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TABLE OF CONTENTS
LIST OF TABLES .
Page
. . . . . . . iv
SUMMARY. . . . .
INTRODUCTION . . . .
PROCEDURES . . . .
HARVESTING COSTS, 1972-73 SEASON .
Machinery Ownership and Operation
Labor . . . .
RETURNS TO PRODUCTION AND HARVESTING .
Revenue . . . .
Sugarcane Sales. . .
Government Sugar Payment .
Molasses Payment . .
Costs and Net Returns . .
RETURNS TO HAULING AND PROCESSING
Revenue . . . .
Raw Sugar Sales . .
Molasses Sales . .
Costs . . . .
Hauling . . .
Mill Operation . ..
Sugarcane Purchases .
Net Returns . . .
. . . . 1
. . . . 3
. . . . 5
. . . . 7
. . . . 7
. . . 8
. . . . 11
. . . . 11
. . . . 13
. . . . 13
. . . . 14
. . . . 15
.~15
TABLE OF CONTENTS (Continued)
SUMMARY OF RETURNS TO ALL OPERATIONS . . .
EFFECTS OF HIGHER WAGES ON COSTS AND RETURNS . .
HARVESTING COSTS WITH PROJECTED 1974-75 OPERATING RATES
EFFECTS OF HIGHER WAGES AND PROJECTED 1974-75 OPERATING
RATES ON COSTS AND RETURNS . . . .
EFFECTS OF MECHANICAL HARVESTING ON CAPITAL REQUIREMENTS
ADDITIONAL ASPECTS OF MECHANICAL HARVESTING . .
Freeze Damage . . . . .
Wind Damage . . . . .
Ratoon Damage . . . . .
Availability of Cane Cutters . . .
Mill Capacity . . . .
APPENDICES . . . . . .
REFERENCES . . . . . .
. . 19
. . 20
. . 22
------------~--~-~----~- ;9"a"~B
. .e
LIST OF TABLES
Table Page
1 Estimated initial investment and average annual ownership
and operating costs for mechanically harvesting sugarcane
in South Florida, 1972-73 season . . . 9
2 Estimated initial investment and annual ownership and
operating costs for harvesting sugarcane in South Florida
with the hand-cut-continuous-loader system, 1972-73 season .10
3 Estimated labor use and costs per 100,000 gross tons sugar-
cane for mechanical harvesting and hand cutting in Florida,
1972-73 season . . . . ... . 11
4 Estimated revenue, costs and net returns for growing and
harvesting from mechanically harvested and hand cut sugar-
cane in Florida, 1972-73 season . .. . .. 12
5 Estimated revenue, costs and net returns for hauling and
processing mechanically harvested and hand cut sugarcane
in Florida, 1972-73 season . . .. . 16
6 Summary of revenue, costs and net returns for growing,
harvesting, hauling and processing mechanically harvested
and hand cut sugarcane in Florida, 1972-73 season ...... 19
7 Estimated costs for growing, harvesting, hauling, and pro-
cessing sugarcane in Florida at four selected wage levels,
1972-73 season . . . . ... ...... 21
8 Estimated net returns for growing, harvesting, hauling,
and processing sugarcane in Florida at four selected wage
levels, 1972-73 season . . . .... .23
9 Estimated capital investment and machinery and labor costs
for mechanical harvesting and hand cutting sugarcane in
Florida (based on 1972-73 prices and projected 1974-75
operating rates) . . . . . 25
10 Estimated costs for growing, harvesting, hauling, and
processing sugarcane in Florida at four selected wage
levels (based on 1972-73 prices and projected 1974-75
operating rates) . . . .. ...... 26
Table Page
11 Estimated net returns for growing, harvesting, hauling,
and processing sugarcane in Florida at four selected wage
levels (based on 1972-73 prices and projected 1974-75
operating rates) . . . . . 27
12 Estimated new costs for machinery and equipment per 100,000
gross tons of sugarcane for hand cutting and mechanical
harvesting in Florida 1972-73 prices. . . ... 30
13 Trash content and field loss for mechanically harvested
and hand cut sugarcane in Florida, 1972-73 season . 40
14 Estimated trash in cane, percent sucrose in normal juice
(NJS) and percent brix in normal juice (NJB) for hand cut
and mechanically harvested sugarcane in Florida, 1972-73
season (based on experimental data) . . . 43
15 Estimated fiber percent of cane in hand cut and mechanically
harvested sugarcane in Florida, 1972-73 season (based on
experimental data) . . . . .. 45
16 Estimated extraction of normal juice (NJE) with hand cut
and mechanically harvested sugarcane in Florida, 1972-73
season (based on experimental data) . . .. 46
17 Estimated difference in molasses yields between mechanically
harvested and hand cut sugarcane in Florida, 1972-73 season
(based on experimental data) . . . . 48
A COMPARISON OF COSTS AND RETURNS FOR HAND CUTTING AND
MECHANICALLY HARVESTING SUGARCANE IN FLORIDA,
1972-73 SEASON
Glenn A. Zepp and Joe E. Clayton
SUMMARY
Net returns per acre were $40.70 lower for mechanically harvested
sugarcane than for hand cut cane in Florida during the 1972-73 season.
Hauling and processing cane accounted for $30.89 of this reduction, and
growing and harvesting accounted for the other $9 81. The lower returns
to growing and harvesting accrued to independent growers, while those
to hauling and processing accrued to the sugarcane mills.
Direct expenses such as those for machinery and labor were less
per ton of cane for harvesting mechanically than for harvesting by hand
cutting. However, these lower harvesting costs were more than offset
by reduced revenue due to larger field losses and lower sugarcane qual-
ity due to mechanical harvesting. Direct expenses were $3.08 per net
ton of sugarcane for mechanical harvesting.and $3.68 for hand cutting.
A saving in labor accounted for most of the reduction. Labor cost an
estimated $3.01 per net ton of cane for hand cutting but only $1.58
for mechanical harvesting.
Higer wages would reduce net returns with both types of harvest-
ing systems. If labor costs were to rise relative to other costs, me-
chanical harvesting would become more profitable relative to hand cut-
ting. A 15 percent higher field labor wage during 1972-73 would
GLENN A. ZEPP is an agricultural economist in the Economic Research
Service, USDA, and associate professor of food and resource economics at
the University of Florida. JOE E. CLAYTON is agricultural engineer and
leader of Sugarcane Harvesting Research, Agricultural Research Service,
USDA, Belle Glade, Florida.
have produced approximately equal net returns to growing and harvesting
systems. At higher wage levels, net returns to growing and harvesting
operations would turn in favor of mechanical harvesting, However,
total net returns for growing, harvesting, hauling, and processing
with a 50 percent increase in wages would favor hand cutting by
$15.68 per acre.
Mechanical harvesting during 1972-73 was partly experimental and
harvesters were not operated at average daily outputs anticipated for
future crops. Projected 1974-75 operating efficiencies and 1972-73
prices were used to determine the effects of mechanical harvesting on
costs.
Direct machinery and labor costs per ton for harvesting were sub-
stantially lower when projected 1974-75 operating rates were used--
$2.09 for mechanical harvesting compared with $3.69 for hand cutting.
Substituting these lower harvesting costs for the 1972-73 season di-
rect harvesting costs produced net returns per acre for growing and
harvesting that were $26.78 higher for mechanical harvesting than for
hand cutting. The resulting total net returns for growing, harvesting,
hauling, and processing would have been about equal for the two har-
vesting methods--$223.14 per acre for mechanical harvesting and $227.25
for hand cutting.
Sugarcane harvest mechanization increases capital requirements
for machinery and equipment by $1.87 pet additional ton of cane mechani-
cally harvested. About $2.81 million additional investment was need-
ed for harvesting 1 5 percent of the 1972 crop mechanically. If
50 percent of the 1972 crop had been harvested mechanically (about
five million tons of cane), the value of added investment would have
been about $9.35 million. In addition, some factories may have had to
expand some parts of their processing facilities to handle that amount
of mechanically harvested cane. Such expansion would have further in-
creased new investment. Some equipment for hand cutting cane, such as
continuous loaders and labor support equipment and housing would have
become obsolete if mechanical harvesting had been widely adopted.
Considerations other than the direct costs and returns are impor-
tant in determining the long-run profitableness of harvesting sugar-
cane mechanically. There is added risk with mechanical harvesting due
to larger losses from freeze or wind damage, and uncertainty about dam-
age mechanical systems will do to sugarcane ratoons which could affect
the long-term profits from mechanical harvesting. In addition, the
availability of sufficient processing capacity to handle mechanically
harvested cane will affect the profitableness of mechanical harvesting.
INTRODUCTION
The Florida sugarcane industry is located mainly on the organic
soils around the southern half of Lake Okeechobee. Almost one million
tons of cane were grown on 141 farms and processed through eight mills
during the 1972-73 season. The farms ranged in size from 12 acres
of cane to about 60,000 acres. The average was 1,729 acres of cane
grown for sugar. Although a few independent growers harvest their own,
most sugarcane in Florida is harvested by mills or grower cooperatives.
In the past, cane was harvested by foreign workers using machetes
or cane knives. Each cane stalk was cut near the base and the immature
top removed. The worker cuts two rows and two workers pile their rows
together to form a "heaprow". Continuous loaders take the cane from
heaprows, cut it into short pieces and convey it to field carts. The
cane is then taken to the mill for processing.
Research, development, and experimentation with mechanically har-
vesting sugarcane in Florida have been conducted sporadically since 1930.
The 1972 crop was the first in which a mill in Florida depended on mechan-
ical harvesting as the primary method of harvesting. About'15 per-
cent of the 1972 crop was harvested mechanically and one mill harvested
all its cane mechanically. About 50 mechanical harvesters were used
either experimentally or commercially during the 1972-73 season. Four
different mechanical harvesting systems were used extensively. Several
other mechanical harvesters were available but received less use. Addi-
tional investment in mechanical harvesting equipment has been committed
for future crops.
A brief description of the different mechanical harvesters oper-
ated in Florida during the 1972-73 season is presented in Appendix A.
Sugarcane grown in Florida presents many unique problems for
mechanical harvesting. Most of the cane is grown on organic soils
and tends to lodge and entangle before harvest which makes mechani-
cal harvesting difficult. Mechanical harvesting results in larger loss-
es of millable cane in the field and more "trash" in the cane deliver-
ed to the mill than with hand cutting. *Trash in the cane delivered
to the mill--unburned leaves, immature stalks, and sucker growth--is
a problem that is worsened by mechanical harvesting. Additional trash
increases the amount of non-sucrose solubles and dry matter hauled to
the mill, which increases the amount of sugar lost in "bagasse" and
2
molasses.2 Sugarcane tops create a particularly diff. ...Lt problem.
