U.S. Department of Agriculture

Forest Service Research Note SE-315 June 1982

High-Gum-Yielding Slash Pines Survive and Grow Well

by S. V. Kossuth, W. J. Peters, and C. R. Gansell

ABSTRACT. --Plantings in Georgia and Florida were established

with slash pine seedlings of three genetic types: selections

improved for high gum yield (IHGY), selections with improved

growth and form (IGF), and commercial stock (CS). Under adverse environmental conditions in Florida, IHGY survived

best at age 3, CS next best, and IGF poorest. Survival was

more than twice as high in Georgia at age 4; it was uniformly high except for IGF seedlings from one nursery.

Significantly more fusiform rust was found in CS than in

IHGY or IGF stock. IHGY had 44.8 percent more volume than

CS at age 10; no lo-year-old IGF were available for

comparison.

Keywords: Pinus elliottii, tree improvement, commercial

stock, growth and yield, survival.

In the mid-1970's, reduced survival in young slash pine (Pinus

elliottii Engelm.) plantations caused

by hot summers or other unknown factors

led to concerns about the survivability

of specially bred selections of the

species. The objective of the study

described here was to compare survival

and early growth of three genetic types

of slash pine: improved high gum yielders (IHGY), selections improved for

growth and form (IGF), and commercial

stock (CS). Stock was obtained from

three nurseries, and growth was observed in three field plantings.

1

Research Plant Geneticist and

Research Forester, respectively, Southeastern Forest Experiment Station,

Olustee, Florida, and former Research

Plant Geneticist, now at USDA Forest

Service, Dorena Tree Improvement

Center, Cottage Grove, Oregon.

Southeastern Forest Experiment Station-Asheville, North Carolina

METHODS

IHGY, IGF, and CS seedlings were

obtained from the Florida Division of

Forestry's Munson Nursery; IHGY and IGF

from the Georgia Forestry Commission's

Reidsville Nursery; and CS from the

Florida Division of Forestry's Andrews

Nursery. Seedlings were planted by

hand near Soperton, Georgia, in February 1977 and by machine near Live Oak,

Florida, in December 1977. The Live

Oak site had previously been a soybean

field; the Soperton site had been occupied by pines which were clearcut.

Logging slash was piled and burned, and

low beds were made at Soperton. At

both sites, t.rees were planted at a

1.83- by 3.66-m spacing in 12 randomized blocks with 52 seedlings per

source. In all, 3,844 seedlings were

planted at each location. Survival and

total height were observed at both

locations in the late fall of 1980.
Occurrence of fusiform rust was recorded only in Georgia since very few

trees were infected in Florida. Survival percentages were transformed by

arc sine, and both height and survival

data were subjected to analysis of

variance.

The lo-year-old plantation was

machine planted in 1968 on the Osceola

National Forest in Florida on beds 4.5

m apart. Spacing on beds was 3.6 m.

High-gum-yielding tree seeds were obtained from the U.S. Forest Service

McColskey Still seed orchard. Volume

was calculated using the formula ft3 =

0.02408 + 0.0021058 (D'H) and converted

to m3/ha. In December 1977, five (0.1

acre) plots were measured for height

and d.b.h. Data were analyzed by an

analysis of variance.

RESULTS AND DISCUSSION

Survival in the younger plantings

through fall 1980 was significantly

greater in Georgia than in Florida

(table 1). In Florida the IHGY stock

had the highest survival (38.8 and 44.4

percent) and IGF the lowest (25.6 and

29.0 percent). A severe drought during

this year killed so many seedlings that

the entire planting was a failure by

commercial standards. Heights in Florida ranged from 1.35 to 1.52 m, and no

significant differences attributable to

planting stock were observed. In Georgia, survival ranged from 78.4 percent

for CS seedlings from Munson, Florida,

to 47.4 percent for the IGF trees from

Reidsville, Georgia. Survival of the

latter was significantly less than for

any other group. Average height difTable 1. --Performance of slash pine seedlings of three genetiE types

in a 4-year-old Georgia and a 3-year-old Florida plantation

Percent Percent

Nursery location survival fusiform Height

and genetic type

of stock GA FL GA FL GA FL

FDF, Munson, FL:

