Title: Costs of harvesting snap beans by machine
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Title: Costs of harvesting snap beans by machine
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Creator: Brooke, Donald Lloyd,
Publisher: University of Florida, Institute of Food and Agricultural Sciences, Department of Agricultural Economics
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Full Text


D. L. Brooke and A. H. Spurlock*


As the supply of hired farm labor has decreased due to farm-non-

farm job migration resulting from expanded non-farm income opportunities,

changes in unemployment in the economy and changes in the size of the

civilian labor force, etc., real wages of hired farm labor have increased,

and as a consequence, farm producers have tended to substitute other prod-

uctive inputs for hired labor in production.

One means by which this substitution is effected is through

the mechanization of harvesting processes which heretofore required vast

quantities of stoop labor. In mechanizing, a shift in the demand for hired

labor is effected since farm operators generally accept as given the prices

they must pay for inputs other than labor and the prices they receive for

their products, and adjust their hirings in the light of these prices,

the prices of hired labor, and the technological alternatives open to

them in production.

Mechanization probably does not raise the productivity of all

hired farm labor, but rather just that of the "more highly skilled machine

operator labor' since the increased capital input in harvesting machines'

replaces stoop labor. Not only involved is a "capital-for-labor" type

substitution, but also a "labor-for-labor' type substitution where one

quality of labor, i.e., machine operators, replaces another quality of

*Agricultural Economists, I. F. A. S., Florida Agricultural
Experiment Stations, Gainesville, Florida.

labor, i.e., stoop labor. In terms of the question of whether it will

pay to mechanize harvesting processes one must also become concerned with

the "expected" supply and real wage rate for skilled machine operators

relative to the "expected" supply and real wage rate for hired stoop labor.

Florida farmers who grow bush type snap beans must depend heavily

upon a supply of stoop labor at harvest time. They have, in many instances,

adjusted their whole farming operation around the average number of harvest

hands they could expect to employ on a daily basis. In times of labor

shortage, large acreages have been abandoned with a consequent loss of


Labor itself creates shortages by being selective in employment,

choosing to work where the most constant employment is available during

a season. In some cases this may have the effect of reducing the supply

of labor to smaller farms where work is less consistently available.

Rising wage rates in other agricultural employment and an in-

creasing number of non-farm job opportunities are gradually draining off

the supply of bean harvest labor. Realizing this, the more progressive

farmers are using mechanical bean harvesters to help solve the harvest

labor shortage in Florida.

Canning companies brought the first machines into Florida and

used them to harvest beans from contracted acreage. A few enterprising

individuals who had harvested beans on a contract basis in other areas

followed. They were interested in reducing fixed costs on the machines

by expanding their use. After observing these harvesters for a couple

of seasons, some growers purchased machines and experimented with them

in harvesting snap beans for the fresh market, as well as for processing.

First attempts at selling machine harvested snap beans as a

fresh market product met resistance from wholesale buyers. They either

refused the beans or discounted them over hand picked beans. This dis-

crimination has now largely disappeared because buyers found they could

not easily distinguish between them.

Purpose and Method of Study

The purposes of this study were to compare the costs of mech-

anical harvesting of snap beans with the hand picked method under vary-

ing rates of use of mechanical harvester and alternative yield situations,

and to estimate the minimum acreage required for profitable machine in-

vestment under these conditions.

Harvesters were observed at work and timed for speed and output.

Picking efficiency was estimated by sampling for total yield immediately

ahead of the harvester and the remaining marketable beans on vines and

ground after harvesting. Hand picking efficiency was obtained in the

same manner from adjacent fields where possible.

Development of Costs

Costs of operating machinery are of two types, fixed and direct

costs. Fixed costs are those of depreciation, licenses, taxes, insurance

and interest on the initial purchase price of the machine. Their cost

per hour of use decreases as the number of hours the machines are used

increases. Direct costs are those incurred when the machines are being

operated. They include fuel, oil, grease and repairs. They are approx-

imately the same for the one-hundredth hour of use as for the first hour

of use, assuming continued operation and maintenance of the equipment.

Fixed costs: Fixed costs were developed independently of the hours used

per season, and were based upon new equipment valued at the April, 1967

price level. All of the harvesters observed, except two, were Chisholm-

Ryder 2-row machines with trailer and sacking chute. Various trucks were

used to haul beans from the field. A composite of Ford and Chevrolet

prices for a one-ton stake body, dual rear wheel, power steering truck

of standard wheel base was selected. One truck could haul beans for two

harvesters working together but since one cannot easily invest in one-half

of a truck total costs are included here.

