of Pounds of Potatoes per 100 Pounds of
Facilities for Field-Run Potatoes with Injuries
Receiving Scored as *
Potatoes I Digger


I Minor I Major
Hastings Area


I Cuts


I Total


Good
Good
Average
Poor to average
Poor


Good
Average
Average
Poor


Alabama

35.5
S 36.3
S 47.0
S 42.4


7.1
7.4
7.0
14.0


* All samples collected from the washer in the packinghouse.


Packing-
house







Florida Agricultural Experiment Stations


TABLE 15.-AMOUNT AND KIND OF INJURIES TO PONTIAC POTATOES HARVEST-
ED WITH TWO-Row DIGGER AND HANDLED IN FIELD BAGS AND HARVESTED
WITH MECHANICAL HARVESTER AND HANDLED IN BULK TRUCKS, DADE
COUNTY, FLORIDA, 1953*.


Extent of Injury




Minor injury ...........
Major injury ..............
Digger cuts ..................


Total ......................


Pounds of Injured Potatoes per 100 Pounds
of Field-Run Potatoes When
S Harvested with
Harvested and Handled Mechanical Harvester
in Field Bags and Handled in Bulk
S Trucks

10.9 13.9
2.0 3.1
2.7 0.5


15.6 17.5


Average of 3 samplings from same or nearby fields on same dates. All samples col-
lected from the washer in the packinghouse.

TABLE 16.-COMPARISON OF INJURIES IN POTATOES DUG WITH CONVEN-
TIONAL DIGGERS AND HANDLED IN FIELD BAGS AND DUG WITH MECHANI-
CAL HARVESTERS AND HANDLED IN BULK TRUCKS, ALABAMA AND FLORIDA,
1954 AND 1955.


Extent of Injury


Pounds of Injured Potatoes per 100 Pounds
of Field-Run Potatoes
SHarvested with
Harvested and Handled Mechanical Harvester
in Field Bags and Handled in
Bulk Trucks
Red Potatoes, Alabama, 1954


Minor injury ............... 30.2
Major injury ................ 3.3
Digger cuts ................. 0.8


Total ................... 34.3
Sebago Potatoes, Hastings Area,

Minor injury ..... .. 20.2
Major injury ............ 1.9
Digger cuts ..................


Total ..................... 22.1


Florida, 1954

11
4


Sebago Potatoes, Hastings Area, Florida, 1955


Minor injury .....
Major injury ....
Digger cuts ......


Total ....-.. I
Total ....................---


:::::: I
......... I







Harvesting and Handling Potatoes Mechanically


(Fig. 2). These samples were collected during the early part
of the harvesting season. The potatoes were very easily bruised
and damage by both methods was high. Injuries decreased for
both methods of harvesting as the potatoes became more mature.


Legend:
Pounds of injured potatoes per 100
70 pounds of field run potatoes when:
Dug with conventional digger
0 and handled in field bags.
60
X Dug with mechanical harvester
X and handled in bulk.
50
4 x x

30 x
0
i 30 _--

" r . ..- . .- -
20

10

0 I I I I I I I I I I I I I I I I I I I
20 21 22 23 24 25 26 27 28 29 30 1 2 3 4 5 6 7 8 9 10 11 12 13
April Date May

Fig. 2.-Amount of injury to Bliss Triumph potatoes dug with a 2-
row digger and handled in field bags and dug with mechanical harvester
and handled in bulk, Baldwin County, Alabama, April 20-May 13, 1953. (All
samples from the washer in the packinghouse.)

In Alabama in 1954 samples of potatoes were collected in
various packinghouses on the same day from lots harvested by
each of the 2 methods. Physical injuries amounted to 34.3 per-
cent for those hauled and handled in field bags and 35.1 percent
for those dug with a mechanical digger and hauled in bulk
(Table 16).
In the Hastings area in 1954 and 1955, samples of potatoes
were collected on 2 occasions each year from lots dug with me-
chanical equipment and the conventional way in the same or
adjacent fields. The potatoes were packed in the same packing-
house. Results showed less total damage both years in the
mechanically harvested potatoes than for the regular method
of digging and handling (Table 16). The mechanically harvested
potatoes contained more major damage in 1954, but less in 1955.






Florida Agricultural Experiment Stations


PLACE WHERE INJURIES OCCURRED
In the direct and indirect methods of harvesting and handling
potatoes mechanically, several machines and operations are used.
The amount of injuries occurring at various points in the har-
vesting and handling process was studied. In lots of red po-
tatoes harvested with the Make A harvesters in Alabama, total
injuries amounted to 47.9 pounds per 100 pounds in 1953 and
49.1 pounds in 1954 (Fig. 3). In the 1954 season the proportion
of the damage occurring at the packinghouses decreased. Facili-
ties at the packinghouse for receiving potatoes had been im-
proved. However, because of dry conditions, chains on the har-
vesters were operated faster to break up the clods. This re-
sulted in more total damage to the potatoes.


1951 1954


1953 1954 1954


Fig. 3.-Amount of potatoes receiving injuries on harvester, loading
bulk trucks and unloading, conveying to washer and washing, selected pack-
inghouses, Baldwin County, Alabama and Hastings Area, Florida, 1953
and 1954.

A similar comparison for Make B equipment in Alabama in
1953 showed 25.3 pounds of each 100 pounds injured on the har-
vester, 10.4 pounds in loading the bulk trucks and 6.7 pounds in
unloading the potatoes and conveying them to the washer (Fig.
3). On the same equipment in 1954, for each 100 pounds of






Harvesting and Handling Potatoes Mechanically


potatoes harvested, 22.1 pounds were injured on the harvester,
5.4 pounds in loading the bulk trucks and 23.3 pounds in unload-
ing and conveying them to the washer. One packinghouse had
very unsatisfactory equipment for receiving potatoes hauled in
bulk; this accounted for the large amount of injury in unloading
the potatoes.
In Sebago potatoes harvested with Make B equipment in
Hastings in 1954, of each 100 pounds, only 8.3 pounds were in-
jured on the harvester, 1.0 pound in loading the bulk trucks and
2.5 pounds in unloading and conveying to the washer. In the
Hastings area about 1/4 of the total injuries occurred in the
packinghouses.
Indirect harvesters have been used in the Southeast relatively
little. Some of the equipment has been used mostly on a demon-
stration basis. Farmers have been reluctant to use this method
because they feel that it is too slow. Also, since warm and dry
weather prevails at harvest time, the potatoes may damage from
exposure if left in the window very long. Such damage was
observed on several occasions, especially when a mechanical
breakdown caused a delay in picking up the potatoes.
In each 100 pounds of Bliss Triumph potatoes harvested by
the indirect method with harvester E in Alabama in 1953, 11.0
pounds were injured in digging and windrowing, 12.5 pounds on
the harvester, 4.6 pounds in bulk trucks and 8.8 pounds in un-
loading and conveying to the washer (Table 17). Pontiac pota-
toes harvested in Dade County in 1954 with Make F harvester
on a demonstration basis showed that in each 100 pounds of po-
tatoes, 3.7 pounds received injuries in digging and windrowing,
14.1 pounds on the harvester and 2.3 pounds in handling through
the bulk trucks and conveying to the washer.
Injuries to Potatoes When Run through Bins.-Many pack-
inghouses in the Hastings area are operated by cooperative asso-
ciations and others on a custom basis. Each time potatoes are
run for a grower the operators usually desire to pack at least a
truck or carload. In many of the houses bins are used for tem-
porary storage to accumulate a sufficient quantity to fill a car
or truck with potatoes from a single grower. In such houses
when mechanically harvested potatoes are packed, some may be
transferred from the bulk trucks to the bins. To place the po-
tatoes in the bins requires special equipment and also results in
additional handling (Fig. 4).
In 1955 samples of Sebago potatoes were collected to measure







Florida Agricultural Experiment Stations


TABLE 17.-AMOUNT OF INJURIES OCCURRING AT DIFFERENT POINTS TO
POTATOES WHEN HARVESTED BY THE INDIRECT METHOD OF MECHANICAL
HARVESTING, ALABAMA AND FLORIDA, 1953 AND 1954.

Pounds of Potatoes Injured per Each 100 Pounds
of Field-Run Potatoes by
Extent of Digger I
Injury and Bulk Unloading Total
Wind- Harvester Trucks and Injuries
rowers 1 Washing _
Bliss Triumph Potatoes, Baldwin County, Alabama, 1953 *


7.8
2.4
0.8

11.0 |



29.8


10.0
2.9
-0.4**

12.5



33.9


2.6 5.8
1.9 3.0
0.1 .0

4.6 8.8



12.5 I 23.8


26.2
10.2
0.5

36.9



100.0


Pontiac Potatoes, Dade County, Florida, 1954 t


2.3 20.1



9.6 100.0


Minor injury
Major injury
Digger cuts

Total ..

Relative
amount
(percent)



Minor injury
Major injury
Digger cuts

Total ..

Relative
amount
(percent)


Average of 4 samplings harvested with Make E harvester.
** Negative value due to sampling error.
SAverage of 2 samplings harvested with Make F harvester.
$ No breakdown of injuries was made for bulk trucks. Damage in unloading and wash-
ing includes damage incurred in bulk trucks.

TABLE 18.-COMPARISON OF INJURIES IN SEBAGO POTATOES WHEN DUG WITH
DIRECT MECHANICAL HARVESTERS AND UNLOADED DIRECT FROM BULK
TRUCKS AT PACKINGHOUSE OR UNLOADED THROUGH TEMPORARY STORAGE
BINS, HASTINGS AREA, FLORIDA, 1955 *.


Extent of Injury



Minor injury ..........--.
Major injury ...............
Digger cuts ..................

Total ...........

Percent skinning .....


Pounds of Injured Potatoes per 100 Pounds
of Field-Run Potatoes When
Unloaded Direct into
Flume from Bulk Unloaded Through
Trucks I Bins into Flume


* Average of 5 samplings, all samples collected from the washer in the packinghouse.


S 18.8 | 71.6






Harvesting and Handling Potatoes Mechanically


the amount of damage resulting from running them from bulk
trucks through bins. The packinghouse had a very satisfactory
elevator for placing the potatoes in the bins. A flume moved the
potatoes from the bulk trucks or bins to the elevator which car-
ried them to the washer.
Potatoes in each set of tests were dug by the same harvester
from the same field. Part were unloaded through bins and part
directly into the flume. Injuries in potatoes run through bins
were 1.8 pounds more per 100 pounds (all minor) than those
dumped directly into the flume (Table 18). Amount of skin-
ning was estimated at 5 percent for the potatoes run directly
into the flume, and 13 percent for those into bins and then into
the flume. Observation of the various lots in the tests after
washing showed those run direct to be cleaner and brighter than
those run through bins. Potatoes dug with a conventional dig-
ger and handled in field bags through bins had a poorer appear-
ance than any of the mechanically harvested potatoes.

REDUCTION OF INJURIES
The amount of injuries in early Irish potatoes harvested
with mechanical equipment can be reduced. Tests at Hastings,
Florida, and in Charleston County, South Carolina, in 1951 and
1952 showed that rubber tubing, belting and padding reduced
injuries caused by conventional diggers 9. Tests in 1953 and
1954 indicated that similar protection also helped to reduce in-
juries to potatoes when dug and handled with mechanical equip-
ment.

9 B. J. Todd and R. E. L. Greene, "Reduction of Physical Injuries to
Early Irish Potatoes During Digging and Picking up," South Carolina
Agricultural Experiment Station, Southern Cooperative Series, Bul. 32,
March 1953.


Fig. 4.-Elevator used for placing potatoes in bins.






Florida Agricultural Experiment Stations


On the 1-row Make G harvester, potatoes are dropped 22
inches from the top of the digger chain to a cross conveyor chain.
Damage on 1 machine where the rods of the cross conveyor were
covered with rubber was only half as much as on a second ma-
chine where the rods were not covered (Table 19). Another
test with 1-row harvesters showed 8.0 pounds of damaged po-
tatoes per 100 pounds on a harvester with the elevator chains
rubberized and the digger chain not covered with rubber. An-
other harvester with the digger chain covered and the elevator
chains not covered showed 14 pounds of damaged potatoes per
100 pounds. The amount of dirt carried on the digger chain
provided protection but the elevator chain had no protection
when not rubberized.

TABLE 19.-AMOUNT OF INJURIES TO SEBAGO POTATOES HARVESTED WITH
A 1-Row HARVESTER, MAKE G, WITH CROSS CONVEYOR CHAIN NOT COV-
ERED AND COVERED WITH RUBBER TUBES, HASTINGS, FLORIDA, 1953.