The present mechanical systems do not adequately remove tops from the
recumbent Florida sugarcane. Cane tops tend to have low sucrose and
high non-sucrose soluble contents which create problems in processing.
The high non-sucrose soluble content results in a higher yield of low
value molasses and a lower yield of higher value raw sugar. The prob-
lem of not being able to separate sugarcane tops with mechanical
harvesters is compounded during those years when cane is killed
by freezing. The sugarcane stalk begins to deteriorate from the top
downward after a killing freeze. When cane is hand cut, the deter-
iorated portion of the stalk is discarded and the good cane sent to
the mill. Mechanical harvesters mix the deteriorated -..., ,' c.3n, with
the good and the mixing results in a lower qii:-l' cane being deliv-
ered to the mill. Juice from deteriorated cane gives a lower sugar
yield and even may not process into raw sugar.
All these problems have economic effects which must be consider-
ed when comparing costs of harvesting sugarcane mechanically and by
hand cutting. The objective of this report was to identify and esti-
mate cost differences for harvesting, hauling, and processing hand
cut and mechanically harvested sugarcane in Florida during the 1972-73
season. An additional objective was to determine the effects of high-
er field labor wages and the effects of using p'.i :-te-1i 1974-75 har-
vester operating rates on 1972-73 season costs for hand cutting and for
mechanical harvesting systems.
2
Bagasse-is the residue from crushing cane. The reader is re-
ferred to [73 for !" I !, re,! r. l )., in .:.- .. ,,
5
PROCEDURES
Hand cutting and mechanical harvesting were evaluated by compar-
ing estimated net returns from the 1972 crop when using each system.
Net returns were calculated by subtracting estimated total costs from
3
estimated total revenue.
Four operations were identified in the production of raw sugar--
growing, harvesting, hauling to the mill, and processing. Net returns
for growing and harvesting were estimated separately from those for
the hauling and processing. Differences in net returns from growing
and harvesting represent the effect of mechanical harvesting on the
independent growers. The differences in net returns in hauling and
processing represent the effect of mechanical harvesting on sugarcane
mills. The combined differences in net returns for all operations
represent the impacts of mechanical harvesting on costs and returns
to mills and cooperatives in which all operations are under the same
ownership.
Revenues from growing and harvesting included sugarcane sales,
government sugar payments, and molasses payments. Harvesting expenses
included machinery ownership and operation, materials, labor and over-
head costs. Growing expenses were estimated from a previous report
by Walker [14]. Revenue from hauling and processing consisted of raw
sugar and molasses sales. Costs included operating costs, fixed
charges and costs of personnel services in milling, the hauling costs
and sugarcane purchases and molasses payments to producers.
To estimate costs it was necessary to determine the effects of
mechanical harvesting on the quality and amount of sugarcane deliver-
ed to the mill. Field studies were conducted by the authors for both
hand cutting and mechanical systems to determine effects of mechani-
cal harvesting on field losses and trash in cane delivered to the mill
[3]. Milling tests were conducted with the experimental mill at the
USDA Sugarcane Field Station, Canal Point, Florida, to determine the
This measure of returns is intended only to indicate the relative
profitability of the two methods of harvesting sugarcane. It may not
indicate actual returns from sugarcane production. For an analysis of
returns from sugarcane production in Florida see [10, 14].
effects of additional trash in mechanically harvested cane on fiber
content in cane, percent sucrose in normal juice (NJS), percent brix
in normal juice (NJB), and extraction of normal juice (NJE). Results
from these field studies and milling tests, together with results from
other milling studies, provided the basis for estimating the effects of
mechanical harvesting on field losses and esgarcane quality during the
1972-73 harvesting season (see Appendices B and C).
Costs and returns estimates were selected to be representative of
hand cutting and mechanical harvesting for the Florida industry during
the 1972-73 season. Harvesting cost estimates were derived by a budgeting
method. Cost and machinery usage data were obtained from three mills
using mechanical harvesting during the 1972-73 season. These data and
additional information provided by industry personnel using the mechan-
ical harvesting systems were used to develop budgets of harvesting costs
for each system. Since each mill has different methods for loading and
hauling, different lengths of harvest season, and different soil and pro-
duction rates, the costs developed herein may not be applicable for any
particular mill.
The mechanical harvesting cost estimates are weighted averages of
cost for three mechanical systems. The weighting was based on the amount
of cane harvested by each system. These three systems harvested a total
of 1,343,826 tons, which represented ninety percent of all mechanically
harvested sugarcane in Florida during the 1972-73 season.
Since determining differences in costs between mechanical harvesting
and hand cutting systems was the major purpose of the study, only the har-
vesting costs were developed in detail. Costs for growing, hauling, and
processing hand cut cane were based on results of other studies El0, 14].
The non-harvest costs for hand cut cane were scaled upward on the basis of
field studies and milling test results (Appendices B and C) to determine
The 1972 crop refers to sugarcane growing during the 1972 calendar
year and harvested during' late 1972 and early 1973. The terms 1972 crop
and 1972-73 season refer to the same crop of sugarcane.
Costs for the separate harvesting systems were not reported so as
to avoid disclosure of individual firms' costs.
the effects of mechanical harvesting on these other costs. Per acre
growing costs were assumed to be equal for hand cut and mechanically
harvested cane. Growing costs were based on a 1971 study of sugarcane
production costs in Florida f14]. The hauling costs were based on a
15-mile hauling distance. Contract hauling for a 15-mile distance
cost about $1.00 per gross ton during the 1972-73 season. Mill costs
for hand cut sugarcane were based on a study of costs for the 1967-69
crops [10]. Both growing and processing costs were adjusted for
1972-73 prices. Costs for processing mechanically harvested cane were
based on the adjusted mill costs for hand cut sugarcane plus a computed
theoretical increase. This computed increase was in direct proportion
to reduced mill capacity caused by high-fiber-content mechanically har-
vested cane.
HARVESTING COSTS, 1972-73 SEASON
Machinery Ownership and Operation
Machinery ownership and operating costs for both harvesting meth-
ods included annual depreciation, repairs, maintenance, taxes, insur-
ance, fuel, oil, grease, interest, and highway licenses. Depreciation,
calculated by the straight line method, was based on equipment having
a 10 percent salvage value after the normal useful service life.
Length of service life was based on estimates by industry personnel
who were using the different harvesting systems. Repair and maintenance
costs included costs for field repairs and end of season overhaul.
Mechanical harvesting costs were based on actual cost data when these
data were available. If actual data were not available for specific
items, costs were estimated in the following ways. Taxes and insurance
were estimated at 0.035 times the average value of investment in equip-
ment. Fuel, oil, and grease costs were based on requirements reported
in the American Society of Agricultural Engineers Annual Yearbook for
similar equipment [4]. Interest costs were estimated at 8 percent of the
average value of investment.6
The total equipment ownership costs were charged to harvesting. This
may have biased harvesting costs upward because some of the equipment
(such as supervisors' pickup trucks and some tractors) may be used for
other tasks during the year. However, any bias is small and similar
for both harvesting systems. It would not change the relative costs of
mechanical harvesting versus hand cutting.
The estimated average machinery costs for mechanically harvesting
sugarcane in Florida during the 1972-73 season were $1.34 per gross ton
of cane (Table 1). The major items of expense were depreciation, repairs,
and maintenance. fuel, oil and grease, and interest were other important
costs. The mechanical harvesters and the field towing units were the most
costly pieces of equipment. Costs were $0.60 per gross ton of cane for the
field towing units. The average cost for the field transfer station (ramp,
dumper, conveyor ) was low because one of the three mechanical systems did
not use this operation.
The estimated machinery costs for the hand cut harvesting system
were $0.64 per gross ton of cane (Table 2). The most costly items were
the field towing units, accounting for $0.30 of the $0.64 total. The
continuous loader and the field carts each cost about $0.10 per ton.
Labor
Labor costs included expenses for equipment operators, cane cutters,
supervisors, dump operators, ticket writers, scrapperss," and usually a
"utility man". Labor costs were based on wages earned plus a 25 percent
overhead allowance for the costs of employee benefits such as housing,
transportation, medical insurance, social security, and other benefits
paid for by the employer. Actual overhead costs were used when the
data were available.
Labor costs were $2.85 per gross ton of cane for hand cut and $1.39
per ton for mechanically harvested sugarcane (Table 3). The most
striking difference between labor costs for mechanical harvesting and
hand cutting was the cost of cane cutters. Cane cutters cost $2.41
per gross ton of cane, or 85 percent of total harvesting labor cost
for the hand cutting system. No cane cutter costs were charged against
mechanical harvesting.
7The difference in costs for field towing units ($0.53 per ton for
the mechanical systems vs. $0.30 per ton for the hand cut systems) oc-
curred because the mechanical systems cut and loaded only one or two rows
at a time, while the continuous loader loaded four rows at a time. This
resulted in substantially more travel and loading time for field towing
units in the mechanical systems and increased the number of such units
needed to handle a given tonnage of cane.
Table 1.--Estimated initial investment and average annual ownership and operating costs for mechanically
harvesting sugarcane in South Florida, 1972-73 season
Mechan- Field Ramp, Pickup Mainte-
ical towing Field dumper, truck, nance
Item harvesters units carts conveyor buses equipmenta Total
------------------------Dollars per 100,000 gross tons--------------------------
Initial investment 177,274 128,283 47,593 10,700 8,504 2,669 375,023
Annual costs
Depreciation d 16,490 14,159 2,880 822 1,793 351 36,495
Repair and maintenance 28,086 21,340 8,407 298 655 596 59,382
Taxes, licenses,
e
insurance f 989 713 284 93 244 45 2,368
Fuel, oil, grease 6,971 10,989 17 320 864 160 19,321
Interestg 7,800 5,644 2,094 471 359 117 16,485
Total 60,336 52,845 13,682 2,004 3,915 1,269 134,051
Cost per gross ton 0.60 0.53 0.14 0.02 0.04 0.01 1.34
Includes equipment such as fuel trucks, small tractors, air compressor, and grease trailer.
Estimated as (new cost of equipment used for mechanical harvesting) (tons of cane harvested mechanical-
ly during 1972-73 season) X (100,000).
c
Depreciation estimated at 0.9 X (initial investment) + (service life). Length of service life was
based on estimates by industry personnel who were working with the different systems.
dRepair and maintenance included costs for field repairs and end of season overhaul. Taxes and insur-
ance for some mills were reported with repair and maintenance costs.
e
Taxes and insurance were estimated at 0.035 X (average value of investment) unless reported differently
by the mills.
fBased on fuel, oil, and grease requirements reported in [4], for similar equipment, unless reported
differently by the mills.
gEstimated at 8 percent of the average value of investment.