The physical life of the harvester was estimated at 10 years

with no salvage value. The life of the truck was estimated at six years

with a 10 percent salvage value, Table 1. In actual practice equipment

sufficient for hauling beans to the grader is already available on most

farms. However, it too depreciates and must be replaced. Licenses and

taxes were estimated at 2 percent and insurance at 1 percent of replace-

ment value annually. Interest on the investment was calculated at 3 per-

cent of replacement value annually. This is equal to about 5 percent

computed on the undepreciated balance method. Total annual fixed cost

for the harvester was $2,560 and for the truck $538.


Table l.--Estimated fixed cost of equipment for mechanical harvesting
of snap beans, Florida East Coast, 1967.

Item Hechanical 1-ton
harvester truck

Replacement costa $16,000.00 $2,800.00
Salvage value none 280.00
Service life 10 years 6 years
Annual fixed cost:
Depreciationb $ 1,600.00 $ 420.00
Licenses taxes, Insurancec 400.00 84.00
Interest 480.00 84.00
Total annual fixed cost $ 2,560.00 $ 588.00

aBased on April 1967 price. Chisholm-Ryder, 2-row, with trailer
and sacking chute. 1-ton truck with stake body.
bDepreciation is calculated by the straight line method. Annual
percentage charge is found by dividing 100 by the estimated life.
CLicenses and taxes, 2.0 percent; insurance 1.0 percent of
replacement cost.
dInterest, 3.0 percent of replacement (equal to approximately
5.0 percent on undepreciated balance).

The fixed costs per acre of beans harvested for the harvester

and the truck are estimated in Table 2. Average fixed cost is related

directly to the amount of use of the machine. The maximum rate of use

of the harvester was computed on the basis of seven hours of operating

time per day for five days a week. It is possible to harvest snap beans

from about November 1 to May 1 in the Lower East Coast area a period

of about 25 weeks. On that basis a harvester could operate a maximum

of 875 hours. At the observed rate of 0.63 acres per hour, 550 acres

could be harvested in a given season. Only by operating six or seven

days per week or at night with lights, could a harvester cover more than

550 acres at the observed rate. Thus the minimum fixed cost per acre

is estimated at $5.72.


Table 2.--Estimated fixed cost of equipment for mechanical harvesting of
snap beans at various annual rates of use, Florida East Coast,

Mechanical Trk T
Item or rate of use haTruck Tota

Total annual fixed costa $2,560.00 $ 588.00C $3,148.00

Acres harvested Cost per acre harvested
25 $ 102.40 $ 23.52 $ 125.92
50 51.20 11.76 62.96
100 25.60 5.88 31.48
150 17.07 3.92 20.99
200 12.80 2.94 15.74
300 8.53 1.96 10.49
425 6.03 1.38 7.41
550b 4.65 1.07 5.72

'As estimated in Table 1.
bEstimated maximum use for one harvester during Florida East
Coast bean harvesting season (Nov. 1 ilay 1). Seven hours per day,
5 days per week for 25 weeks. Harvesting rate of 0.63 acres per hour
of machine operation.
cAssumes one truck per harvester. Costs would be lower if
two harvesters worked together.

Direct costs: Direct costs have been calculated on the basis of average

crew size and machine performance at the observed rate (0.63 acres per hour).

Since labor is not added in partial increments it is possible for some

labor to service more than one harvester, hence an incremental charge for

each acre. Labor requirements are based on an eight hour day with one

hour devoted to routine machine maintenance. Labor cost, including an

8 percent surcharge for payroll taxes, at prevailing hourly rates totalled

$14.01 per acre (Table 3).

Machinery costs were computed on the basis of 30 gallons of

gasoline per day and three quarts of oil plus a repair cost of 8 percent

of replacement cost annually for the harvester. Truck costs were computed

oh the basis of 10 gallons of gas and one quart of oi3 per day plus a re-

pair cost of 5 percent of replacement cost annually. Machinery costs

plus a charge for use of sacks to hold beans were $6.23 per acre, making

total direct costs $20.24 per acre.