Pounds of Potatoes Injured per 100 Pounds
Type of Defect of Field-Run Potatoes When Cross
Conveyor Was
Non-Rubberized | Rubberized
Minor damage ................ 12.3 6.6
Major damage ................ 1.1 0.5
Digger cuts ...................... 0.2 0.6

Total ............... .. 13.6 I 7.7


In Dade County in 1953 some tests were conducted with 1
make of a 2-row direct harvester. These tests compared the
amount of damage in Pontiac potatoes from 1 side of the har-
vester with the conveyors partially covered with rubber with
the damage on the other side with no protection. Damage was
reduced about /3.
If the indirect method of harvesting is used, placing rubber
tubing on each high link of the digger chain, covering the link
ends with belting, digging slowly with ample soil on the digger
chain and using a rubberized chain on the windrower should help
in reducing injuries as shown in previous studies 10. Using rub-
ber tubing on the pick-up chain of the indirect harvester and
protection over the link ends should help reduce injuries in pick-
ing up and loading potatoes.

1" Ibid., page 31.






Harvesting and Handling Potatoes Mechanically


Observation of the use of mechanical equipment during this
study indicate that 1 of the most critical problems at present
from the standpoint of injuries to the potatoes is the failure to
set up proper facilities at the packinghouse for receiving pota-
toes hauled in bulk. In houses with poor receiving facilities as
much or more damage may be done in unloading the potatoes
from the bulk trucks and conveying them to the washer as is
done on the harvester and loading the potatoes in the trucks.
Samples were collected for 1 house in the Hastings area in
1954 with poor equipment for unloading potatoes. In Sebago
potatoes 8 pounds per 100 pounds were damaged on the har-
vester and loading the bulk trucks, but 13 pounds were damaged
in unloading, conveying to the washer and washing. A similar
check in 1 house in Alabama showed 21 pounds per 100 pounds
injured in harvesting and loading, but 38 pounds injured in un-
loading, conveying to the washer and washing. These were red
potatoes and the arrangement for unloading the potatoes was
especially bad. About I/ of the potatoes injured at the pack-
inghouse in Alabama received injuries severe enough to have
been scored as grade defects.
In packinghouses where damage was high, it was usually
because the potatoes were dropped a considerable distance onto
a rod-type conveyor with no protection; also, quite often there
were long drops from 1 conveyor to another or into the washer.
Tests with Bliss Triumph potatoes that were fairly immature
showed the value of protecting rod-type conveyors with rubber
tubing. These potatoes were dropped 20 inches from a bulk
body onto a rod conveyor chain. Covering the rods of the con-
veyor with rubber tubing reduced the potatoes injured from 18
to 6 pounds per 100 pounds unloaded. Major injuries were re-
duced from 5 pounds to 11/ pounds per 100 pounds. Rolling the
potatoes down a rubber chute provided on some of the bulk bodies
for unloading reduced the amount of total damage from 22 to 11
pounds and major damage from nearly 8 to 0 pounds in each
100 pounds.

COST OF HARVESTING AND HANDLING POTATOES
WITH DIFFERENT SYSTEMS
The cost of harvesting and handling potatoes varies among
systems and also for different methods within a system. To
compare harvesting cost with various methods and types of
equipment and also to study variation in costs, data were ob-






Florida Agricultural Experiment Stations


trained from farmers using the conventional system of harvest-
ing, the completely mechanized system and the partially mech-
anized system.

ITEMS INCLUDED AND METHOD OF CALCULATING COST
Items included in calculating costs for the various systems
were labor, use of equipment, power and truck cost and miscel-
laneous items such as pick-up containers and field bags or boxes.
Labor was charged at the prevailing rate in the area, based on
estimates of the amount required. If an operation such as pick-
ing up and hauling was hired on a "piece rate" basis, the contract
rate was used. Normally, in the conventional system, picking
up and hauling are contracted in this manner. Even when po-
tatoes are hauled in bulk, trucks may be hired on a "piece rate"
of so much per packed bag equivalent hauled.
Costs of operating potato harvesting equipment included
both direct and fixed costs. The direct costs consisted of such
items as fuel, oil, grease and repairs and were based on estimates
of growers. Fixed costs included depreciation and a charge to
cover interest, taxes and insurance. The latter costs were based
on a charge of 5 percent (3 percent for interest, 1 percent for
taxes and 1 percent for insurance) on the purchase price of the
equipment. Depreciation was based on the farmer's estimated
(actual service) life of the equipment. No salvage value was
assumed. The amount of depreciation to charge for mechanical
harvesters was difficult to estimate. Farmers have not had
enough experience with such equipment to make reliable esti-
mates of expected life. The equipment is also being improved il:
design, so obsolescence could make present machines depreciate
very fast.
Use of tractors and trucks, except where trucks were hired
on a piece rate, was charged at a fixed rate per hour for the esti-
mated amount of use. The charge for use of tractors was 75
cents, 85 cents and $1.00 per hour for small, medium and large
tractors, respectively. Truck use was charged at $2.00 per hour.
All miscellaneous items were charged at their estimated cost.
In summarizing the data on costs of harvesting potatoes
with different methods and equipment, cost was calculated on
a per acre and a per unit basis (100 or 50-pound equivalent
packed bag). Cost per unit for the conventional system was
based on a normal yield and rate of harvesting per acre. Cost
of harvesting with mechanical equipment was based on the rate






Harvesting and Handling Potatoes Mechanically


of harvesting and yield per acre as determined from data collected
during the 1953 and 1954 seasons. Actual rather than normal
yields and rates of harvesting were used for mechanical equip-
ment because farmers had not had enough experience with me-
chanical equipment to make reliable estimates except under con-
ditions as they had operated.
To place all systems and methods of harvesting on the same
basis for comparison, total costs as calculated include all opera-
tions up to placing the potatoes on the conveyor to the washer
in the packinghouse. This was necessary because the method
of handling potatoes in the packinghouse is changed when po-
tatoes are hauled in bulk. Therefore, it was necessary to con-
sider differences in cost of receiving and handling the potatoes
to the washer in the packinghouse in comparing the different
methods.
In appraising the applicability of these data to his situation,
the individual grower must consider differences due to rate of
harvesting, expected life of equipment, cost of operating equip-
ment, wages paid, packinghouse facilities and other factors.
Cost for the individual grower may be higher or lower, depend-
ing on whether or not he is above or below the average given
for the different factors. Also, cost for the individual grower,
if he used methods or equipment different from those given,
would depend on his performance rates in comparison with those
on which various calculations were based.

THE CONVENTIONAL SYSTEM
Data on cost for the conventional system are presented first
to show the cost ot berating various kinds of harvesting equip-
ment and then the estimated cost per acre and per unit of har-
vesting potatoes.
Investment, Estimated Life and Cost of Operating Harvest-
ing Equipment.-Equipment for harvesting potatoes with the
conventional system usually consists of a roto-beater or cutter,
a 2-row standard digger, field boxes or bags and pick-up con-
tainers when field bags are used. The number of field and pick-up
containers depends on the number of acres harvested and method
of handling the potatoes at the packinghouse. Investment in
harvesting equipment varies among areas, and also among farm-
ers within an area. Differences in investment are due mainly to
variations in makes of equipment, year purchased and types of
field containers for handling potatoes.






Florida Agricultural Experiment Stations


Roto-Beaters.-The estimated annual cost of operating a
roto-beater varied from $313 in the Fort Myers area to $207 in
the Hastings area (Table 20). The annual cost of a roto-cutter
in Alabama was estimated at $126. Annual use of the equip-
ment varied from 99 acres in Alabama to 228 acres in Dade
County. The per acre cost for operating the roto-beater was
approximately $1.00 in Dade County and the Hastings area and
$1.71 in the Fort Myers area. Repairs accounted for about half
of the annual cost of operating the roto-beater in the Fort Myers
area but only about 2/5 of the cost in Dade County and the Hast-
ings area. Repairs accounted for only about 1/5 of the cost of
operating a roto-cutter in Alabama.

TABLE 20.-ESTIMATED PURCHASE PRICE, PRESENT AGE, EXPECTED LIFE,
ANNUAL USE AND COST OF OPERATING ROTO-BEATERS, SELECTED AREAS,
FLORIDA AND ALABAMA, 1954.

Florida
Items Fort Dade I Hastings Alabama
Myers County I Area
Estimated Purchase Price, Age, Expected Life and Annual Use

Purchase price ....................... $894 $805 $675 $470*
Present age (years) ....-........... 4 5 4 3
Expected life (years)** ........ 9 8 8 6
Annual use (acres) ............. 183 228 213 99

Annual Cost of Operation

Repairs .................................... $159 $ 87 $ 82 $ 24+
Miscellaneous expenses .......... 10 5 7 -
Depreciation .......................... 99 101 84 78
Interest, insurance, taxes .... 45 40 34 24


Total cost ......................... 313 233 207 126
Cost per Acre of Use

Repairs ..................................... $0.87 $0.38 $0.38 $0.24
Miscellaneous ........................... 0.05 0.02 0.03
Depreciation .--.................-.... 0.54 0.44 0.39 0.79
Interest, insurance, taxes -.... 0.25 0.18 0.16 0.24


Total cost .................... 1.71 1.02 0.96 1.27
Farmers in Alabama use a roto-cutter rather than a roto-beater.
** Estimated (actual service) life, taking account of seasonal operation. No salvage
value is assumed at the end of the use period.
t Also includes miscellaneous expenses.
$ Insurance 1 percent, taxes 1 percent and interest 3 percent of purchase price (interest
at 3 percent equals approximately 5 percent of the undepreciated balance).







Harvesting and Handling Potatoes Mechanically


Diggers.-The annual cost of operating a digger varied from
a low of $205 in Dade County to a high of $476 in the Fort Myers
area (Table 21). The low cost in Dade County was due largely
to no charge for digger chains. In many sandy areas a set of
digger chains will last 100 acres or less. On the marl soils of
Dade County digger chains will often last the life of a digger.

TABLE 21.-ESTIMATED PURCHASE PRICE, PRESENT AGE, EXPECTED LIFE,
ANNUAL USE AND COST OF OPERATING 2-Row CONVENTIONAL POTATO
DIGGERS, SELECTED AREAS, FLORIDA AND ALABAMA, 1954.


Items


Florida
Fort j Dade I Hastings Alabama
Myers I County I Area


Estimated Purchase Price, Age, Expected Life and Annual Use

Purchase price ........ ....... $844 $775 $838 $725
Present age (years) .......... 5 6 7 7
Expected life (years)* .......... 10 9 9 14
Annual use (acres) ............... 122 188 126 99

Annual Cost of Operation

Repairs ............... ................ $ 92 $ 77 $109 $178t
Digger chains ........-........... ... 249 169 -
Miscellaneous expenses ........ 9 6 12 -
Depreciation ........................... 84 84 93 52
Interest, insurance, taxes .... 42 38 42 36


Total cost ...................... 476 205 425 266
Cost per Acre of Use


R epairs ..................................
Digger chains .........................
Miscellaneous expenses ........
Depreciation ..--.----.. --...........
Interest, insurance, taxes t..-


Total cost ........................


$ .75 $ .41 $ .87
2.04 1.34
.07 .03 .10
.69 .45 .74
.35 .20 .33


3.90 1.09 3.38


$1.80t

.53
.36


2.69


Estimated (actual service) life, taking account of seasonal operation. Assumes no
salvage value at end of use period.
** No charge is made for cost of digger chains. Because of the fine texture of the soil,
the original chains o'ten last the li'e of the digger.
t Also includes cost of digger chains and miscellaneous expenses.
t Insurance 1 percent, taxes 1 percent and interest 3 percent of purchase price (interest
at 3 percent equals approximately 5 percent of the undepreciated balance).

The cost per acre of operating a digger was $1.09 in Dade
County and $3.90 in the Fort Myers area. The annual use of
diggers in Dade County was considerably more than in other
areas. This resulted in a relatively wider difference in cost per






Florida Agricultural Experiment Stations


acre of operating diggers between areas than was true for total
costs.
Field and Pick-Up Containers.-Potatoes in the Fort Myers
area are normally picked up and handled in field boxes. Field
boxes are used by many growers in Dade County but a number
used field bags (Fig. 5). Field bags are used in the Hastings
and Alabama areas. When potatoes are handled in field boxes,
they are normally picked up and placed directly in the boxes.
When field bags are used, the potatoes are first picked up in a
pick-up container and then poured in a bag. In most cases used
seed potato or fertilizer bags are used as field bags.


Fig. 5.-Field bags (above) and field boxes used for field containers in
the conventional method of harvesting in Dade County.







Harvesting and Handling Potatoes Mechanically


TABLE 22.-EXPECTED LIFE, ANNUAL USE, TOTAL VALUE AND COST FOR
FIELD AND PICK-UP CONTAINERS, SELECTED AREAS, FLORIDA AND ALA-
BAMA, 1954.


Item


Field Boxes Field Bags
Fort Dade I Dade Hastings
Myers County County Area | Alabama


Number of Field Containers per Acre, Expected Life,
Annual Use and Total Value


Average number
per acre .............
Expected life (years)
Annual use (acres).


