Assessment of tolerance in wheat and barley to common root rot (Cochliobolus sativus)

1993 ◽  
Vol 73 (4) ◽  
pp. 1177-1187 ◽  
Author(s):  
L. J. Duczek ◽  
G. B. Wildermuth
Keyword(s):  
Grain Yield ◽  
Root Rot ◽  
Dry Matter ◽  
Field Tests ◽  
Cochliobolus Sativus ◽  
Disease Assessment ◽  
Growth Stages ◽  
Common Root ◽  
Common Root Rot ◽  
The Relationship

Field tests at Saskatoon, Saskatchewan, Canada indicated no evidence of tolerance to common root rot in four spring wheat cultivars. There was a relationship between increased yield losses and increasing disease. In barley, the relationship was inconsistent in four cultivars and there was evidence of tolerance or recovery in Melvin with the number of seeds per head increasing with the level of disease. In Queensland, Australia there was evidence of tolerance in the wheat cultivar Banks across two locations, but the response was not consistent in all cultivars. Dry matter loss at immature growth stages was not related to grain yield loss. The inconsistent expression of tolerance in wheat, the difficulty of assessing it, and the difficulty of distinguishing tolerance from recovery suggest that the assessment of tolerance is not a reliable method of determining the reaction to common root rot. The relationship between loss in dry matter and grain yield, as disease increased, indicates that disease assessment should continue to be based on severity of symptoms. The evidence of tolerance to common root rot in barley suggests research on tolerance should concentrate on barley instead of wheat. Key words: Cochliobolus sativus, common root rot, tolerance, wheat, barley

The effect of common root rot on components of grain yield in Manitou wheat

1976 ◽  
Vol 54 (24) ◽  
pp. 2888-2892 ◽  
Author(s):  
P. R. Verma ◽  
R. A. A. Morrall ◽  
R. D. Tinline
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Disease Severity ◽  
Root Rot ◽  
Major Effect ◽  
Kernel Weight ◽  
The Other ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Common Root Rot

The effects of common root rot (Cochliobolus sativus) on components of grain yield in naturally infected Triticum aestivum cultivar Manitou were studied at Matador, Saskatchewan, by sampling plants at maturity in 1969, 1970, and 1971. Plants were sorted into severe (SE), moderate (MO), slight (SL), and clean (CL) categories based mainly on the extent of lesions on the subcrown internodes. The number of tillers per plant, the number and weight of grains per head, the weight per head, and the 1000-kernel weight in each category were determined. Increasing values of all five components were consistently associated with decreasing disease severity. SE was mostly significantly different from the other three categories in all components except 1000-kernel weight; differences between SL and MO were usually non-significant. CL and SL were mostly significantly different for the number of tillers per plant and weight per head but non-significant for the weight and number of grains per head and 1000-kernel weight. Apparently, the major effect of common root rot was to reduce the number of tillers per plant and number of grains per head.

The relationship between the spore density of Cochliobolus sativus in soil and its saprophytic activity and parasitism

1968 ◽  
Vol 8 (32) ◽  
pp. 371 ◽  
Author(s):  
LW Burgess ◽  
DM Griffin
Keyword(s):  
Wheat Straw ◽  
Root Rot ◽  
Cochliobolus Sativus ◽  
Spore Density ◽  
Common Root ◽  
Common Root Rot ◽  
The Relationship ◽  
Seedling Infection

Both saprophytic colonization of wheat straw and seedling infection by Cochlioholus sativus (Ito and Kur.) Drechsl. ex Dastur, which causes common root rot of wheat, were correlated with spore density. The results indicate that straw colonization is possible at 10�C even when the spore density is too low to cause seedling infection. Saprophytic activity may thus raise the spore density over the threshold necessary for parasitism.

The effect of soil salinity on common root rot of spring wheat and barley

1993 ◽  
Vol 73 (1) ◽  
pp. 323-330 ◽  
Author(s):  
L. J. Duczek
Keyword(s):  
Spring Wheat ◽  
Soil Salinity ◽  
Root Rot ◽  
Salinity Gradient ◽  
Cochliobolus Sativus ◽  
Liquid Media ◽  
Common Root ◽  
Inoculum Level ◽  
Common Root Rot ◽  
The Relationship