Table 3.--Estimated direct labor and equipment cost per acre for the
harvester and truck for mechanical harvesting of snap beans,
Florida East Coast, 1967.
Job and equipment No. Man-hours Hourly Cost per
unit men per acre rate acre
Foreman .25 .45 $ 2.50 $ 1.13
Harvester driver 1.0 1.81 1.50 2.72
Sack and set-off men 2.0 3.63 1.25 4.54
Load beans .63 1.14 1.25 1.42
Haul to grader .75 1.36 1.50 2.04
Maintenance man .25 .45 2.50 1.13
Payroll taxes (8%)b 1.03
Total labor $ 14.01
Harvester 1.60 $ 3.11 $ 4.98
Truck 1.60 .70 1.12
Sacks (2 bu. @ $0.20 ea.,400 per year on 600 ac.) .13
Total equipment $ 6.23
Total cost per acre $ 20.24

aBased on 8 hour day
bSocial security and workmen's compensation.
CBased on 7 hour running time per day, 125 days per year.
Harvester, fuel, oil, grease, cost $1.65 per hour; repairs 8 percent of
replacement cost, $1.46 per hour. Truck, fuel, oil, grease $0.54 per
hour; repairs, 5 percent of replacement cost, $0.16 per hour.

Total costs: A summation of the fixed and direct costs as developed in

Tables 3 and 3 are shown in Table 4 for specified amounts of use of a

harvester. On a per acre basis these range from $146.16 per acre for

25 acres of use to $25.96 per acre for 550 acres of use annually.

1Diesel fuel consumption and cost would be somewhat less but
may be offset by higher initial and overhaul costs.

Figure 1 shows graphically what happens to annual fixed cost, direct

cost2 and total cost (the summation of the two), when the equipment is

used to harvest various acreages at an average packed yield of 100 bush-

els per acre.

Economic Feasibility

One can make a direct comparison of the difference in cost

between hand picking and mechanical harvesting given certain assumptions.

Those assumptions are that; (1) the farmer will continue to grow a

given amount of beans for the useful life of the machinery to guarantee

its continued operational possibilities, and (2) labor will continue to

be available to harvest "first picking" beans at the rate specified.

Table 4.--Estimated total and per acre cost of harvesting snap beans
with mechanical harvesters for varying annual rates of use,
Florida East Coast, 1967.

harvested Fixedb

25 $3,148.00 $
50 3,148.00
100 3,148.00
150 3,148.00
200 3,148.00
300 3,148.00
425 3,148.00
550 3,148.00

aDelivered to grader or p
bAs estimated in Table 1.
cAs estimated in Table 3.





ine picked cost


$ 3,654.00 $

truck if ungraded.

2It has been assumed that direct cost would be constant over the
range of annual use because of lack of data to prove otherwise. Direct
costs are normally expected to decrease gradually with increasing use to
some minimum point and then increase again.

Per acre


Given the above assumptions, Figure 1 indicates that compared

to hand picking a grower can afford to purchase the equipment necessary

to harvest snap beans mechanically if he grows 32 or more acres per year

and harvests at least 100 bushels per acre.3

If custom harvesters continue to be available at $0.40 per

packed out bushel, one can read from Figure 1 also that a grower can

afford his own equipment if he grows 160 or more acres annually and

harvests at least 100 bushels per acre.

Table 5 shows the estimated per bushel costs of harvesting snap

beans by harvester at varying rates of use and expected yields per acre.

The more intensively the harvester is used and the higher the yield of

beans the lower the per bushel cost of operation. This is shown graph-

ically in Figure 2 which also permits visual comparison of hand picking

and harvester picking costs.

Table 5.--Estimated cost per bushel for harvesting snap beans mechani-
cally at varying acres harvested and yields per acre,
Florida East Coast, 1967.

Acres Total Harvested yields per acrea(bushels)
harvested mac
cost 75 00 125 150

Cost per bushel(dollars)
25 $ 3,654 1.95 1.46 1.17 0.97
50 4,160 1.11 .83 .67 .55
100 5,172 .69 .52 .41 .34
150 6,184 .55 .41 .33 .27
200 7,196 .48 .36 .29 .24
300 9,220 .41 .31 .25 .20
425 11,750 .37 .28 .22 .18
550 14,280 .35 .26 .21 .17

aPacked out equals total yield in field less average loss of
21.7 percent in harvesting.

3This considers only annual costs as developed in Tables 1 to
4 and implicitly assumes time has a zero cost to the grower. If the
capital required for harvesting equipment and hand picking are capital-
ized at 5 percent for 10 years one finds that growers can afford mech-
anical harvesters if 32 acres yielding 100 bushels per acre are grown
annually for 10 years.


