United States 

Department of 

Agriculture 

Forest 

Service 

Northern 

Region 

200 East Broadway 

P.O. Box 7669 

Missoula, MT 59807 

Report 04-12 June 2004

PREPLANT SOIL TREATMENT EFFECTS ON PRODUCTION OF 

DOUGLAS-FIR SEEDLINGS AT THE USDA FOREST SERVICE NURSERY, 

COEUR D’ALENE, IDAHO 

R. L. James, G. R. Knudsen, and M. J. Morra 

ABSTRACT 

Four preplant soil treatments were compared for their effects on presowing populations of potential soilborne 

pathogens (Fusarium and Pythium), potential antagonists (Trichoderma) and production of bare root western 

white pine seedlings at the USDA Forest Service Nursery, Coeur d’Alene, Idaho. The most effective treatment 

in reducing pathogen populations and producing high-quality seedlings was dazomet fumigation. Fallowing 

with periodic cultivation was less effective than fumigation but superior to incorporating winter-grown Brassica

cultivars (Dwarf Essex and Stonewall) prior to sowing the conifer crop. Applying a biological control 

formulation of Trichoderma harzianum did not have significant effects on seedling production. Dazomet 

fumigation provided the best means of ensuring production of high-quality seedlings at the nursery. Brassica

cover/green manure crops tested thus far at the nursery have been much less effective than chemical soil 

fumigation for soilborne disease management.. Fallowing may be an effective alternative to fumigation, 

particularly if organic matter is not added to fields between seedling crops. 

INTRODUCTION 

Bare root forest seedling production in the United 

States has often depended on preplant soil 

fumigation with chemical biocides to ensure 

production of high-quality stock for reforestation. 

Most nurseries have relied on methyl 

bromide/chloropicrin (MBC) mixtures for fumigation 

(Boone 1988; Cordell 1982; James 1989; Miller 

and Norris 1970; Smith and Bega 1966). However, 

methyl bromide is currently being phased out and 

scheduled for elimination as a soil fumigant by 

January 2005, primarily because it significantly 

contributes to deterioration of the ultraviolet lightprotective stratospheric ozone layer (Evans and 

Greczy 1995; Linderman et al. 1994; Shaheen 

1996; World Meterological Association 1995). 

Potential alternatives to methyl bromide and/or 

preplant chemical soil fumigation have recently 

been evaluated at some forest nurseries. 

The USDA Forest Service Nursery in Coeur 

d’Alene, Idaho has a history of using preplant soil 

fumigants to control soilborne plant pathogens and 

weeds. MBC had been the fumigant of choice 

(Boyd 1971; Williams 1976), but was replaced with 

dazomet (Basamid® granular) several years ago 

because it was as effective as MBC (James et al. 
2 

1990, 1996), but caused less environmental 

concerns. Dazomet is usually applied in the late 

summer or early fall prior to sowing the following 

spring (Kelpsas and Campbell 1994; Tanaka et al. 

1986). It is applied topically, cultivated into the soil 

and activated/sealed with overhead irrigation 

(Barnard et al. 1994; Chapman 1992; Shugert 

1989; Stenlund et al. 1997). The chemical 

becomes volatile when wetted and does not 

require covering with plastic polyethylene sheets 

like MBC (Chapman 1992; McIntyre et al. 1990; 

Shugert 1989). 

Although dazomet is effective at Coeur d’Alene 

(James et al. 1990, 1996), it is expensive, requires 

expert application, and still presents some 

potential environmental risks at the nursery. 

Therefore, growers have encouraged development 

of possible alternatives to all chemical soil 

fumigation. A series of tests have been conducted 

at the nursery to evaluate cost-effective, 

efficacious alternatives to chemical soil fumigation 

(James et al. 1993, 1994, 1996, 2004; Stone et al. 

1995). This report summarizes findings of tests 

involving four different soil treatments on the 

production of western white pine (Pinus monticola

Dougl.) seedlings at the nursery. 

MATERIALS AND METHODS 

Tests were initiated during the summer of 2000. 

Each treatment was replicated five times; 

treatment blocks were located within two sections 

of Field 9 in a complete randomized block design 

(figure 1). Each treatment block was 50 ft. in length 

and one seedling bed wide, with the exception of 

the dazomet treatments that were two bed widths 

because of application machinery requirements. 