0
Table 2.--Estimated initial investment and annual ownership and operating costs for harvesting sugarcane
in South Florida with the hand-cut-continuous-loader system, 1972-73 season
Contin- Field Ramp, Mainte-- Labor
uous towing Field dumper, Pickup nance support b
Item loader units carts conveyor trucks equipment equipment Total
-------------------------Dollars per 100,000 gross tons--- -----------
Initial investment 36,362 90,502 41,372 31,837 3,232 4,956 10,235 218,496
Annual costs
Depreciationd 3,273 9,818 2,482 3,149 727 517 970 20,936
Repair and maintenance 3,636 10,909 5,172 2,219 485 404 404 23,229
Taxes, licenses,
insurance 700 1,742 796 613 100 114 254 4,319
Fuel, oi grease 1,108 3,709 ---- 198 431 240 323 6,009
Interest 1,600 3,982 1,820 1,401 142 218 450 9,613
Total 10,317 30,160 10,270 7,580 1,885 1,493 2,401 64,106
Cost per gross ton 0.10 0.30 0.10 0.08 0.02 0.01 0.02 0.64
aIncludes fuel trucks, grease trailer, field water cart, and a small tractor.
Includes wagon for drinking water, food truck, large van, and small van.
cEstimated as (new cost of equipment used for mechanical harvesting) + (tons of cane harvested mechan-
ically during 1972-73 season) X (100,000).
dDepreciation estimated at 0.9 X (initial investment) + (service life).
eRepair and maintenance included costs for field repairs and end of season overhaul.
fTaxes and insurance were estimated at 0.035 X (average value of investment).
gBased on fuel, oil, and grease requirements reported in 14], for similar equipment.
hEstimated at 8 percent of the average value of investment.
Table 3.--Estimated labor use and costs per 100,000 gross tons sugarcane
for mechanical harvesting and hand cutting in Florida, 1972-73
season
Mechanical harvest Hand cut
Type job Use Cost Use Cost
Hours Dollars Hours Dollars
Cane cutter --- ---- 80,290 240,872
Cutter or loader operator 9,409 38,263 727 2,400
Tractor driver 19,236 53,812 5,090 15,273
Dump operator 558 1,684 1,454 4,364
Ticket writer 279 824 727 2,036
Supervisor 3,039 11,579 1,454 7,273
Maintenance and repair 6,691 26,112 1,454 7,273
Scrapper 1,115 3,100 1,454 3,636
Utility man 139 399 727 2,182
Othera 1,045 2,927 -
Total 41,511 138,700 93,377 285,309
Use and costs per gross
ton of cane 0.415 1.39 0.934 2.85
aIncluded some of the time and costs for timekeeper, fuel truck oper-
ator, crane operator, and compressor operator that were reported together
by one mill and could not be separated in the data available.
RETURNS TO GROWING AND HARVESTING
Revenue, costs, and net returns for growing and harvesting are
summarized in Table 4.
Revenue
Revenue consisted of sugarcane sales, government sugar payments,
and molasses payments.
Table 4.--Estimated revenue, costs and net returns for growing and harv-
esting from mechanically harvested and hand cut sugarcane in
Florida, 1972-73 season
Mechanical harvest Hand cut
Harvested Net ton Harvested Net ton
Item acre of cane acre of cane
-------------------.-Dollars--------------------
Revenue
Sugarcanea 433.57 11.71 467.15 12.18
Sugar payment 36.83 0.99 39.63 1.03
Molasses payments 14.76 0.40 15.29 0.40
Total 485.16 13,10 522.07 13.61
Costs
Production 280.92 7.59 280.92 7.33
Harvesting
Labore 58.49 1.58 115.43 3.01
f
Machinery 55.53 1.50 25.69 0.67
Total 394.94 10.67 422.04 11.01
Net returns 90.22 2.43 100.03 2.60
a(Net tons cane per acre) X (standard sugarcane quality factor) X
(price per standard ton). Price per standard ton = ($1.12 X 9.31) =
$10.43. (Based on USDA Fair Price Formula [ll]). Net tons per acre were
38.35 for hand cut cane and 37.02 for mechanically harvested cane. Net
tons = (gross tons) X (1 proportion of trash in cane). Standard sugar-
cane quality factors were 1.168 for hand cut cane and 1.123 for mechani-
cally harvested cane.
b
(Hundredweight of commercially recoverable sugar per net ton of
cane) X (net tons of cane harvested per acre) X (estimated government
sugar payment of $0.48 per hundredweight of commercially recoverable
sugar).
c (5.8 gallons per net ton) X 1/2(average price of molasses $0.0475)
X (net tons harvested per acre). Average price per gallon for 1972
crop was estimated at $0.185
dBased on 1971 season costs [14, p. 27]. Estimated as total costs
for land preparation, planting, cultivation, and overhead taxes, and
land cost divided by acres of cane for harvest. Costs were assumed to
increase by 5 percent between 1971 and 1972.
eFrom Table 3.
From Tables 1 and 2.
Sugarcane Sales
Sugarcane sales were calculated from standard tons of cane delivered
to the mill and the "basic price" formula for the 1972 sugarcane crop
[11]. Average sugarcane production per acre harvested during the 1972-73
season was 38.1 net tons per acre [8]. This was equivalent to an "in-
field" yield of 40.5 net tons. Mechanical harvesting recovered, on the
average, 91.4 percent of the in-field yield or 37.02 net tons of cane
per acre (Table 13, Appendix B). The hand cutting system recovered
an average of 38.35 net tons of cane per acre.
Standard tons of sugarcane were obtained by multiplying net tons
of sugarcane by the "standard sugarcane quality factors". The average
standard sugarcane quality factors were 1.123 for mechanically harvest-
ed cane and 1.168 for hand cut cane (Appendix C). Standard tons of
sugarcane harvested per acre were 41.57 for mechanical harvesting and
44.79 for hand cutting.
The price formula used for estimating the value of a standard ton
of sugarcane for the 1972 crop was "$1.12 per ton for each one cent per
pound of the season's average price of raw sugar" [11]. The season aver-
age price for raw sugar was estimated at 9.31 cents per pound. The
resulting standard ton price for cane was $10.43. Revenue per acre
from sugarcane sales was $433.57 for mechanical harvesting and $467.15
for hand cutting.
Government Sugar Payment
The Sugar Act of 1948, as amended, provided for a sugar payment
for production of commercially recoverable sugar [12]. The schedule
for estimating commercially recoverable sugar per net ton of cane was
Net tons = (gross tons) X (1 proportion of trash in cane).
Because of differences in the amount of trash in mechanically har-
vested and hand cut cane, comparisons were made using a net ton
basis in this study.
directly related to percent sucrose in normal juice (NJS) of the sugarcane.
The relationship applicable to this study was as follows:
Percent sucrose in Rate of recoverable sugar
normal juice 100 Ibs. per net ton sugarcane
13.0 1.945
14.0 2.121
15.0 2.296
The NJS was 13.73 for mechanically harvested sugarcane and 14.18 for hand
cut cane (Table 14, Appendix C). Commercially recoverable sugar per net
ton of cane was determined by interpolation to be 207.3 pounds for mechan-
ical harvesting and 215.3 pounds for hand cutting.
The average Government sugar payment for the 1971 crop was $0.48 per
hundred pounds of commercially recoverable sugar. This average payment
was selected as representative of that expected for the 1972 crop.
Government sugar payments would be $36.83 per acre for mechanical
harvesting and $39.63 for hand cutting.
Molasses Payment
Independent growers received a "molasses payment" from the mill
at the end of the season representing their share of revenue from mol-
asses sales. The molasses payment was based on the average price of
molasses and a projected molasses yield coefficient. The molasses pay-
ment per net ton of sugarcane for the 1972 crop was based on the formu-
la [5.8 X 1/2(P .0475)] where "P" equals the "weighted average net
sales price per gallon of blackstrap or final molasses sold during the
twelve month period ending May 31, 1973" and "5.8" was the projected
molasses yield coefficient for the 1972-73 season [111. The average
price per gallon of molasses for the 1972 season was estimated at $0.185.10
The molasses payment per net ton of cane was $0.39875, or $14.76 per
11
acre for mechanical harvesting and $15.29 per acre for hand cutting.
Source was [12, P. 12].
10Based on data obtained from the State office of the Agricultural
Stabilization and Conservation Service, USDA, Gainesville, Florida.
11The coefficient for gallons of molasses per net ton of sugarcane
was based on an historical yield. This average yield will undoubtedly
increase as a larger proportion of the total sugarcane crop consists of
Costs and Net Returns
Estimated growing costs per acre were $280.92 per acre for each
harvesting method. Harvesting costs per acre were taken from Tables 1,
2, and 3. Costs per net ton of cane were derived by dividing per acre
costs by net tons of cane harvested per acre.
Net returns from growing and harvesting were $2.60 per net ton
for hand cut cane, or about $0.17 per ton higher than for mechanically
harvested cane. The harvesting cost advantage achieved with mechani-
cal systems was more than offset by the lower revenue under this sys-
tem. These differences in net returns represent what the effects of
mechanical harvesting would have been on independent growers for the
1972 crop.
RETURNS TO HAULING AND PROCESSING
The purpose of this section is to evaluate the effects of mechani-
cal harvesting on returns to processing sugarcane in Florida.
Revenue
Raw Sugar Sales
Estimated raw sugar production was based on the commercially recov-
erable sugar value determined for Government sugar payment purposes.
This estimate was 207.3 pounds for mechanical harvesting and 215.3
pounds for hand cutting. The average raw value price of sugar for the
1972 crop was 9.31 cents per pound. Estimated raw sugar sales were
$19.30 per net ton of cane for mechanical harvesting and $20.04 per
net ton of cane for hand cutting (Table 5).
mechanically harvested cane having a high non-sucrose solids content
in the juice. The yield coefficient for the 1973 crop increased to 6.0
gallons. If the industry changes to predominately mechanical harvesting,
the increase in yield coefficient may result in higher molasses payments
than if most of the crop was hand cut (see Table 17, Appendix C).
Table 5.--Estimated revenue, costs, and net returns for hauling and
processing mechanically harvested and hand cut sugarcane
in Florida, 1972-73 season
Mechanical harvest Hand cut
Harvested Net ton Harvested Net ton
Item acre of cane acre of cane
_,__-- T ----______oir~-- --"----
--------------------Dollars--------------------
Revenue
Raw sugar sales 714.49 19.30 768.53 20.04
Molasses sales 47.94 1.30 41.15 1,07
Total 762.43 20.60 809.68 21.11
Costs
Transportation 41.55 1.12 40.48 1.06
Mill operation 176.22 4.76 159.54 4.16
c
Sugarcane purchase 433.57 11.71 467.15 12.18
Molasses payment 14.76 .40 15.29 .40
Total 666.10 17.99 682.46 17.80
Net returns 96.33 2.61) 127.22 3.31
a(Estimated pounds commercially recoverable sugar) X (9.31 cents per
pound average price).