Total value or


cost


14
4
157


$3187


$4634 $ 376 $ 330 $ 198


Annual Cost


Repairs ....................
Depreciation .....-
Interest, insurance,
taxes .................


$ 242 $ 179 $ $ $ -
796 1158 376 330 198

159 232 -


1197 1569


376 330 198


Repairs ......................
Depreciation .............
Interest, insurance,
taxes .................


Total cost ..........
I


Cost per Acre of Use

1.54 $ .951 $
5.071 6.161


1.011


7.62
1


- $ -
2.00 2.1
- -


8.35 2.001 2.16'
I I 1


Value and Cost of Pick-Up Containers


Total value or cost..
Expected life (years)
Annual cost .............-
Cost per acre .........


Cost per acre for
field and pick-up
containers .........
I


I
$ 38 $ 123
2 4
$ 19 $ 37
$ 0.10 $ 0.241


7.62 $ 8.35| $ 2.10 $ 2.401


Insurance 1 percent, taxes 1 percent and interest 3 percent of purchase price (interest
at 3 percent equals approximately 5 percent of the undepreciated balance).


Total cost


25
1
25
0.25


$ 2.25






Florida Agricultural Experiment Stations


Field boxes are much more expensive field containers than
field bags. The estimated annual life of a field box was four
years (Table 22). At the end of each season a considerable
expense is necessary in repairing broken boxes. The annual
cost per acre for field boxes was estimated at $7.62 in the Fort
Myers area and $8.35 in Dade County. The cost per acre for
field bags was $2.00 per acre in Dade County and Alabama and
$2.16 in the Hastings area. To this cost must be added 10 cents
for pick-up containers in Dade County and approximately 25
cents in the Hastings area and Alabama.
Per Acre and Per Unit Cost.-The total cost of harvesting
and handling potatoes included a charge for labor, power and
use of equipment. Cost for each area included all operations
from vine killing, if performed, to placing the potatoes on the
washer in the packinghouse. Costs in each area were summar-
ized on a per acre and per unit basis (50- or 100-pound equiva-
lent packed bag) and represent the estimated cost for average
rates of performance and normal yields indicated.
The estimated normal yield per acre was 277 and 328 50-
pound bag equivalents in Fort Myers and Dade County and 155
and 132 100-pound bag equivalents in the Hastings area and Ala-
bama, respectively. The per acre costs of harvesting and hand-
ling potatoes varied from $42.07 in the Hastings area to $60.60
for growers using field boxes in Dade County (Table 23). In each
area the 2 major items of costs were picking up and hauling,
which accounted for 70 percent or more of the total costs.
Since a "piece wage rate" is normally paid for these 2 operations,
an increase in yield per acre results in very little reduction in
the per unit cost of harvesting potatoes by the conventional
method.
In Dade County, where growers used both field boxes and field
bags, the estimated cost per acre for growers using field bags
was $47.06, or about $13 per acre less than those using field
boxes. This difference was due to a lower cost per acre for field
containers, slightly more potatoes placed in a container and a
lower cost for handling at the packinghouse.
The estimated cost per unit of harvesting potatoes and plac-
ing them on the washer in the packinghouse was 20.59 cents per
50-pound bag for farmers in the Fort Myers area (Table 24).
In Dade County costs were estimated at 18.47 cents per 50-
pound bag for the farmers using field boxes and 14.57 cents for
farmers using field bags, a difference of 3.90 cents per bag. Cost







Harvesting and Handling Potatoes Mechanically


TABLE 23.-COST PER ACRE OF HARVESTING AND HANDLING POTATOES IN
THE USUAL MANNER, SELECTED AREAS, FLORIDA AND ALABAMA, 1954.


Florida

Item Dade County
Fort Potatoes Handled in I
Myers Field Field
Boxes Bags
Vine killing:
Tractor driver ...... $ 0.26 $ 0.17 $ 0.17
Spray operator .... 0.21 0.15 0.15
Use of tractor .... 0.30 0.20 0.20
Material ................ 1.88 1.20 1.20

Total ................. 2.65 1.72 1.72

Roto-beating
or cutting:
Tractor driver ...... 0.51 0.43 0.43
Use of tractor ...... 0.57 0.50 0.50
Equipment cost .... 1.71 1.02 1.02

Total ................ 2.79 1.95 1.95


SAlabama
Hastings
I


Digging potatoes:
Tractor driver ...... 0.68 0.68 0.68 0.85 0.88
Digger operator .. 0.58 0.68 0.68 0.80 -
Use of tractor .... 0.80 0.80 0.80 1.00 1.18
Equipment cost .... 3.90 1.09 1.09 3.38 2.69

Total .................. 5.96 3.25 3.25 6.03 4.75

Picking up, check-
ing and hauling:
Contract
picking up ...... 16.62 18.90 16.98 15.90 27.72*
Cost of
field containers 7.62 8.35 2.10 2.40 2.25
Contract hauling 16.62 18.90 16.98 13.25 11.88
Supervision .......... 0.80 0.91 0.91 1.09 -

Total ................. 41.66 47.06 36.97 32.64 j 41.85

Total harvesting
cost to packing-
house ............ 53.06 53.98 43.89 40.50 48.67
Unloading and han-
dling to washer 3.99 6.62 3.87 1.57 2.24

Grand total cost .... 57.05 60.60 47.76 42.07 50.91

Estimated
normal yield:
Field boxes
or bags .............. 277 315 283 265 132**
Packed bags
equivalent ......... 277 328 328 155 132
Most farmers contracted the picking up, checking, loading and hauling at 30 cents
per 100-pound packed bag. For sake of comparison this cost was divided: 70 percent for
picking up, checking and loading and 30 percent for hauling.
** Hundredweight equivalents.







Florida Agricultural Experiment Stations


TABLE 24.-ESTIMATED COST PER UNIT OF HARVESTING AND HANDLING
POTATOES IN THE USUAL MANNER, SELECTED AREAS, FLORIDA AND ALA-
BAMA, 1954.


50-pound Equivalent


Item

Fort
SMyers

Cents
Vine killing:
Tractor driver ..- 0.09
Spray operator .... 0.08
Use of tractor ...... 0.11
M material ................ 0.68
Total .---..-.......- 0.96

Roto-beating
or cutting:
Tractor driver ..... 0.18
Use of tractor ...... 0.21
Equipment cost .... 0.62
Total ............. ..- 1.01


Digging potatoes:
Tractor driver ......
Digger operator ..
Use of tractor ......
Equipment cost ..
Total .................

Picking up, check-
ing and hauling:
Contract
picking up ........
Cost of field
containers .......
Contract hauling .
Supervision ........


0.24
0.21
0.29
1.41


Florida

Dade County--
Potatoes Handled in


Field
Boxes
Cents

0.05
0.05
0.06
0.37
0.53 |


0.13
0.15
0.31
0.59

0.21
0.21
0.24
0.33


Field
Bags
Cents

0.05
0.05
0.06
0.37
0.53


0.13
0.15
0.31
0.59


100-pound
Equivalent



Hastings Alabama
Area

Cents Cents








0.26 0.29
0.30 0.32
0.62 0.96
1.18 1.57


2.15 1 0.99 0.99 | 3.89 3.60


10.26

1.55
8.55
0.70


21.00*

1.70
9.00*


Total .................. 15.04 1 14.35 11.28 21.06 T 31.70


Total harvesting
cost to packing-
house .....-..... .. -- 19.16
Unloading and han-
dling to washer 1.43

Grand total cost ...... 20.59

Estimated
normal yield:
Field boxes
or bags .............. 277
Packed bags
equivalent ...... 277


16.46

2.01

18.47



315

328


13.39

1.18

14.57



283

328


26.13

1.02

27.15



265

155


36.87

1.70

38.57



132**

132


Most farmers contracted the picking up, checking, loading and hauling at 30 cents
per 100-pound packed bag. For sake of comparison this cost was divided: 70 percent for
picking up, checking and loading and 30 percent for hauling.
** Hundredweight equivalents.


.


!






Harvesting and Handling Potatoes Mechanically


of harvesting per 100-pound bag was estimated at 27.15 cents
in the Hastings area and 38.57 cents in Alabama.

THE COMPLETELY MECHANIZED SYSTEM
Normally 4 different operations are performed when the har-
vesting of potatoes is completely mechanized: (1) roto-beating
or cutting the tops, (2) digging, separating the potatoes from
dirt and vines and conveying them in bulk into truck bodies,
(3) driving the trucks in the field and hauling the potatoes to
the packinghouse and (4) unloading and removing trash. The
potatoes may be unloaded directly onto the conveyor to the
washer or placed by means of a conveyor in bins for temporary
storage. Some operators do not roto-beat or cut the vines un-
less there are excessive vines or weeds in the field. When the
indirect method of harvesting is used, the potatoes are first
dug with a conventional digger equipped with a windrower
which places the potatoes from 2 rows together in a window.
The potatoes are then picked up from the window with the
indirect harvester and loaded in bulk.
The cost of harvesting and handling potatoes with completely
mechanized equipment is based on data collected from all grow-
ers operating harvesters in the Hastings area and in Alabama
during the 1954 season.
Investment, Estimated Life and Cost of Operating Harvest-
ing Equipment.-A unit of equipment for harvesting potatoes
with the completely mechanized system normally consists of a
harvester, 3 or 4 hopper-type bodies and an electric motor for
unloading the potatoes from the bodies. The investment in a
unit of equipment varies from $8,000 to $10,000 or more, de-
pending on the make of equipment. This amount does not in-
clude the cost of a tractor for pulling the harvester or trucks
for hauling the potatoes. A farmer may use a roto-beater or
cutter, depending on the make or type of equipment. With
the indirect method of harvesting, it is also necessary to have
a digger equipped with a windrower.
In the Hastings area, growers estimated the life of the equip-
ment to be 7 years for a roto-beater, 7 years for a harvester
(Make B), 10 years for bulk bodies and 5 years for an electric
motor (Table 25). Alabama growers estimated the life of a
roto-cutter to be 6 years, a conventional digger 14 years, a wind-
rower 7 years, each of the mechanical harvesters 7 years (Makes
A, B and E), bulk bodies 10 years and an electric motor 5 years.






Florida Agricultural Experiment Stations


TABLE 25.-PURCHASE PRICE, ESTIMATED LIFE, ANNUAL USE AND ESTI-
MATED COST OF OPERATING VARIOUS TYPES OF POTATO HARVESTING
EQUIPMENT, HASTINGS AREA, FLORIDA, AND ALABAMA, 1954.

| Purchase Esti- Annual Estimated Annual
Item Price mated Use Cost of Operation
Life* I Total I Per Acre
Hastings Area, Florida

Roto-beater .............. $ 800 7 242 $ 232 $ 0.96
Direct mechanical
harvester:
Make B .............. 6100 7 145 1750** 12.07
Bulk Bodies t .......... 2700 10 145 445 3.07
Electric motor ..... 180 5 145 45 0.30

Alabama

Roto-cutter .............. $ 470 6 99 $ 126 $ 1.27
Digger .............. 725 14 125 313 2.50
Windrower .............. 210 7 125 81 0.65
Direct mechanical
harvester:
Make A .................. 6000 7 99 1612 16.28
Make B .................. 6100 7 99 1512 15.27
Indirect mechanical
harvester:
Make E .............. 2800 7 125 832 1 6.66
Bulk bodies tt ........-. 1890 10 99 314 3.17$1
Electric motor .......... 130 5 99 33 0.33

Estimated actual service life, taking account of seasonal operation, assuming no sal-
vage value at the end of the use period.
** See Table 26.
t Cost for 4 hopper-type bodies.
$ Data obtained in 1953.
See Table 27.
tt Cost for 3 hopper-type bodies.
$$ Cost for an annual use on 125 acres, $2.51 per acre.

A harvester in the Hastings area was estimated to harvest
145 acres of potatoes a year. Based on a life of 7 years, the
annual costs of operating a harvester, not including cost of a
tractor for pulling the machine or labor on the harvester, was
$1,750 (Table 26) ; of the total costs, 1/3 were operating and 2
fixed costs. For an annual use of 145 acres, the per acre cost
of the harvester would be $12.07 and bulk bodies $3.07.
Growers in Alabama operated 2 makes of direct and 1 make
of indirect harvesters. Annual use was estimated at 99 and
125 acres for the 2 types of harvesters, respectively. The life
of each make of harvester was estimated at 7 years. Annual
operating costs were $1,612 for Make A and $1,512 for Make B
direct harvesters, or $16.28 and $15.27 per acre, respectively
(Table 27). The annual costs of operating the indirect har-








TABLE 26.-ESTIMATED ANNUAL COSTS AND COSTS PER HOUR AND PER ACRE OF OPERATING MECHANICAL HARVESTER MAKE
B, HASTINGS AREA, 1954.


Item



Operating cost:
F u e l ....................................... ............... ..................
M otor oil ..................................................................
Grease ...................................
Service labor ..............................
Digger chains ...................................................
Repairs ................ ............ ..........................


