THE EFFECT OF CROP DEBRIS ON THE PATHOGENICITY OF CEREAL ROOT-ROTTING FUNGI

1940 ◽  
Vol 18c (7) ◽  
pp. 289-306 ◽  
Author(s):  
L. E. Tyner
Keyword(s):  
Plant Pathogens ◽  
Fusarium Culmorum ◽  
Barley Straw ◽  
Seedling Vigour ◽  
Wheat Seedlings ◽  
Helminthosporium Sativum ◽  
Nitrogen Ratio ◽  
Oat Straw ◽  
Micro Organisms ◽  
Cereal Root

The effect of wheat, oat, and barley straw, composted with soil, on the development of disease on the basal parts of wheat seedlings was studied in a series of greenhouse experiments during three seasons. The pathogens used were Ophiobolus graminis Sacc., Helminthosporium sativum P. K. and B., and Fusarium culmorum (W. G. Sm.) Sacc. The wheat-straw composts were distinctly more favourable to the development of disease than the composts of either oat or barley straw. The least injury occurred on seedlings grown in composts of oat straw. It is suggested that the micro-organisms associated with the decomposition of oat straw bring about some degree of biological control of the plant pathogens also present.Although the amount of straw applied sometimes influenced severity of disease, the effects were not consistent from planting to planting. Apparently the actual carbon to nitrogen ratio had less effect upon disease development than did the chemical nature of the straw.The kind and amount of straw in the composts also influenced seedling vigour. This vigour was, in general, inversely proportional to the degree of infection.The introduction of a short fallow period between plantings decreased infection somewhat and increased vigour.The pathogenicity of the artificial inoculum added at the first planting was practically vitiated before the second planting. Subsequently, the infection ratings tended to increase and were about the same as those in the uninoculated series.

EFFECT OF CROP DEBRIS, PLANT ROOTS, AND CROP SEQUENCE ON THE MICROBIAL FLORA OF THE SOIL IN RELATION TO ROOT ROT IN CEREAL CROPS

1948 ◽  
Vol 26c (1) ◽  
pp. 86-93 ◽  
Author(s):  
L. E. Tyner
Keyword(s):  
Barley Straw ◽  
Wheat Roots ◽  
Wheat Seedlings ◽  
Fallow Soil ◽  
Helminthosporium Sativum ◽  
Plate Counts ◽  
Oat Straw ◽  
Field Plots ◽  
Penicillium Spp ◽  
Crop Sequence

The decomposition of wheat, oat, or barley straw in soil caused a marked increase in the microflora, as indicated by plate counts. The oat straw compost yielded significantly more colonies of fungi than either the wheat or barley straw composts. The population of bacteria and actinomycetes was increased to about the same degree by all three of the composts.In another laboratory experiment, wheat, oats, barley, and beans were planted in various rotations in pots of soil from field plots known to be heavily infested with the root-rotting pathogens Helminthosporium sativum P. K. and B., Ophiobolus graminis Sacc., and Fusarium spp. Fungi, mostly Penicillium spp. and Mucor spp., were up to 15 times more abundant from the rhizosphere of wheat roots than from the rhizosphere of oat, barley, or bean roots, regardless of crop sequence. It is assumed that the higher counts of saprophytic fungi obtained from the rhizosphere of wheat seedlings were directly correlated with the greater amount of dead root tissue on this crop, since disease on the wheat seedlings was more severe than on the other hosts. In a duplicate experiment in fallow soil, the rhizospheres of wheat, oats, barley, and beans yielded about equal numbers of fungi.

RELATIVE DECLINE OF OPHIOBOLUS GRAMINIS, HELMINTHOSPORIUM SATIVUM AND FUSARIUM CULMORUM IN THE SOIL

1960 ◽  
Vol 40 (2) ◽  
pp. 288-294 ◽  
Author(s):  
G. Semeniuk ◽  
A. W. Henry
Keyword(s):  
Fusarium Culmorum ◽  
Wheat Crop ◽  
Natural Soil ◽  
Large Measure ◽  
Wheat Seedlings ◽  
Helminthosporium Sativum ◽  
Loam Soil ◽  
Marked Decline ◽  
Relative Decline ◽  
Micro Organisms