Samples were taken from several sites across a salinity gradient from areas where plants were visibly unaffected to the edge of saline areas where no plants grew, from commercial fields located near Saskatoon in 1984, 1987, 1990 and 1991. There was a significant (P = 0.05) positive correlation for wheat and barley between salinity and common root rot in all years, except 1991 (1984: r = 0.445, n = 26; 1987: r = 0.390, n = 54; 1990: r = 0.244, n = 75; 1991: r = 0.247, n = 40). The correlation between inoculum level and disease was not significant, except for one barley field in 1990. However, when inoculum level was used as a covariate, the significance of the relationship between salinity and common root rot increased. Growth of Cochliobolus sativus was unaffected on solid and liquid media until conductivity levels were higher than 30–50 mmhos cm−1. Since wheat and barley do not grow at levels higher than 10–15 mmhos cm−1, salinity would have a greater affect on plants than on the pathogen. The relationship between salinity and disease is consistent with the theory that stress increases common root rot in plants. However, the variation in salinity only explains about 20% of the variation in common root rot. Key words: Cochliobolus sativus, common root rot, salinity, cereals

The effect of common root rot on the yield of resistant and susceptible wheat

1996 ◽  
Vol 76 (4) ◽  
pp. 869-877 ◽  
Author(s):  
R. L. Conner ◽  
G. C. Kozub ◽  
K. L. Bailey
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Field Tests ◽  
Cochliobolus Sativus ◽  
Common Root ◽  
Back Cross ◽  
Common Root Rot ◽  
The Impact ◽  
Disease Free

The impact of common root rot, caused by Cochliobolus sativus, on the yield of mixtures of resistant and susceptible backcross-6 derivative lines of Neepawa and Chester wheat was examined in field tests at three locations between 1991 and 1994. Different blends consisting of all 25% incremental combinations of resistant and susceptible back-cross lines within each cultivar were evaluated for disease severity and yield at root rot nurseries and disease-free sites. Significant (P < 0.05) differences in yield were often detected among cultivars. However, within cultivars, no consistent yield differences were observed among blends of resistant and susceptible lines of the same cultivar regardless of root rot severity. Key words:Cochliobolus sativus, common root rot, yield, wheat

The effect of KCl, KNO3, and CaCl2 fertilization under conventional- and zero-till systems on common root rot, dry matter yield and grain yield of Heartland barley

1994 ◽  
Vol 74 (1) ◽  
pp. 1-6 ◽  
Author(s):  
C. A. Grant ◽  
L D. Bailey
Keyword(s):  
Grain Yield ◽  
Root Rot ◽  
Dry Matter ◽  
Sandy Loam ◽  
Conventional Tillage ◽  
System Response ◽  
Silty Clay ◽  
Dry Matter Yield ◽  
Common Root ◽  
Common Root Rot

Field studies were conducted on two soil types testing low in Clover a 4-yr period to assess the influence of K and Cl fertilization under zero (ZT) and conventional tillage (CT) management on common root rot, dry matter yield at heading, and grain yield of Heartland barley. Tillage did not influence incidence of common root rot in the 4 site-yr where assessments could be taken. Common root rot incidence was reduced by KCl applications in 1 out of 4 site-yr. Dry matter yield at heading and grain yields were consistently higher with ZT than with CT on the silty clay soil, but only in 1988 on the fine sandy loam soil. The higher yields with ZT than with CT may be due to greater moisture conservation under the ZT management system. Response to K or Cl applications was generally not influenced by tillage treatment. Applications of Cl had little influence on either dry matter yield at heading or grain yield, despite the low initial Cl levels in the soils. Application of fertilizers containing Cl, therefore, may not be consistently beneficial, even on soils testing low in Cl. Key words: Potassium, chloride, tillage, barley, common root rot

YIELD LOSSES IN WHEAT AND BARLEY CULTIVARS FROM COMMON ROOT ROT IN FIELD TESTS

1979 ◽  
Vol 59 (2) ◽  
pp. 313-320 ◽  
Author(s):  
R. D. TINLINE ◽  
R. J. LEDINGHAM
Keyword(s):  
Grain Yield ◽  
Root Rot ◽  
Field Tests ◽  
Yield Losses ◽  
Common Root ◽  
Potential Yield ◽  
Disease Reaction ◽  
Barley Cultivars ◽  
Common Root Rot ◽  
Highly Correlated

Intensity of and losses from common root rot in wheat and barley cultivars in field tests were estimated. Disease intensity was based upon the severity and prevalence of lesions on the subcrown internodes of plants. Losses were calculated relative to the potential yield of clean plants. Disease intensities and losses usually were highly correlated in wheat; the most resistant cultivars incurred the lowest losses. In barley the association was variable; some of the cultivars intermediate in disease reaction frequently showed the least reductions in yield. Differences in tolerance may account for these results. The frequent lack of a correlation between grain yield and disease is discussed.