Total .................. ................................


Overhead costs:
Depreciation ......................................
Interest, insurance, taxes ................................


Total ................. .....................................


Total cost of operation ............................................


Cost per Unit of Operation *


Unit




al.
k4O .


Price




$0.25
0.22
0.15
1.00


Annual Cost *

Amount Cost


243 $ 60.75
15 3.30
48 7.20
29 29.00
148.00
325.00


573.25



871.43
305.00


1176.43


1749.68


* Based on an annual use of 145 acres per year and a rate of harvesting of .71 acre per hour or a total
** Interest 3 percent, insurance 1 percent and taxes 1 percent of purchase price.


annual use of 204 hours.


Per Hour

Amount Cost


1.19 $0.30
0.07 0.02
0.24 0.03
0.14 0.14
0.72
1.60


2.81



4.27
1.50


5.77


8.58


Per Acre

Amount Cost


1.68 $0.42
0.10 0.02
0.33 0.05
0.20 0.20
1.02
2.25


3.96



6.01
2.10


8.11


12.07










TABLE 27.-ESTIMATED ANNUAL COSTS AND COST PER HOUR AND PER ACRE OF OPERATING SELECTED TYPES
OF MECHANICAL HARVESTERS, ALABAMA, 1954.

SDirect Make A Harvester Direct Make B Harvester** Indirect Make E Harvester t
SCost
Item Unit i Price Annual Cost I per Unit Annual Cost Cost per Unit Annual Cost Cost per Unit
I- I Per Per | ] Per Per I Per Per
IAmount | Cost Hour Acre Amount I Cost Hour Acre Amount Cost Hour | Acre

Operating costs: I
Fuel .................... Gal. $0.24 240 $ 57.60 $0.36 $ 0.58 128 $ 30.72 $ 0.25 $ 0.31 118 $ 28.32 $ 0.18 $0.23
Motor oil .......... Qt. 0.25 15 3.75 0.02 0.04 15 3.75 0.03 0.04 18 4.50 0.03 0.04
Grease .............. Lb. 0.15 20 3.00 0.02 0.03 26 3.90 0.03 0.04 18 2.70 0.02 0.02
Service labor .... Hr. 0.83 9 7.47 0.05 0.08 13 10.79 0.09 0.11 8 6.64 0.04 0.05
Digger chains 100.98 0.63 1.02 1 100.98 0.84 1.02
Repairs .......... 282.15 1.76 2.85 185.13 1.53 1.87 250.00 1.60 2.00

Total .............. 454.95 2.84 4.60 335.27 2.77 3.39 292.16 1.87 2.34

Overhead costs: I
Depreciation .... 857.14 5.36 8.65 871.43 7.20 8.80 400.00 2.56 3.20
Interest, insur- I
ance, taxes 300.00 1.87 3.03 305.00 2.52 3.08 140.00 .90 1.12

Total ............. i 1157.141 7.23 11.68 I 1176.43 9.72 11.88 540.00 3.46 4.32

Total cost of i
operation ...... 1612.09 10.07 16.28 1511.70 12.49 15.27 832.16 5.33 6.66

Based on an annual use of 99 ares per year and a rate of harvesting of .62 acre per hour or a total annual use of 160 hours.
Based on an annual use of 99 acres per year and a rate of harvesting of .82 acre per hour or a total annual use of 121 hours.
t Based on an annual use of 125 acres per year and a rate of harvesting of .8 acre per hour or a total annual use of 156 hours.
$ Interest 3 percent, insurance 1 percent and taxes 1 percent of purchase price.






Harvesting and Handling Potatoes Mechanically


vesters were only $832, or $6.66 per acre. In the indirect method
of harvesting the cost of operating the digger and windrowers
was $3.15 per acre. The annual cost of bulk bodies was esti-
mated at $3.17 per acre.
Per Acre and Per Unit Cost of Harvesting and Handling
Potatoes.-In the Hastings area the estimated cost of harvesting
potatoes with the Make B type harvester and placing them on
the conveyor to the washer was $47.16 per acre, or 24.31 cents
per 100-pounds equivalent packed bag (Tables 28 and 29). This
cost was based on harvesting 0.71 acre per hour that yielded
194 100-pound equivalent packed bags per acre. The largest
single cost was that of operating the harvester-$24.77 per
acre or 12.77 cents per packed bag. The use of the harvester
amounted to almost half of this cost, while labor and power
accounted for the remainder. The next largest item of cost was
hauling potatoes, which amounted to $18.58 per acre or 9.57
cents per packed bag. The cost of unloading the trucks, re-
moving trash and miscellaneous charges amounted to $1.99 per
acre or 1.03 cents per packed bag. Roto-cutting was the least
costly of the harvesting operations, amounting to only $1.82
per acre or 0.94 cent per packed bag.
In Alabama data were summarized for 3 growers using Make
A direct harvesters and 7 growers using Make B harvesters.
The estimated cost of harvesting and handling potatoes to the
washer with the Make A harvester was $42.84 per acre, or 32.46
cents per 100-pound packed bag, and for the Make B harvester
$40.47 per acre, or 30.66 cents per packed bag (Tables 28 and 29).
In each case cost was based on a normal yield of 132 100-pound
equivalent packed bags per acre and a harvesting rate of 0.62
acre per hour for Make A and 0.82 acre per hour for Make B
equipment. As in the Hastings area, operating the harvester
accounted for more than half of the total cost and hauling the
potatoes about a third.
The cost of harvesting potatoes by the indirect method in
Alabama in 1953 was estimated to be $37.50 per acre or 31.25
cents per packed 100-pound bag. This cost was based on an
annual use of equipment on 125 acres, a rate of harvesting of
0.80 acre per hour and a normal yield of 120 100-pound equiva-
lent packed bags per acre. The cost of digging and windrowing
the potatoes was $5.21 per acre and the cost of loading them out
of the window $16.83. In the indirect method the cost of op-
erating the harvester for picking up potatoes was only 40 per-







TABLE 28.-COST PER ACRE OF HARVESTING AND HANDLING POTATOES WITH
DIFFERENT MAKES OF COMPLETE MECHANICAL EQUIPMENT, HASTINGS
AREA, FLORIDA, AND ALABAMA, 1954.

Florida Alabama

Item Direct Direct Harvester Indirect
Harvester | Harvester
Make B Make A Make B I Make E
Dollars Dollars Dollars Dollars
Roto-beating or cutting:
Tractor driver .................. 0.41 0.31 0.31 0.31
Use of tractor .................. 0.45 0.45 0.45 0.45
Equipment cost ............ 0.96 1.27 1.27 1.27
Total .............................. 1.82 2.03 2.03 2.03

Digging and windrowing:
Tractor driver .................. 0.88
Use of tractor ................ 1.18
Use of digger
and windrower ........ 3.15
Total .............................. 5.21

Operating harvester:
Man labor
Tractor driver .............. 1.27 1.13 0.85 0.88
Machine operator ...... 2.12 1.34 1.01 1.04
Other labor ................. 7.90 3.38 5.98 7.00
Use of tractor ........... ...... 1.41 1.61 1.22 1.25
Equipment cost ** .......... 12.07 16.28 15.27 6.66
Total .............................. 24.77 j 23.74 24.33 | 16.83

Hauling potatoes:
Truck driver .................... 4.23 2.42 1.83 1.88
Use of truck .................... 11.28 9.66 7.32 7.50
Equipment cost* ........... 3.07 3.17 3.17 2.51
Total .............................. 18.58 15.25 12.32 11.89

Total harvesting cost
to packinghouse .......... 45.17 41.02 38.68 35.96
Unloading and
removing trash:
Unloading ........................ 0.78 0.41 0.40 0.60
Removing trash .............. 0.59 0.76 0.74 0.84
Equipment cost ..... 0.30 0.33 0.33 0.10
Dirt removal .................... 0.32 0.32 0.32 -
Total .............................. 1.99 1.82 1.79 1.54

Grand total cost .................. 47.16 42.84 40.47 37.50

Performance rates-
acres per hour:
Roto-beating or cutting 2.22 2.22 2.22 2.22
Digging and windrowing 0.85
Operating harvester ...... 0.71 0.62 0.82 0.80
Normal yield per
acre (cwts) .................. 194 132 132 120
Amount harvested
per hour (cwts) .......... 138 82 108 96
Rate of packing per hour
for unloading (cwts).. 250 250 '250 200
See Table 25.
** See Tables 26 and 27.







Harvesting and Handling Potatoes Mechanically


TABLE 29.-COST PER HUNDREDWEIGHT OF HARVESTING AND HANDLING
POTATOES WITH DIFFERENT MAKES OF COMPLETE MECHANICAL EQUIP-
MENT, HASTINGS AREA, FLORIDA, AND ALABAMA, 1954.

Florida Alabama

Item Direct Direct Harvester Indirect
Harvester Harvester
Make B Make A Make B Make E
Cents Cents Cents Cents
Roto-beating or cutting:
Tractor driver ............... 0.21 0.24 0.24 0.26
Use of tractor ................. 0.23 0.34 0.34 0.37
Equipment cost ............ 0.50 0.96 0.96 1.06
Total .......................... 0.94 1.54 1.54 1.69

Digging and windrowing:
Tractor driver ........ .... ... 0.73
Use of tractor ................. 0.98
Use of digger
and windrower .......... 2.64
Total ............................ -4.35

Operating harvester:
Man labor
Tractor driver ............ 0.66 0.86 0.64 0.73
Machine operator ........ 1.09 1.02 0.77 0.87
Other labor .................. 4.07 2.56 4.53 5.83
Use of tractor ................1 0.73 1.22 0.92 1.04
Equipment cost .......... 6.22 12.33 11.57 5.55
Total ........................... | 12.77 17.99 18.43 14.02
I I I
Hauling potatoes:
Truck driver ................... 2.18 1.83 1.39 1.57
Use of trucks .................. 5.81 7.32 5.55 6.25
Equipment cost ............ 1.58 2.40 2.40 2.09
Total ............................ 9.57 11.55 9.34 9.91

Total harvesting cost
to packinghouse ....... 23.28 31.08 29.31 29.97
Unload and remove trash:
Unloading ........................ 0.40 i 0.31 0.30 0.50
Remove trash ................. 0.30 0.58 0.56 0.70
Equipment cost *............ 0.16 0.25 0.25 0.08
Dirt removal ................... 0.17 0.24 i 0.24 -
Total .............................. 1.03 1.38 1.35 1.28

Grand total cost ................. 24.31 32.46 30.66 31.25

Yield and rate
of harvesting:
(100-pound equivalent
packed bags)
Normal yield per acre 194 132 132 120
Rate of harvesting
per hour .................... 138 82 108 96
Rate of packing per
hour for unloading I 250 250 250 200

See Table 25.
** See Tables 26 and 27.






Florida Agricultural Experiment Stations


cent of the total costs, whereas, for Make A direct harvesters,
equipment cost was 2/ of the total cost of digging and hauling
the potatoes. The cost of an indirect harvester is only about
half of that of a direct harvester, thus the lower cost.

THE PARTIALLY MECHANIZED SYSTEM
Two methods of partial mechanization were used to harvest
and handle potatoes. Some growers harvested with a 1-row
machine that placed the potatoes in field bags. The field bags
were handled from the field to the packing shed in the usual
way. In a second method, potatoes were dug and picked up in
field bags in the conventional manner but were field loaded and
hauled in bulk to the packinghouse.
Cost of Harvesting Potatoes with a 1-Row Bagger-Type
Harvester.-Data were collected from 5 growers who operated
11 1-row machines in the Hastings area. Farmers using 1-row
bagger-type harvesters (Make G) used an average of 29 field
bags per acre. The estimated life of the harvester was 9 years
and of field bags 1 year (Table 30). Based on an annual use of
51 acres per harvester, the estimated annual cost for this equip-
ment, exclusive of labor and power, was $13.25 per acre for the
harvester and $1.74 for the field bags.
The estimated cost of harvesting potatoes and placing them
on the conveyor to the washer when the 1-row harvester was
used was $47.42 per acre or 25.91 cents per 100-pound packed
bag (Table 31). This cost was based on a harvesting rate of
0.34 acre per hour and a yield of 183 100-pound equivalent packed
bags per acre. Operating the harvester, including labor, power
and equipment, was the largest item of cost and amounted to
16.88 cents per packed bag. Hauling the potatoes to the pack-
inghouse, including the cost of field bags, was 8.03 cents per
packed bag. Hauling was contracted at 5 cents per field bag.
With a 1-row harvester field bags are filled fuller than when the
potatoes are picked up by hand. Growers using 1-row machines
estimated it required 1.42 field bags to pack a 100-pound equiva-
lent bag of potatoes, compared to 1.71 bags for growers whose
potatoes were picked up by hand.
Cost of Bulk Handling of Potatoes in Field Bags.-A unit
of equipment for bulk handling potatoes in field bags was com-
posed of a field loader, 3 bulk bodies and 2 motors. The average
life of this equipment was estimated at 10 years (Table 30).
Based on an annual use of 286 acres, the estimated annual op-







Harvesting and Handling Potatoes Mechanically 51



TABLE 30.-PURCHASE PRICE, PRESENT AGE, ESTIMATED LIFE, ANNUAL USE
AND COST OF OPERATING VARIOUS TYPES OF HARVESTING EQUIPMENT ON
FARMS USING PARTIALLY MECHANIZED EQUIPMENT, HASTINGS, FLORIDA,
1954.


