United States 

Department of 

Agriculture Survival, Growth, and Target Canker 

Forest Service Infection of Black Walnut Families 

Northeastern Forest 15 Years After Establishment 

Experiment Station In West Virginia 

Research Paper NE-674 

Thomas M. Schuler 
Abstract 

The survival, growth, and rate of target canker infection of 34 black walnut (Juglans 

nigra L.) families were evaluated 15 years after establishment in north-central West 

Virginia. The progenies originated at locations in Pennsylvania, West Virginia, 

Tennessee, and North Carolina. There were significant differences between 

families in survival, incidence of target canker infection, total height, and diameter 

at breast height. The North Carolina and Tennessee sources were less suitable for 

the growing conditions of the test site; local and slightly more northern sources 

seem more suitable. Near the northern extremity of the range of black walnut, 

maintaining a viable native population of this species and using local seed sources 

in artificial regeneration activities are recommended. 

The Author 

1 

THOMAS M. SCHULER, research forester, received a B.S. degree in forestry from 

Purdue University and an M.S. degree in silviculture from Colorado State University. 

In 1992, he joined the forest management research project at the Northeastern 

Forest Experiment Station's Timber and Watershed Laboratory at Parsons, West 

Virginia. 

I Manuscript received for publication 14 April 1993 

Northeastern Forest Experiment Station 

5 Radnor Corporate Center 

100 Matsonford Road, Suite 200 

Radnor, Pennsylvania 19087-8775 

July 1993 
Introduction Methods 

The range of black walnut (Juglans nigra L.) extends 

southward from Ontario, Canada, to Florida in the east 

and from South Dakota to Texas in the west. It grows 

on a variety of sites but does best in coves and well-drained 

bottoms in the Appalachians and Midwest (Williams 1990). 

Black walnut usually is found in small groups or as 

individual trees throughout the forest landscape. 

The wood of black walnut is highly valued for commercial 

purposes and, as a result, has been heavily utilized. In the 

Central Appalachian region, periodic removal of individual 

black walnut trees from the forest has virtually eliminated 

most good local seed sources. Those trees that remain 

are of poor form and do not indicate the potential for this 

species. Evidence suggests that black walnut grew on sites 

up to 3,000 feet in elevation with the best development on 

limestone-in:' ~enced soils. The reestablishment of this 

species to the range of sites it previously inhabited likely 

will occur only with management intervention. 

As might be expected from its extensive natural range, 

black walnut has considerable genetic variation related to 

geographic origin (Bey 1980; Waite and others 1988). This 

variation expressed in growth characteristics affords an 

opportunity for selecting and breeding superior trees. The 

objective of this study was to demonstrate the potential for 

producing genetically improved black walnut seed suited to 

growing conditions similar to those found in the Central 

Appalachian region. This can be done by establishing an 

open-pollinated walnut progeny test that can be converted 

into a seed orchard. In order for the seed orchard to 

develop with only the most suitable trees for this region, the 

first step must be to identify the best families within the test 

site. 

Since this study's inception, there has been an outbreak of 

the perennial target canker caused by the fungus Nectria 

galligena within the outplanting. N. galligena attacks many 

hardwoods and is particularly virulent in black walnut 

(Manion 1991). This endemic stem disease, first noted after 

the 1988 growing season, could become a major factor 

influencing the viability of the outplanting as a potential 

seed orchard. Cankers that develop on the stems and 

branches of trees can cause severe defects, stunting, or 

death. Development of cankers on the main stem can 

destroy the economic value of the tree, so any differences 

in resistance to N. galligena among families would be an 

important selection criterion. 

This paper reports the 15-year growth, survival, and 

resistance of target canker infection of black walnut 

progenies from Pennsylvania, West Virginia, Tennessee, 

and North Carolina that were planted in north-central West 

Virginia. The significance of these results to forest 

management activities in the Central Appalachian region is 

discussed. 

The black walnut outplanting was established on the 

Fernow Experimental Forest (3g02'N, 7g040'W), near 

Parsons, West Virginia. Mean annual precipitation on the 

Fernow is about 58 inches and is distributed evenly 

throughout the year. Mean annual temperature is 48OF and 

the length of the frost-free season is approximately 145 

days. Because of space limitations, the outplanting was 

divided into two areas. The first area is at an elevation of 

2,800 feet. The soil is a Belmont silt-loam derived from the 

Greenbrier limestone formation. The soil at the second area 

(elevation of 2,720 feet) is a Meckesville silt loam, which is 

colluvial in origin. However, the Meckesville soil also has 

some limestone influence as it lies just downslope from the 

limestone-derived Belmont series. The site index for both 

areas is between 80 and 85 for northern red oak. 