The relative decline of three cereal root pathogens, Ophiobolus graminis Sacc., Helminthosporium sativum P. K. B., and Fusarium culmorum (W. G. Sm.) Sacc., in natural and sterilized black loam soil, was studied using inoculum grown in a sterilized soil-cornmeal medium. Since the severity of infection of wheat seedlings by the above fungi proved directly proportional to the amount of inoculum added to natural soil, it was used as a measure of the amount of effective inoculum in the soil at a given time. It was found by this means that inoculum of all three pathogens diminished greatly in amount in natural soil during the first few days following its addition, with that of O. graminis declining least, that of H. sativum more, and that of F. culmorum most. The decline rate was proportional to the amount of inoculum. After one week the decline had progressed further, but it was less for O. graminis than for the other two pathogens. In 3–4 weeks the amount of all three had reached a near-zero quantity. In sterilized soil the decline was similar to that in natural soil after the sterilized soil became recontaminated. However, that of F. culmorum was less pronounced here than in natural soil. Marked decline of O. graminis also occurred in natural soil supporting a seedling wheat crop. In large measure the decline studied appeared to be a quantitative degenerating process resulting from the activity of soil micro-organisms.

VARIABILITY IN ASSOCIATION EFFECTS OF OTHER SOIL FUNGI ON THE VIRULENCE OF HELMINTHOSPORIUM SATIVUM ON WHEAT SEEDLINGS

1940 ◽  
Vol 18c (11) ◽  
pp. 562-565 ◽  
Author(s):  
G. B. Sanford ◽  
M. W. Cormack
Keyword(s):  
Pure Culture ◽  
Plant Pathogens ◽  
Soil Fungi ◽  
Culture Conditions ◽  
Wheat Seedlings ◽  
Helminthosporium Sativum ◽  
Preliminary Study

Random isolates of Penicillium, Actinomyces, and certain miscellaneous soil-inhabiting fungi were tested in steam sterilized soil, under pure culture conditions, for their association effects on the virulence of Helminthosporium sativum P. K. and B. on wheat seedlings. Certain isolates of the first two genera mentioned exerted a marked degree of suppression, some had no effect, while others increased the virulence. Similarly, these effects varied widely within certain species of Penicillium. This preliminary study indicates that the random isolates of many genera and species of fungi may differ widely in ability to affect the virulence of certain plant pathogens.

STUDIES ON FOOT AND ROOT ROT OF WHEAT: I. EFFECT OF AGE OF THE WHEAT PLANT UPON THE DEVELOPMENT OF FOOT AND ROOT ROT

1933 ◽  
Vol 8 (5) ◽  
pp. 483-491 ◽  
Author(s):  
W. C. Broadfoot
Keyword(s):  
Root Rot ◽  
Fusarium Culmorum ◽  
Wheat Plant ◽  
Seedling Stage ◽  
Critical Studies ◽  
Helminthosporium Sativum ◽  
Unsterilized Soil ◽  
Micro Organisms ◽  
Effect Of Age ◽  
Made In

Studies were made to determine whether, in sterilized inoculated soil, Marquis wheat plants became more or less susceptible during the post-seedling stage to Ophiobolus graminis, Helminthosporium sativum, and Fusarium culmorum. While it was found that the plants in the seedling stage were more susceptible than at later stages, there was, with the technique used, no evidence that the plants become more or less susceptible during the post-seedling stage. The reasons for indefinite evidence on this important question are given. In sterilized soil, in open pot culture, inoculum of O. graminis was definitely more virulent when alone than when mixed singly or in combination with H. sativum, F. culmorum or Leptosphaeria herpotrichoides. The virulence of all pathogenes mentioned decreased progressively in sterilized soil, the greatest decrease taking place during the first 40 days, after which they were only slightly pathogenic and at the end of 120 days inoculum of O. graminis was impotent. The virulence of inoculum when added to unsterilized soil was greatly reduced in contrast with that in sterilized soil, and after 10 days it was practically at a minimum. These results emphasize the necessity of protecting inoculated sterilized soil against contamination by other micro-organisms in critical studies made in soil. They also throw light on the much recognized difficulty of producing foot rot in the field by prepared inoculum added to such soil.

