U.S. Department of Agriculture

Forest Seruice Research Note SE- 274 February I979

GUM PRODUCERS CAN

IMPROVE QUALITY OF GUM MARKETED

AND GET HIGHER PRICES

by Ralph W. Clements’

Abstract.-Acid waste from over-treatment and old, wornout iron cups have contributed significantly to the generally poor quality of gum marketed. Today producers are reluctant to purchase new

cups and gutters and invest up to $1.80 per tree for production when the market price for gum

averages 14.54 per pound annually. Guidelines are given for improving the quality by eliminating the

impurities and marketing cleaner gum. From 1%9 to 1978, comparative data show that prices and

demand for high-quality WW and WG grades of pine gum have increased, yet the percentage of the

annual production in the top grades has not kept pace. Gum prices for this period increased 110

percent, while production decreased by 72 percent. Only 34 percent of the annual production graded

WW or WG.

KEYWORDS: Gum grades, acid corrosion, old and new cups, market prices.

ACID DAMAGE OF IRON

CUPS AND GUTTERS

It is estimated that 99.9 percent of the timber

worked for gum production in the United States is

treated with sulfuric acid to prolong gum flow.

Workers have been using acid since 1947, but

many have become careless and too hasty in applying it. Often, they apply twice the amount that

is required for adequate treatment. The excess

runs down the tree and concentrates on gutters

and in the cups. The galvanized iron is eroded,

exposing the base metal (iron); then iron contaminates infiltrate the gum and lower the grades of

rosin processed (fig. 1). The ash content of rosin

reflects the presence of contaminates, and only

l/l0 of 1 percent iron ash is sufficient to lower the

rosin grade from WW to KATE (Lawrence 1942).

New galvanized iron cups can be damaged

sufficiently to affect grades the first year of use if

acid waste is excessive (Clements l%la). Fresh

gum does not protect the new cup as many producers and workers believe (fig. 2). Iron gutters

Uements is Naval Stores Specialist, Naval Stores and

Timber Production Laboratory, Olustee, Florida.

and aprons are damaged to a similar degree by

waste acid. When a gutter becomes clogged and

the gum remains in contact with the iron for 4

Figure 1 .-Each cup shown is 4 years old. Gum in cup at left is

from tree treated with water solution of 24-D for 4 years.

That on right is from tree treated with 50 percent solution

of sulfuric acid for the same period. Both galvanized iron

cups were new when study began. Iron contaminates

from the cup have discolored and degraded the gum from

the acid-treated tree.

Ssastheastern Forest Experiment Startion - Asheville, North Carolina
Figure 2.-Fresh gum will not protect the clean surface of a

new galvanized iron cup. Acid will infiltrate the gum and

erode the zinc coating, exposing the base metal (iron).

Water will dilute the acid and spread the corrosive action,

and the galvanized surface is not seriously damaged in

any one spot.

weeks, the top surface of the gum will be glistening white but the gum that has been in contact with

the iron gutter will be dark brown.

GUM PRICES

Although the demand and prices for quality

gum rosins have increased appreciably in the past

IO years, the quality of the crude gum mar&ted

has not improved. In 1968-69, WW rosin was

selling for an annual average of $11.39 per pound.

The corresponding price in 1977-78 was $28.91.

The range in prices ;:I-:tvieen WW and KATIE

rosins has increased shnrply in 10 years, reflecting

the demand for the top grades. In 1968-69, the

difference in the prices for WW and KATE was

only $1.87. This difference increased to $5.25 for

100 pounds of rosin in 1977-78 (USDA 1%9-

1978b).

Ten years ago the U.S. industry produced

277,648 barrels of crude gum, and 34.3 percent of

the annual production graded WW or WG. The

average price paid the gum farmer for all grades

was $30.01 per barrel. Production for the 1977-78

crop year was only 77,132 barrels of crude-a 72

percent drop in 10 years-and 33.7 percent of this

total production graded WW or WG. The average

price paid for a barrel of gum in 1977-78 was

$63.01, an increase of 110 percent (table I).

Table 1 .-Proportion of annual production of gum

grading WW and WG, with average

prices for crop years 1968-69, 1977-78

Month

April 27 25 29.20 62.41

May 42 34 29.90 64.26

June 67 61 31.30 66.61

July 71 73 31.70 68.46

August 69 75 31.85 68.46

September 71 76 32.20 68.65

October 46 41 30.90 64.83

November 9 9 28.60 61.10

December 3 4 28.50 60.84

January I 5 28.25 58.85

February 2 0 28.40 54.47

March 4 I 29.35 56.19

Percent Dollarslharrel

Average 34.3 33.7 30.01 63.01

The highest average price for gum during

1977,-78 ($68.65) was recorded in September,

when 76 percent of the gum marketed graded WW

or WG. But a preponderance of low grades in

December, January, February, and March reduced the average to $63.01 (table 2). The range in

average prices reflected the demand for quality

gum: $70.73 for WW and $54.38 for KATE

(tab& 2). Gum prices in 1977-78 were not particuTable 2.-Value of gum produced by grades for

1977-78 crop year

Gum PrUpIXliLL? Weighted Value of

grades of a,:nkai Volume average production

prodtic ritin price by grades

Dollars/

Percent Barrels barrel Dollars

UW 20.2 15,581 70.73 1,102,044.13

WCi 13.5 10,412 67.83 706.245.96

NANCY 23.7 18,280 64.05 I, 170,834.OO

MARY 33. I 25,532 58.08 1,482,898.56

KATE 9.5 7,327 54.38 398,442.26

Total 100.0 77,132 - 4,860,464.91

Average for crop year 63.01

2
larly favorable to the producer, and many gum

farmers abandoned their operations.