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The dollar savings of machine over hand picking costs at select-

ed rates of use and yields per acre are shown in Table 6. Savings by

machine harvesting are sufficient at a yield of 100 bushels and an annual

rate of use of 200 acres to repay the cost of the harvester in the first

year of use.

Table 6.--Estimated savings of mechanical harvesting over hand picking
costa of snap beans at varying acres harvested and yields per
acre, Florida East Coast, 1967.

Acres Harvested yields per acreb (bushels)
75 100 125 150

Dollars saved over hand picking cost
25 -1,406 650 94 862
50 338 1,850 3,312 4,875
100 3,825 6,800 9,875 12,900
150 7,312 11,850 16,312 20,925
200 10,800 16,800 22,750 28,800
300 17,775 26,700 35,625 45,000
425 26,456 39,100 52,062 65,025
550 35,062 51,700 68,062 84,975

aMechanical harvesting as estimated in Table 5. Hand harvest-
ing at $1.20 per bushel.
bPacked out equals total yield in field less average loss of
21.7 percent in harvesting.

Picking Efficiency

Picking efficiency was estimated by sampling for total yield

immediately ahead of the harvester and the remaining marketable beans on

vines and ground after harvesting. The percent of total marketable yield

picked by the harvester was the picking efficiency. Several observations

were made of the picking efficiency of the machines operating at different

ground speeds and in three varieties of snap beans. Machine ground speed

was higher in beans being picked for processing than when they were being

picked for fresh market (Table 7). No facilities were available to meas-

ure reel or fan speeds on the machines.

Table 7.--Estimated picking efficiency of snap bean harvesters by
variety, intended use and machine ground speed, Lower East
Coast, Florida, 1967.
Bean use and No. of Variety Ground speed efficiency
observation No. machines Variety (mph) (percent)

Fresh market:
1 3 Harvester 1.22 83.6
2 2 Extender .80 79.6
3 2 Harvester .92 77.8
Average -.98 80.3

4 3 Harvester 1.31 67.5
5 3 Sprite 1.37 76.7
6 2 Sprite 1.28 84.6
Average -1.32 76.3

Average all observations 1.15 78.3

Picking efficiency was slightly higher for fresh market beans

than for beans to be sold to processors. Again, this may be directly

related to ground speed of the harvester and to other factors not measured.

There appears to be some relationship between variety of bean

and picking efficiency of the machine. The picking efficiency in Harves-

ter's in two of three cases was lower than that in the other varieties.

Workers noted that Harvesters were harder to pick by hand than Sprite or


Two checks on the efficiency of hand pickers resulted in a

rate of 75 percent in Harvester's and 83 percent in beans of the Provider

variety. An average of those observations is 79 percent, very close to

that of the machines. For that reason no yield loss calculations for the

machine harvested beans are required in comparing costs by the two methods.

Thus the only real loss from the machine method is the opportunity of a

second picking. This will be discussed in a later section.


The foregoing information indicated when it would be economic-

ally feasible for snap bean growers to purchase and operate mechanical

bean harvesters in Florida. It was indicated also that cost would be

least on those machines which were operated at the maximum capacity.

Once a machine is purchased, however, a grower may decide to use it at

less than the maximum capacity. This increases his fixed cost per unit

of use but does not change total fixed cost. If total fixed cost does

not change, then a decision to use or not to use the machine, in the short

run4, is based upon direct costs. It is this type of reasoning which

prompts a grower to use the harvester for "second picking" beans.

If the yield of "second picking" beans is sufficient to pay

more than the direct costs of the labor and machine expense a grower

would presume it to be profitable. It may appear profitable unless the

alternatives are taken into account and a direct comparison is made.

Let us assume a 200 acre grower has two 4-acre fields of beans

which must be harvested on a given day or be lost. Field A is "first

picking" beans which will yield 100 packed bushels per acre. Field B,

having been picked once by hand is ready for "second picking" and will

yield 30 bushels per acre for sale to the cannery. In Alternative I

Field A can be picked by hand since labor is available and since this

method allows a second picking for machine harvest and Field B can be

picked by machine. The costs and net returns of the two operations in

41n day-to-day harvesting operations. A period too short to
allow modification of acreage or capital plant outlay

Alternative 1 are as follows:

Item .Field Field Total

Harvest & haul to grader $ 480.00a $143.92b $ 623.92
Containers @ $0.38 152.00 152.00
Grading and packing @ $0.20 80.00 24.OOc 104.00
Hauling to market or cannery
@ $0.10 40.00 12.00c 52.00
Commission @ $0.07 28.00 28.00
Total expense $ 780.00 $179.92 $ 959.92
Selling price per unit 3.50 2.00 -
Total sales $1,400.00 $240.00 $1,640.00
Net return $ 620.00 $ 60.08 $ 680.08

a$1.20 per packed bushel.
bTotal cost of machine harvest @ 200 acre per year rate,
Tables 2 and 3.
CNot always a grower cost.