The treatments were: standard dazomet soil 

fumigation (300 lbs./acre [335 kg/ha]) in 

September 2000, bare fallowing with periodic 

cultivation, and two Brassica green manure crops 

(cultivars “Dwarf Essex” and “Stonewall”) that were 

sown in the fall of 2000, grown over the winter, and 

incorporated into the soil 10 days before sowing in 

the spring of 2001. To evaluate potential effects of 

a biological control agent on these treatments, a 

formulation of Trichoderma harzianum (strain 

ThzID1) was added to half of the dazomet, fallow, 

and Brassica plots (resulting in 8 total treatments) 

just prior to sowing. 

Soil populations of potential pathogens in the 

genera Fusarium and Pythium and potential 

antagonists in the genus Trichoderma were 

assayed prior to sowing. Samples were collected 

from within each replicate plot; three collections 

within each plot were collected and mixed together 

to represent a single sample. Each collection 

consisted of a soil core taken to a depth of about 8 

inches (20 cm). Soil was placed in plastic bags, 

kept refrigerated and transported to the laboratory 

for analysis.

. Figure 1. Plot layout in Field 9 for testing effects of preplant soil 

treatments on production of western white pine seedlings – USDA 

Forest Service Nursery, Coeur d’Alene, Idaho 
3 

Standard soil dilutions (Hildebrand and Dinkel 

1988, James et al. 1990, 1996, Stone et al. 1995) 

were conducted to estimate populations of 

Fusarium, Trichoderma, and Pythium spp. Soil 

from each sample was initially sieved (2 mm sieve) 

to remove rocks, pieces of organic matter, and soil 

aggregates. From each sample, an approximate 5 

g subsample was oven-dried at about 100o

C for at 

least 24 h until sample weight stabilized. Oven-dry 

weight was then calculated to provide a standard 

for sample comparison. For assays of Fusarium

and Trichoderma populations, 0.05 g of field-moist 

soil was combined with 10 ml of 0.3% water agar 

(WA) and thoroughly mixed. One mililiter of 

solution was placed on each of three plates of 

selective agar medium for Fusarium and closelyrelated fungi (Komada 1975) and spread uniformly. 

Trichoderma propagules were also enumerated on 

Komada’s medium because it readily supports 

growth of this fungus unless the medium is 

amended with benomyl or lithium chloride. Plates 

were incubated for 7 days at about 24o

C under 

diurnal cycles of cool, fluorescent light. Fusarium

and Trichoderma colonies were identified by their 

morphology on the selective medium; populations 

were expressed as number of colony-forming units 

(cfu) per g of oven-dried soil (it was assumed that 

each fungal colony originated from one propagule). 

Selected Fusarium isolates were transferred to 

carnation leaf agar (Fisher et al. 1982) and potato 

dextrose agar (PDA) for identification to species 

using the taxonomy of Nelson et al. (1983). 

Isolates of Trichoderma were not identified to 

species. 

For assays of Pythium populations, 0.5 g of soil 

was combined with 10 ml of 0.3% WA. One mililiter 

of solution was placed on each of three plates 

containing another selective medium consisting of 

V-8 juice agar amended with the antibiotics 

pimaricin, rifamycin, and ampicillin and the 

fungicide penta-chloronitrobenzene (James et al. 

1990, 1996; Stone et al. 1995). Plates were 

incubated in the dark at about 24o

C for 3 days. 

Pythium colonies were identified on the basis of 

their diameter after 3 days (15-20 mm), feathery 

margin, and growth within rather than superficially 

on the agar surface. Populations were expressed 

as cfu/g of oven-dried soil. Selected Pythium

isolates were transferred to PDA for identification 

using the taxonomy of Waterhouse (1968). All 

plots were sown during early May, 2001 with the 

same seedlot of western white pine using standard 

nursery procedures and covered with hydro-mulch. 