Both areas previously were forested with 65- to 70-year-old 

stands of mixed Appalachian hardwoods, including a high 

proportion of black cherry (Prunus serotina Ehrh.), yellowpoplar (Liriodendron tulipifera L.), northern red oak 

(Quercus rubra L.), sugar maple (Acer saccharum Marsh.), 

and white ash (Fraxinus americana L.). There were few 

scattered black walnut trees near both sites. In preparation 

for planting, the sawtimber and pulpwood were harvested 

and all remaining stems were felled. Brush and small stems 

were removed from the sites to facilitate planting. Both 

areas have northwest aspects with slopes not exceeding 10 

percent. 

The outplanting design is a randomized complete-block of 

open-pollinated families with six rectangular blocks laid out 

parallel with the contour of the area topography. Four 

blocks were installed on the Belmont site and two were 

installed on the Meckesville site. Trees were planted 6 feet 

apart, in rows 12 feet apart. Each of the 34 families (Table 

1) was represented in each of the six blocks by a five-tree 

plot. A border row of black walnut nursery stock was laid out 

around the perimeter of the area on each site; an additional 

buffer of planted yellow-poplar seedlings was established 

outside the black walnut. The sequence of the family plots 

on each block was randomized. Nursery 1-0 bare-foot 

seedlings from 34 families were planted on March 29 and 

30, 1976. Average seedling height was 1 .O foot and roats 

were pruned to 10 inches at planting time. Postplanting site 

treatment has included several herbicide applications and 

cuttings that were necessary to control competing 

herbaceous and woody vegetation. 

Total height of the tree, diameter at breast height (d.b.h.), 

survival, and incidence of target canker infection on the 

main stem were recorded every 5 years, most recently in 

January 1991, 15 years after establishment. Data were 

analyzed by analysis of variance using linear model 

procedures incorporating the randomized-block design.. Plot 

means of the surviving trees only were used for all anallyses 

(Bresnan and others 1992; Freese 1967; Rink and Kung 1991) 
Table I .-Family code, geographic origin, and mean family percent survival of 34 black 

walnut families 15 years after establishment in a north-central West Virginia progeny study 

Family 

code Oriain 

Latitude N Longitude W Percent O I O I survival 

Tucker, WV 

Greene, PA 

Berks, PA 

Lewis, WV 

Pendleton, WV 

Boone, WV 

Boone, WV 

Buncombe, NC 

Braxton, WV 

Monroe, WV 

Braxton, WV 

Alexander, NC 

Kanawha, WV 

Braxton, WV 

McDowell, NC 

Pocahontas, WV 

Greenbrier, WV 

Boone, WV 

Cumberland, PA 

Greenbrier, WV 

York, PA 

Monongalia, WV 

Summers, WV 

Cumberland, PA 

Upshur, WV 

Wayne, TN 

Pocahontas, WV 

Tucker, WV 

Chester, PA 

Morgan, TN 

Gilmer, WV 

Chester, PA 

Clay, WV 

Rowan, NC 

and were given equal weight regardless of the number of 

trees they represented. Where appropriate, regression 

analysis was used to estimate relationships between 

performance factors and family origin. A two-sample t test 

was used to test for differences in the evaluation criteria 

among the Meckesville and Belmont sites. Data were 

analyzed and tested for significance at the 5-percent level. 

The 7-year results as reported by Wendel and Dorn (1985) 

were used for contrast where appropriate. 

Table 1 summarizes identification information for each 

family. The distance between the most easterly and 

westerly family is approximately 600 miles. The distance 

between the most northern and southern family is about 350 

miles. There are two families from Tennessee, four from 

North Carolina, seven from Pennsylvania, and 21 from West 

Virginia, including two seed sources from the same county 

(Tucker) as the outplanting site. The outplanting is about 

100 miles north of the center of the collection area. Parenttree elevation was not recorded for most sources. Elevation 

estimates from location descriptions were uncertain and 

were not included in the analysis. 
Results 

Site Differences 

At the end of 15 growing seasons, trees growing on the 

Belmont site and those growing on the Meckesville site did 

not (differ significantly in survival, incidence of canker 

infection, total height, or d.b.h. 