1-Row,
Bagger-Type

Make G Field
SHarvester] Bags


Field Loader and
Equipment
SHopper
Field [ Boxes
Loader and Total
Motor


Purchase Price, Age, Estimated Life and Annual Use


Purchase price ..........
Present age (years)..
Estimated
life (years) t ......
Estimated annual
use (acres) .....




G rease ..........................
Service labor ..............
Digger chains ...........
R epairs .......................
Depreciation ................
Interest, insurance,
taxes ..................


Total cost


$ 3270
2


$ 89* $ 995**[ $2205**
1 2 2


$3110


9 1 10 10

51 51 286 286


Annual Operating Cost


$ 1.53
4.59
61.20
81.60
363.33

163.50


675.75


$ 18
$ 89 90

45


89


Cost per Acre


G rease ............. ........
Service labor ..............
Digger chains ............
R epairs .......... -..... ....
Depreciation ..............
Interest, insurance,
taxes I ...............


Total cost ............


$ 0.03
0.09
1.20
1.60 $ 0.06 $ 0.11
7.13 $ 1.74 0.32 0.77'
I i
3.20 0.16 0.381


13.25 1.74 0.54 1.261


Based on an average of 29 field bags per acre.
** Data for purchase cost of bulk loader based on 1953 prices and for bulk bodies and
motors, 1954 prices. Includes 3 bulk bodies and 2 motors per farm unit.
f Estimated (actual service) life, taking account of seasonal operation, assuming no
salvage value at the end of the use period.
: Interest 3 percent, insurance 1 percent and taxes 1 percent of the purchase price (inter-
est at 3 percent equals approximately 5 percent of the undepreciated balance).


Item


$ 30 $ 48
221 311

110 155


153 361 514


$ 0.17
1.09

0.54


1.80






Florida Agricultural Experiment Stations


rating cost of this equipment, exclusive of labor and power,
was 54 cents per acre for the loader and $1.26 for the bulk boxes
and motors.

TABLE 31.-COST PER HOUR, PER ACRE AND PER 100-POUND EQUIVALENT
PACKED BAG FOR HARVESTING POTATOES WITH 1-ROW MAKE G ME-
CHANICAL HARVESTING AND HANDLING IN FIELD BAGS, HASTINGS AREA,
FLORIDA, 1954.
SCost per
Cost per Hour* Cost per Acre* | 100-
Item Rate pound
iI | | Packed
Number Cost Hours Cost Bag*
Cents
Operating harvester:
Man labor:
Tractor driver
and harvester
operator ........ $0.90 1 $ 0.90 2.94 $ 2.65 1.45
Fill and handle
field bags ....... 0.85 2 1.70 5.88 5.00 2.73
Other labor ....--.. 0.80 3** 2.40 8.82 7.05 3.85
Use of tractor ........- 1.00 1 1.00 2.94 2.94 1.61
Equipment cost t ...... 4.51 13.25 7.24

Total .................... _10.51 30.89 16.88

Hauling potatoes:
Contract hauling 0.05 259 4.40 12.95 7.08
Cost of field bags 0.59 1.74 0.95

Total ................... 4.99 14.69 8.03

Total harvesting cost 48
to packinghouse 15.50__45.58 24.91

Unloading and
removing trash$:
Move out
of storage .......... 0.90 1 0.90 0.47 0.26
Remove trash ........ 0.75 1 0.75 0.39 0.21
Supervise and
check unloading 1.18 1 1.18 0.61 0.33
Clean out washer.. 0.72 1 0.72 0.37 0.20

Total ................ 3.55 1.84 1.00

Grand total cost ...... 47.42 25.91
Based on a rate of harvesting of .34 acre per hour, an annual use of 51 acres per
harvester per year and a yield of 183 100-pound equivalent packed bags per acre.
** Two people removing vines and trash and one picking up behind harvester.
SSee Table 30.
T Cost of unloading and removing trash calculated on basis of 350 packed bags per hour.

The cost of loading, hauling and handling potatoes from the
field and placing them on the conveyor to the washer was 4.81
cents per field bag or 8.12 cents per 100-pound packed bag (Table







Harvesting and Handling Potatoes Mechanically


32). Labor for loading and handling and the use of trucks was
contracted at a "piece rate" of 3.75 cents per field bag. The bulk
bodies were placed on trucks furnished by the contractor. The
contractor used 3 trucks and 6 laborers-2 drivers for the trucks,
3 men to dump the field bags into the loader and 1 man to drive
the tractor that pulled the loader. The charge for the use of a
tractor for pulling the field loader and for the use of the equip-
ment was 0.15 and 0.46 cent per field bag, respectively. Un-
loading and removing trash at the packinghouse amounted to
$1.77 per acre or 0.76 cent per 100-pound packed bag.

TABLE 32.-COST PER ACRE AND PER UNIT OF LOADING, HAULING AND
HANDLING POTATOES FROM THE FIELD TO THE WASHER WITH BULK
EQUIPMENT, HASTINGS, FLORIDA, 1954.


Item

Unit

Loading and hauling:
Man labor and Field
truck rental ........ bag
Use of tractor ........ hour
Cost of equipment _


Average per Acre *


Amount Rate


392 $.0375
0.77 0.75


Cost per Unit
SPer
100- Per
Sound Field
IPacked Bagt
Cost Bag**
ICents Cents


$14.70 6.34
0.58 0.25
1.80 0.77


Total ..................... 1 17.08 7.36 4.36

Unloading and
handling to
washer:
Unloading ............ hour 0.95 0.73 0.31 0.19
Remove trash .......... hour| 0.675 1.04 0.45 0.26

Total .................... [ 1.77 0.76 0.45


Grand total cost


J I


18.85 8.12


Based on a rate of harvesting of 1.37 acres per hour.
** Based on a yield of 232 100-pound equivalent packed bags per acre.
t Based on a yield of 392 field bags per acre (requires 1.69 field bags to pack a 100-
pound equivalent packed bag).

The farmer using the bulk handling equipment said a field
bag lasted about twice as long with bulk equipment as compared
to loading and hauling in the usual way. He also said much
less dirt was carried to the packinghouse, since it was emptied
in the field as the potatoes were loaded. The farmer also felt
he obtained a higher rate of packing in his packinghouse, as it
was possible to maintain a more even flow of potatoes on the
equipment when they were unloaded from bulk trucks than






Florida Agricultural Experiment Stations


when the field bags were dumped directly as they were unloaded
from field trucks.

COMPARISON OF COST OF HARVESTING AND HANDLING
POTATOES WITH VARIOUS SYSTEMS
In studying the data on cost of harvesting by various sys-
tems, keep in mind that they are based on average conditions
and type of equipment being used in 1953 and 1954. Costs vary
widely among farms and for the same type of equipment within
an area. As the rate of harvesting per hour is increased for
mechanical equipment, there is a marked decrease in cost per
unit.
Under average conditions in Florida the estimated cost of
harvesting potatoes and placing them on the conveyor to the
washer with completely mechanical equipment was about $47
per acre, or 24.3 cents per 100-pound packed bag (Table 33).
This was about 1.6 cents per bag less than the cost with the
1-row bagger type harvesters and about 2.8 cents less than the
cost with the conventional method.
In Alabama 2 makes of direct and 1 of indirect harvester
were used. Each make of equipment varied in features and
amount of labor used. However, the estimated cost for harvest-
ing potatoes with each make of equipment was almost the same.
The cost for the Make A equipment was highest, due partly to
a higher cost for repairs and a slightly lower rate of harvesting
because of mechanical breakdown. The cost per unit for me-
chanical harvesting was 6 to 8 cents less per bag than the cost
to harvest and handle the potatoes in the usual way.

FACTORS AFFECTING COST PER UNIT OF HARVESTING
AND HANDLING POTATOES
A number of factors affect the cost of harvesting and han-
dling potatoes with mechanical equipment. The more important
of these are variation in total acres harvested or total amount
of potatoes harvested per season, volume of potatoes harvested
per hour and expected life and cost of the equipment. As indi-
cated earlier, the main factor affecting volume of potatoes har-
vested per hour is yield per acre. The amount of potatoes har-
vested during the season depends on the number of hours the
equipment is operated and the average volume of potatoes har-
vested per hour. The time required to harvest an acre of po-








Harvesting and Handling Potatoes Mechanically


TABLE 33.-COMPARISON OF COST PER ACRE AND COST PER 100-POUND
EQUIVALENT PACKED BAG OF HARVESTING AND HANDLING POTATOES WITH
VARIOUS SYSTEMS, HASTINGS AREA, FLORIDA, AND ALABAMA, 1954.


Item





Hastings area,
Florida:
Completely mech-
anized, Make
B ** ...................
Partially mechan-
ized, Make G t-.
Conventional
system ...........

Alabama:
Completely mech-
anized system:
Direct harvester
Make A** ....
Bake B** ......
Indirect har-
vester Make
E **
Conventional
system I ..-.......
I


Roto- Digging, I
Beating Picking
or up and
Cutting Loading* |

Cost per Acre


$ 1.82


1.83




2.03
2.03


2.03

2.07


$24.77

30.89

25.42




23.74
24.33

22.04

34.72


S Un- I
S loading
Haul- and Pick- Total
ing ing out
I Trash


$18.58

14.69

13.25




15.25
12.32


11.89

11.88


Cost per 100-pound Packed Bag


Cents
Hastings area,
Florida:
Completely mech-
anized, Make
B ** ............... 0.94
Partially mechan-
ized, Make Gt ..
Conventional
system I ............ 1.18
Alabama:
Completely mech-
anized system:
Direct harvest-
ers Make A** 1.54
Make B** ...... 1.54
Indirect harvest-
ers, Make E** 1.69
Conventional
system $ ............ 1.57


Cents



12.77

16.88

16.40




17.99
18.43

18.37

26.30


Cents


9.57

8.03

8.55




11.55
9.34

9.91

9.00


$ 1.99

1.84

1.57


$47.16

47.42

42.07


1.82 42.84
1.79 40.47

1.54 37.50

2.24 50.91



Cents I Cents


1.03

1.00

1.02




1.38
1.35

1.28

1.70


24.31

25.91

27.15




32.46
30.66

31.25

38.57


* Includes cost of dirging
** S-e Tables 28 and 29.
t See Table 31.
$ See Tables 23 and 24.


and windrowing for the indirect harvester Make E.







Florida Agricultural Experiment Stations


tatoes is determined by the yield per acre and the average rate
of harvesting per hour. In analyzing variations in cost, these
factors are considered independently and then in combination.