After seedling emergence was deemed nearly 

complete (late July), three sampling sub-plots 

(0.5 m2

) were installed within each replicate-plot; 

these subplots were located approximately 

equidistant from each other and concentrated 

within the center of each replicate-plot. Seedling 

emergence and post-emergence damping-off were 

determined in each sub-plot in July; selected 

damped-off seedlings were collected for laboratory 

analysis of associated pathogens. At the end of the 

first growing season (October), seedling density 

and disease were determined within each of the 

sub-plots. Selected diseased seedlings were again 

collected for laboratory analysis, which included 

thoroughly washing roots of diseased seedlings 

and incubating them on Komada’s medium and 

identifying associated organisms as described 

above for soil samples. 

At the end of the second growing season 

(November 2002), sample seedlings were carefully 

extracted from beds by hand for morphology 

measurements. Sample seedlings were located 

within inner seedling rows (to eliminate edge 

effects) and entire root systems were included with 

each seedling. Fifty “average” seedlings were 

collected from each replicate plot. Seedlings were 

transported to the laboratory for measurement. 

Seedling height (from basal cotyledon scar to the 

tip of the terminal bud), diameter (just above the 

groundline) and root mass (oven-dry weight of all 

roots below the groundline) were determined for 

each sample seedling. Seedling heights, 

diameters, and root masses were compared 

among the treatments with an analysis of variance. 

Significant differences (P=0.05) in these three 

morphology categories were located using the LSD 

procedure. 

RESULTS 

Presowing soil populations of Fusarium, Pythium

and Trichoderma spp. within treatment plots are 

summarized in table 1. The lowest Fusarium

populations were in the dazomet treatment areas, 

followed by fallow plots; much higher populations 

were in the two Brassica treatment areas, with 

Dwarf Essex plots being the highest. Pythium

populations had similar trends with highest 

populations in the Brassica plots. Trichoderma

pop-ulations, including those isolates added just 

prior to sowing, were generally high in all plots 

except the dazomet treatments. Ratios of 

Trichoderma to Fusarium populations, which may 

roughly estimate potential disease 

suppressiveness (James et al. 1990, 1996; 

Papavizas 1985), were highest for the dazomettreated plots (table 1). 
4 

Table 1. Effects of selected preplant soil treatments on presowing soil populations of Fusarium, 

Trichoderma, and Pythium spp. at the USDA Forest Service Nursery, Coeur d’Alene, Idaho. 

Colony-forming Units/g Oven-dry Soil1

Treatment Fusarium Trichoderma2 Pythium 

Dazomet 56 [0-134] 638 [67-2223] 4 [0-33] 

Fallow/Cultivation 527 [338-803] 1350 [737-1744] 173 [0-408] 

Dwarf Essex 1211 [471-1965] 1568 [479-2479] 290 [0-481] 

Stonewall 889 [67-1814] 1620 [942-2160] 445 [216-612] 

1

Values in bold are means; ranges are in brackets; means are from 5 replicate plots per treatment. 

2 Trichoderma/Fusarium ratios: Dazomet [11.40], Fallow [2.56], Dwarf Essex [1.29], Stonewall [1.82]; 

the higher the ratio the greater potential for disease suppressiveness. 

Four Fusarium species were isolated from soil in 

pre-sowing assays (table 2). By far the most 

prevalent species was F. oxysporum Schlecht., 

which comprised more than 75% of the population. 

Other species included F. equiseti (Corda) Sacc., 

F. sporotrichioides Sherb. and F. solani (Mart.) 

Appel & Wollenw. Two species of Pythium were 

routinely isolated from nursery soil: P. irregulare 

Buisman and P. ultimum Trow. 

Emergence, survival, first-year height growth and 

disease severity of seedlings are summarized in 

table 3. The two Brassica treatments had 

deleterious effects on seedling production during 

the first growing season. Fewer and smaller 

seedlings were produced in plots with incorporated 

Brassica crops. More and taller seedlings were 

produced in dazomet-treated plots. First-year 

disease was low in all treatments. Diseased 

seedlings initially turned chlorotic and later necrotic 

(figure 2). Fusarium oxysporum was isolated from 

all sampled diseased seedlings. 