(Gallons molasses per net ton of cane) X (18.5 cents per gallon
average price). Molasses production estimated at 5.8 gallons per net ton
for hand cut cane and 7.0 gallons per net ton for mechanically cut cane
(Table 17, Appendix C).
cFrom Table 4.
Molasses Sales
Estimated molasses production for hand cut cane was based on the
5.8 gallons per net ton historical average used for calculating molasses
payments. Molasses production with mechanical harvesting would increase
an estimated 14.6 pounds or about 1.2 gallons per net ton of cane above
that for hand cut cane (Table 17, Appendix C). The estimated molasses price for
for the 1972 crop was 18.5 cents per gallon. Estimated molasses sales were
$47.94 per acre for mechanical harvesting and $41.15 for hand cutting.
Costs
Hauling
Cost per gross ton for transportation from the field to the mill
was assumed to be $1.00 for both hand cut and mechanically harvested
cane. Cost per acre was derived by dividing "net cane factors" into
net tons delivered to the mill and multiplying by the cost per gross
ton. The resulting transportation cost was $41.55 er acre for mechani-
cal harvesting and $40.48 fdr hand cutting.12
Mill Operation
Trash and fiber contents of mechanically harvested sugarcane were
higher than for hand harvested cane. Additional trash and fiber reduce
the amount of sugarcane a mill could process and thereby increase mill
13
operating costs per net ton of cane. However, it was difficult to
assess the effects of mechanical harvesting on mill operating costs
during the 1972-73 season. Most mills receiving mechanically harvest-
ed sugarcane were simultaneously processing hand cut cane. Further,
the mechanically harvested cane was usually the smaller portion of the
total amount of cane being processed. This made it impossible to deter-
mine what portion of processing costs was for mechanically harvested
cane and what portion was for hand cut cane.
The approach in this study was to base the reduction in mill
grinding capacity due to mechanical harvesting on the assumption that
grinding capacity declined in direct proportion to the increase in fiber
in cane. Processing costs were assumed to increase in direct proportion
to the reduction in grinding capacity. The reader should note that this
12[(3702 + 0.891) X $1.00] for mechanical harvesting and [(38.35 +
0.9473) X $1.00] for hand cutting. Net cane factors are the ratio of
net cane to gross cane calculated as (1.0 proportion of trash in
gross cane).
13
3Studies conducted at the Audubon Sugar Factory at Baton Rouge,
Louisiana, indicated that a percentage increase in cane trash reduced
grinding rates by 5.85 percent, increased power requirements, and
reduced sucrose extraction [5, P. 31].
is a computed estimate of the increase in costs and not the actual
14
increase for the 1972-73 season.
The average fiber content for the 1972 crop was estimated at 11.24
percent for hand cut and 12.87 for mechanically harvested cane (Table 15,
Appendix C). Mechanical harvesting caused a 14.5 percent increase of
fiber in cane [(12.87 + 11.24) X 1001. Typical milling costs for hand
cut sugarcane were estimated at $4.16 per net ton of cane for the 1972
15
crop. A 14.5 percent decrease in mill grinding capacity would increase
milling costs $0.60 per net ton of cane to $4.76 ($4.16 X 114.5 percent =
$4.76). Mill operating costs per acre were $176.22 for mechanical har-
vesting and $159.54 for hand cutting.
Sugarcane Purchases
Sugarcane purchases are payments to independent growers for cane de-
livered to the mill. Mills and cooperatives that grow and process their
own cane should view this item as an internal transfer from the processing
to the growing operation. Since sugarcane purchases and sugarcane sales
are the same item, the value was taken from Table 4.
Net Returns
Mechanical harvesting reduced net returns to the processing opera-
tion. Returns for mechanical harvesting were $96.33 per acre or about
$2.61 per net ton of cane, while for hand cutting the net returns were
$127.22 per acre or about $3.31 per net ton of cane. Larger raw sugar
sales and lower mill operating costs were the principal reasons that net
returns were higher for hand cut than for mechanically harvested cane.
14The actual reduction in mill throughput may be different from
this estimated reduction in capacity. For example, the additional fiber
may be compensated for by opening mill roller settings. Such adjust-
ment has a corresponding secondary effect on costs and returns for
milling. The study of such secondary and tertiary effects was beyond
the scope of this study.
15Based on mill costs, fixed charges, and services to personnel
reported in [10]. Costs were assumed to increase five percent per
year between 1969 and 1972. Costs per hundredweight raw sugar were
converted to a per net ton of cane basis by multiplying by 2.05.
SUMMARY OF RETURNS TO ALL OPERATIONS
Most sugarcane in Florida is produced by grower-processor firms.
The important returns to these firms is the total to all operations.
Costs and returns for firms performing all operations are summarized
in Table 6.
Net returns were $40.70 per acre lower for mechanical harvesting
than for hand cutting. While mechanical harvesting reduced total
direct costs, this reduction was more than offset by reduced value of
sugar sales. Sugar sales were lower because larger field losses due
to mechanical harvesting resulted in fewer net tons of cane per acre
being delivered to the mill. In addition, higher trash content in
mechanically harvested sugarcane caused lower sugar recovery per net ton
of cane.
As pointed out above, the estimate of additional mill operation
costs was a computed increase due to mechanical harvesting. The
effects of mechanical harvesting on costs during the 1972-73 season may
Table 6.--Summary of revenue, costs, and net returns for growing,
harvesting, hauling, and processing mechanically harvested
and hand cut sugarcane in Florida, 1972-73 season a
Mechanical harvest Hand cut
Harvested Net ton Harvested Net ton
Item acre of cane acre of cane
--------------------Dollars------------- ----
Revenue
Raw sugar sales 714.48 19.30 768.53 20.04
Molasses sales 47.94 1.30 41.15 1.07
Sugar payment 36.83 .99 39.63 1.03
Total 799.26 21.59 849.31 22.14
Costs
Growing 280.92 7.59 280.92 7.33
Harvesting 114.02 3.08 141.12 3.68
Hauling 41.55 1.12 40.48 1.06
Mill operation 176.22 4.76 159.54 4.16
Total 612.71 16.55 622.06 16.23
Net returns 186.55 5.04 227.25 5.91
Based on Tables 4 and 5.
have been less than those estimated in this study. If processing costs
were the same for both mechanically harvested and hand cut sugarcane, net
returns would have been closer for the two harvesting methods, but hand
cutting would still show a profit advantage over mechanical harvesting.
EFFECTS OF HIGHER WAGES ON COSTS AND RETURNS
The Sugar Act of 1948, as amended, calls for payment of "fair and
reasonable wages" for persons employed in production, cultivation, or
harvesting of sugarcane. During the 1972-73 harvest period, the fair and
reasonable wage was "at least $2.30 per hour for tractor drivers and
principal operators of mechanical harvesting and loading equipment, and
$2.00 per hour for all other workers" [13].
Labor accounted for a larger portion of total harvesting costs for
hand cutting than for mechanical harvesting. An increase.in wages that
raised labor costs relative to other costs would cause hand harvesting
to become more expensive relative to mechanical harvesting. In this sec-
tion, the effects of wage level increases on net returns were examined by
estimating net returns at several different wage levels while holding
other costs constant. These wage levels were 100 percent, 110 percent,
125 percent, and 150 percent of the 1972-73 season level. Corresponding
Sugar Act minimum hourly wages would be $2.00, $2.20, $2.50, and $3.00,
respectively.
It was assumed that a change in the field labor wage level would
result in proportionate changes for all workers. For example, if the
wage level were 10 percent higher than the 1972-73 level, workers earn-
ing $2.00 per hour would receive $2,20 per hour, while those previously
earning $2.20 per hour would receive $2.42 per hour. Costs at the high-
er wage levels were estimated by increasing the labor component of total
costs by the same precentage as the wage levels increased.
Growing and harvesting costs increased faster for hand cutting than
for mechanical harvesting at higher wage levels (Table 7). Mechanical
harvesting had a $27.10 per acre cost advantage for growing and harvest-
ing operations with 1972-73 wages. If the field labor wage level had
been ten percent higher, mechanical harvesting would have had a $32.80
per acre cost advantage for growing and harvesting. Relative costs for
hauling and processing for the two harvesting systems remained about the
~
Table 7.--Estimated costs for growing, harvesting, hauling, and process-
ing sugarcane in Florida at four selected wage levels,1972-73
season
Mechanical harvest Hand cut
Harvested Net ton Harvested Net ton
Item acre of cane acre of cane
-----------------Dollars-----------------
Growing and harvesting
Labor costs 87.71 2.36 144.65 3.77
Other costs 307.23 8.31 277.39 7.24
Total
with 1972-73 wages 394.94 10.67 422.04 11.01
wages 10% higherc 403.71 10.90 436,51 11.38
wages 25% higher 416.87 11.26 458.20 11.95
wages 50% higher 438.80 11.85 494.36 12.90
Hauling and processing
Labor costsf 83.68 2.26 76.79 2.00
Other costsg 134.09 3.62 123.23 3.21
Total
with 1972-73 wages 217.77 5.88 200.02 5.21
wages 10% higher 226.14 6.11 207.70 5.42
wages 25% higher 238.69 6.45 219.22 5.72
wages 50% higher 259.61 7.01 238.42 6.22
Total: Growing, harvesting,
hauling, and processing
Labor costs 171.39 4.62 221.44 5.77
Other costs 441.32 11.93 400.62 10.45
Total
with 1972-73 wages 612.71 16.55 622.06 16.22
wages 10% higher 629.85 17.01 644.21 16.80
wages 25% higher 655.56 17.71 677.42 17.67
wages 50% higher 698.41 18.86 732.78 19.12
aFrom Table 4. Equals (harvest labor) + (0.104) X (growing costs).
Based on proportion of growing costs that were for labor in 1971 [14,
Table 5].
From Table 4. Equals total growing and harvesting cost minus
labor costs for growing and harvesting.
Based on costs with 1972 wages 0 percent of labor costs
Based on costs with 1972 wages + 25 percent of labor costs.
Based on costs with 1972 wages + 25 percent of labor costs.
e
Based on costs with 1972 wages + 50 percent of labor costs.
Equals (0.36) X (hauling costs) X (0.39) X (mill operating
costs). Based on proportion of hauling and mill operating costs
that were for labor in 1969 [10, p. 16].
Equals (total hauling and mill operating costs) (labor
costs for hauling and mill operation) from Table 5.
same at all wage levels. Costs for hauling and processing mechanically
harvested cane were about $17.75 per acre more than for hand cut cane in
1972-73. If wages had been 10 percent higher, hauling and processing
costs for mechanically harvested cane would have been about $18.44
per acre more than for hand cut cane.