RELATION OF TOTAL ACRES HARVESTED PER SEASON AND
RATE OF HARVESTING PER HOUR TO COST PER UNIT
Assuming the same average rate of harvesting per hour, the
main factor affecting the per unit cost of harvesting and handling
potatoes with mechanical equipment is the acres harvested per
year. On the other hand, for a given number of acres of pota-
toes harvested, the main factor affecting per unit cost is the
rate of harvesting per hour. In each of these cases the per unit
cost depends on the yield per acre, as this determines the total
volume harvested.
Cost of operating mechanical equipment includes both fixed
and operating costs. Since fixed costs are more or less constant,
cost per acre decreases as acres harvested annually increases.
In contrast, operating costs per acre remain relatively constant,
regardless of the acreage harvested annually. Operating costs
include the cost of labor for operating the equipment, use of
tractor and trucks and direct equipment costs such as repairs,
digger chains, fuel for the motor, lubricants and so forth.
To show the effects of variation in acres harvested and rate
of harvesting per hour on per unit cost independently and in
combination with each other, the data in this study were used
to estimate cost for various combinations of acres harvested,
rate of harvesting per hour and yield per acre. In making these
calculations the value of the mechanical equipment and the esti-
mated life were those used in calculating the cost of harvesting
potatoes with mechanical equipment as shown in Table 25. The
average rate per hour for labor and the cost of trucks and
tractors were also the same as those used in calculating average
costs. The cost of fuel and lubricants for operating the har-
vester were varied with the estimated hours used, and the cost
of digger chains and repairs with estimated acres harvested.
It was assumed that costs for roto-beating the potatoes and
unloading and handling to the washer in the packinghouse would
not be affected by variation in the acres harvested or rate of
harvesting per hour, since these are separate operations. Roto-
beating was calculated on a per acre basis; therefore, cost per
unit would vary with variation in yield per acre. Unloading and
handling at the packinghouse was based on the volume handled







Harvesting and Handling Potatoes Mechanically


per hour at the packinghouse and would not be affected by the
use of the mechanical equipment or the yield per acre.
For the Make B harvester in the Hastings area, increasing
the annual use from 105 to 185 acres would result in a reduction
of 3.1 to 5.0 cents per 100-pound equivalent packed bag, depend-
ing on yield per acre (Table 34). On the other hand, for a given
acreage and yield per acre, increasing the rate of harvesting
from 90 to 190 bags per hour would reduce cost about 12 cents
per bag. Increasing the rate of harvesting per hour has more
effect on per unit cost than increasing the amount of annual use.
This is because a large share of the costs are variable. Total
cost per hour is about the same regardless of the volume har-
vested per hour. Therefore, there is a marked reduction in cost
per unit as rate of harvesting is increased.
The data also show the combined effect on cost per unit of
increasing both amount of annual use and average rate of har-
vesting per hour. For example, for the 2-row harvester at
Hastings and a yield of 174 hundredweights per acre, cost
would be 35.7 cents per bag with a rate of harvesting of 90 bags
per hour and an annual use of 105 acres. If a machine were
used to harvest 185 acres and the average rate of harvesting
was 190 bags per hour, the cost per bag would be 19.9 cents,
or a difference of 15.8 cents.
Similar relations between annual use and rate of harvesting
to costs are shown in Table 35 for the Make B harvester in Ala-
bama and in Table 36 for the Make G 1-row harvester in Hast-
ings. The data for Alabama show that increasing the number
of acres harvested has a marked effect on cost when the amount
of annual use is relatively low. The combined effect of in-
creasing both annual use and rate of harvesting results in big
reductions in cost per unit. For the Make G 1-row harvester a
smaller percent of the total costs are variable than with com-
plete mechanization. Increasing use results in about the same
reduction in cost per unit as increasing rate of harvesting per
hour. The data in Tables 34 to 36 can be used also to obtain
an estimate of cost per unit for various combinations of acres
harvested per season, rate of harvesting per hour and yield
per acre. To estimate cost, one would select the combination
most nearly fitting the situation desired. For example, if one
expected to use a 2-row harvester in the Hastings area to har-
vest 125 acres per year on potatoes that would yield 174 bags
per acre at an estimated average rate of harvesting of 140 bags







58 Florida Agricultural Experiment Stations

TABLE 34.-ESTIMATED COST PER 100-POUND EQUIVALENT PACKED BAG OF
HARVESTING AND HANDLING POTATOES WITH MECHANICAL EQUIPMENT
FOR SELECTED COMBINATIONS OF ACRES HARVESTED PER SEASON PER
HARVESTER, RATES OF HARVESTING PER HOUR AND YIELD PER ACRE,
MAKE B HARVESTER, HASTINGS AREA, FLORIDA.

Rate of Harvesting per Acres Harvested per Season
Hour I I
(100-pound equivalent 105 125 145 165 185
packed bags) Cents I Cents I Cents Cents [ Cents
Estimated Cost for a Yield of 134 100-pound Equivalent Packed Bags
per Acre

90 ................. .. .............. 39.6 37.7 36.4 35.3 34.6
115 .................. .............. 34.7 32.9 31.5 30.4 29.7
140 ................ .................... 31.5 29.6 28.3 27.2 26.5
165 .............................. .. 29.2 27.4 26.0 24.9 24.2
190 ...................... ............. 27.7 25.8 24.5 23.4 22.7

Estimated Cost for a Yield of 154 100-pound Equivalent Packed Bags
per Acre


9
11
14
16
19


0 ..................................... 37.4 35.8 34.6 33.6 33.0
5 ...................... ............... 32.5 30.9 29.7 28.7 28.1
0 ........................................ 29.3 27.7 26.5 25.5 24.9
5 ..................................... 27.0 25.4 24.2 23.3 22.7
0 .................................... 25.4 23.8 22.6 21.7 21.1

Estimated Cost for a Yield of 174 100-pound Equivalent Packed Bags
per Acre


90 .................. .............. ..... 35.7 34.2 33.2 32.4 31.8
115 ....................................... 30.7 29.3 28.3 27.4 26.9
140 ...................................... 27.5 26.1 25.1 24.2 23.7
165 ...................................... 25.3 23.9 22.9 22.0 21.5
190 ..................................... 23.8 22.4 21.3 20.5 19.9

Estimated Cost for a Yield of 194 100-pound Equivalent Packed Bags
per Acre

90 ..................................... 34.4 33.1 32.2 21.5 31.0
115 ..................................... 29.5 28.2 27.3 26.5 26.0
140 .................................. ...... 26.2 24.9 24.0 23.2 22.7
165 ..................................... 24.0 22.8 21.9 21.1 20.6
190 .............................. 22.4 21.1 20.2 19.4 18.9

Estimated Cost for a Yield of 214 100-pound Equivalent Packed Bags
per Acre

90 ........................................ 33.3 32.2 31.3 30.6 30.2
115 ..................................... 28.3 27.2 26.3 25.6 25.2
140 ..................................... 25.2 24.0 23.2 22.5 22.1
165 ..................................... 23.0 21.8 21.0 20.3 19.9
190 .................................. 21.3 20.2 19.4 18.7 18.2
1







Harvesting and Handling Potatoes Mechanically


TABLE 35.-ESTIMATED COST PER 100-POUND EQUIVALENT PACKED BAG OF
HARVESTING AND HANDLING POTATOES WITH MECHANICAL EQUIPMENT
FOR SELECTED COMBINATIONS OF ACRES HARVESTED PER SEASON PER
HARVESTER, RATES OF HARVESTING PER HOUR AND YIELD PER ACRE, MAKE
B HARVESTER, ALABAMA.


Rate of Harvesting per Acres Harvested per Season
Hour I
(100-pound equivalent 50 75 100 125 150
packed bags) Cents I Cents I Cents Cents i Cents
Estimated Cost for a Yield of 92 100-pound Equivalent Packed Bags
per Acre

68 ...................... ............. 63.27 51.38 45.98 42.74 40.58
88 ....................................... 58.12 46.23 40.82 37.58 35.44
08 ...................................... 54.94 43.06 37.65 34.41 32.26
28 .................-... ........ 52.78 40.89 35.49 32.25 30.10
48 -.-.-.--- ....-.....- ...-...- .-... 51.11 39.22 33.82 30.58 28.42

Estimated Cost for a Yield of 112 100-pound Equivalent Packed Bags
per Acre
[ I Ii


1(
12
14


68 .............-.- ...-..-...--- .- 56.08 46.32 41.88 39.22 37.46
88 -.....-....-......-..- .........-...... 50.88 41.10 36.66 34.00 32.24
08 ................. .................... 47.74 37.97 33.54 30.88 29.11
8 ........................................ 45.54 35.78 31.34 28.68 26.91
48 .......... . .............- .. 43.89 34.12 29.68 27.02 25.26

Estimated Cost for a Yield of 132 100-pound Equivalent Packed Bags
per Acre


68 ....................................... 50.96 42.67 38.90 36.65 35.15
88 ....................... ............... 45.84 37.55 33.78 31.53 30.03
108 ..................-................... 42.59 34.30 30.54 28.28 26.78
128 ........................................ 40.38 32.09 28.32 26.06 24.56
148 ....................................... 38.76 30.48 26.71 24.45 22.95

Estimated Cost for a Yield of 152 100-pound Equivalent Packed Bags
per Acre

68 .................................... 47.17 39.97 36.70 34.74 33.44
88 .....---...-......... ......-.. --- 42.14 34.94 31.67 29.71 28.40
108 ...... ............................... 38.90 31.71 28.44 26.48 25.18
128 ........-................ ........ 36.68 29.48 26.22 24.26 22.95
148 ................... ............... 35.06 27.86 24.60 22.64 21.34

Estimated Cost for a Yield of 172 100-pound Equivalent Packed Bags
per Acre


68 ................................
88 ....................................
108 ....................................
128 ............ ..............
148 ................- ...............|


44.37
39.19
35.98
33.76
32.14


38.01
32.83
29.62
27.40
25.78


35.12
29.94
26.73
24.51
22.90


33.39
28.20
25.00
22.78
21.16


32.24
27.06
23.84
21.62
20.01


I I I


1
1
1







60 Florida Agricultural Experiment Stations

TABLE 36.-ESTIMATED COST PER 100-POUND EQUIVALENT PACKED BAG OF
HARVESTING AND HANDLING POTATOES WITH MECHANICAL EQUIPMENT
FOR SELECTED COMBINATIONS OF ACRES HARVESTED PER SEASON PER
HARVESTER, RATES OF HARVESTING PER HOUR AND YIELD PER ACRE, MAKE
G HARVESTER, HASTINGS AREA, FLORIDA.

Rate of Harvesting per Acres Harvested per Season
Hour I I I
(100-pound equivalent 30 40 | 50 60 70
packed bags) I Cents I Cents | Cents | Cents Cents
Estimated Cost for a Yield of 134 100-pound Equivalent Packed Bags
per Acre

42 ..............-....... ........... 39.19 35.92 33.94 32.63 31.70
52 ...................................... 36.34 33.06 31.10 29.78 28.85
62 .................................. 34.54 31.26 29.30 27.98 27.05
72 ........-............ ............... 33.18 29.91 27.94 26.62 25.69
82 ................. .................. 32.16 28.88 26.91 25.60 24.66

Estimated Cost for a Yield of 154 100-pound Equivalent Packed Bags
per Acre

42 .............. ...................... 36.90 34.04 32.33 31.18 30.38
52 ............................... ....... 34.10 31.25 29.54 28.40 27.58
62 ..................................... 32.22 29.38 27.66 26.52 25.70
72 ..................................... 30.90 28.05 26.34 25.20 24.38
82 ................................... 29.88 27.02 25.31 24.16 23.36

Estimated Cost for a Yield of 174 100-pound Equivalent Packed Bags
per Acre

42 ..................................... 35.09 32.56 31.05 30.04 29.32
52 .................................... 32.29 29.77 28.25 27.24 26.52
62 ....................................... 30.47 27.94 26.43 25.42 24.70
72 ........................................ 29.12 26.60 25.08 24.06 23.35
82 ......................................... 28.08 25.55 24.03 23.02 22.30

Estimated Cost for a Yield of 194 100-pound Equivalent Packed Bags
per Acre

42 .................................. 33.71 31.44 30.08 29.18 28.54
52 ...................................... 30.94 28.68 27.32 26.41 25.76
62 ...................................... 29.07 26.81 25.44 24.54 23.90
72 ...................................... 27.70 25.44 24.08 23.18 22.53
82 ....................................... 26.67 24.41 23.04 22.14 21.50

Estimated Cost for a Yield of 214 100-pound Equivalent Packed Bags
per Acre

42 ..................................... 32.09 30.04 28.80 27.99 27.40
52 ................................. 29.42 27.36 26.13 25.30 24.72
62 ................... .................. 27.59 25.54 24.30 23.49 22.90
72 ........................................ 26.28 24.23 23.00 22.18 21.59
82 ........................................ 25.30 23.24 22.01 21.19 20.61







Harvesting and Handling Potatoes Mechanically


of potatoes per hour, the estimated cost per unit would be 26.1
cents (Table 34). On the other hand, if one expected to harvest
165 acres of potatoes that would yield 214 bags per acre at
an average rate of harvesting of 165 bags per hour, the estimated
cost would be 20.3 cents per bag.