Effects of the soil treatments on height, diameter 

and root mass of 2-0 seedlings are summarized in 

table 4. Data comparisons for the four preplant soil 

treatments without considering bio-control 

amendments are collated in table 5. The only 

significant treatment effects were taller seedlings in 

the dazomet-treated plots. No differences were 

found among other treatments and biocontrol 

amendments did not significantly affect seedling 

growth. However, treatments may have affected 

seedling density (data not taken) among plots by 

the end of two growing seasons (figure 3).

Table 2. Fusarium species isolated from soil during population assays at the USDA Forest 

Service Nursery, Coeur d’Alene, Idaho. 

Fusarium Species 

Number of 

Isolates Assayed 

Percentage of 

Isolates 

Fusarium oxysporum 186 77.8 

Fusarium equiseti 32 13.4 

Fusarium sporotrichioides 20 8.4 

Fusarium solani 1 0.4 
5 

Table 3. Effects of selected preplant soil treatments on white pine seedling emergence and 

first-year survival, disease and height at the USDA Forest Service Nursery, Coeur d’Alene, Idaho1

. 

Number of seedlings per 0.5m2

Treatment2 Emergence Survival Disease 

Seedling 

Height (cm) 

Dazomet [NoBC] 81.8 [53-119] 80.8 [51-122] 3.1 [0-5] 4.4 [3.9-6.0] 

Dazomet [+ BC] 50.5 [16-105] 50.5 [15-107] 3.0 [1-5] 4.3 [3.4-5.1] 

Fallow [NoBC] 21.0 [14-31] 19.4 [12-28] 1.0 [1-7] 3.0 [2.8-3.3] 

Fallow [+ BC] 29.2 [19-52] 27.4 [17-49] 1.3 [1-7] 3.3 [2.8-3.7] 

DEssex [NoBC] 9.3 [4-18] 9.0 [3-17] 0.5 [0-3] 2.7 [2.4-3.3] 

DEssex [+ BC] 9.0 [3-14] 8.2 [3-14] 0.7 [0-2] 2.9 [2.5-3.3] 

Stonewall [NoBC] 13.3 [5-19] 12.2 [4-17] 0.5 [0-4] 2.9 [2.5-3.3] 

Stonewall [+BC] 17.0 [4-49] 17.5 [3-46] 0.7 [1-3] 3.0 [2.6-3.3] 

1

 Values in bold are means; ranges are in brackets. Density based on number of seedlings within subplots 

measuring 0.5m2

 located within each replicate plot. 

2

 BC denotes biological control agent Trichoderma harzianum 

Figure 2. Mortality of 1-0 western white pine seedlings - USDA Forest Service Nursery, 

Coeur d’Alene, Idaho. Post-emergence damping-off symptoms are indicated by arrows. 
6 

Table 4. Effects of selected preplant soil treatments on height, diameter, and root mass of 2-0 

western white pine seedlings at the USDA Forest Service Nursery, Coeur d’Alene, Idaho1

. 

Treatment Height2 Diameter3 Root Mass4

Dazomet [NoBC] 7.4A 2.4A 0.43A 

Dazomet [+BC] 7.0A 2.4A 0.49A 

Fallow [NoBC] 4.9B 2.3A 0.46A 

Fallow [+BC] 6.4B 2.5A 0.52A 

DEssex [NoBC] 4.5B 2.5A 0.40A 

DEssex [+BC] 4.8B 2.4A 0.47A 

Stonewall [NoBC] 4.5B 2.2A 0.41A 

Stonewall [+BC] 5.1B 2.4A 0.38A 

1 Based on measuring 50 seedlings per replicated plot for each treatment. Within each column, means 

followed by the same capital letter are not significantly different (P=0.05) using LSD. 2

 Measured from the ground line to the tip of the terminal bud (cm). 3

 Measured just above the ground line (mm). 

4

 Based on oven-dry weight of roots at lifting (g). 

Table 5. Collated comparisons of western white pine seedling height, diameter, and root mass 

among different preplant soil treatments - USDA Forest Service Nursery, Coeur d’Alene, Idaho 

Treatment Height2 Diameter3 Root Mass4

Dazomet 7.2A 2.4A 0.46A 

Fallow 5.7B 2.4A 0.49A 

Dwarf Essex 4.6B 2.5A 0.44A 

Stonewall 5.1B 2.3A 0.39A 

All No BC 5.4A 2.4A 0.43A 

All +BC 5.8A 2.4A 0.47A 

1 Averages in the top part of the table compare collated values for treatments with and without addition of the biological 

control agent. Averages in the bottom part of the table compare collated values for all treatments with and without 

biological control agent. Within each column, means followed by the same capital letter are not significantly different 

(P=0.05) using LSD. 

