North Dakota State University * Dickinson Research Extension Center
1133 State Avenue, Dickinson, ND 58601 Voice: (701) 483-2348 FAX: (701) 483-2005


root.jpg (9162 bytes)

 

DIAGNOSIS AND MANAGEMENT
OF ROOT DISEASE
IN DRYLAND WHEAT
IN WESTERN NORTH DAKOTA


 

R.O. Ashley, Area Extension Specialist/Cropping Systems, Dickinson Research Extension Center, Dickinson, ND
M.P. McMullen, Extension Plant Pathologist, NDSU, Fargo, ND
P.M. Carr, Agronomist, Dickinson Research Extension Center, Dickinson, ND
J.A. Staricka, Soil Scientist, Williston Research Extension Center, Williston, ND
E.D. Eriksmoen, Agronomist, Hettinger Research Extension Center, Hettinger, ND
B. Schmidt, Mercer County Agent, Beulah, ND
D. Barondeau, Hettinger County Agent, Mott, ND
P. Carpentier, McLean County Agent, Washburn, ND
K. Brown, Divide County Agent, Crosby, ND
K. Eraas, McHenery County Agent, Towner, ND

Summary

Western North Dakota spring wheat and durum producers commonly plant into ground previously planted to wheat (Triticum aestivum L.), durum (Triticum turgidum L. Durum Group), or barley (Hordeum vulgare L.). The objective of this project was to demonstrate the extent that root diseases affect yield and quality of wheat in continuous wheat sequences and the effect that crop rotations have on reducing root disease. Field demonstrations were initiated at eight locations in western North Dakota. Methyl bromide fumigant was used in plots to control fungal root diseases. Root disease ratings were consistently lower in fumigated plots than in natural (non-fumigated) soil plots. Under continuous wheat sequences, yields from fumigated plots were 20% to 42% greater than from wheat grown in natural soil plots. Grain protein and test weight were often greater from fumigated than natural soil plots. When wheat was grown in fields having a two-year break from cereals, yields in the fumigated plots were not significantly different compared to natural soil plots. No significant differences in root rot ratings were found between treatments in wheat following a two-year break with non-cereal crops. Plots which included rotational, non-host crops for wheat and barley root pathogens, produced wheat yields nearly equal to fumigated plots yields.

Introduction

The flexibility allowed producers by the Federal Agriculture Improvement and Reform (FAIR) Act of 1996 and favorable prices for hard red spring wheat, durum, and barley in 1996 and 1997 prompted many western North Dakota producers to abandon summer fallow and initiate continuous cropping of these cereal grains. Statewide, North Dakota producers in 1997 seeded nearly 62% of their wheat acres on fields that were either in wheat or barley the previous year (McMullen, 1998). In western North Dakota, of the known previous crops reported in this study, 75% of the wheat grown had been in fields where wheat was grown the previous year.

Research conducted by North Dakota State University (NDSU) (Stack and McMullen, 1995) and Canadian (Ledingham, et. al., 1973; Mathieson, 1943; Butler, 1961) scientists suggests that root and crown diseases reduce yields on an average of between five and ten percent. In continuous cereal and cereal fallow rotations, yields are commonly lower than can be expected based on available soil moisture and growing season precipitation. Cook (1990) found over a 15-year period that when root and crown diseases were controlled with fumigation in continuous winter wheat rotations, an average 70% yield increase could be expected. A one-year break and two-year break between wheat crops produced a 22% and 7% yield increase, respectively, for fumigated compared to non-fumigated plots. Producers are encouraged to incorporate crop rotations into their farming practices. Crop rotations have been shown to reduce problems with insects, weeds, and diseases while improving yields and quality of subsequent crops (Black and Siddoway, 1975). Many producers do not fully realize the extent of yield and quality losses as a result of root and crown disease problems.

This project demonstrated the impact of root diseases on dryland wheat and durum wheat in western North Dakota and the role that crop rotation can play in their control.

Materials and Methods

Eight locations with a crop rotation history (Table 1) of either continuous cereal grain or cereal grain with a two year break of a crop other than wheat or barley were selected. Agronomic practices, estimated stored soil water and precipitation were recorded (Table 2). Stored soil water was estimated at the time of fumigation with the use of a Paul Brown Soil Moisture Probe (Brown and Carlson, 1990). Precipitation was recorded by producers for the on-farm locations and by the North Dakota Agricultural Weather Network (NDAWN) at the Dickinson Research Extension Center and at the Williston Research Extension Center locations.