Survival 

Fifteen years after the outplanting was established, overall 

survival averaged 71 percent. Survival by family ranged 

from 97 percent for the Tucker County, West Virginia, family 

(1 660) to 50 percent for the Rowan County, North Carolina, 

family (1582). Ranking of survival for all families is shown in 

Table 1. Analysis of variance indicated a contrast in family 

survival rate that was significant, indicating a meaningful 

genetic component in the variation. 

Regression analyses revealed no trends of mean family 

survival related to latitude or longitude of seed source. 

Families from three of the four North Carolina sources 

(1 588, 1589, and 1607) had above-average survival rates 

despite their southern origins from about 250 miles south of 

the test site. However, trees from both Tennessee families 

(1578, 1615) had mean family survival rates of 57 percent 

and 60 percent, respectively. The Tennessee families are at 

or near the southern limit and the most westerly in origin of 

the families represented in the study. 

Target Canker 

Analysis of variance indicated some contrast in the 

incidence of target canker infection that was significant. The 

target canker caused by the fungus N. galligena has 

become established in all blocks and all families within the 

study (Fig. 1). The rate of target canker infection for all 

blocks and all families was 53 percent. Family infection 

rates ranged from 18 percent for the Greenbrier County, 

West Virginia, family (1645) to 86 percent for the Braxton 

County, West Virginia, family (1630). The family with the 

second lowest rate of target canker infection also was from 

Greenbrier County (1646). Similar results for the two 

Greenbrier families may indicate the presence of a shared 

genetic component that pertains to the lower canker 

infection rates observed in these two families. Ranking of 

infection by family is shown in Table 2. 

Neither regression analysis nor plotting revealed correlations 

between mean canker infection rate and family geographic 

origin of families expressed as latitude, longitude, or both. 

Families from the same general latitude and longitude as 

the test site showed a wide range of canker infection. 

Families that were more widely separated in geographic 

origin from the test site had canker infection rates near 

the median of the distribution of infection rates. 

Figure 1. Black walnut plantation 15 years after 

establishment showing the presence of the target canker. 

The relationships between family infection rate and survival 

and d.b.h. also were examined. Neither relationship exhibited 

a substantial correlation (Table 3). It is expected that the 

target canker will become a principal cause of mortality in 

the future. And while individual trees may not yet be dying 

as a direct effect of target canker infection, the loss in 

potential monetary value of an infected tree is great if the 

target canker develops on the main stem (Fig. 2). 

Total Height and Stem Diameter 

Mean total height for all blocks and all families was 18.2 

feet (average: 22.9 to 13.0 feet). Ranking of height by family 

is shown in Table 4. Analysis of variance revealed a 

significant difference in family total height. The family with 

the tallest mean height (1660) was from a local seed source 

(Tucker County, West Virginia). 
Figure 2. Black walnut stem showing the typical effects of target canker infection caused 

by the fungus Nectria galligena. 

The family with the shortest mean total height, from 

Greenbrier County, West Virginia (1645), also was the 

family with the lowest observed target canker infection, 

indicating a possible negative relationship between growth 

rate or canopy position and canker infection. Further analysis 

of mean family height and canker infection did not show 

such a relationship (Table 3). There was no relationship 

between mean total height and geographic origin, though the 

family from Wayne County, Tennessee (1615), the most western 

and nearly the most southern in origin, ranked 33rd in mean 

family height (14. I feet). 

past 8 years, these same families have been growing at a 

rate of 1.8 feet per year. These results show that height 

growth rate is increasing and that family differences likely 

will become more apparent as well. 

Average d.b.h, for all blocks and families was 2.6 inches. 

For families, d.b.h. ranged from 3.3 inches for the Tucker 

County, West Virginia, family (1660) to 1.5 inches for the 

Greenbrier County, West Virginia, family (1645). Ranking of 

d.b.h. by family is shown in Table 5. Analysis of variance 

revealed a significant difference in mean family d.b.h. 

Height growth has averaged about 1.1 feet per year since As expected after 15 years, mean family d.b.h. and mean 

establishment. Average annual height growth after 7 years was total height are highly correlated (Table 3). This suggests 

even less at 0.8 foot. Height growth of the five fastest growing that height measurements, being the most time consuming, 

families after the first 7 years was only a little better could be dropped from future analyses. However, Bresnan 

at 0.9 foot per year. However, average annual height growth of and others (1992) showed that correlations between total 

the top five families after 15 years was 1.4 feet. For the height and d.b.h. declined after 20 growing seasons. 
Table2.-Ranking of 34 blackwalnut families 15 yearsafter 