2

 Measured from the ground line to the tip of the terminal bud (cm). 3

 Measured just above the ground line (mm). 

4

 Based on oven-dry weight of roots at lifting (g). 
7 

Figure 3. Preplant soil treatment effects on 2-0 

western white pine seedlings—USDA Forest 

Service Nursery, Coeur d’Alene, Idaho. Orange 

plastic stakes locate subplots used to determine 

seedling emergency, disease and first-year 

height. Seedling density may have been 

affected by treatments. 

DISCUSSION 

Preplant soil fumigation with chemical biocides has 

been important in production of bare root conifer 

seedlings at the USDA Forest Service Nursery in 

Coeur d’Alene, Idaho for many years (Boyd 1971; 

James et al. 1990, 1996; Williams 1976). Initially, 

methyl bromide/chloropicrin (MBC) mixtures were 

the fumigants of choice (Boyd 1971; Williams 1976 

), but dazomet subsequently replaced MBC. 

Dazomet provides excellent disease control 

(James et al. 1990, 1996), but is expensive and 

may cause environmental concerns. Recent efforts 

to develop alternatives to chemical fumigation at 

the nursery have resulted in mixed results. Bare 

fallowing for at least one year, especially coupled 

with periodic cultivation, has often provided a 

viable alternative to fumigation, but only if organic 

soil amendments are not added to soil prior to 

sowing (James et al. 1993, 1994, 1996; Stone et 

al. 1995). Tested organic amendments have 

included sawdust or composted sewage sludge 

(James et al. 1993, 1994, 1996, 2004; Stone et al. 

1995) and cover/green manure crops that are 

grown for a few months, chopped and tilled into the 

soil (James et al. 1996, 2004). All of these tend to 

result in soil population increases of potential 

pathogens and adversely affect seedling 

production. In addition, growers have recently 

grown sweet and field corn to maturity, and 

incorporated this biomass into soil to add organic 

matter needed to maintain desired soil tilth (James 

2000). When organic matter is added to nursery 

soil, soil microorganism activity greatly increases 

(Bloomberg 1963; Borken et al. 2002; Chen et al. 

1988; Linderman 1970). Unfortunately, enhanced 

microbial activity may result in large population 

increases of potential pathogenic fungi (Hamm and 

Hansen 1990; Hansen et al. 1990; James et al. 

1993, 1994, 1996, 2004; Stone et al. 1995). 

Although not all population increases may involve 

pathogens, sufficient pathogen buildup occurs to 
8 

usually adversely affect subsequent seedling 

production (Hansen et al. 1990; Hamm and 

Hansen 1990; James et al. 1996, 2004). With 

organic matter additions, preplant chemical soil 

fumigation is required to sufficiently lower 

pathogen populations and improve seedling 

production (Hansen et al. 1990; James 2000). 

Both cultivars of Brassica (Dwarf Essex and 

Stonewall) tested in this study caused buildup of 

pathogen populations when incorporated into soil. 

They also adversely affected production of western 

white pine seedlings. Apparently, the 

glucosinolates associated Brassica tissues were 

not sufficient to overcome the deleterious effects of 

enhanced organic matter on soil pathogens. In 

addition, amending soil with Trichoderma 

harzianum did not improve treatment effects on 

seedling production. The isolate of T. harzianum

used in this evaluation was previously effective in 

agricultural systems (Knudsen and Bin 1990; 

Knudsen et al. 1991) and has shown promise 

against F. oxysporum in forest seedling nurseries 

(Mousseaux et al. 1998). However, in our 

evaluation, this biocontrol agent apparently did not 

sufficiently suppress soil Fusarium activity enough 

to ameliorate the adverse effects of organic 

amendments on seedling production. 