RELATION OF TOTAL HOURS HARVESTER OPERATED PER
SEASON AND RATE OF HARVESTING PER HOUR
TO COST PER UNIT
In the previous section it was assumed for a given acreage
and yield per acre of potatoes that, as average rate of harvesting
per hour increased, the number of hours a harvester would be
operated would decrease; that is, the total volume harvested
would not change. This would result in an increase in cost per
hour for fixed costs, thus less reduction in cost per unit than
would occur otherwise. In many cases this is not a realistic
assumption. If an operator could increase his average rate of
harvesting, he would no doubt plan to harvest more acres with
his equipment. In the final analysis it is the volume harvested
per season and not acres harvested that determines cost. The
greatest volume is obtained with a high rate of harvesting per
hour and a maximum number of hours operated per season.
Cost per unit was estimated for 2-row harvesters in the
Hastings area for various combinations of hours operated per
season, rate of harvesting per hour and yield per acre. In these
calculations the same assumptions were made as to cost of the
harvester, estimated life, cost of labor and other factors as were
made in the calculations above. It was assumed, however, that
for a given number of hours of operation per season, the amount
harvested would increase as the average rate of harvesting per
hour increased. For potatoes of the same yield this would mean
that the number of acres harvested would increase as the rate
of harvesting per hour increased.
The effect of change in hours of annual use, change in rate
of harvesting or the combined effect of both on cost per unit
in this assumption differed from that when acres and rate per
hour were varied. There was more variation in cost per unit
from high to low. This was true because, for a given yield
per acre and amount of annual use, an increase in rate of har-
vesting increased volume harvested; whereas in the calculations
above, for a given yield and acreage harvested, the volume har-
vested was assumed not to change as rate of harvesting in-






Florida Agricultural Experiment Stations


creased. For a yield of 174 bags per acre, an annual use of 100
hours and a rate of harvesting of only 90 bags per hour, the esti-
mated cost per unit was 44.3 cents per bag. For the same yield,
with a rate of harvesting of 190 bags per hour and an annual
use of 200 hours, the cost per unit was estimated at 18.9 or a
difference of 25.4 cents per bag (Table 37).
The data in Table 37 can be used also to obtain an estimate
of cost per unit for various combinations of operating hours per
season, rate of harvesting per hour and yield per acre. The data
also show that the cost of harvesting with mechanical equipment
is high if the amount of use is small and the rate of harvesting
is low. On the other hand, they indicate for the Make B equip-
ment in the Hastings area that cost per unit will not go much
below 20 cents per 100-pound equivalent packed bag, regardless
of the rate of harvesting or amount of annual use.
As is shown elsewhere in this report, the volume of potatoes
harvested per hour with mechanical equipment varies with yield
per acre, digging conditions and other factors. For a given
yield, some of the principal items reducing volume harvested
are weeds and grass in the field, short rows, difficulty in turning,
poor traction, delay in unloading bulk trucks at the packinghouse
and mechanical breakdown.
Rate of harvesting per hour will increase as changes and
improvements are made in mechanical equipment. This is true
for the self-propelled harvesters that have better traction and
lose less time in turning at the end of the rows. Good crew
management and improvements in operating techniques will
also increase volume harvested. In fields with excessive weeds
and grass, roto-beating and then barring-off the rows help to
reduce the amount of vegetation that must pass over the ma-
chine and thus increase the speed of operation. The extra cost
of barring-off the rows will usually be less than the increase
in cost of harvesting due to a decrease in volume harvested.
Under adverse conditions it may be cheaper to maintain a rate
of harvesting even though excessive weeds and grass are loaded
with the potatoes if the material can be removed cheaper at the
packinghouse.
Careful attention to proper maintenance of equipment can
materially reduce time loss due to mechanical breakdown. Daily
oiling and greasing of the equipment (preferably at the end of
the day), coupled with a complete inspection, will pay. Replace-
ments of parts that are worn to the extent that they probably







Harvesting and Handling Potatoes Mechanically


TABLE 37.-ESTIMATED COST PER 100-POUND EQUIVALENT PACKED BAG OF
HARVESTING AND HANDLING POTATOES WITH MECHANICAL EQUIPMENT
FOR SELECTED COMBINATIONS OF HOURS USED PER SEASON PER HARVESTER,
RATES OF HARVESTING PER HOUR AND YIELD PER ACRE, MAKE B HAR-
VESTER, HASTINGS AREA, FLORIDA.

Rate of Harvesting per Hours Harvester Operated per Season
Hour I I
(100-pound equivalent 100 1 150 200 250 300
packed bags) Cents Cents Cents Cents I Cents
Estimated Cost for a Yield of 134 100-pound Equivalent Packed Bags
per Acre

90 .--....... ..................... 46.0 40.1 37.1 35.3 34.0
115 .................................... 37.3 32.6 30.2 28.9 28.1
140 ...................................... 31.5 27.6 25.8 24.6 23.8
165 ......... .........................- 27.5 24.2 22.6 21.6 21.0
190 ..... .. ........ ................. 24.7 21.8 20.4 19.6 19.0

Estimated Cost for a Yield of 154 100-pound Equivalent Packed Bags
per Acre

90 .................. ................. 45.4 39.4 36.4 34.5 33.3
115 ...................... ................ 36.5 31.8 29.5 28.1 27.3
140 .. .................................. 30.8 27.0 25.0 23.9 23.1
165 ....... ........-.............. 26.8 23.5 21.9 20.9 20.2
190 ................... .................. 23.9 21.1 19.6 18.8 18.2

Estimated Cost for a Yield of 174 100-pound Equivalent Packed Bags
per Acre

90 ................... ................- 44.3 38.3 35.3 33.4 32.2
115 .......... .......................... 35.5 i 30.8 28.5 27.0 26.2
140 ...................................... 29.9 26.0 24.1 23.0 22.2
165 .................................... 25.9 22.7 21.1 20.0 19.4
190 ...... ...... ...... .......... 23.2 20.4 18.9 18.1 17.5

Estimated Cost for a Yield of 194 100-pound Equivalent Packed Bags
per Acre

90 ................................... 44.5 38.5 35.5 33.7 32.5
115 ................................... 35.6 30.9 28.6 27.2 26.2
140 ..............-........................ 29.8 25.9 24.0 22.8 22.1
165 ................... ................ | 25.8 22.6 20.9 19.9 19.3
190 ... .. ................... 23.0 20.1 18.7 17.8 17.3

Estimated Cost for a Yield of 214 100-pound Equivalent Packed Bags
per Acre


90 ..................... .................. 44.1
115 .................. .................. 35.2
140 ...................................... 29.5
165 ... .........- ................. 25.6
190 .................................... 22.7


38.1 35.1 33.3 32.1
30.5 28.2 26.8 26.0
25.6 23.7 22.6 21.8
22.3 20.7 19.7 19.0
19.8 18.4 17.6 17.0






Florida Agricultural Experiment Stations


will break before the end of a day's operation, will prevent in-
terruption of work of a crew, or crews, that is costing many
dollars per hour.

EFFECT OF VARIATION IN EXPECTED LIFE AND
COST OF EQUIPMENT ON PER UNIT COST
The fixed costs of operating potato equipment include de-
preciation and a charge to cover interest, insurance and taxes.
The amount of the annual depreciation is determined by the
cost and estimated life of the equipment. The charge for in-
terest, insurance and taxes is a flat charge based on the cost
of the equipment. For a stated expected life of a machine, the
annual charge for depreciation increases as the cost of the
equipment increases; for a given cost the amount of the depreci-
ation increases as the expected life is decreased. The amount
of the annual fixed cost per unit depends on the volume of po-
tatoes harvested, which is determined by the acres harvested
and the yield per acre.
The effects of variation in life and cost of equipment on total
harvesting costs per unit can be estimated by calculating the
difference in fixed cost for selected combinations of expected
life and equipment cost. Since most of the investment in me-
chanical harvesting equipment is in the harvester and also since
the life of this equipment is likely to vary more than the bulk
bodies, only the harvester needs to be considered in this com-
parison.
There is a wide range in the cost of mechanical harvesters
and also in their estimated life and annual use. To facilitate
the calculation of the amount of fixed cost for harvesters of
different purchase prices, expected life and annual use, the data
in Table 38 have been prepared. This table shows the annual
fixed cost per bag for each $100 invested in a harvester for vari-
ous combinations of estimated life, annual use and yield per
acre. The amount of the annual fixed cost per unit for any har-
vester can be obtained by multiplying the figure in the table
for the combination most nearly representing the situation de-
sired by the number of $100 invested in a harvester. The differ-
ence in cost for machines of different expected life or cost can
be obtained by calculating the cost at 1 combination and com-
paring this with cost for other combinations.
A few examples of the use of this table follows: In 1954
the cost of the Make B harvester used in Florida and Alabama







Harvesting and Handling Potatoes Mechanically


TABLE 38.-ANNUAL FIXED COSTS PER 100-POUND EQUIVALENT PACKED BAG
FOR EACH $100 INVESTED IN A MECHANICAL HARVESTER FOR VARIOUS
COMBINATIONS OF ESTIMATED LIFE, ANNUAL USE AND YIELD PER ACRE.


Annual
Use
(acres)


Estimated Life in Years

4 5 I 6 7 8 1 9 1 10


Cost per Bag

................ 1.022
................. 0.766
................. 0.614
................ 0.511
0.409

............... 0.246
................ 0.205
.........-....... 0.175


when Yield is


0.800
0.600
0.480
0.400
0.320
0.240
0.192
0.160
0.137


0.666
0.500
0.400
0.334
0.266
0.200
0.160
0.134
0.114


125 Bags per Acre (cents)

0.578 0.514 0.466 0.430 0.400
0.434 0.386 0.350 0.322 0.300
0.347 0.309 0.280 0.258 0.240
0.289 0.257 0.234 0.215 0.200
0.231 0.206 0.186 0.172 0.160
0.174 0.154 0.140 0.129 0.120
0.138 0.123 0.112 0.103 0.096
0.115 0.103 0.094 0.086 0.080
0.099 0.088 0.080 0.074 0.069


Cost per Bag when Yield is 150 Bags per Acre (cents)


0.852
0.639
0.511
0.426
0.341
0.255
0.205
0.171
0.146


0.667
0.500
0.400
0.333
0.267
0.200
0.160
0.133
0.114


0.555
0.417
0.333
0.278
0.222
0.167
0.133
0.111
0.095


0.481
0.361
0.289
0.241
0.193
0.145
0.115
0.096
0.083


0.429
0.321
0.257
0.214
0.171
0.129
0.103
0.086
0.073


0.389
0.292
0.233
0.195
0.155
0.117
0.093
0.078
0.067


0.358
0.269
0.215
0.179
0.143
0.107
0.086
0.071
0.061


Cost per Bag when Yield is 175 Bags per Acre (cents)


.I
-



.. . .. . .


0.730
0.547
0.438
0.365
0.292
0.219
0.175
0.146
0.125


0.571
0.429
0.343
0.286
0.229
0.173
0.137
0.114
0.098


0.476
0.357
0.286
0.238
0.190
0.143
0.114
0.095
0.082


0.413
0.310
0.248
0.206
0.165
0.124
0.099
0.082
0.071


0.367
0.275
S0.221
0.183
0.147
0.110
0.088
0.074
1 0.063


0.333
0.250
0.200
0.167
0.133
0.100
0.080
0.067
0.057


0.307
0.230
0.184
0.154
0.123
0.092
0.074
0.061
0.053


Cost per Bag when Yield is 200 Bags per Acre (cents)


................. 0.639
............. .. i 0.479
................ 1 0.384
-..- ..... .. 0.320
.............. .. 0.256
........ .. 0.192
.. .. 0.154
........- ..- 0.128
................. 0.110


0.500
0.375
0.300
0.250
0.200
0.150
0.120
0.100
0.086


0.417
0.313
0.250
0.209
0.167
0.125
0.100
0.084
0.072


0.361
0.271
0.217
0.181
0.145
0.109
0.087
0.072
0.062


0.322
0.241
0.193
0.161
0.129
0.097
0.077
0.065
0.055


0.292
0.219
0.175
0.146
0.117
0.088
0.070
0.059
0.050


0.269
0.202
0.161
0.135
0.108
0.081
0.065
0.054
0.046


0.333
0.250
0.200
0.167
0.133
0.100
0.080
0.067
0.057


0.286
0.214
0.171
0.143
0.114
0.086
0.069
0.057
0.049


0.250
0.188
0.150
0.125
0.100
0.075
0.060
0.050
0.043


.. . . . ...
.. . . . ...
. . . . ...
. . .. . ...
.. . . . ...
.. .. .. I- -
.. . . . ...

.. . . . ... I






Florida Agricultural Experiment Stations


was $6100 and the expected life 7 years. For an annual use of
150 acres and a yield of 175 hundredweights per acre, the fixed
cost per 100-pound bag would be 4.51 cents ($61 x .074). If the
expected life was estimated at 5 years instead of 7, the fixed
cost per bag would be 5.80 cents ($61 x .095), or a difference of
1.29 cents. If the value of the machine was $7000 instead of
$6100, the fixed cost per bag for an estimated life of 7 years
would be 5.18 cents ($70 x .074). On the other hand if the
harvester was used to harvest only 100 acres of potatoes and
the yield was only 125 bags per acre, the fixed cost per bag for
a machine valued at $6100 would be 9.39 cents ($61 x .154) for
an estimated life of 7 years and 12.20 cents ($61 x .200) for an
estimated life of 5 years, or a difference of 2.81 cents.
The data in Table 38 can be used to calculate the fixed cost
per bag for all makes and types of harvesters. Make G 1-row
harvesters were valued at $3,270 each, with an estimated life
of 9 years. The fixed cost per bag for these machines, if used
to harvest 50 acres that yielded 175 bags to the acre, would be
6.02 cents per bag ($32.7 x .184). If the life of the machine
was estimated to be 5 years, the fixed cost per bag would be
9.35 cents ($32.7 x .286), or a difference of 3.33 cents.

CUSTOM MECHANICAL HARVESTING
Custom harvesting is a possible means by which the use of
mechanical equipment can be increased and the per unit har-
vesting cost reduced. Also, it is a means by which growers with
acreages too small to own mechanical equipment might obtain
the use of such equipment.