establishment in north-central West Virginia according to 

mean family target canker infection of surviving trees 

Family 

code 

-- 

Origin 

Greenbrier, WV 

Greenbrier, WV 

Pocahontas, WV 

Pendleton, WV 

Berks, PA 

Braxton, WV 

Pocahontas, WV 

65:3 Boone, WV 

650 Summers, WV 

666 Greene, PA 

61 5 Wayne, TN 

632 Braxton, WV 

602 Cumberland, PA 

589 Alexander, NC 

Percent 

infected 

Lewis, WV 

Tucker, WV 

York, PA 

McDowell, NC 

Tucker, WV 

Clay, WV 

Boone, WV 

Towan, NC 

Morgan, TN 

Monroe, WV 

Chester, PA 

Chester, PA 

Monongalia, WV 

Upshur, WV 

Boone, WV 

Kanawha, WV 

Cumberland, PA 

Gilmer, WV 

Buncombe, NC 

Braxton, WV 

Table 3.-Correlation matrix of black walnut mean family 

survival, incidence of target canker infection, total height, 

and d.b.h. 15 years after establishment in north-central 

West Virginia. 

Item Survival Canker infection Total height 

Canker 0.07 

Total height 0.36 0.38 

D.b.h. 0.30 0.39 0.94 

Table 4.-Ranking of 34 black walnut families 15 years 

after establishment in north-central West Virginia by 

mean family total height of surviving trees 

Family Origin Total height 

Feet 

1660 Tucker, WV 22.9 

1600 Berks, PA 21.9 

1666 Greene, PA 21 .O 

1652 Boone, WV 21 .O 

1655 Kanawha, WV 20.7 

1589 Alexander, NC 20.3 

1625 Upshur, WV 20.2 

1649 Monroe, WV 20.1 

1641 Pocahontas, WV 20.0 

1638 Pendleton, WV 19.5 

1654 Boone, WV 19.5 

1642 Pocahontas, WV 19.4 

1627 Lewis, WV 19.2 

1628 Braxton, WV 19.2 

Monongalia, WV 

Morgan, TN 

Greenbrier, WV 

Braxton, WV 

Boone, WV 

McDowell, NC 

Buncombe, NC 

Braxton, WV 

Clay, WV 

Gilmer, WV 

Tucker, WV 

Chester, PA 

York, PA 

Chester, PA 

Cumberland, PA 

Cumberland, PA 

Rowan, NC 

Summers, WV 

Wayne, TN 

Greenbrier, WV 
Table 5.-Ranking of 34 black walnut families 15 years 

after establishment in north-central West Virginia, by 

mean family d.b.h. of surviving trees 

Family Origin 

Tucker, WV 

Berks, PA 

Kanawha, WV 

Greene, PA 

Upshur, WV 

Boone, WV 

Morgan, TN 

Alexander, NC 

Boone, WV 

Braxton, WV 

Pendleton, WV 

Pocahontas, WV 

McDowell, NC 

Monroe, WV 

Clay, WV 

Monongalia, WV 

Pocahontas, WV 

Boone, WV 

Buncombe, NC 

Lewis, WV 

Braxton, WV 

Braxton, WV 

Greenbrier, WV 

Gilmer WV 

York, PA 

Chester, PA 

Chester, PA 

Cumberland, PA 

Tucker, WV 

Rowan, NC 

Cumberland, PA 

Summers, WV 

Wayne, TN 

Greenbrier, WV 

Inches 

3.3 

3.2 

3.2 

3.1 

3.1 

3.0 

2.9 

2.9 

2.9 

2.9 

2.8 

2.8 

2.8 

2.8 

2.8 

2.7 

2.7 

2.7 

2.7 

2.6 

2.6 

2.5 

2.5 

2.4 

2.2 

2.2 

2.1 

2.1 

2.1 

2.1 

1.9 

1.9 

1.7 

1.5 

Discussion 

Superior families of this progeny test cannot be identified 

objectively 15 years after establishment but trends are 

beginning to emerge. Unlike the results obtained after 7 

years that documented significant differences only in family 

survival rate and stem diameter, the current results reveal 

significant differences in survival rate, total height, d.b.h., 

and rate of target canker infection. Using these four traits as 

criteria, a subjective overall index was developed for the 

families in this test. Multiple-trait selection is not uncommon 

and has been used by othersto evaluate two or more 

traits simultaneously (Sprague 1966; Bey and others 1974). 

To develop the index, the families were ranked in each 

category, allowing for ties, and then the rankings were 

summed for each family. The rankings are taken from 

Tables 1, 2,4, and 5 and provide a measure of relative 

fitness as to their suitability for the growing conditions 

similar to those found on the Fernow Experimental Forest. 