To date, amending forest nursery soils with 

Brassica plant residues to control soilborne 

diseases has been disappointing. Several 

evaluations have consistently shown similar 

results: Brassica plant residues result in increased 

soil populations of pathogens that adversely affect 

conifer seedling production (Hansen et al. 1990; 

Hamm and Hansen 1990; James et al. 1996, 

2004). Efforts to improve efficacy of Brassica spp. 

by using different cultivars, covering with plastic 

tarps to concentrate pathogen-toxic chemicals, or 

adding biocontrol agents have not yet been 

effective in forest nurseries (James et al. 1996, 

2004). It is possible that other Brassica cultivars 

will prove more efficacious. Perhaps amending soil 

directly with Brassica meal containing very high 

glucosinolate concentrations may improve 

effectiveness (Chung et al. 2003). In any case, use 

of Brassica green manure crops cannot currently 

be recommended in forest nurseries in western 

North America. If other Brassica cultivars or 

materials show improved efficacy in the future, this 

recommendation may be changed. 

LITERATURE CITED 

Barnard, E.L., S.P. Gilly & E.C. Ash. 1994. An 

evaluation of dazomet and metam-sodium soil 

fumigants for control of Macrophomina 

phaseolina in a Florida forest nursery. Tree 

Planters' Notes 45(3):91-95. 

Bloomberg, W.J. 1963. Use of organic residues in 

forest nurseries. Canadian Department of 

Forestry, Forest Entomology and Pathology 

Branch. Bi-Monthly Progress Report 19(4):4. 

Boone, A.J. 1988. Soil fumigation in forest tree 

nurseries. Proceedings of the Southern Forest 

Nursery Association – 1988. pp. 33-38. 

Borken, W., A. Muhs and F. Beese. 2002. 

Changes in microbial and soil properties 

following compost treatment of degraded 

temperate forest soils. Soil Biology & 

Biochemistry 34:403-412. 

Boyd, R.J. 1971. Effects of soil fumigation on 

production of conifer nursery stock at two 

northern Rocky Mountain nurseries. USDA 

Forest Service, Intermountain Forest & Range 

Experiment Station. Research Paper INT-91. 

19p. 

Chapman, W. 1992. Alternative treatments to 

methyl bromide. In: Conference Proceedings: 

Southern Forest Nursery Association 1992:96-

103. 

Chen, W., H.A.J. Hoitink, F. Schmitthenner and 

O.H. Tuovinen. 1988. The role of microbial 

activity in suppression of damping-off caused by 

Pythium ultimum. Phytopathology 78:314-322. 

Chung, W.C., J.W. Huang, H.C. Huang and J.F. 

Jen. 2002. Effect of ground Brassica seed meal 

on control of Rhizoctonia damping-off of 

cabbage. Canadian Journal of Plant Pathology 

24:211-218. 

Cordell, C.E. 1982. Effective soil fumigation. In: 

Proceedings of the 1982 Southern Nursery 

Conference, Oklahoma City & Savannah, GA. 

USDA Forest Service, Southern Region. pp. 

196-201. 

Evans, G.R. and L.M. Greczy. 1995. Methyl 

bromide: the cure-all of the horticulture industry 

will be banned by 2001. When this happens, 
9 

what, if anything, will take its place. American 

Nurseryman 182(7):95-105. 

Fisher, N.L., L.W. Burgess, T.A. Toussoun and 

P.E. Nelson. 1982. Carnation leaves as a 

substrate and for preserving cultures of 

Fusarium species. Phytopathology 72:151-153. 

Hamm, P.B. and E.M. Hansen. 1990. Soil 

fumigation, cover cropping, and organic soil 

amendments: their effect on soil-borne 

pathogens and the target seedlings. In: Rose, R., 

S.J. Campbell and T.D. Landis (eds.). Target 

Seedling Symposium: Proceedings Combined 

Meeting of the Western Forest Nursery 

Associations. USDA Forest Service, Rocky 

Mountain Experiment Station. General Technical 

Report RM-200. pp. 174-180. 

Hansen, E.M., D.D. Myrold and P.B. Hamm. 1990. 

Effects of soil fumigation and cover crops on 

potential pathogens, microbial activity, nitrogen 

availability, and seedling quality in conifer 

nurseries. Phytopathology 80:698-704. 