Total costs for growing, harvesting, hauling, and processing were
lower for mechanical harvesting at all wage levels. Total costs per
acre for mechanically harvested cane were $9.35 less than for hand cut
cane during 1972-73. But, if wages had been 10 percent higher, the
mechanical system would have had a $14.36 per acre cost advantage.
Estimated net returns to growing and harvesting operations (returns
to independent growers) for the 1972 crop were $90.22 per acre with
mechanically harvested sugarcane, $9.81 less than for hand cut cane
(Table 8). With wages assumed to be 10 percent higher, the esti-
mated net returns for mechanical harvesting were only $4.11 per acre
less than for hand cutting. The critical wage, where net returns
would have been the same for both systems, was about 15 percent
higher than the 1972-73 level.
Net returns from hauling and processing were lower for mechani-
cally harvested cane at all wage levels. The combined net returns
for all operations also were lower at all wage levels for mechani-
cally harvested cane than for hand cut cane. But, if wages had been
50 percent higher than 1972-73 levels, the difference in combined
returns would have been only about $15.68 per acre.
HARVESTING COSTS WITH PROJECTED 1974-75 OPERATING RATES
Mechanical harvesting during the 1972-73 sugarcane harvesting
season was partially experimental. Often the mechanical harvesting
systems were not operating at daily outputs which supervisors antici-
pated for future crops. Mechanical harvesting costs were estimated
using projected 1974-75 operating rates and 1972-73 prices in order to
gain insights into the likely cost differences between mechanical
harvesting and hand cutting in the future.
Table 8.--Estimated net returns for growing, harvesting, hauling, and
processing sugarcane in Florida at four selected wage levels,
1972-73 season
Mechanical harvest Hand cut
Harvested Net ton Harvested Net ton
Item acre of cane acre of cane
-----------------Dollars -------------- ----
Growing and harvesting
Total revenue 485.16 13.10 522.07 13.61
Net returnsb
with 1972-73 wages 90.22 2.43 100.03 2,60
wages 10% higher 81.45 2.20 85.56 2.23
wages 25% higher 68.29 1.84 63.87 1.66
wages 50% higher 46.36 1.25 27.71 0.71
Hauling and processing
Total revenuec 314.10 8.49 327.24 8.53
Net returns
with 1972-73 wages 96.33 2.61 127.22 3.32
wages 10% higher 87.96 2.38 119.54 3.11
wages 25% higher 75.41 2.04 108.02 2.81
wages 50% higher 54.49 1.48 88.82 2.31
Total: Growing, harvesting,
hauling and processing
Total revenue 799.26 21.59 849.31 22.14
Net returns
with 1972-73 wages 186.55 5.04 227.25 5.92
wages 10% higher 169.41 4.58 205.10 5.34
wages 25% higher 143.70 3.88 171.89 4.47
wages 50% higher 100.85 2.73 116.53 3.02
aFrom Table 4.
Total revenue minus total
CTotal revenue, from Table
molasses payments.
costs from-Table 7.
5, minus sugarcane purchases and producer
Costs were developed for four different mechanical systems using
the projected 1974-75 operating rates (See Appendix A for a description
of the four systems). The simple average of these four costs was sel-
ected as representative of mechanical harvesting. The daily and annual
outputs were based on rates expected by sugarcane industry supervisory
personnel who used the mechanical harvesters during the 1972-73 season.
All systems were assumed to be operating under a typical situation--40.5
, net tons in-field yield per acre, and operating 135 days per season. Cane
would be loaded into field carts and transferred to highway trucks at
portable transfer stations. Field towing units would pull three or four
field carts each. Field losses and trash content of cane would be the
same as those encountered during the 1972 season. The machinery list
included enough capacity to maintain full production on most days.
Estimated total harvesting costs per net ton of cane were $1.60
lower for mechanical harvesting than for hand cutting (Table 9). The
largest cost reduction, using 1974-75 operating rates, was for labor.
Estimated labor costs were $0.69 per gross ton of cane compared with $1.39
during the 1972-73 season (Table 3).
EFFECTS OF HIGHER WAGES AND PROJECTED 1974-75
OPERATING RATES ON COSTS AND RETURNS
In this section the combined effects of wage level increases and
projected 1974-75 machinery operating rates on costs and returns were
examined. As in previous sections, all prices other than wages were
held constant at 1972-73 levels. Therefore, the increase in wages repre-
sents an increase relative to other prices. For the analysis to be appli-
cable for a future situation, future wages would need to rise above
1972-73 wages by a larger percentage than other costs increased above
the 1972-73 prices.
Mechanical harvesting costs for the 1972-73 benchmark wage level
were developed in the same manner as those for the previous section.
Costs at higher wage levels were estimated by increasing the labor com-
ponent of total costs by the same percentage as the wage level was in-
creased, following the same procedure as was used in the earlier section.
Costs and returns were estimated with wage levels of 100 percent, 110,
percent, 125 percent and 150 percent of the 1972-73 season level.
The total cost per net ton of cane for growing and harvesting were
$9.68 (Table 10). Total cost for all operations--growing, harvesting,
hauling, and processing--was lower for mechanically harvested cane
than for hand cut cane at all wage levels. When these costs based on
Table 9.--Estimated capital investment and machinery and labor costs for
mechanical harvesting and hand cutting sugarcane in Florida
(baged on 1972-73 prices and projected 1974-75 operating rates)
Mechanical Hand
Item harvest cut
--------------Dollars---------------
Capital investment 404,683 218,495
Annual machinery costs
per 100,000 gross tons cane
Annual depreciation b 38,246 20,936
Repair and maintenance 42,924 23,229
Taxes, licenses, Ansurance 7,862 4,319
Fuel, oil, grease 11,404 6,009
Interest 17,806 9,613
Total machinery cost 118,242 64,106
Costs per gross ton of cane
Machinery 1.18 0.64
Labor 0.69f 2.858
Total ..87 3,49
Costs per net ton of cane 2.09 3.69
a
Estimated at 0.9 X (initial investment) 4 (service life). Length
of service life was based on estimates by sugarcane industry personnel.
Includes cost for field repairs and end of season overhaul.
c
Taxes and insurance estimated at 0.035 X (average capital invest-
ment).
dBased on fuel, oil, and grease requirements reported in [4] for
similar equipment, unless reported differently by the mills.
e
Estimated at 0.08 X (average capital investment).
f
Labor for harvester operators, tractor drivers, dump operators,
ticket writers, scrappers, supervisors, maintenance man, mechanics, and
utility man.
gLabor for hand cutting, loader operator, tractor drivers, dump
operators, ticket writers, scrappers, supervisors, maintenance man,
mechanics, and utility man,
hEquals (costs per net ton of cane) + (net cane factors of 0,893
for mechanical harvesting and 0.947 for hand cutting).
Table 10.--Estimated costs for growing, harvesting, hauling, and proces-
sing sugarcane in Florida at four selected wage levels (based
on 1972-73 prices and projected 1974-75 operating rates)
Mechanical harvest Hand cut
Harvested Net ton Harvested Net ton
Item acre of cane acre of cane
----------r------Dollars----------------
Growing and harvesting
Labor costs 57.75 1.56 144.65 3.77
Other costs 300.60 8.12 277.39 7.24
Total
with 1972-73 wages 358.35 9.68 422.04 11.01
wages 10% higher 364.12 9.84 436.51 11.38
wages'25% higher 372.79 10.07 458.20 11.95
wages 50% higher 387.22 10.46 494.36 12.90
Hauling and processing
Labor costsf 83.68 2.26 76.79 2.00
Other costs 134.09 3.62 123.23 3.21
Total
with 1972-73 wages 217.77 5.88 200.02 5.21
wages 10% higher 226.14 6.11 207.70 5.42
wages 25% higher 238.69 6,45 219.22 5.72
wages 50% higher 259.61 7.01 238.42 6.22
Total: Growing, harvesting,
hauling, and processing
Labor costs 141.43 3.82 221.44 5.77
Other cpsts 434.96 11.74 400.62 10.45
Total
with 1972-73 wages 576.12 15.56 622.06 16.22
wages 10% higher 590.26 15.95 644.21 16.80
wages 25% higher 611.48 16.52 677.42 17.67
wages 50% higher 646.83 17.47 732.78 19.12
aEquals (harvest labor per net ton from
costs from Table 4). Based on proportion of
labor in 1971 [14, Table 5].
Table 9) + (0,104) X (growing
growing costs that were for
b
Equals total harvesting cost from Table 9 and total growing cost from
Table 4 minus labor costs for growing and harvesting.
CBased on costs with 1972 wages + 10 percent of labor costs.
Based on costs with 1972 wages + 25 percent of labor costs
Based on costs with 1972 wages + 50 percent of labor costs.
Based on costs with 1972 wages + 50 percent of labor costs.
fEquals (0.36) X (hauling costs) X (0.39) X (mill operating
costs), Based on proportion of hauling and mill operating costs
that were for labor in 1969 [10, p. 16].
gEquals (total hauling and mill operating costs) (labor costs
for hauling and mill operation) from Table 5.
Table 11.--Estimated net returns for growing, harvesting, hauling, and
processing sugarcane in Florida at four selected wage levels
(based on 1972-73 prices and projected 1974-75 operating rates)
Mechanical harvest Hand cut
Harvested Net ton Harvested Net ton
Item acre of cane acre of cane
-----------------Dollars-----------------
Growing and harvesting
Total revenue 485.16 13.10 522.07 13.61
Net returns
with 1972-73 wages 126.81 3.42 100.03 2.60
wages 10% higher 121.04 3.26 85.56 2.23
wages 25% higher 112.37 3.03 63.87 1.66
wages 50% higher 97.94 2.64 27.71 0.71
Hauling and processing
Total revenue 314.10 8.49 327.24 8.53
Net returns
with 1972-73 wages 96.33 2.61 127.22 3.32
wages 10% higher 87.96 2.38 119.54 3.11
wages 25% higher 75.41 2.04 108.02 2.81
wages 50% higher 54.49 1.48 88.82 2.31
Total: Growing, harvesting,
hauling and processing
Total revenue 799.26 21.59 849.31 22.14
Net returns
with 1972-73 wages 223.14 6.03 227.25 5.92
wages 10% higher .209.00 5.64 2Q5.10 5.34
wages 25% higher 187.80 5.07 171.89 4.47
wages 50% higher 152.43 4.12 116.53 3.02
aFrom Table 4.
Total revenue, from Table 5, minus sugarcane purchases and pro-
ducer molasses payments.
Total revenue minus total costs from Table 10.
projected 1974-75 operating rates are substituted for the mechanical
harvesting costs in Table 7, the resulting net returns represent those
that would have prevailed during 1972-73 with higher wage levels and the
machinery operating rates projected for 1974-75 (Table 11).