STUDIES ON FOOT AND ROOT ROT OF WHEAT: VII. SOME FACTORS AFFECTING THE HEALTH OF WHEAT SEEDLINGS IN NUTRIENT SOLUTIONS

1943 ◽  
Vol 21c (1) ◽  
pp. 18-25 ◽  
Author(s):  
L. E. Tyner ◽  
W. C. Broadfoot
Keyword(s):  
Nutrient Solution ◽  
Root Rot ◽  
Fusarium Culmorum ◽  
Hydrogen Ion ◽  
Soil Culture ◽  
Wheat Seedlings ◽  
Factors Affecting ◽  
Ion Concentrations ◽  
Helminthosporium Sativum ◽  
Nutrient Solutions

The effect of iron tartrate on the development of chlorosis in wheat seedlings in nutrient solutions, and also the effect of extracts of Helminthosporium sativum P. K. & B. and Fusarium culmorum W. G. Sm. on disease expression, were studied under greenhouse conditions. Iron tartrate was effective in preventing chlorosis. Less iron was required in summer plantings than in winter plantings. Also, less iron was required in solutions with the higher hydrogen ion concentrations. Under the conditions employed, manganese effected no amelioration of chlorotic symptoms in the presence of a deficiency of iron.Sterilized and unsterilized filtered extracts of the pathogens mentioned added to crocks of the nutrient solution inhibited the growth of wheat seedlings, an effect in soil culture which is interpreted as an index of pathogenicity.

ON THE PREVALENCE OF PATHOGENIC FORMS OF HELMINTHOSPORIUM SATIVUM AND FUSARIUM CULMORUM IN THE SOIL OF WHEAT FIELDS AND ITS RELATION TO THE ROOT ROT PROBLEM

1934 ◽  
Vol 10 (3) ◽  
pp. 264-274 ◽  
Author(s):  
G. B. Sanford ◽  
W. C. Broadfoot
Keyword(s):  
Root Rot ◽  
Fusarium Culmorum ◽  
Black Soil ◽  
Seedling Stage ◽  
Infested Soil ◽  
Wheat Seedlings ◽  
Virulent Strains ◽  
Crown Tissue ◽  
Helminthosporium Sativum ◽  
Pot Culture

A total of 227 isolates of Helminthosporium sativum and 286 of Fusarium sp. (culmorum type) were obtained from the diseased crown tissue of wheat stubble in five fields located in the black soil belt of central Alberta, and an attempt was made to determine their relative virulence on wheat seedlings and on mature plants. The experiment was carried out under greenhouse conditions, with a range of soil temperature. Sterilized, artificially infested soil in open pot culture was used. The results indicated that the Helminthosporium isolates were as a rule moderately to weakly pathogenic, and that most of the Fusarium isolates were only weakly pathogenic to wheat plants in the seedling stage. Some isolates of each pathogen exhibited extreme virulence, but judging from the results on seedling plants, virulent strains were rather rare in the fields studied. On mature plants both fungi showed about equal degrees of virulence, which was on the whole weak, and the results were not considered significant for the purpose of the study. More isolates of the greater degrees of virulence were obtained from certain fields than from others. In view of the great susceptibility of seedling plants in sterilized re-infested soil and the variable results, presumably caused by association effects of contaminants of the soil in open pot culture, it was concluded that the object of the study could not be attained by means of data based on the seedling stage, or by the technique employed. The possibility of significant results being secured in sterilized re-infested soil, protected from contamination, and based only on mature plants, is discussed in relation to the root rot problem.

SOME FACTORS AFFECTING THE VIRULENCE OF ARTIFICIAL INOCULUM OF HELMINTHOSPORIUM SATIVUM P. K. AND B. AND OF FUSARIUM CULMORUM (W. G. SM.) SACC.

1941 ◽  
Vol 19c (2) ◽  
pp. 42-48 ◽  
Author(s):  
L. E. Tyner
Keyword(s):  
Fusarium Culmorum ◽  
Corn Meal ◽  
Wheat Seedlings ◽  
Factors Affecting ◽  
Helminthosporium Sativum ◽  
Effect Of Age

Investigations were conducted on the virulence of inoculum of Helminthosporium sativum P. K. and B. and of Fusarium culmorum (W. G. Sm.) Sacc. as affected by the size of the vessel in which the inoculum was increased, the amount of corn meal present in the medium, and the period of incubation. Inoculum of either pathogen containing 12% corn meal caused more disease on wheat seedlings than that with 5%. H. sativum, 14 days old, was more virulent than after 21, 28, or 35 days' incubation, but in the case of F. culmorum, there was no definite tendency with respect to the effect of age. The size of container was unimportant if desiccation was avoided.