Hildebrand, D.M. and G.B. Dinkel. 1988. 

Evaluation of methyl bromide, Basamid granular, 

and solar heating for preplant pest control for 

fall-sown eastern redcedar at Bessey Nursery. 

USDA Forest Service, Rocky Mountain Region, 

Timber, Forest Pest, and Cooperative Forestry 

Management. Technical Report R2-41. 13p. 

James, R.L. 1989. Effects of fumigation on soil 

pathogens and beneficial microorganisms. In: 

Landis, T.D. (tech. coord.). Proceedings: 

Intermountain Forest Nursery Association 

Meeting. USDA Forest Service, Rocky Mountain 

Forest and Range Experiment Station. General 

Technical Report GTR-184. pp. 29-34. 

James, R.L. 2000. Effects of a 2-year fallow period 

on soil populations of Fusarium, Trichoderma

and Pythium species after incorporating corn 

plant residues - USDA Forest Service Nursery, 

Coeur d’Alene, Idaho. USDA Forest Service, 

Northern Region, Forest Health Protection. 

Report 0-17. 11p. 

James, R.L., D.M. Hildebrand, S.J. Frankel, M.M. 

Cram and J.G. O'Brien. 1993. Alternative 

technologies for management of soil-borne 

diseases in bareroot forest nurseries in the 

United States. In: Sutherland, J.R. and R. Perrin 

(eds.). Diseases and Insects in Forest Nurseries. 

Proceedings of the second meeting of IUFRO 

Working Party S7.03.04. Institut National De La 

Recherche Agronomique. Les Colloques No. 68. 

pp. 237-246. 

James, R.L., D.M. Hildebrand, S.J. Frankel, M.M. 

Cram and J G. O'Brien. 1994. Alternative 

technologies for management of soil-borne 

diseases in bareroot forest nurseries in the 

United States. In: Landis, T. D. (tech. coord.). 

Proceedings: Northeastern and Intermountain 

Forest and Conservation Nursery Associations. 

USDA Forest Service. Rocky Mountain 

Research Station, General Technical Report 

RM-243. pp. 91-96. 

James, R.L., G.R. Knudsen and M.J. Morra. 2004. 

Preplant soil treatment effects on production of 

Douglas-fir seedlings at the USDA Forest 

Service Nursery, Coeur d’Alene, Idaho. USDA 

Forest Service, Northern Region, Forest Health 

Protection. Report 04- __. 15p. (In press). 

James, R.L., S. Metzger and C.J. Gilligan. 1990. 

Effects of soil fumigation on conifer seedling 

production at the USDA Forest Service Nursery, 

Coeur d’Alene, Idaho. USDA Forest Service, 

Northern Region, Forest Pest Management. 

Report 90-11. 18p. 

James, R.L., D.S. Page-Dumroese, S.K. Kimball 

and S. Omi. 1996. Effects of Brassica cover 

crop, organic amendment, fallowing, and soil 

fumigation on production of bareroot Douglas-fir 

seedlings - USDA Forest Service Nursery, Coeur 

d’Alene, Idaho. USDA Forest Service, Northern 

Region, Forest Health Protection. Report 96-6. 

10p. 

Kelpsas, B.R. and S.J. Campbell. 1994. Influence 

of mechanical incorporation method on dazomet 

distribution in conifer nursery soil. Tree Planters' 

Notes 45(2):53-57. 

Komada, H. 1975. Development of a selective 

medium for quantitative isolation of Fusarium 

oxysporum from natural soil. Review of Plant 

Protection Research (Japan) 8:114-125. 

Knudsen, G.R. and L. Bin. 1990. Effects of 

temperature, soil moisture, and wheat bran on 

growth of Trichoderma harzianum from alginate 

pellets. Phytopathology 80:724-727. 
10 

Knudsen, G.R., D.J. Eschew, L.M. Dandurand and 

Z.G. Wang. 1991. Method to enhance growth 

and sporulation of pelletized biocontrol fungi. 

Applied and Environmental Microbiology 

57:2864-2867. 

Linderman, R.G. 1970. Plant residue 

decomposition products and their effects on host 

roots and fungi pathogenic to roots. 

Phytopathology 60:19-21. 