Because of the high correlation between total height and 

d.b.h. (Table 3), including both of these in the index 

essentially weights size at 50 percent of the total weight, 

survival at 25 percent, and target canker infection at 25 

percent. Other weights as well as other selection criteria 

could be used depending on the sought after characteristics 

and management objectives (Kucera and others 1975). 

The results of the multiple trait index are summarized in 

Table 6. The first trend made evident by this summary is the 

relatively poor performance of the more southern families. 

These families were represented by a total of six families 

from North Carolina and Tennessee. From this group, only 

one lies within the top half of the overall ranking. By 

contrast, past work has shown that seed sources from more 

southern locations, up to 200 miles south of the planting 

zone, tend to grow as fast or faster than local seed sources 

(Bey 1980; Bresnan and others 1992). However, Rink and 

Kung (1992) suggest this may not hold true for planting sites 

near the northern extremity of the natural range of a 

species. Black walnut growing at the latitude and elevation 

of the Fernow Experimental Forest does belong in this 

category (Williams 1990). Thus, study results indicate that 

expected performance gains did not occur when southern 

seed sources of black walnut were planted on the Fernow. 

The second trend made evident by the results of the 

multiple trait index is that superior families may be found 

locally or even north of the planting site. This is suggested 

by the geographic origin of the top four performing families. 

Of the four, two are northern sources from Pennsylvania 

and two are local sources. The two local sources consist of 

one family from Pendleton County, West Virginia, that is 

immediately next to the county of the study. The second 

local source is from the same county as the study. The top 

ranked family, from Berks County, Pennsylvania (1600), 

ranked second in survival, total height, and d.b.h. It was 

ranked first overall because it displayed the lowest canker 

infection rate of any of the faster growing or better surviving 

families. The family from Tucker County, West Virginia 

(1660), a local source, ranked first in survival, total height, 

and d.b.h. It was ranked second overall due to its average 

target canker infection rate. The third ranked family was 

from Greene County, Pennsylvania (1666). In addition, 

being a northern source, this family also is from a county 

that is in the extreme southwest corner of Pennsylvania and 

is adjacent to West Virginia. Thus, its origin is closer than 

many West Virginia families. 

Unfortunately, the role of elevation in combination with the 

latitude of the seed source cannot be evaluated. These 

attributes in part represent adaptations to cold 

temperatures. In areas where black walnut grows over a 

wide range of elevations, latitude alone is an inadequate 

indicator of cold hardiness. In West Virginia, black walnut 
Table 6.-Categorical and overall ranking of 34 black walnut families 15 years after 

establishment in north-central West Virginia 

Familv Canker Overall Overall 

code Origin Survival infection Height D.b.h. suma ranking 

Berks, PA 

Tucker, WV 

Greene, PA 

Pendleton, WV 

Alexander, NC 

Pocahontas, WV 

Boone, WV 

Braxton, WV 

Pocahontas, WV 

Greenbrier, WV 

Kanawha, WV 

Boone, WV 

Monroe, WV 

Lewis, WV 

Boone, WV 

Upshur, WV 

Braxton, WV 

McDowell, NC 

Morgan, TN 

Clay, WV 

Monongalia, WV 

Greenbrier, WV 

Buncombe, NC 

Braxton, WV 

Summers, WV 

York, PA 

Cumberland, PA 

Tucker, WV 

Chester, PA 

Chester, PA 

Gilmer, WV 

Wayne, TN 

Rowan, NC 

Cumberland, PA 

asurn of individual rankings for each family. 

grows at about the same latitude at elevations ranging from 

around 500 feet in the eastern panhandle to nearly 3,000 

feet in the Allegheny mountains. Further work in selecting 

superior black walnut families should include both of these 

environmental factors and their relationship to family 

characteristics. 

The top ranking families and their viability as components of 

a potential seed orchard cannot yet be determined. For 

recommendations to be valid, it must be assumed that the 

number of individual trees infected with the target canker 

will not continue to increase significantly. In Michigan, rates 

of black walnut growth were 30 percent less in infected 

versus uninfected trees (Thomas and Hart 1986). In this 

study, target canker infection was first noted 13 years after 

establishment and may have been too recent to evaluate. 

Thus, due to the high ranking performance of two local 

sources in this study, it would seem appropriate to engage 

in management activities that will preserve local seed 

sources for black walnut near the northern range of this 

species. Continued overcutting of local stock may result in a 

loss of black walnut adaptations to an environment that 

could not be easily replaced by more southern sources. 