EXTENT OF USE
Custom operation by individuals who own equipment is a
common practice in harvesting various crops and performing
other farm operations in many sections of the United States.
However, custom operation of mechanical potato harvesters has
been limited. To introduce mechanical harvesting and bulk
handling of potatoes in the Southeast, 1 manufacturer did cus-
tom harvesting in 1953 largely for demonstration purposes. Of
the acres of potatoes harvested mechanically in the 2 states in
1953, 17 percent was on a custom basis in Alabama and 27 per-
cent in Florida (Table 39).
In 1954 a few of the farmers in Florida and Alabama who
owned mechanical equipment did some custom harvesting. One







Harvesting and Handling Potatoes Mechanically


operator in Florida purchased three harvesters which he used
entirely for custom work. He followed the potato harvest from
Florida to New York. In 1954, of the acreage harvested me-
chanically, 7 percent in Alabama and 54 percent in Florida was
on a custom basis. Of the 1,016 acres custom harvested in Flor-
ida, 810 acres were harvested by the operator doing only custom
work. This man did not operate his equipment in Alabama.
TABLE 39.-TOTAL ACRES OF POTATOES HARVESTED MECHANICALLY, NUMBER
AND PERCENT OF ACRES CUSTOM HARVESTED, ALABAMA AND FLORIDA,
1953-54.

Item 1953 1954
SAlabama i Florida Alabama Florida
Total acres of potatoes
harvested mechanically .. 2,050 1,125 1,755 1,897
Acres harvested on
custom basis .................... 350 300 117 1,016
Percent of acres harvested
mechanically, harvested
on custom basis .............. 17.1 I 26.7 6.7 j 53.6

Custom rates varied from 22 cents per 100-pound packed bag
to as high as 30 cents. Rates within an area were based, in some
instances, on the amount of weeds and grass in the field. In
some cases the charge was $30 per bulk load. This amounted
to about 30 cents per packed bag, as a load packed out about
100 100-pound bags.
The rate charged for custom harvesting must be acceptable
to both machine owners and farmers hiring their potatoes har-
vested. If sufficient labor is available for picking up the po-
tatoes, farmers are not likely to pay a rate higher than the cost
by conventional harvesting. However, if there is a shortage
of labor, they may be willing to pay higher rates for mechanical
harvesting than would normally be paid for hand picking.
A person doing custom work with mechanical equipment
would not find any advantage in doing custom harvesting at rates
that did not cover variable costs. An operator using his equip-
ment only for custom work would expect a return high enough
to cover both variable and fixed costs. In addition, he would
expect some return for his efforts in operating the equipment.
PROBLEMS OF CUSTOM HARVESTING
People operating mechanical equipment experienced a num-
ber of problems in the 1953 and 1954 seasons. When mechani-






Florida Agricultural Experiment Stations


cal equipment was first introduced in the area, packinghouses
were not equipped to receive potatoes hauled in bulk. Many of
the packinghouse operators were reluctant to make the neces-
sary changes, especially since they did not know whether me-
chanical harvesting would be successful and thus a permanent
operation. They were also concerned over the problem of co-
ordinating the harvesting and packing operations and fitting
mechanical harvesting in with the conventional method of han-
dling potatoes.
The operators of mechanical equipment also experienced a
number of problems in operating the equipment. The more im-
portant were caused by the width of rows not being the same
as the width between the digger blades of the harvester, short
headlands, insufficient traction for turning at the end of the
rows and irrigation and drainage ditches over which the equip-
ment had to be moved. They also had to learn by experience
how best to organize a crew and operate the equipment for most
efficient production.
Another difficulty in custom operation of bulk harvesting
equipment in 1953 and 1954 was the relationship between the
harvester operator and the grower. When such a new method
was first used, neither the operator nor the grower could see
all of the problems involved. Usually the agreement to harvest
the potatoes was on a flat price per packed bag. Regardless of
the condition of the field at time of digging, the farmer too
often felt that the problems of harvesting were the responsibility
of the man who had contracted to dig the potatoes. Growers
were reluctant to perform certain practices that would have
made it easier to operate mechanical equipment, since it would
have meant some increase in cost of harvesting to them.
Many of the problems encountered with custom harvesting
were due to the use of a new method of harvesting. Most of
these problems can be and are being solved as more experience
is gained. Improvements in equipment are reducing operating
problems and also increasing the volume of potatoes that can
be harvested in a given period.
Growers who wish to have their potatoes custom harvested
should plan for this before planting. Sufficient headlands should
be left for turning the equipment at the end of the row. Short
rows should be avoided where possible. The custom operator
should discuss problems fully with the individual grower be-
fore a custom agreement is made. Both parties should under-






Harvesting and Handling Potatoes Mechanically


stand what is expected of each other, and be willing to work
together to insure the success of the operation. An agreement
should also be worked out with the operator of the packinghouse
that is to pack the growers' potatoes so there will be a satis-
factory arrangement and equipment for receiving potatoes
hauled in bulk.
As the number of mechanical harvesters increases in an
area, the necessity of growers considering custom harvesting or
joint ownership will increase. This will be especially true for
those hauling potatoes to packinghouses packing for a number
of growers. Since the investment is not large, growers can
afford to own more conventional diggers than are needed to har-
vest the acreage of potatoes grown. This problem is much
more important when mechanical equipment is used. Because
of the large investment, it is much more expensive to own more
mechanical equipment than is needed. Per unit cost of harvest-
ing potatoes will be high unless harvesters can be operated at
capacity to harvest a large volume per hour and also a large
acreage of potatoes in a season. To accomplish this, only the
number of harvesters necessary to harvest the total acreage of
potatoes grown must be used. Also, with increase in use of me-
chanical equipment the problem of coordinating the digging and
packing operation will become more difficult. In some cases
packinghouse operators may find it necessary to consider custom
operation of mechanical equipment.

SUMMARY AND CONCLUSIONS
This report presents data on amount of use, performance,
harvesting practices, quality and costs of harvesting and han-
dling potatoes with mechanical equipment in Florida and Ala-
bama in 1953 and 1954. Data are also presented on the costs
of harvesting and handling potatoes with conventional methods.
In 1953 1,125 acres of potatoes in Florida and 2,050 in Ala-
bama were harvested with mechanical equipment. Potatoes on
about 500 acres in Florida were conventionally dug and bulk
loaded to be hauled from the field to the packinghouse. In 1954
1,897 acres in Florida and 1,755 acres in Alabama were harvested
and handled with mechanical equipment. Potatoes on 746 acres
in Florida and 321 acres in Alabama were dug by conventional
methods but bulk loaded to be hauled to the packinghouse.
Since 1954 the use of mechanical equipment has decreased
in Alabama. It has increased rapidly in Florida, especially in






Florida Agricultural Experiment Stations


the Hastings area. Observations during the 1957 season would
indicate that about 35 1-row machines and 50 2-row machines
operated in the Hastings area. These 85 machines probably
dug from 1/4 to /3 of all the potatoes in the area in 1957.
In both Florida and Alabama most units of commercially
built 2-row harvesters have been used to harvest from 100 to
125 acres per season, with an occasional machine harvesting
about 175 acres. One-row harvesters averaged about 50 acres per
machine per season. The rate of harvesting for direct 2-row
machines has varied from 1/, to 1 acre per hour and the volume
of potatoes harvested from 75 to 225 packed hundredweights
equivalent. Rate of harvesting for 1-row harvesters was
from 0.25 to 0.43 acres per hour and volume per hour from 50
to 75 100-pound bags.
Some of the more important factors affecting the amount
of physical injuries in potatoes harvested and handled with
mechanical equipment are variety, condition of the field at
time of harvest, type of protection on the equipment, care with
which it is operated and adequacy of packinghouse facilities
used to receive potatoes hauled in bulk.
The amount of physical injuries in early Irish potatoes har-
vested with mechanical equipment can be reduced. Placing
rubber tubing on rod conveyors and padding equipment is a
help. Data collected in both 1953 and 1954 showed that the
most critical problem in the use of mechanical equipment from
the standpoint of injuries was the failure to set up proper facili-
ties at the packinghouse for receiving potatoes hauled in bulk.
Data on costs of harvesting and handling potatoes were ob-
tained from farmers using conventional systems of harvesting,
completely mechanized systems and partially mechanized sys-
tems. Costs included all expenses and all operations from the
removal of vines to placing the potatoes on the conveyor to the
washer in the packinghouse.
Cost of harvesting potatoes with the conventional method
was estimated to be 20.59 cents per 50-pound bag in the Fort
Myers area, 18.47 cents in Dade County when the potatoes were
handled in field boxes and 14.57 cents when they were handled
in field bags. Costs by the conventional method were estimated
to be 27.15 cents per 100-pound bag in the Hastings area and
38.57 cents in Alabama. Costs in Alabama were higher as most
farmers paid a contract rate of 30 cents per packed bag for
picking-up, loading and hauling.






Harvesting and Handling Potatoes Mechanically


Under conditions and rate of harvesting that obtained in
the Hastings, Florida, area in 1954, the estimated cost of dig-
ging potatoes and placing them on the conveyor to the washer
with a mechanical harvester and bulk equipment was $47.16
per acre, or 24.3 cents per packed hundredweight. This amount
was about 2.8 cents less per bag than the estimated cost of har-
vesting potatoes with conventional methods. Cost with a 1-row
harvester was about 1.6 cents per bag more than that with a
complete 2-row direct harvester.
In Alabama in 1954 costs with the various makes of me-
chanical equipment were about 31.5 cents per hundredweight,
about 8 cents less than harvesting in the usual way.
The main factors affecting costs per unit of harvesting and
handling potatoes with mechanical equipment were variations
in the volume of potatoes harvested per hour and the number
of hours the equipment was used per season. In the Hastings
area for Make B equipment, assuming a yield of 154 bags per
acre, cost was estimated at 45.4 cents per bag for an annual
use of only 100 hours and a rate of harvesting of only 90 bags
per hour. This compared to 18.2 cents for the same yield with
an annual use of 300 hours and a rate of 190 bags per hour.
Custom harvesting is a possible way to increase the use
of mechanical equipment and reduce per unit harvesting cost.
It also may be a means of making mechanical equipment avail-
able to farmers with an acreage of potatoes too small to justify
buying such equipment. In 1954 7 and 54 percent, respectively,
of the potatoes harvested mechanically in Alabama and Florida
were on a custom basis.
The operators of mechanical equipment on a custom basis
encountered many problems associated with a new method of
harvesting. Many of the problems resulted because neither the
owners of the equipment, growers nor packinghouse operators
knew what to expect. Most of the problems can be and are
being solved as more experience is gained. Successful custom
operation depends on the cooperation of all parties. Each should
understand what is expected of each other and be willing to
work together to insure the success of the operation.
The results of this study show that mechanical harvesting
and handling equipment has worked reasonably satisfactorily
in areas where it is being used. Farmers are obtaining more
experience with its use. Manufacturers are learning the prob-
lems of harvesting potatoes in various areas and are improving






Florida Agricultural Experiment Stations


their equipment to increase its efficiency and also increase rate
of harvesting per hour.
The amount of physical injuries in potatoes harvested with
mechanical equipment depends largely on kind of equipment
used and care with which it is operated. Engineers and others
responsible for designing and developing equipment have in-
corporated some changes because of the data collected in this
study which indicated an opportunity or need for reducing in-
jury. The data indicate the need for additional improvements.
Manufacturers should continue to give attention to this prob-
lem. To make needed improvements they should develop data
on injury caused by their machines in the various potato areas
where used because of wide differences in cultural practices,
periods of harvest, kinds of soil and other factors.
The importance of injuries in handling early potatoes cannot
be overemphasized. They are usually more numerous and more
often objectionable to the consumer than other defects. Also,
injuries are 1 of the major causes for removing potatoes during
grading. Although all injuries cannot be eliminated, it should
be possible to reduce them. An ideal place to start is with har-
vesting. The opportunity to eliminate the human element to a
large extent and design equipment causing a minimum of in-
jury appears to be present in mechanical harvesting.
The use of mechanical harvesters and bulk handling of po-
tatoes will increase in many of the potato areas in the South-
east. The cost per unit with such equipment will depend on rate
of harvesting per hour and total hours operated per season.
For many growers the use of mechanical equipment will make
it easier to get their potatoes harvested. For those hauling to
packinghouses packing for a number of growers, there is need
for coordination of the harvesting and packing operations to
get maximum efficiency and use.
The amount of investment in a unit of mechanical equipment
and the fact that the per hour cost of operation changes very
little with volume harvested makes the problem of coordinating
digging and packing much more serious than when harvesting
is by conventional methods. Generally, the problems that have
been solved less successfully at present are those connected with
receiving and handling potatoes at the packinghouse. For the
most successful operation of mechanical equipment, the coop-
eration of the manufacturer, the dealer, the farmer and the
packinghouse operator is necessary.




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