A randomized complete block design with four replications was used at all locations except at Dickinson where a split block design was used. Each plot was 300 ft2 (28 m2). Plots to be fumigated were covered with a six mil plastic sheet, edges buried in trenches four to six inches deep (Figure 1) to seal the covered area, and methyl bromide was metered through plastic hoses at the rate of one pound per 100 ft2 (50g m-2). The fumigated plots remained covered for 48 to 72 hours after which time the plastic was removed (Figure 2). Non-fumigated or natural soil plots served as checks. After the plastic was removed, producers farmed through the fumigated and natural soil plots with their normal management practices (Figure 3).

Root samples were collected from plots between Haun stage 5 and 11.4 and again at Haun stage 14.5. Samples were carefully washed by hand. A visual evaluation of the first group of samples was completed at the Dickinson Research Extension Center. Root counts, evaluation of subcrown internodes, Take-all, and Rhizoctonia symptoms were noted. The second group was sent to the NDSU plant clinic for culture plate evaluation and a visual evaluation of root mass, root color, and extent of root rot lesions on the subcrown internode. Soil moisture was measured in fumigated and natural soil plots at the Williston Research Extension Center location with a neutron probe once a week.

Head density and mature plant height measurements were made at harvest. Except at Williston, yield samples were harvested from each plot by hand from an area four rows wide by 8 ft (2.4 m) long, bagged, threshed, and yield and quality factors measured. At Williston samples were machine harvested from an area 4 ft (1.2 m) wide by 16 ft (4.9 m) long. Protein was analyzed with an NIR analyzer at Southwest Grain Inc., Dickinson, ND.

All data was statistically analyzed using SAS Statistical software version 6.12 (SAS Institute Inc., 1996).

Results and Discussion

Yield and Quality

Significant differences in grain yield were detected between fumigated and natural soil plots in continuous cereal rotations except at Regent and Williston locations (Table 3). Wheat and durum grain yields were 34% greater at Dickinson (Table 4) to 42% greater at Hazen from fumigated plots compared to natural soil plots when grown in continuous wheat rotations and available water was 12 inches or more (Table 2 and Table 3). When less than 12 inches of water was available, grain yields were 20 to 26% greater from fumigated plots compared to natural soil plots when grown in continuous wheat rotations.

When two consecutive years of non-host crops were introduced into the rotation, fumigated plot grain yields were nearly the same as natural plot grain yields. Continuous wheat grain yields from fumigated plots at Amidon and Beach in 1997 were 40% greater than from natural soil plots (Ashley et. al., 1997) but with two years of non-host crops in the crop sequence, fumigated and natural soil plots yields were almost equal. The experimental design at Dickinson allowed for a direct statistical comparison between rotations but not between fumigation and natural soil plots (Table 4). When pea or millet was included in the rotation after oat, a significant improvement in grain yield of 20 to 30% occurred compared to the wheat-oat-wheat-wheat rotation. Oat is generally thought to not be a host or a poor host to many of the root pathogens that attack wheat. No significant improvement in yields was observed at Dickinson between rotations when the rotations were overlaid by fumigation.

Total above ground biomass was measured at the Williston site (data not shown). This amounted to 1519 pounds/acre (1702 kg/ha) more from the fumigated plots than from the natural soil plots. This difference was significant at the 0.05 level.

Test weight and protein content often improved with fumigation or when two consecutive years of non-cereal crops were included in the rotation (Table 3 and Table 4).

The hard red spring wheat variety, 2371, planted at Regent exhibited symptoms similar to those caused by the Septoria fungus. However upon close examination of chlorotic spots found on these plants (Figure 4), Septoria was dismissed as being the cause. Some varieties of soft white wheat are known to be sensitive to methyl bromide treated soils and symptoms similar to those described by Cook (1998) were found on 2371. Slight chlorotic spotting was seen at Amidon on 2398.

Plant Length, Mature Plant Height, and Head Density

Plant length measured during the first wheat plant-root evaluation was significantly longer for plants grown on fumigated plots at Williston and Hazen locations (Table 5). Plant length tended to be longer when a two-year break in wheat crops occurred compared to the wheat-oat-wheat-wheat rotation at Dickinson (Table 6). The significant difference in plant height was maintained to maturity only at the Hazen location (Table 3).

Plant population counts were made only at Williston (625,000 plants/acre fumigated vs. 465,000 plants/acre natural soil plots) but differences between fumigated and natural soil plots were visibly apparent where this demonstration was conducted in fields having a history of continuous wheat (Figure 5).