Forest managers should guard against reducing the natural 

range of any species. As such, managers of northern black 

walnut regions should maintain a viable native black walnut 

population and use local seed sources in plantations and in 

artificial regeneration activities. Perhaps the most prudent 

action would be to identify any remaining good local black 

walnut trees so they can be protected as future seed 

sources for use in artificial regeneration. 
Literature Cited 

Bey, Calvin F. 1980. Growth gains from moving black 

walnut provenances northward. Journal of Forestry. 

78(10): 640-645. 

Bey, C.F.: Kung, J.H.; Kucera, J.M. 1974. Multiple-trait 

selection in black walnut (Juglans nigra L.). In: 

Proceedings Joint AFFRAY Meeting S.02.04.1-3, session 

II; Stockholm, Sweden. Stockholm, Sweden: Department 

of Forest Genetics, Royal College of Forestry: 117-128. 

Bresnan, Daniel F.; Geyer, Wayne A.; Lynch, Keith D.; Rink, 

George. 1992. Black walnut provenance performance 

in Kansas. Northern Journal of Applied Forestry. 9(2): 

41-43. 

Freese, Frank. 1967. Elementary statistical methods for 

foresters. Agric. Handb. 317. Washington, DC: U.S. 

Department of Agriculture. 87 p. 

Kucera, James M.; Bey, Calvin F.; Kung, Fan H. 1975. 

Genetic gain for five traits in black walnut. In: 

Proceedings, 9th central states tree improvement 

conference; 1974 October 10-1 1; Ames, IA. Wooster, 

OH: Ohio Agriculture Research and Development 

Center: 112-1 19. 

Manion, Paul D. 1991. Tree disease concepts. Englewood 

Cliffs, NJ: Prentice-Hall. 402 p. 

Rink, George; Kung, Fan H. 1991. Height and diameter 

variation in twelve white ash provenancelprogeny 

tests in eastern United States. In: Proceedings, 8th 

central hardwood forest conference; 1991 March 3-6; 

University Park, PA. Gen. Tech. Rep. NE-148, Radnor, 

PA: U.S. Department of Agriculture, Forest Service, 

Northeastern Forest Experiment Station: 179-187. 

Sprague, G.F. 1966. Quantitative genetics in plant 

improvement. In: Frey, Kenneth J., ed. Plant breeding. 

Ames, IA. Iowa State University Press: 315-354. 

Thomas, C.S.; Hart, J.H. 1986. Relationship between year 

of infection, tree age, tree growth, and Nectria canker 

of black walnut in Michigan. Plant Disease. 70: 

1117-1121. 

Waite, C.E.; DeHayes, Donald H.; Turner, Jerry L.; Brynn, 

David J.; Baron, William A. 1988. Black walnut seed 

sources for planting in Vermont. Northern Journal of 

Applied Forestry. 5: 40-45. 

Wendel, G.W.; Dorn, Donald E. 1985. Survival and growth 

of black walnut families after 7 years in West Virginia. 

Res. Pap. NE-569. Broomall, PA: U.S. Department of 

Agriculture, Forest Service, Northeastern Forest 

Experiment Station. 6 p. 

Williams, Robert D. 1990. Black walnut. In: Burns, Russell 

M.; Honkala, Barbara H,, tech. coords. Silvics of North 

America: Volume 2. Hardwoods. Agric. Handb. 654. 

Washington, DC: US. Department of Agriculture: 

391 -399. 
Schuler, Thomas M. 1993. Survival, growth, and target canker infection 

of black walnut families 15 years after establishment in West Virginia. 

Res. Pap. NE-674. Radnor, PA: U.S. Department of Agriculture, Forest 

Service, Northeastern Forest Experiment Station. 8 p. 

The survival, growth, and rate of target canker infection of 34 black walnut 

(Juglans nigra L.) families were evaluated 15 years after establishment in 

north-central West Virginia. The progenies originated at locations in 

Pennsylvania, West Virginia, Tennessee, and North Carolina. There were 

significant differences between families in survival, incidence of target canker 

infection, total height, and diameter at breast height. The North Carolina and 

Tennessee sources were less suitable for the growing conditions of the test 

site, local and slightly more northern sources seem more suitable. Near the 

northern extremity of the range of black walnut, maintaining a viable native 

population of this species and using local seed sources in artificial 

regeneration activities are recommended. 

I Keywords: Juglans nigra; artificial regeneration; progeny test; seed sources 

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