The net return to growing and harvesting with mechanical harvest-
ing would be $3.42 per net ton or $126.81 per acre. This was a net
return per acre of $26.78 higher than that for hand cut cane during
1972-73. The combined net returns per acre for growing, harvesting,
hauling, and processing would have been about equal for both harvest-
ing methods--$223.14 for mechanically harvested cane and $227.25 for
hand cut cane, although the hand cut system maintained a slight net
returns advantage. If the wage level were 10 percent higher relative
to other costs, the net returns advantage would have shifted to mechani-
cal harvesting--$209.00 per acre net returns for mechanically harvest-
ed cane and $205.10 for hand cut cane.
The implications of this section are that although net returns
per acre were higher for hand cut cane than for mechanically harvest-
ed cane during the 1972-73 season, this net returns advantage would
diminish as the mechanical harvesting systems achieve greater through-
put efficiency in the future. Further, if labor wages rise relative
to other costs along with greater throughput efficiency, mechanically
harvested cane will have a net returns advantage over hand cut cane.
EFFECTS OF MECHANICAL HARVESTING ON CAPITAL REQUIREMENTS
Adoption of mechanical harvesting raises the capital investment
for sugarcane harvesting machinery and equipment about $1.87 per ton
of additional cane harvested mechanically. The estimated new cost of
machinery and equipment for mechanical harvesting was about $405,000
per 100,000 gross tons of sugarcane during the 1972-73 season, or about
$4.05 per ton (Table 12). New cost of equipment for the hand cut method
of harvesting was about $218,000 or $2.18 per gross ton of cane. Most
of the additional investment was the cost for mechanical harvesters.
During the 1972-73 season, nearly 10 million tons of sugarcane
were harvested in Florida. About 1.5 million tons were harvested
mechanically. The following illustrates changes in new value of invest-
ment with selected amounts of sugar cane harvested mechanically:
29
Sugarcane harvested Increased investment for
mechanically harvesting equipment
(mil. tons) (mil. dollars)
1.5 2.81
2.5 4.68
5.0 9.35
10.0 18.70
The 1.5 million ton level was representative of the amount of cane har-
vested mechanically during the 1972-73 season. If 50 percent of the 1972
crop had been harvested mechanically, the 5.0 million ton level, the
value of added investment would have been about $9.35 million.
The average value of investment would be something less than the
new value. If one assumes a 10 percent salvage value for equipment
after average service life, and if one uses straight line depreciation,
the average value of investment can be derived by multiplying the new
value times 0.55.
Some equipment for the hand cutting system would become obsolete if
mechanical harvesting were adopted--the labor-support equipment and con-
tinuous loaders, for example. Gradual adoption of harvest mechanization
would permit amortization of much of this specialized investment.
The above capital investment for hand cutting did not include labor
housing. Adoption of mechanical harvesting reduces the number of foreign
workers needed to hand cut cane and the need for worker housing.16
Present investment in labor camps may become a "worthless asset" to the
mill when mechanical harvesting is adopted.
In addition to the investment for harvesting equipment, added invest-
ment may be needed for expanding processing capacity for handling mechan-
ically harvested sugarcane. The additional trash in mechanically har-
vested sugarcane could reduce a mill's daily and season capacity for net
cane. Some factories may find it necessary to expand some part of the
processing capacity to handle its sugarcane. Such added investment was
not included in the above estimates.
1The effects of mechanical harvesting on labor needs is consider-
ed in a forthcoming report entitled Effects of Harvest Mechanization on
the Demand for Labor in the Florida Sugarcane Industry.
Table 12.--Estimated new costs for machinery and equipment per 100,000
gross tons of sugarcane for hand cutting and mechanical har-
vesting in Florida, 1972-73 prices a
Method of harvest
Item Mechanical harvest Hand cut
Dollars per 100,000 gross tons of cane
Harvesters 185,266
Continuous loader --- 36,362
Field towing units 119,263 90,502
Field carts 47,409 41,372
Portable transfer station 41,955 31,837
Pick up trucks 4,259 3,232
Maintenance equipment 6,531 4,956
Labor support equipment --- 10,235
Total 404,683 218,496
Both systems based on loading into field carts and transferring
into highway carriers at a portable transfer station.
Based on average of projected equipment requirements for four
different mechanical harvesting systems.
CIncludes fuel truck, grease trailer, water cart, and small trac-
tor,
includes wagon for drinking water, food truck, large van, and
small van.
ADDITIONAL ASPECTS OF MECHANICAL HARVESTING
Considerations other than the above direct costs and returns are
important in determining the long run profitableness of harvesting sugar-
cane mechanically.
Freeze Damage
Loss of sugar may be greater following a severe freeze when cane
is being harvested mechanically than whep it is being hand cut. Sugar-
cane growth stops following a freeze that kills the terminal bud. After
freezing, deterioration begins in which sucrose converts to other com-
ponents which interfere with the recovery of raw sugar. The deteriora-
tion may progress rapidly or slowly depending upon weather conditions,
the variety of cane, and the severity of the freeze. If a freeze is
only moderately severe or is followed by cool dry weather, deteriora-
tion may be gradual and the sugarcane quality could remain high enough
to process during the remainder of the season. But, if the freeze is
very severe or is followed by warm and wet weather, the sugarcane may
deteriorate rapidly and become such low quality that sugar could no
longer be manufactured.
Sugarcane delivered to the mill may be maintained at processing
quality longer when hand cut than when harvested mechanically. The
reason for this is that the cane cutter is able to "top" cane accur-
ately when hand cutting, and as the cane stalk deteriorates, the cut-
ter can lower the topping level,thereby eliminating the deteriorated
top portion of the stalk. Although the deteriorated cane is an eco-
nomic loss, the good cane can be separated and processed.
The recumbent sugarcane grown in Florida cannot be topped as
accurately when harvested mechanically as when cut by hand. When
harvesting frozen sugarcane, most of the deteriorated tops which would
have been removed by hand cutting are recovered by the mechanical
harvesters and mixed with the good cane. The result is that some deteri-
orated cane is milled reducing recovery of available raw sugar. In
addition, the average quality of mechanically harvested sugarcane
may fall below the critical minimum processing quality sooner follow-
ing a freeze than would hand cut cane. The threat of loss from
freeze damage during some years may retard adoption of harvest mechani-
zation.
Wind Damage
A current uncertainty about mechanical harvesting of sugarcane
is how well the harvesters can handle very recumbent cane. Florida
sugarcane production occurs in a hurricane-prone area, and wind dam-
age can be expected periodically. The current mechanical harvesting
systems have not been operated extensively on wind damaged cane. If
some wind damaged sugarcane is lost because the mechanical systems
cannot handle it satisfactorily, this will be an added cost considera-
tion due to mechanical harvesting.
Ratoon Damage
There is uncertainty about the effects mechanical harvesting will
have on sugarcane ratoons. The following year's crop grows from the
ratoons of a current crop. Equipment traffic is heavier over the harv-
ested cane field with mechanical harvesting than with hand cutting.
If the additional traffic damages the ratoons and causes lower yields
in following crops, it would be an added cost to mechanical harvesting.
Opinions differ about the effects of mechanical harvesting on ratoon
crops, but industry personnel who were involved in much of the mechani-
cal harvesting of the 1972 sugarcane crop report that regrowth in their
mechanically harvested fields compared favorably with regrowth in their
hand cut fields [2]. In this study, yields from ratoon crops were as-
sumed to be the same for the mechanically harvested and for the hand cut
sugarcane.
Availability of Cane Cutters
Currently almost all sugarcane cutters are foreign workers who come
to Florida during the sugarcane harvesting season. The importation of
these offshore workers is regulated by the U. S. Department of Labor (USDL).
The need for importing cane cutters is reviewed annually by the Depart-
ment. If the importation of sugarcane cutters to Florida were termi-
nated, the industry would have little practical alternative other than
to attempt mechanizing the harvesting operation.
As long as the USDL permits importation of foreign cane cutters,
the Florida sugarcane industry might find it desirable to stop short of
harvesting 100 percent of its crop mechanically. If, for example, a
mill were harvesting only 50 percent of its crop mechanically, it
would have greater flexibility in handling contingency situations such
as harvesting following a severe freeze or hurricane.
Mill Capacity
Florida sugarcane factories may find it profitable to expand pro-
cessing capacity. The added trash in mechanically harvested cane may
increase processing time for a given crop. There is a "trade off" in
costs between fully utilizing mill capacity over a long period of
time and having enough capacity to process the crop during a short
period of time. Using the mill fully permits spreading fixed invest-
ment Costs over more tonnage, thereby reducing fixed cost per ton.
However, having excess capacity permits harvesting the crop more quick-
ly, providing less "exposure" to the effects of freeze damage and per-
mitting the harvesting of a larger part of the crop when sugar content
of the cane is highest.
Each mill has to evaluate this trade-off when deciding on amount
of capacity needed. The increased risk from freeze damage due to
mechanical harvesting and the need to process on a timely basis may
make it desirable for some mills to expand their mill capacity.
APPENDICES
APPENDIX A
HARVESTING SYSTEMS
Hand Cutting
Most sugarcane in Florida is cut by hand. The cane cutters
(mostly foreign workers) cut the cane at top and bottom, remove
some unburned leaves, and place the clean stalks in "heap rows".
A "continuous loader" picks the cane from the heap row, cuts it into
lengths of about 18 inches and conveys the cut cane into either
a "field cart" or a highway conveyance. Cane loaded into a field cart
is hauled to a field transfer station where it is loaded into a rail-
road car or highway vehicle for transport to the mill.
Mechanical Harvesting
Two types of cane harvesters are used in Florida. One is "row"
harvesters designed for upright cane. These machines have been adapt-
ed to handle lodged and recumbent cane. The second is "mat-type"
harvesters designed to handle recumbent cane. Most of the harvest-
ers are combined cutter and loader machines. The following is a
description of the four mechanical harvesting systems studied in
developing cost estimates for this report.7
J & L Harvester
The J & L harvester (J & L), manufactured by the J & L Corpora-
tion of Jeaneratte, La., is a two-row mat-type harvester which cuts
17
17se of trade names is for identification only and does not
imply endorsement by the U.S. Department of Agriculture.
and loads in one operation. It is a track-mounted machine weighing
about 54,000 pounds. It is powered by a 430 h.p. engine. Purchase
price of the J & L harvester during 1972 was estimated at $80,000 per
machine.
Massey-Ferguson Harvester
The Massey-Ferguson harvester (M-F) is manufactured by Massey-Fer-
guson, Ltd., Bundaberg, Australia. It is a one-row, cut and load machine
designed for harvesting upright cane. The M-F harvester is powered
by a 150 h.p. engine and weighs about 22,000 pounds. The purchase price
during 1972 was estimated at $60,000.