Head density was significantly greater for fumigated plots compared to natural soil plots in continuous cereal rotations except at Crosby (Table 3). In rotations where wheat was preceded with non-host crops for two years, no significant differences were detected in head density (Table 3 and Table 4).

Root Assessments

Significant differences were noted in the subcrown internode rating for the Garrison location during the initial root evaluation (Table 5) and at the Hazen, Crosby, and Williston locations for root evaluations done at the soft dough stage (Table 7). There was a trend towards more root rot lesions on subcrown internodes taken from natural soil plots than from fumigated soil plots at both early Haun stages and Haun stage 14.5. There were no significant differences in subcrown internode ratings at Dickinson at either the initial (Table 8) or at the soft dough stage (Table 9). Cochliobolus santivus and Fusarium are thought to primarily manifest symptoms on the subcrown internode and crown area of the plant (Wiese, 1987).

Rhizoctonia symptoms were often detected in continuous cereal rotations but were absent when non-cereals were included for two years between wheat crops or when fumigation was utilized to control root disease. Rhizoctonia and Pythium infections occur on smaller roots and rootlets rather than the subcrown internode and crown area of the plant, making detection difficult (Wiese, 1987).

Take-all caused by Gaeumannomyces graminis was not detected in any of the samples collected during these demonstrations.

Seminal and crown root counts were always greater on plants from fumigated than natural soil plots except at locations where a two-year break between host cereal crops in the rotation was used (Table 5). There was no significant difference in root counts between rotations at Dickinson for fumigated plots (Table 8). However there were significantly greater numbers of seminal and crown roots in rotations that incorporated a two-year break of oat and field pea or oat and millet compared to the single year of oat followed by two consecutive wheat crops.

Cochliobolus symptoms were detected in both fumigated and natural soil plots but Rhizoctonia symptoms were never detected in fumigated plots. Root mass was always larger and root color always whiter on plant samples from fumigated than from natural soil plots but not significantly whiter in rotations which included non-cereal crops the previous two years (Table 7 and Table 9).

Water-use

Water content of soils at the Williston Research Extension Center location was measured weekly with a neutron moisture gauge and water-use calculated (Table 10). Wheat grown on the fumigated plots tended to use more water earlier than wheat grown on natural soil plots. Water-use during the growing season in the fumigated plots was significantly greater in the 1 to 2 foot (0.3 to 0.6 m) depth than occurred in the natural soil plots. Water use by plants grown on the natural soil plots exceeded that of plants grown on the fumigated plots for the 0 to 1 foot (0.0 to 0.3 m) and the 1 to 2 foot (0.3 to 0.6 m) depths during the time period of July 15 to July 21. This corresponds with drier soils at these depths in the fumigated plots compared to the natural soil plots. The crop growing on the fumigated soils had essentially used all of the available water at these depths.

Implications of Demonstration

Rhizoctonia and Pythium are particularly sensitive to methyl bromide, and Fusarium to a lesser extent (Vanachter, 1979). In partial soil fumigation such as used in these demonstrations, sufficiently high concentrations for an extended period of time are not obtained to kill all fungi and microbial activity in the soil. Chloropicrin and fumigants containing sufficient concentrations of Chloropicrin injected into soils are known to be less selective and more detrimental to soil microbiology than methyl bromide. Methyl bromide's selectivity and relatively short after-effect may explain the subcrown internode ratings and the expected yield loss due to root disease. Further work is required to differentiate the yield loss cause by plant pathogens.

Root disease ratings were consistently lower in fumigated plots than non-fumigated plots when the field had a history of continuous wheat. When crop rotations included crops that are poor hosts to wheat root disease, wheat yield and quality was nearly the same from fumigated and natural soil plots.

Producers can expect reduced wheat and durum grain yields and quality when wheat or durum is grown in continuous wheat, durum, or barley rotations. Producers can also expect less straw returned to the soil by smaller and poorly tillered plants, typical of wheat with root disease. Less straw means less coverage, making soil more susceptible to water and wind erosion. This could eventually lead to a decline in soil health and productivity. Wheat plants with root disease are inefficient in utilizing water and nutrients, especially nitrogen. Also a crop with root disease can leave a wheat crop more vulnerable to weeds because diseased plants are less competitive.

Climatic conditions and crop rotations will affect the severity of disease. Dry conditions will reduce grain yield difference between fumigated and natural soil plots. Although soil fumigation is not economic for cereal growing, it does provide a valuable technique to demonstrate the potential productivity of soil. This demonstration has shown that crop rotations that include non-host crops will reduce the impact that root disease has on wheat and durum yields.