OLD VERSUS NEW CUPS

Another factor contributing to the low percentage of the annual production grading WW and

WG is the number of old, rusty, acid-damaged

cups currently in use. The average cup used in the

woods to collect gum today is estimated to be over

10 years old.

In 1968-69, there were 1,595 producers working 15.3 million faces for gum production, and

145,000 new metal cups were sold for the crop

year (USDA 1969-1978a). The record dropped to

654 producers and 4.5 million faces during 1977-

78, when only 30,000 new cups were purchased.

Economy-minded producers have been purchasing used cups from gum farmers who abandoned

gum extraction as an unprofitable enterprise.

Over the past 10 years, new cups (iron, aluminum,

and plastic) were purchased at the rate of 164,000

per year to collect gum from over 80 million

trees2

Fluctuations in gum prices and unstable

market conditions do not encourage producers to

invest 65e per tree for new hardware and labor for

installation before production begins. producers

who lease timber will have to invest about $1.80

per tree for gum production by the end of the

season. With gum at 14.51 per pound ($63.01 per

barrel), the producer will have to produce 12.4

pounds of gum per tree, or 27 barrels per 1,000

faces, just to break even. The average gum production for all producers and timber worked in

1977-78 was only 17 barrels per 1,000 faces

(USDA 1%9-1978a). Low gum prices and high

cost of production do not support the purchase of

new hardware for improving the quality of gum

marketed.

IMPROVING GUM GRADES

Gum grades can be improved appreciably

merely by deviating from the centuries-old ways

of doing things in the woods, such as:

1. Gradually replacing old, wornout cups

with plastic cups which are acid resistant and will

not discolor the gum (Clements 1977).

2. Insisting that the chipper use a cup cover

2The Lerio Corporation. 1978. Record of sales of gum

cups 1%9-1978. Valdosta, Ga., and Mobile, Ala. Personal

correspondence.

to keep bark and chips out of the clean gum.

3. Punching and cleaning gutters and aprons

on every dipping to prevent clogging and discoloring the gum caused by long contact with the

iron gutter.

4. Punching and removing scrape as it forms

on the face of the tree, when the scrape is

‘ ‘green, ” and has not crystallized; this will reduce

the volume of low grades marketed in January and

February, when 76 percent of the gum-scrape sold

will grade MARY or KATE (Clements 1961b).

When possible, haul and sell the gum within a

week following dipping to prevent grade loss.

Acid-treated gum collected and “held” in the customary iron shipping barrel will discolor and drop

1 color grade in less than 30 days if acid waste has

been excessive.

IMPROVING QUALITY

AND PRICES

Gum rosin is classified by the selling and

using industries as a specialty product to upgrade

and stabilize the cheaper and inferior imports

glutting the market (Thomason 1977). Gum

processors and producers should promote and

cultivate the superiority and versatility of gum

rosins to create demand for the specialized product. At least 75 percent of the crude gum marketed

annually should produce WW or WG rosins to

stabilize the annual supply and to assure the consumer of a dependable market for top grades of

gum rosins.

Gum flows from the pine tree clean and pure.

Contamination and the loss in value are caused by

a decrepit collection system and improper handling. If 75 percent of the annual production in

1977-78 had been graded WW or WG, the average

annual price received for a barrel of gum (all

grades) would have increased by $3.64. Grades

can be improved by eliminating the causes for

contamination.

3
LITERATURE CITED

Clements, Ralph W.

l%la. Longer life for new metal cups on acid-treated

trees. AT-FA J. 23(4):!3-14.

Clements, Ralph W.

I%lb. Scrape yield from longleaf, slash greater than

others. Nav. Stores Rev. 71(6):4-5.

Clements, Ralph W.

1977. New plastic cup for the gum naval stores industry. U.S. Dep. Agric. For. Serv., Res. Note

SE-258, 4 p. Southeast. For. Exp. Stn., Asheville, N. C.

Lawrence, Ray V.

1942. Removal of metallic contaminants from pine

oleoresin. Ind. and Eng. Chem. 34:984..

Thomason, Frances G.

1977. U.S. naval stores situation-production and

consumption. U.S. Dep. Agric.-Agric. Stab.

Conserv. Serv. Rep. [Presented as an address

before the Annu. AT-FA Meet., Valdosta, Ga.]

U.S. Department of Agriculture

1%9-197ga. Annual participation reports. Nav. Stores

Conserv. Program, Agric. Stab. Conserv. Serv.,

Washington, D.C.

U.S. Department of Agriculture

1%9-1978b. Monthly crude pine gum reports. Agric.

Mark. Serv., Tob. Div., Raleigh, N. C.