Toft Harvester
The Toft harvester (Taft) is a one-row, cut and load machine
manufactured by Toft Brothers, Ltd., of Queensland, Australia. It is
a track-mounted machine weighing about 40,000 pounds. The harvester is
powered by two 150 h.p. engines. Purchase price of the Toft harvester
during 1972 was estimated at $75,000 each.
United States Sugar Corporation Harvester
The United States Sugar Corporation harvester (USSC) is a one-row
cut and load mat-type machine. It was designed by the United States
Sugar Corporation, Clewiston, Florida, and built by the J & L Corpora-
tion. The USSC harvester weighs about 30,000 pounds and is a wheel-
mounted machine. Estimated cost of this machine during 1972 was $65,000.
APPENDIX B
SUGARCANE TRASH AND FIELD LOSSES
Trash in cane increases both the bulk and the weight of cane
hauled to the mill for processing. In addition, the composition of
the trash (amount of green and dry matter) may have an effect on the
quality of juice extracted and the recovery of raw sugar. Field
losses are important because they may result in less net sugarcane
being delivered to the mill and reduced revenue when harvesting mechani-
cally. The authors conducted studies at two week intervals through-
out the 1972-73 season to determine differences in trash content and
field losses between mechanically harvested and hand cut sugarcane.
Results of these studies and other available data were used to esti-
mate the effects of mechanical harvesting on trash in sugarcane and
on field losses.
Trash Content
Two sugarcane samples of about 40 pounds each were collected
from under the loading conveyors of each of two hand-cut-continuous-
loader operations and four different mechanical harvesting systems.l8
The samples were weighed, cleaned in accordance with USDA instruc-
tions, and reweighed [ 9]. Trash was separated into green and dry
material and the amount of each type was weighed and recorded as a
percent of the gross weight (Table 13). The hand cut cane had an
average of 5.5 percent total trash. Dry material accounted for 2.8
percent and green material amounted to 2.7 percent. The mechani-
cally harvested cane averaged 8.3 percent total trash--l.9 percent
18ee [3] for a further discussion of these tests.
See [3] for a further discussion of these tests.
dry material and 6.4 percent green.
USDA regulations required mills to perform trash content determina-
tions separately for hand cut and mechanically harvested sugarcane dur-
ing the 1972-73 season [9 p. 6]. Four 100-pound or larger samples of
hand cut and/or mechanically harvested cane were examined weekly by
each mill to determine the amount of trash. The weighted average total
trash content for the 1972 crop was 5.27 percent of gross cane fpr hand
cut sugarcane and 10.9 percent of gross cane for mechanically harvested
19
sugarcane. These ASCS data were based on more observations than obtain-
ed in the tests reported in Table 13. In addition, they were a weight-
ed average for the Florida industry. The authors felt these ASCS data
would be the most representative data available of differences in total
trash between hand cut and mechanically harvested sugarcane in Florida.
However, the trash content data reported to ASCS by the mills did not
distinguish between green and dry trash. In this study the ratio be-
tween green and dry trash determined from the data in Table 13 was used
as representative of differences between hand cut and mechanically
harvested sugarcane in Florida.
Trash in hand cut sugarcane averaged about half dry matter and half
green material. However, there was a range of dry trash to green trash
ratios among the four mechanical harvesting systems. The ratio for
several mechanical systems was 1:5, while one system had a ratio of 1:3.
For the remainder of this study, trash in hand cut cane was estimated
at 50 percent dry and 50 percent green, and trash in mechanically
harvested cane was estimated at 25 percent dry and 75 percent green.
Using the ASCS total trash data of 5.27 percent for hand cut cane and
10.9 percent for mechanically cut cane, and the dry trash:green trash
ratio of 50:50 for hand cut and 25:75 for mechanically harvested cane,
the trash composition for sugarcane harvested during 1972-73 was as
follows:
19Based on data from the state office of ASCS, USDA, Gainesville,
Florida.
Hand cut Mechanically harvested
20
%, gross %, net %, gross %, net
cane cane cane cane
Dry trash 2.635 2.78 2.725 3.06
Green trash 2.635 2.78 8.175 9.17
Field Loss
Both types of harvesting systems result in some sugar-bearing cane
being left in the field. With the hand cutting system, the cutter may
cut some of the cane several inches above the ground level, leaving some
of the high-sugar content cane in the stubble. In addition, some cane
will be topped lower than desirable, and some sugar-bearing cane will
be discarded with the tops. Some cane is missed by the continuous load-
er, and some will be lost off the wagons as the cane from the conveyor
misses the field carts or falls from the carts. Similar losses of
"good" sugarcane may occur with mechanical harvesting.
Field loss studies were conducted at the same time trash samples
were collected. An area behind each harvester or loader was marked and
all the millable sugarcane remaining in that area was collected and
weighed. The field loss samples were taken before workers passed over
the area to recover some of the cane lost by the machinery. A four-
row width behind the continuous loader, a two-row width behind the two-
row harvester, and a one-row section behind the one-row harvester were
measured for the field loss tests.
Field losses for hand cutting average 2.84 net tons of cane per
acre or an average loss of 5.3 percent of the in-field yield (Table 13).
The average field loss for the mechanical harvesters was 3.75 net tons
of cane per acre or 8.6 percent of the total in-field yield. These
average field losses were used as representative of hand cutting and
mechanical harvesting for the 1972 crop.
20
Trash, % net cane = [(trash, % gross cane) (100 trash, %
gross cane)] X 100.
Table 13.--Trash content and field loss for mechanically harvested and hand cut sugarcane in Florida,
1972-73 season
Trash in cane Field loss
Dry Green Total
%, gross %, total %, gross %, total %, gross Net tons %, total
Sample cane trash cane trash cane per acre yield
Hand-cut
1 2.5 50 2.5 50 5.0 2.83 5.1
2 3.1 52 2.9 48 6.0 2.86 5.5
Average 2.8 51 2.7 49 5.5 2.84 5.3
Mechanically-harvested
1 2.1 19 8.9 81 11.0 3.43 6.8
2 2.0 22 7.1 78 9.1 4.44 11.9
3 2.1 31 4.7 69 6.8 3.69 7.7
4 1.3 20 5.1 80 6.4 3.44 7.9
Average 1.9 23 6.4 77 8.3 3.75 8.6
aSamples were taken at 2-week
samples had received freeze damage.
intervals, from November 7, 1972, to May 22, 1973. None of the
APPENDIX C
SUGARCANE QUALITY
Milling tests were conducted during the 1972-73 season at one
month intervals from November through March. The sugarcane was milled
with the experimental mill at the USDA Sugarcane Field Station, Canal
Point, Florida. Each sample was crushed, and the bagasse was milled
three times. Cold maceration was added at a rate of 20 percent of
the weight of clean cane in the course of milling. Juice from each
sample was weighed and analyzed to determine extraction, brix, and
purity. Fiber determinations were made to determine amount in cane
and amount in bagasse. Sucrose extraction was calculated for each
sample. Results of these tests and findings from studies by other
researchers served as the basis for estimating the effects of mechani-
cal harvesting on sugarcane quality and on the mill operations during
the 1972-73 season [1, 6].
In the first two tests, 80-pound samples of cane from each of
the harvester systems (two hand cut and four mechanically harvested)
were milled. Green and dry trash were added to the 80-pound samples
of clean cane in the same proportions as existed in the cane samples
obtained from the mechanical harvesters and continuous loaders. It
was impossible to control the effects of non-trash variables on the
samples. The mechanical harvesters from which the samples were
taken were operating in different cane varieties, at different loca-
tions, and in cane of different maturities. Variations among samples
due to the above factors were too great and the number of samples
too few to draw conclusions about the effects of trash content on
the sugarcane.
After these first two tests, all cane samples were taken from
one location and were of the same variety. In addition, duplicates
41
of each sample were milled and sample size was reduced to 40 pounds of
clean sugarcane each. Trash was addeq to these samples in the follow-
ing amounts: One and two pounds of dry leaves, and two and four pounds
of green leaves and immature stalk. One sample consisted of two pounds
of dry trash and four pounds of green trash.
Effects of Mechanical Harvesting on Percent Sucrose
in Normal Juice and Percent Brix in Normal Juice
The two variables which had the greatest effect on the percent
sucrose in the normal juice (NJS) were time (the month during which the
cane was harvested) and the amount of green trash added to the sugar-
cane sample. Regression parameters were estimated using the data from
all five months and then using only data from the last three months.
Equation I represents results with data from all five tests, and equa-
tion II represents results with data from just the last three tests.
2
I. NJS = 11.90 0.11GRTR + 0.96T, R2 = 0.61
(0.037) (0.132)
II. NJS = 10.95 0.07GRTR + 1.14T R2 = 0.68
(0.027) (0.14)
Where NJS = sucrose, percent of normal juice
GRTR = green trash, percent of net cane
T = time where Nov. = 1, Dec. = 2, Jan. = 3, Feb. = 4, and
Mar. 5 5.
The numbers in parenthesis are standard errors. Equation I should be
interpreted as: a percentage increase of green trash in cane results
in a 0.11 percentage point decrease in NJS. Equation II indicates that
a percentage point increase of green trash reduces NJS by 0.07 per-
centage point.
Tests conducted in Louisiana by Arceneaux and Davidson in 1944
resulted in a 0.06 percentage point decrease in NJS for every percen-
tage point increase in green trash [1]. Legendre and Irvine recently
21
The ratio between the mean square for regression and the mean
square error (the F ratio) was 39.1 for equation I and 35.7 for equation II.
conducted tests in which trash consisting of 60 percent green mater-
ial and 40 percent dry matter was added to clean cane [6]. They
found that a percentage point increase in 60/40 trash reduced NJS by
0.1 percentage point.
Equation II was used as representative of the effect of trash on
2
NJS in Florida. The R value for equation II was higher than for equa-
tion I, and the effects of green trash on NJS are closer to the find-
ings reported by Arceneaux and Davidson in 1944 and by Legendre and
Irvine in 1973.
The effects of mechanical harvesting on the NJS of sugarcane was
estimated by using the relationship bqeween trash and NJS from equar
tion II and the amount of green trash in hand cut and mechanically
harvested sugarcane. The estimated NJS was 14.18 percent for hand cut
sugarcane and 13,73 percent for mechanically harvested cane (Table 14).
The average percent brix in normal juice (NJB) for all the samples
milled was 17.15 percent. The percent brix in normal juice did not
change much with changes in the amounts and composition of trash in the
cane. Since trash did not have much effect on NJB, the average for all
samples, 17.15 percent, was used as representative of both hand cut
and mechanically harvested sugarcane (Table 14).