Cooperating Producers

The authors wish to thank the following producers for cooperating in conducting this demonstration. These cooperators shared their time, equipment, and knowledge in making this demonstration a success. Producers are: Sharold Geist, Hazen; August and Perry Kirschmann, Regent; Ernie Holzemer, Amidon; Mike Zook, Beach; Bruce Klabunde, Garrison; and Landy Bummer, Crosby. Also a thank you is extended to Southwest Grain for use of their NIR analyzer in determining grain protein.

Literature Cited:

Ashley, R.O., M.P. McMullen, E.D. Eriksmoen, B. Schmidt, D. Barondeau, D. Duerre, and K. Eraas. 1997. Diagnosis and management of root disease in dryland wheat in southwest North Dakota. Dickinson Research Extension Center Annual Report, 1997.

Black, A.L., and F.H. Siddoway. 1975. Dryland cropping sequences within a tall wheatgrass barrier system. Proceedings Regional Saline Seep Control Symposium, Montana Cooperative Extension Service Bull. 1132.

Brown, P.L., and G.R. Carlson. 1990. Grain yields related to stored soil water and growing season rainfall. Spec. Report 35. Mt. Agric. Exp. Mt. State Univ., Bozeman.

Butler, F.C. 1961. Root and foot rot disease of wheat. Sci. Bull. 77, Agric. Res. Inst. Wagga Wagga. N.S.W.

Cook, R.J. 1998. Personal communication.

Cook, R.J. 1990. Diseases caused by root-infecting pathogens in dryland agriculture. Adv. Soil Sci 13:215-239.

Ledingham, R.J., T.G. Atkinson, J.S. Horricks, J.T. Mills, L.J. Piening, and R.D. Tinline. 1973. Wheat losses due to common root rot in prairie provinces of Canada, 1969-71. Can Plant Dis Surv. 53: 113-122.

Mathieson, J.E. 1943. An estimate of loss in Manitoba from common root-rot in wheat. Sci Agric. 24:70-77.

McMullen, M.P. 1998. Effect of previous crop on tan spot and Fusarium head blight in wheat 1997 In Phytopahtology 88:S116.

SAS Institute, 1996. Release 6.12 ed. SAS Institute, Inc., Cray, N.C.

Stack, R.W., and M. McMullen. 1995. Root and crown rots of small grains. NDSU Extension Service Bull. PP-785.

Vanachter, V. 1979. Fumigation against fungi. pp 163-183. In D. Munson (ed.) Developments in Agricultural and Managed-Forest Ecology, 6, Soil Disinfestation. Laboratory of Phytopathology, Agricultural University, Wageningen, The Netherlands. Elsevier Scientific Publishing Company, Amsterdam.

Wiese, M.V. (ed.) 1987. Compendium of Wheat Diseases, 2nd ed. APS Press, St. Paul, MN.

Table 1. Cropping history1 of selected fields in western North Dakota.
Location

1997

1996

1995

1994

1993

1992

Amidon

soybean

fallow

hrsw

fallow

hrsw

fallow

Beach

field pea

corn

hrsw

hrsw

barley

hrsw

Crosby

durum

durum

durum

fallow

durum

fallow

Dickinson

hrsw

oat

hrsw

fallow

hrsw

fallow

Dickinson

field pea

oat

hrsw

fallow

hrsw

fallow

Dickinson

millet

oat

hrsw

fallow

hrsw

fallow

Garrison

durum

durum

durum

wheat

fallow

durum

Hazen

durum

durum

chem-fallow

durum

durum

durum

Regent

hrsw

hrsw

hrsw

hrsw

hrsw

hrsw

Williston

hrsw

hrsw

hrsw

hrsw

hrsw

hrsw

1 Cropping history: hrsw = hard red spring wheat; durum = durum wheat.

 

Table 2. Agronomic practices and water, 1998.
Location Cultivar Tillage system

Weed severity rating

Seed treatment

Estimated stored soil water
inches

Growing season precipitation
inches

Total available water
inches

Continuous wheat
Hazen Renville durum no-till hoe opener none Agsco DB Green/Double R (mancozeb + lindane + imazalil)

7.7

7.9

15.6

Crosby Monroe durum minimum-till low-mod RTU Vitavax Extra (carboxin + imazalil + Thiabendazole)