Linderman, R., W. Dixon, S. Fraedrich and R.S. 

Smith, Jr. 1994. Alternatives to methyl bromide: 

assessment of research needs and priorities for 

forestry, nursery, and ornamental crops. Tree 

Planters' Notes 45:43-47. 

McIntyre, B.W., K.M. Durand, R. Anderson and W. 

Heartsfield. 1990 . Field trial with Basamid® as a 

soil fumigant in nursery seedbeds. American 

Pulpwood Association, Technical Release 90-R53. 2p. 

Miller, W.O. and M.G. Norris. 1970. A new review 

of soil fumigation practices for use in forest 

nurseries. Down to Earth 26(3):9-12. 

Mousseaux, M.R., R.K. Dumroese, R.L. James, 

D.L. Wenny and G.R. Knudsen. 1998. Efficacy 

of Trichoderma harzianum as a biological control 

of Fusarium oxysporum in container-grown 

Douglas-fir seedlings. New Forests 15:11-21. 

Nelson, P.E. T.A. Toussoun and W.F.O. Marasas. 

1983. Fusarium species: an illustrated manual 

for identification. The Pennsylvania State 

University Press, University Park. 193p. 

Papavizas, G.C. 1985. Trichoderma and 

Gliocladium: biology, ecology, and potential for 

biocontrol. Annual Review of Phytopathology 

23:23-54. 

Shaheen, L. 1996. Potential loss of methyl bromide 

to prompt changes in Clean Air Act. Pest Control 

64(5):68,74. 

Shugert, R. 1989. Basamid-update. In: Combined 

Proceedings of the International Plant 

Propagators' Society 38:525-526. 

Smith, R.S., Jr. and R.V. Bega. 1966. Root 

disease control by fumigation in forest nurseries. 

Plant Disease Reporter 50:245-248. 

Stenlund, D.L., J. Juzwik, R.R. Allmaras and S.M. 

Copeland. 1997. Incorporation of surface-applied 

materials by tillage implements. In: Landis, T.D. 

and J.R. Thompson (tech. coords.). National 

Proceedings: Forest and Conservation Nursery 

Associations. USDA Forest Service, General 

Technical Report. PNW-GTR-419. pp. 29-30. 

Stone, J.K., D.M. Hildebrand, R.L. James, S.M. 

Frankel and D.S. Germandt. 1995. Alternatives 

to methyl bromide for control of soil-borne 

diseases in bare root forest nurseries. In: 

Proceedings: Annual International Research 

Conference on Methyl Bromide Alternatives and 

Emissions Reductions. November 6-8, 1995, 

San Diego, CA. Methyl Bromide Alternatives 

Outreach, US Environmental Protection Agency 

and US Department of Agriculture. pp. 77-1 – 

77-4. 

Tanaka, Y., K.W. Russell and R.G. Linderman. 

1986. Fumigation effects on soil-borne 

pathogens, mycorrhizae, and growth of Douglasfir seedlings. In: Proceedings of the Western 

Forest Nursery Council Meeting, Tumwater, WA. 

12p. 

Waterhouse, G.M. 1968. The genus Pythium

Pringsheim. Commonwealth Mycological 

Institute, Kew, Surrey, England. Mycological 

Papers No. 110. 70p. 

Williams, R.E. 1976. Response of selected soil 

fungi to fumigation at the 

Coeur d'Alene Nursery. USDA Forest Service, 

Northern Region, Forest Environmental 

Protection. Report 76-2. 8p. 

World Meteorological Association. 1995. Scientific 

assessment of ozone depletion: 1994 executive 

summary. Global Ozone Research and 

Monitoring Project Report No. 37. Global Ozone 

Observing System, Geneva, Switzerland. 36p. 

R.L. James is Plant Pathologist, USDA Forest Service, Northern Region, Forest Health Protection. Address: USDA Forest 

Service, 3815 Schreiber Way, Coeur d’Alene, ID 83814; email rjames@fs.fed.us. G.R. Knudsen and M.J. Morra are with 

the Soil Science Division, University of Idaho, Moscow 83844-2339; email: G.R. Knudsen: microbes@moscow.com; 

M.J. Morra: mmorra@uidaho.edu.