The epidemiology of common root rot in Manitou wheat: disease progression during the growing season

1974 ◽  
Vol 52 (7) ◽  
pp. 1757-1764 ◽  
Author(s):  
P. R. Verma ◽  
R. A. A. Morrall ◽  
R. D. Tinline
Keyword(s):  
Triticum Aestivum ◽  
Disease Severity ◽  
Plant Development ◽  
Root Rot ◽  
Growing Season ◽  
Cochliobolus Sativus ◽  
Infection Rates ◽  
Common Root ◽  
Common Root Rot ◽  
Disease Rating

Common root rot in Triticum aestivum cultivar Manitou caused primarily by Cochliobolus sativus was followed during plant development in 1969, 1970, and 1971 at Matador, Saskatchewan. Plants were sampled at intervals, and three variables based mainly on the occurrence of lesions on subcrown internodes were studied: number of diseased plants per square meter; percentage of diseased plants; and disease rating which integrated percentage of diseased plants and disease severity on each plant. All variables increased with time, and the progression curves in all 3 years were hyperbolic, indicating that the increases were like those of a simple interest disease as described by Van der Plank. In two of the years, almost 100% of the plants were diseased considerably before the end of the season. The transformation proposed by Van der Plank for simple interest diseases, log10[1/(1 − x)], was applied to the percentages of diseased plants, and regressions were calculated. The slopes of these lines (infection rates) were as follows: 1969, 0.99% plants per day; 1970, 1.32%; and 1971, 1.96%. In 1969 the onset of disease was later than in 1970 and 1971, and there was correspondingly less disease at the end of the growing season.

Effects of cultivation on Rhizoctonia root rot, cereal cyst nematode, common root rot and yield of wheat in the Victorian Mallee

1991 ◽  
Vol 31 (3) ◽  
pp. 367 ◽  
Author(s):  
RFde Boer ◽  
JF Kollmorgen ◽  
BJ Macauley ◽  
PR Franz ◽  
Boer RF De
Keyword(s):  
Grain Yield ◽  
Root Rot ◽  
Dry Weight ◽  
Cyst Nematode ◽  
Cereal Cyst Nematode ◽  
Common Root ◽  
Common Root Rot ◽  
Root Diseases ◽  
Rhizoctonia Root Rot ◽  
Direct Drilling

The effects of method, time and number of cultivations on root diseases and yield of wheat were studied in a field experiment, in 1985, on a calcareous sandy loam in the Victorian Mallee. The incidence and severity of rhizoctonia root rot (Rhizoctonia solani) were higher in direct-drilled wheat than in wheat sown after cultivation. Compared with direct drilling, the severity of rhizoctonia root rot in seedlings was reduced by 40% with cultivation 20 weeks before sowing; by 70% with cultivation 1 day before sowing; and by 90% with 2 cultivations, the first at 16 weeks and the second 1 day before sowing. Cultivation generally increased the incidence of common root rot (Bipolaris sorokiniana) but had no significant effects on the severity of damage by the cereal cyst nematode (Heterodera avenae) or the number of nematode cysts produced, compared with direct drilling. The incidence and severity of root diseases, and the number of H. avenae cysts produced, were not significantly different in wheat sown after rotary hoeing than in wheat sown after scarifying. The severity of damage by H. avenae, the number of nematode cysts and the incidence of common root rot were higher (45, 70 and 36%, respectively) when scarifying was done 1 day before sowing, compared with scarifying 20 weeks earlier. Differences in sowing depth probably caused this effect since seed was sown deeper (as indicated by subcrown internode lengths) and plant emergence was less in the latter treatment. The timing and number of cultivations with a rotary hoe, however, did not significantly affect the severity of damage by H. avenae, the number of nematode cysts or the incidence of common root rot. The incidence of common root rot was correlated (r = 0.71) with the subcrown internode lengths, indicating that the deeper the seed was sown the greater the proportion of plants with the disease. Dry weight of seedlings and grain yield were negatively correlated (r = -0.79 and -0.66) with the severity of damage caused by H. avenae. Plant dry weight and grain yield were, however, not correlated with the severity of rhizoctonia root rot or the incidence of common root rot.

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