4.5

7.4

11.9

Williston Ernest hrsw no-till disc opener none none

3.3

6.2

9.5

Garrison Munich durum minimum-till hoe opener low none

3.3

7.0

10.3

Regent 2371 hrsw conventional hoe opener none Agsco DB Green/Double R (mancozeb + lindane + imazalil)

4.0

9.4

13.4

Two-year break between wheat crops
Beach Ben durum no-till
hoe opener
none none

7.7

7.1

14.8

Amidon 2398 hrsw no-till disc opener none RTU Vitavax Extra (carboxin + imazalil + Thiabendazole)

7.0

9.3

16.3

DREC Crop Rotation Study
Dickinson Trenton HRSW no-till disc opener none none

4.5

9.7

14.2

 

Table 3. Yield, test weight, protein, height, and head density of hard red spring wheat at selected locations in western North Dakota, 1998.
Location/Treatment

Head density
no./yd2

Height
inches

Yield
bu/a

Test weight
lb/bu

Protein
%

Continuous wheat
Hazen
Fumigated

439.9

37.1

39.3

59.0

14.2

Natural

296.4

34.0

27.6

57.7

13.1

Mean

368.1

35.5

33.5

58.4

13.7

CV%

15.7

1.3

11.8

0.6

3.5

LSD0.05

129.9

1.0

8.9

0.8

1.0

Crosby
Fumigated

450.0

31.8

44.7

60.6

10.5

Natural

321.9

31.3

37.3

60.1

9.0

Mean

386.0

31.5

41.0

60.4

9.7

CV%

19.2

3.7

7.4

0.8

4.8

LSD0.05

NS

NS

6.8

NS

1.1

Williston
Fumigated

524.9

34.9

45.4

57.9

16.8

Natural

346.4

34.4

37.6

58.1

16.3

Mean

435.7

34.7

41.5

58.0

16.6

CV%

10.4

2.3

9.2

1.7

2.2

LSD0.05

102.0

NS

NS

NS

NS

Garrison
Fumigated

614.7

34.8

46.1

59.0

14.4

Natural

412.0

33.2

37.0

57.9

14.8

Mean

513.4

34.0

41.6

58.4

14.6

CV%

11.0

4.8

9.2

0.9

3.2

LSD0.05

126.9

NS

8.6

NS

NS

Regent
Fumigated

626.9

32.6

52.0

56.5

15.1

Natural

485.9

35.7

49.6

55.5

14.8

Mean

556.4

35.9

50.8

56.0

15.0

CV%

9.2

2.7

2.3

0.9

0.7

LSD0.05

115.2

NS

NS

NS

0.2

Two year break between wheat crops
Beach
Fumigated

382.1

36.0

55.9

61.6

12.6

Natural

349.1

35.7

55.1

61.5

12.7

Mean

365.6

35.9

55.5

61.6

12.7

CV%

6.4

1.1

8.2

1.8

1.7

LSD0.05

NS

NS

NS

NS

NS

Amidon
Fumigated

461.3

30.4

53.9

61.1

13.2

Natural

420.8

30.3

57.8

60.3

13.6

Mean

441.1

30.4

55.9

60.7

13.4

CV%

4.2

3.3

10.7

1.1

2.9

LSD0.05

NS

NS

NS

NS

NS

 

Table 4. Yield, test weight, protein, height, and head density of hard red spring wheat at Dickinson, ND, 1998.
Rotation1

Head density

Height

Yield

Test weight

Protein

Fum

Nat

Fum

Nat

Fum

Nat

Fum

Nat

Fum

Nat

no./yd2

inches

bu/a

lb/bu

%

W-O-W-W

543

410

41.4

41.4

58.7

43.8

60.1

60.9

15.1

13.9
W-O-P-W

554

466

41.6

43.5

59.5

52.5

61.1

60.1

15.2

14.2
W-O-M-W

559

465

41.4

42.9

58.6

56.8

60.6

61.6

15.4

14.8
Mean

552

447

41.5

42.6

58.9

51.0

60.6

60.9

15.2

14.3
CV%

9.2

5.9

3.6

2.1

5.8

6.9

1.2

1.5

4.4

4.4
LSD0.05

NS

3.6

NS

1.1

NS

1.3

NS

NS

NS

NS
1 Rotation.
W-O-W-W = 1995 Wheat-1996 Oat hay- 1997 Wheat-1998 Wheat.
W-O-P-W = 1995 Wheat-1996 Oat hay-1997 Pea-1998 Wheat.
W-O-M-W = 1995 Wheat-1996 Oat hay-1997 Millet-1998 Wheat.