IHGY 72.7a 38.8ab

IGF 68.9a 25.6b

cs 78.4a 34.4ab

GFC, Reidsville, GA:

IHGY 75.7a 44.4a

IGF 47.4b 29.0b

FDF, Andrews, FL:

cs 75.0a 34.lab

---m---

-

26.0b -- 2.85a 1.49a

23.3b -- 2.83ab 1.46a

34.4a -- 2.62ab 1.46a

20.8b -- 2.81ab 1.52a

24.8b -- 2.62b 1.45a

37.0a -- 2.7ab 1.35a

Within columns, means followed by the same letter do not differ

significantly at the 0.05 level according to Duncan's new multiple

range test.

'Seedlings were produced in nurseries of the Florida Division of

Forestry (FDF) and Georgia Forestry Commission (GFC). IHGY = improved

for high gum yield; IGF = improved growth and form; CS = commercial

stock.
fered significantly among the selections in the Georgia planting, ranging

from 2.62 to 2.85 m.

Although large differences in

height among the three genetic types

were not evident at ages 3 and 4, survival data indicated a clear superiority of the IHGY trees, especially in

Florida under high stress conditions.

In both locations the IGF stock had

lower height growth, and these preliminary measurements indicate the IHGY may

be superior to both CS and IGF stock.

Significantly more fusiform rust

was found in the two groups of CS seedlings than in the IHGY or IGF stock.

Apparently, selection of IHGY and IGF

trees yielded some gain in resistance

to fusiform rust. This gain is important because lower rust infection may

translate into higher volume production

at rotation age. Also, if fusiform

rust was responsible for the low survival of the IGF trees, those surviving

may be somewhat resistant to rust.

At age 10, volume of IHGY stock

averaged 17.32 m3/ha, compared to 11.96

m3 for the CS (table 2). Survival for

the IHGY was slightly less, but volume

was 44.8 percent greater than for the

CS stock.

l'n,se data confirm earlier observations that IHGY trees grow as well as

ordinary commercial stock, if not better. A large volume advantage for IHGY

stock was apparent by age 10. If commercial gum production is even a remote

possibility, IHGY trees are obviously

the best alternative for slash pine

plantation establishment. IHGY trees

are also an attractive alternative in

other situations because they grow

faster than most CS. Since lo-year

tests did not include IGF trees, their

value cannot be compared with that of

IHGY at this time.

ACKNOWLEDGMENT

We thank the Georgia Forestry

Commission, the Florida Division of

Forestry, Claude Crapps III, and Jim

Gillis, Jr., for their cooperation in

providing labor, planting stock, and

planting sites for this study.

Table 2. --Yields of improved high-gum-yielding (IHGY) and

commercial stock (CS) of slash pine on the Osceola

National Forest after 10 years of growth

-m -cm m3/ha

IHGY 524 8.07 11.45 17.32

cs 549 6.85 9.42 11.96

Percent difference 17.8* 21.6* 44.8**

* and ** indicate statistically significant differences at the 0.05 and 0.01 level, respectively.
The Forest Service, U.S. Department of Agriculture, is dedicated to the principle of multiple

use management of the Nation’s

forest resources for sustained

yields of wood, water, forage,

wildlife, and recreation. Through

forestry research, cooperation

with the States and private forest

owners, and management of the

National Forests and National

Grasslands, it strives-as directed by Congress-to provide

increasingly greater service to a

growing Nation.

USDA policy does not permit discrimination because of

race, color, national origin, sex or religion. Any person

who believes he or she has been discriminated against in

any USDA-related activity should write immediately to

the Secretary of Agriculture, Washington, D.C. 20250.

fZ U.S. GOVERNMENT PRINTING OFFICE: 1982-539-000/4011