In Alternative 2, Field A can be harvested by machine and

Field B abandoned. The costs and net returns of Alternative 2 are:

Item Field
Harvest and haul to grader $ 143.92a
Containers @ $0.38 152.00
Grading & packing @ $0.20 80.00
Haulitig to market @ $0.10 40.00
Commission @ $0.07 28.00
Total expense $ 443.92
Selling price per unit 3.50
Total sales $1,400.00
Net return $ 956.08

aTotal cost of machine harvest @ 200 acre
per year rate, Tables 2 and 3.

In Alternative 2 by electing to harvest 'first picking" beans

mechanically, forego a possible second picking, and abandon 120 bushels

of "second picking" beans, income for the day has been increased $276

or $69 per acre harvested. To have achieved the same income in Alter-

native 1 for the two fields would have required a yield of more than

70 bushels per acre of "second picking" beans at $2.00 per bushel.

A grower faces such a decision daily as long as he continues

to harvest 'first picking" beans by hand. Some growers still use hand

pickers because (1) "they depend on me for a living", (2) "they kept me

in business for years and I don't want to let them down" or (3) "I may get

in a tight and need some help". These are all commendable humanitarian

reasons, but-they are economically indefensible. Thus, as shown above,

even in the short run, under what are believed to be realistically assum-

ed conditions, a grower is not justified in using a harvester for "second

picking" beans if "first picking" beans are available for harvest.

Based on the information presented, it appears that mechani-

cal harvesting of snap beans, in the short run at least, is economically

feasible. Our model grower is convinced and has taken to mechanical har-

vesting of his 200 acres on a "first picking" basis. However, as the

season progresses5 he finds his harvesting machine and labor are idle

part of the time. Economically this is expensive for, as mentioned

earlier, fixed cost decreases with increasing use. The grower, there-

fore, can reduce fixed cost and employ labor more efficiently by adding

more acres of beans to be harvested. His savings of $69 per acre, by

deciding to harvest mechanically, will permit an expansion of acreage

of about 32 percent (64 acres) in the first year,6 if he makes the de-

cision early in the crop year. This will reduce his fixed cost from

$15.74 per acre to $11.92 per acre.

5Economically this is the intermediate period. A length of
time permitting modification of production, assuming land is available,
but not long enough to permit modification of the basic capital structure.

6Growing costs of $192.61 per acre. D. L. Brooke, IFAS,
Florida Agricultural Experiment Station, Economics Himeo Report ED 67-8,p.2.


Having been restricted by time and capital in his first season

of mechanical harvesting our model grower was able to expand acreage only

about 32 percent. By the end of the season he is convinced he made the

right decision but is still concerned about fixed cost and efficiency in

the use of labor. With time to prepare for major adjustments in farm

organization and capital structure (the long run) the grower would expand

his snap bean acreage to approach 550 acres. This is the point at which

he would attain maximum efficiency and least cost in the use of one mech-

anical harvester, or as an alternative he may decide to expand to the

capacity of two or more harvesters.

Such an adjustment, if adopted by many growers, would increase

acreage and total supply. An increase in supply will, in the long run,

reduce season average prices received for snap beans. A price reduction

lowers grower profits and eventually is reflected in a smaller total

supply of beans.

To this point the discussion has been related to the growing

of beans on sand, rock or marl lands of the Lower East Coast. The use

of mechanical harvesters on the muck soils of western Palm Beach County

has been confined to beans to be sold to processors. The muck adheres to

bruised and broken beans and cannot be removed except by washing. The

washing and moisture left on the beans increases chances of intransit

disease in fresh market beans.

Beans for processing can be harvested mechanically with savings

on the muck soils. With their lower costs per acre7 the production of

beans for that purpose may expand on the muck soils. This will be the

case only if profits from beans are equal to or greater than profits from

alternative uses of the same land at the same time.

7Growing costs of $116.57 per acre. Ibid. p.l.

DLB:gh 10/23/67 -- 500 copies
Ag. Ec., Ag. Exp. Sta.

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