 

Table 5. Initial root and plant evaluations of wheat in various rotations in selected fields in North Dakota, 1998.
Location/ Treatment

Development stage
Haun

Length1
inches

Tillers
no.

Subcrown rating2

Seminal Root

Crown root

No of roots

Rhizoc3

No of roots

Rhizoc3

Continuous wheat
Hazen
Fumigated

5.5

18.8

2.9

0.2

5.8

0.0

10.3

0.0

Natural

4.9

14.3

1.4

0.3

4.6

0.4

6.0

0.3

Mean

5.3

16.6

2.2

0.2

5.2

0.2

8.1

0.2

CV%

4.5

3.3

16.2

55.0

4.6

76.1

12.1

37.5

LSD0.05

0.5

1.2

0.8

NS

0.3

0.3

2.2

0.1

Crosby
Fumigated

6.6

18.5

1.7

0.2

5.3

0.0

8.7

0.0

Natural

6.1

16.6

1.7

0.4

5.1

0.1

8.2

0.2

Mean

6.4

17.5

1.7

0.3

5.2

0.1

8.4

0.1

CV%

4.5

8.6

37.8

147

10.6

97.3

42.4

52.6

LSD0.05

NS

NS

NS

NS

NS

NS

NS

0.1

Williston
Fumigated

11.3

23.2

2.3

0.2

5.1

0.0

14.6

0.0

Natural

9.0

20.2

1.5

0.6

4.8

0.5

11.5

0.4

Mean

10.2

21.7

1.9

0.4

4.9

0.3

13.0

0.2

CV%

60.7

3.8

12.7

49.7

11.2

73.9

9.8

164

LSD0.05

NS

1.9

0.6

NS

NS

0.4

2.9

NS

Garrison
Fumigated

11.4

28.3

0.9

0.0

5.6

0.0

13.2

0.0

Natural

10.9

27.9

0.6

0.9

4.9

0.1

10.9

0.1

Mean

11.1

28.1

0.8

0.5

5.2

0.1

12.1

0.1

CV%

0.9

4.0

39.7

37.6

3.4

177

17.5

75.3

LSD0.05

0.2

NS

NS

0.4

0.4

NS

NS

NS

Regent
Fumigated

11.4

25.5

2.3

0.0

5.6

0.0

19.4

0.0

Natural

10.5

24.4

1.4

0.6

4.7

0.1

15.3

0.3

Mean

11.0

25.0

1.9

0.3

5.2

0.1

17.3

0.2

CV%

1.4

3.6

6.7

96.8

3.8

191

5.3

66

LSD0.05

0.4

NS

0.3

NS

0.4

NS

2.1

0.2

Two-year break between wheat crops

Beach
Fumigated

6.4

22.6

2.7

0.4

5.8

0.0

16.4

0.0

Natural

6.4

22.6

2.8

0.2

5.9

0.0

17.0

0.0

Mean

6.4

22.6

2.8

0.3

5.8

0.0

16.7

0.0

CV%

2.5

6.7

6.6

60.7

2.5

-

6.4

-

LSD0.05

NS

NS

NS

NS

NS

NS

NS

NS

Amidon
Fumigated

6.2

19.0

2.2

0.1

5.6

0.0

15.6

0.0

Natural

6.2

17.8

2.1

0.3

5.6

0.0

18.0

0.0

Mean

6.2

18.4

2.1

0.2

5.6

0.0

16.8

0.0

CV%

2.0

6.0

18.7

96.5

4.5

-

16.8

-

LSD0.05

NS

NS

NS

NS

NS

NS

NS

NS

1Length measured from the crown to the tip of the last fully extended leaf of the plant.
2 Subcrown internode rating, 0-4. 0= no infection, 1= less than 25% of internode infected, 2= 25-50% of internode infected, 3= 51-75% of internode infected, multiple lesions, and 4= 75-100% of internode infected, lesions coalesced.
3 Number of roots per plant which exhibited rhizoctonia symptoms.

 

Table 6. Wheat plant evaluation on July 3, 1998 at Dickinson, ND.
Rotation1

Development stage

Length2

Tillers

Fumigation

Natural

Fumigation

Natural

Fumigation

Natural

Haun

inches

number

W-O-W-W

10.7

9.9

33.0

33.1

1.5

0.7

W-O-P-W

10.7

10.1

32.2

34.0

1.5

1.3

W-O-M-W

10.8

10.3

32.3

33.5

1.3

1.3

Mean

10.7

10.1

32.5

33.5

1.4

1.1

CV%

1.5

2.6

4.0

4.3

19.2

23.3

LSD0.05

NS

NS

NS

NS

NS

0.4

1 Rotation.
W-O-W-W = 1995 Wheat-1996 Oat hay-1997 Wheat-1998 Wheat.
W-O-P-W = 1995 Wheat-1996 Oat hay-1997 Pea-1998 Wheat.
W-O-M-W = 1995 Wheat-1996 Oat hay-1997 Millet-1998 Wheat.
2 Length measured from the crown to the tip of the last fully extended leaf of the plant.