Table 14.--Estimated trash in cane, percent sucrose in normal juice (NJS)
and percent brix in normal juice (NJB) for hand cut and mechan-
ically harvested sugarcane in Florida, 1972-73 season (based
on experimental data)
Harvesting Green trash Sucrose in Brix in
method in sugarcane normal juice normal juice
%, net cane %, normal juice
Hand cut 2.78 14.18 17.15
Mechanical 9.17 13.73 17.15
aBased on equation II with T set to 3.
Effects of Mechanical Harvesting on Fiber in Cane
Fiber is the dry,,insoluble matter in the cane [7]. The estimated
percent fiber in cane was based on amounts of dry trash and green trash
in the cane. Regression parameters were estimated using both the 5-
months data (Equation III) and the 3-months data (Equation IV).
III. FIBCAN = 9.81 + 0.41DRTR + 0.09GRTR, R2 .46
(0.07) (O.Q3)
IV. EIBCAN = 8.96 + 0.59DRTR + 0.23GRTR R = .84
(0.05) (0.03)
Where FIBCAN = fiber, percent of net cane
DRTR = dry trash, percent of net cane
GRTR = green trash, percent of net cane
The numbers in parentheses are standard errors for the regression coeffi-
cients.
Equation III indicates that fiber as a percentage of net cane in-
creased 0.41 percentage points with each percentage point increase in dry
trash and 0.09 percentage points with each percentage point increase in
green trash. Equation IV indicates a 0.59 percentage point increase in
fiber percent of net cane for each percentage point increase in dry
trash and a 0.23 percentage point increase for each percentage point in-
crease in green trash, Legendre and Irvine found that a percentage
point increase in 60/40 trash resulted ip a 0.16 percentage point increase
in fiber in cane [6]. In the study conducted by Keller and Schaffer [5]
the fiber in gross cane increased 0.43 percentage point for each percen-
tage point increase in trash,
The effect of mechanical harvesting on the fiber in cane was esti-
mated by using the relationship between trash and fiber in cane from
equation IV and the amount of trash for hand cut and mechanically harv-
ested cane. The estimated fiber content of cane was 11.24 for hand cut
and 12.87 for mechanically harvested cane (Table 15).
Table 15.--Estimated fiber percent of cane in hand cut and mechani-
cally harvested sugarcane in Florida, 1972-73 season (Based
on experimental data)
Harvesting
method Dry trash Green trash Fiber
%, net cane %, net cane
Hand cut 2.78 2.78 11.24
Mechanical 3.06 9.17 12.87
Effects of Mechanical Harvesting on Extraction of Normal Juice
Results from the milling tests showed that extraction of normal
juice (NJE) increased with increases in the amount of green trash in
the cane. Dry trash had no effect on NJE. The relationship between
NJE and green trash in cane is represented by equation V.
V. NJE = 84.1 + 0.32GRTR 1.2T R = .40
(0.09) (.35)
Where NJE = extraction of normal juice, percent of net cane
GRTR = green trash, percent of net cane
T = time where Nov. = 1, Dec. = 2, Jan. = 3, Feb. = 4,
and Mar. = 5.
The numbers in parentheses are standard errors for the regression coef-
ficients. Equation V can be interpreted as a percentage point increase
in green trash in cane results in a 0.32 percentage point increase in
NJE.
The above results are similar to those obtained by Arceneaux and
Davidson [1]. Their samples of clean cane gave a NJE of 80.5 percent.
Each percentage point increase in green trash increased NJE by 0.34
of the weight of clean cane, Dry trash had very little effect on NJE
in the Arceneaux-Davidson tests. Legendre and Irvine found that NJE
decreased with increases in 60/40 trash in their tests [6].
The effects of mechanical harvesting on NJE were estimated by
using the relationship between green trash and NJE from equation V
(with T set to 3) and the trash contents for hand cut and mechanically
harvested cane. The estimated NJE was 81.39 percent for hand cut and
83.43 percent for mechanically harvested cane (Table 16).
Table 16.
Estimated extraction of normal juice (NJE) with hand cut and
mechanically harvested sugarcane in Florida, 1972-73 season
(Based on experimental data)
------.------- ---------------- ------------, --- --------
Harvesting Green trash Extraction of
method in sugarcane normal juice
%, net cane %, net cane
Hand cut 2.78 81,39
Mechanical 9.17 83.43
Mechanical harvesting raised NJE by 1.78 percentage points over hand cut
22
cane.
Effects of Mechanical Harvesting on Standard Sugarcane Quality Factor
Payment for sugarcane is made on the number of standard tons of
cane delivered to the mill. Standard tons of sugarcane are derived by
multiplying net tons by a standard sugarcane quality factor. The stand-
ard sugarcane quality factor is used to convert net tons of sugarcane
with different sucrose contents to a unit of measure having a standard
sucrose content. A standard ton is equivalent to a net ton having 12.5
percent sucrose in the normal juice. The relationship between NJS and the
standard sugarcane quality factor is as follows [11]:
22
The apparent reason for the increased NJE for mechanically harv-
ested cane is that more green material was being crushed per ton of net
cane yielding more juice, but having a lower NJS.
Average percept sucrose Standard sugarcane
in normal juice quality factor
9.5 0.70
10,0 0.75
10.5 0.80
11.0 0.85
11.5 0.90
12.0 0.95
12.5 1.00
13.0 1.05
13.5 1.10
14.0 1.15
14.5 1.20
15.0 1.25
15.5 1.30
The standard sugarcane quality factor for hand cut and mechani-
cally harvested sugarcane was estimated from the above relationship,
using the NJS estimates from Table 14. The estimated standard sugar-
cane quality factors were 1.168 for hand cut sugarcane and 1.123 for
mechanically harvested sugarcane. The difference of 0.045 can be inter-
preted as follows: each net ton of hand cut sugarcane was equivalent
to 0.045 more standard tons than a net ton of mechanically harvested
sugarcane.
Effects of Mechanical Harvesting on Molasses Yield
Additional green trash in mechanically harvested cane tends to raise
the amount of non-sucrose soluble solids (NSS) in the juice. Increases
in NSS are expected to result in a higher molasses yield per net ton of
cane. The procedure used to estimate increased molasses yield due to
mechanical harvesting was to: (1) estimate increases in NSS extraction,
(2) estimate the relationship between NSS extracted and molasses produc-
tion, and (3) estimate increased molasses production from the estimates
of additional NSS and the relationship derived in steps 1 and 2 (Table 17).
The NSS extraction per net ton of cane was about 7.5 pounds higher
due to mechanical harvesting. One pound of NSS was estimated to produce
about 1.68 pounds of molasses (Table 17, footnote e). Hence the 7.5 pounds
additional NSS from mechanically harvested sugarcane would result in pro-
duction of about 12.6 pounds or about 1 gallon additional molasses per
net ton of cane. Molasses yields per net ton of hand cut sugarcane was
estimated at 5.8 gallons from the molasses payment formula [il]. Hence,
molasses yields per net ton of cane for the 1972 crop used in this study
were 5.8 gallons for hand cutting and 6.8 for mechanical harvesting.
Table 17.--Estimated difference in molasses yields between mechanically
harvested and hand cut sugarcane in Florida, 1972-73 season
(Based on experimental data)
Item Quantity
Pounds per net
ton of cane
Normal juice extracteda
Hand cut, @ 81.39% 1,627.8
Mechanically harvested, @ 83.43% 1,668.6
Total solids extracted
Hand cut 279.2
Mechanically harvested 286.2
Sucrose Extractedc
Hand cut, @ 14.18% 230.8
Mechanically harvested, @ 13.73% 229.1
Non-sucrose soluble solidsd
Hand cut 48.4
Mechanically harvested 57.1
Additional non-sucrose soluble solids 8.7
Additional molasses yielde 14.6
a(NJE from Table 14) X (2,000 pounds).
b
(NJB of 17.15) X (pounds normal juice).
c(NJS from Table 12) X (pounds normal juice).
(Total solids) (sucrose).
e(Additional NSS) X (1.68). Based on the relationship that each
additional pound of non-sucrose soluble solids carries about 0.4 pounds
of molasses per pounds of NSS = (1 pound NSS + 0.4 pound sucrose) +
(.8333 brix in molasses) = 1.68 pounds molasses.
I_
REFERENCES
[11 Arceneaux, George and Lester Davidson. "Some Effects of Trash in
Cane on Milling Results", Sugar Journal 35:10 (Mar. 1973).
[2] Castro, J. and J. J. Balardi. "Mechanical Harvesting of Sugar-
cane and its Effects in the Factory at Talisman Sugar Corp-
oration", Proc. ASSCT 2 (N.S.), 1973.
[3] Clayton, J. E. et al. "Field Losses and Trash Contents of Hand
Cut and Mechanically Harvested Sugarcane in Florida", Proc.
ASSCT 3 (N.S.), 1974, pp. 146-148.
[4] "Farm Machinery Costs and Use", Agricultural Engineers Yearbook,
1969. St. Joseph, Mich.; American Society of Agricultural
Engineers, 1969, pp. 278-283.
[5] Keller, Arthur G. and Francis C. Schaeffer. The Effects of Cane
Trash on the Milling Operation. La. State Univ. Eng. Exp.
Sta. Bul. 25, 1951.
[6] Legendre, B. L. and T. E. Irvine. "Some Effects of Cane Trash
on Milling Qualities". Proc, ASSCT 3 (N.S.), 1973, pp. 167-
173.
[7] Spencer, G. L. and G. P. Meade. Cane Sugar Handbook (Ed. 8).
New York: John Wiley and Sons, Inc., 1945.
[8] U. S. Agricultural Stabilization and Conservation Service. Sugar
Reports. Washington:. Jan. 1973.
[9] ASCS
Handbook: Sampling, Testing, and Reporting for Florida Sugar
Processors (Short Reference 9-St), Washington: 1972.
[10] Returns,
Costs, and Profits, Florida 1967-69 Crops, Everglades Area.
Washington: n.d.
[11] U. S. Congress. "Sugarcane: Florida. Fair and Reasonable Prices
for 1972 Crop". (Subchapter I--Determination of Prices, Part
873 of document relating to Title 7--Agriculture), U. S. Federal
Register 37: F. R. 25997. Washington: Dec. 7, 1972.
[12] U.S. Congress. "General Conditional Payments Provisions--Main-
land Cane Sugar Area" (Subchapter K--Chapter VIII, Title 7
Agriculture). U.S. Federal Register 37: F. R. 18693, Sept.
15, 1972.
[13] ___. "Wages: Sugarcane: Florida. Fair and Reasonable
Wage Rates" (Subchapter H--Chapter VIII, Title 7--Agriculture).
U. S. Federal Register 37: F. R. 23094, Oct. 28, 1972.
[14] Walker, Charles. Costs and Returns from Sugarcane in South Florida.
Univ. of Florida Cooperative Extension Service Cir. 374.
Gainesville: June, 1972.
275 copies
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