 

Table 7. Visual root scores for wheat at soft dough stage grown at select locations in North Dakota, 1998.
Location/Treatment

Subcrown1 internode rating

Color index2

Root mass3

Continuous wheat
Hazen
Fumigated

1.6

1.5

3.5

Natural

1.9

2.8

3.0

Mean

1.8

2.1

3.3

CV%

4.1

9.6

1.8

LSD0.05

0.2

0.5

0.1

Crosby
Fumigated

2.1

1.8

3.5

Natural

2.7

2.8

2.6

Mean

2.4

2.3

3.1

CV%

4.0

12.8

11.1

LSD0.05

0.2

0.6

0.8

Williston
Fumigated

2.6

2.6

3.0

Natural

3.4

3.1

2.5

Mean

3.0

2.9

2.8

CV%

6.1

17.4

2.6

LSD0.05

0.4

NS

0.2

Garrison
Fumigated

1.7

3.0

2.8

Natural

1.7

3.6

2.3

Mean

1.7

3.3

2.5

CV%

8.6

5.3

11.5

LSD0.05

NS

0.4

NS

Regent
Fumigated

1.6

2.1

3.3

Natural

2.0

2.5

2.8

Mean

1.8

2.3

3.0

CV%

15.1

7.6

16.7

LSD0.05

NS

NS

NS

Two-year break between wheat crops
Beach
Fumigated

1.4

2.3

3.4

Natural

2.0

2.9

2.5

Mean

1.7

2.6

2.9

CV%

29.2

13.2

6.0

LSD0.05

NS

NS

0.4

Amidon
Fumigated

1.7

1.8

3.4

Natural

1.8

2.6

2.5

Mean

1.7

2.2

2.9

CV%

13.5

20.3

6.0

LSD0.05

NS

NS

0.4

1 Subcrown internode rating, 0-4. 0= no infection, 1= less than 25% internode infected, 2= 25-50% of internode infected, 3= 51-75% of internode infected, multiple lesions and 4= 75 to 100% of internode infected, lesions coalesced.
2 Root color index at soft dough stage, 1 to 4. 1= white, 4= dark brown.
3 Root mass rating at soft dough stage, 1 to 4. 1= few roots and 4= substantial root system.

 

Table 8. Initial root evaluation of wheat in various rotations at Dickinson, ND, July 3, 1998.
Rotation1

Subcrown rating2

Seminal roots

Crown roots

No. of roots

Rhizoctonia3

No. of roots

Rhizoctonia3

Fum

Nat

Fum

Nat

Fum

Nat

Fum

Nat

Fum

Nat

W-O-W-W

0.1

0.3

5.6

5.1

0.0

0.1

20.9

13.0

0.0

0.2

W-O-P-W

0.1

0.1

5.6

5.6

0.0

0.0

19.3

19.9

0.0

0.0

W-O-M-W

0.1

0.2

5.6

5.3

0.0

0.0

19.1

19.3

0.0

0.0

Mean

0.1

0.2

5.6

5.3

0.0

0.03

19.8

18.2

0.0

0.1

CV%

194

105

1.6

3.7

-

173

9.5

10.2

-

183

LSD0.05

NS

NS

NS

0.3

NS

NS

NS

0.9

NS

NS

1 Rotation.
W-O-W-W =1995 Wheat-1996 Oat hay-1997 Wheat-1998 Wheat
W-O-P-W =1995 Wheat-1996 Oat hay-1997 Pea-1998 Wheat
W-O-M-W =1995 Wheat-1996 Oat hay-1997 Millet-1998 Wheat
2 Subcrown internode rating, 0-4. 0 = no infection, 1 = less than 25% of internode infected, 2 = 25-50% of internode infected, 3 = 51-75% of internode infected, multiple lesions, and 4 = 75-100% of internode infected, lesions coalesced.
3 Number of roots per plant which exhibited Rhizoctonia symptoms.

 

Table 9. Root evaluation of hard red spring wheat at soft dough stage grown in various rotations at the Dickinson Research Extension Center, Dickinson, ND, 1998.
Rotation1

Subcrown internode rating2

Root mass3

Color index4

Fumigated

Natural

Fumigated

Natural

Fumigated

Natural

W-O-W-W 2.1 2.6 3.0 2.4 2.9 3.2
W-O-P-W 2.0 3.0 3.5 2.5 2.1 2.7
W-O-M-W 2.5 3.0 3.6 3.0 2.4 2.7
Mean 2.2 2.8 3.4 2.6 2.5 2.9
CV% 19.3 17.3 11.8 10.5 11.7 12.6
LSD0.05

NS

NS

NS

0.37

NS

0.38

1 Rotation
W-O-W-W = 1995 Wheat-1996 Oat hay-1997 Wheat-1998 Wheat
W-O-P-W = 1995 Wheat-1996 Oat hay-1997 Pea-1998 Wheat
W-O-M-W = 1995 Wheat-1996 Oat hay-1997 Millet-1998 Wheat
2 Subcrown internode rating, 0 to 4. 0 = no infection, 1 = less than 25% of internode infected, 2 = 25 to 50% of internode infected, 3 = 51 to 75% of internode infected, multiple lesions, and 4 = 75 to 100% of internode infected, lesions coalesced.
3 Root mass rating, 1 to 4. 1 = few roots and 4 = substantial root system.
4 Root color index, 1 to 4. 1 = white and 4 = dark brown.

 

Table 10. Water-use at various soil depths over specific periods for hard red spring wheat grown on fumigated and natural soil plots at Williston Research Extension Center, 1998.

Depth (ft)

Treatment

Water-use

Time period

11 May
18 May
19 May
26 May
27 May
1 Jun
2 Jun
8 Jun
9 Jun
15 Jun
16 Jun
23 Jun
24 Jun
30 Jun
1 Jul
7 Jul
8 Jul
14 Jul
15 Jul
21 Jul
22 Jul
28 Jul
29 Jul
4 Aug
SUM

inches

0-1

Natural

0.22

0.16

0.28

0.31

0.49

0.55

1.27

0.89

1.39

0.35

0.06

-0.36

5.59

Fumigated

0.21

0.37

0.39

0.30

0.61

0.34

1.46

0.97

1.03

0.19

0.01

-0.04

5.85

LSD0.05

NS

0.05

NS

NS

0.47

NS

0.04

NS

NS

0.04

NS

NS

NS

1-2

Natural

-0.10

-0.05

0.04

0.04

0.12

-0.18

0.14

0.01

0.58

0.46

0.11

-0.04

1.14

Fumigated

-0.05

-0.05

0.16

0.11

0.11

0.01

0.15

0.06

0.58

0.28

0.06

0.01

1.44

LSD0.05

NS

NS

NS

NS

NS

NS

NS

NS

NS

0.90

NS

NS

0.04

2-3

Natural

-0.05

-0.02

0.02

0.01

0.01

0.04

-0.01

0.00

0.26

0.34

0.13

-0.01

0.72

Fumigated

-0.11

-0.04

0.03

0.06

0.06

0.04

0.11

0.06

0.34

0.30

0.14

-0.04

0.95

LSD0.05

NS

NS

NS

NS

NS

NS

0.67

NS

NS

NS

NS

NS

NS

3-4

Natural

0.04

-0.14

0.02

0.09

-0.10

0.06

0.01

0.02

-0.01

0.08

0.07

0.09

0.22

Fumigated

-0.07

0.03

-0.01

0.03

-0.03

0.01

0.04

-0.02

0.10

0.06

0.03

0.07

0.24

LSD0.05

NS

0.60

NS

NS

NS

NS

NS

NS

0.03

NS

NS

NS

NS

4-5

Natural

-0.01

-0.22

0.10

-0.05

0.01

0.02

-0.03

0.04

-0.01

0.05

-0.09

0.07

-0.10

Fumigated

0.07

-0.08

-0.06

0.08

-0.08

-0.11

0.08

0.05

-0.02

0.13

-0.11

0.00

-0.05

LSD0.05

NS

NS

NS

0.90

NS

NS

NS

NS

NS

NS

NS

NS

NS

SUM Natural

0.11

-0.27

0.46

0.40

0.52

0.49

1.37

0.95

2.21

1.29

0.28

-0.25

7.57

Fumigated

0.04

0.22

0.51

0.58

0.68

0.29

1.84

1.11

2.03

0.96

0.14

0.01

8.43

LSD0.05

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS

NS


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