STUDIES ON FOOT- AND ROOT-ROT OF WHEAT: VI. METHODS OF SECURING INFECTION OF WHEAT SEEDLINGS FOR STUDY IN NUTRIENT SOLUTIONS

1938 ◽  
Vol 16c (6) ◽  
pp. 253-261 ◽  
Author(s):  
W. C. Broadfoot ◽  
L. E. Tyner
Keyword(s):  
Nutrient Solution ◽  
Fusarium Culmorum ◽  
Spore Suspension ◽  
Hypodermic Needle ◽  
Culture Solution ◽  
Wheat Seedlings ◽  
Nutrient Culture ◽  
Entire Plant ◽  
Helminthosporium Sativum ◽  
Nutrient Solutions

The two foot-rot diseases of wheat caused by Helminthosporium sativum P. K. & B. and Fusarium culmorum W. G. Sm. were studied in nutrient culture solutions instead of in the usual substrates of soil or sand. The most satisfactory results were obtained by first germinating the grains in a specially designed tray, then securing infection of the young plants by adding inoculum to the tray, after which the seedlings were transplanted to the nutrient culture solution. Infection of the seedlings was distinctly increased when sucrose was added to a nutrient solution infested previous to the time of transplantation. Infection was less satisfactory when the seed was immersed in a spore suspension, dried, and germinated on the tray. Very unsatisfactory infection was secured by adding a spore suspension in water, with or without sugar, to the nutrient solution at the time of transplanting the seedlings. Inoculating the seedlings with a spore suspension by means of a hypodermic needle produced practically no infection. Length of shoot, and particularly the dry and the green weight of the entire plant were reliable quantitative criteria for the evaluation of disease. The first method indicated appears to offer several important advantages in that the degree of infection can be controlled.

scholarly journals Effect of Thiosemicarbazone Derivatives and Fusarium culmorum (Wm.G. Sm.) Sacc. Infection of Winter Wheat Seedlings on Their Health Status and Soil Biological Activity

Agronomy ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 116
Author(s):  
Agnieszka Jamiołkowska ◽  
Barbara Skwaryło-Bednarz ◽  
Elżbieta Mielniczuk ◽  
Franco Bisceglie ◽  
Giorgio Pelosi ◽  
...  
Keyword(s):  
Biological Activity ◽  
Health Status ◽  
Winter Wheat ◽  
Plant Pathogens ◽  
Developmental Stages ◽  
Fusarium Culmorum ◽  
Infectious Agent ◽  
Wheat Seedlings ◽  
Soil Biological Activity ◽  
Positive Effect

Climate change has an impact on agricultural production, including the greater persistence of plant pathogens in the environment. Therefore, the question arises as to how to effectively and safely protect plants by using chemicals, the number of which is decreasing each year. The aim of this study was to evaluate the fungistatic effect of 2 acetylthiophenethiosemicarbazone (2actpTS) and Cis-jasmonethiosemicarbazone (JTS) against Fusarium culmorum (Fc) on winter wheat seedlings. The influence of thiosemicarbazones (TSs) on the health status and phytotoxicity of seedlings and soil biological activity was investigated. Before TSs application (watering or spraying), soil was infected with F. culmorum (strain No. 37). The substance type and method of its application significantly influenced only the fresh weight of the seedlings. The varying phytotoxicity of the molecules depended primarily on their application method to the plants. The highest seedling phytotoxicity was recorded when compounds were applied during watering and the lowest when they were sprayed. The results showed that the application of substances 2actpTS and JTS, both in the form of watering and spraying, had a positive effect on plant health status, as expressed by the disease index (DI) value. The presence of the infectious agent and the type of chemical compound increased soil enzyme activity. The highest total number of bacteria was found in the soil that was infected with Fc and in soil samples where JTS was applied by watering and spraying. The highest utilization of amines, amides and amino acids by microorganisms was found in the samples where JTS was applied. The obtained results will be used to create intermediate products for the protection of cereals against Fusarium diseases, not only at the stage of germination and tillage of plants, but also at subsequent developmental stages.

scholarly journals The Potential of Rhizoctonia-Like Fungi for the Biological Protection of Cereals against Fungal Pathogens

Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 349
Author(s):  
Dominik Bleša ◽  
Pavel Matušinský ◽  
Romana Sedmíková ◽  
Milan Baláž
Keyword(s):  
Biological Control ◽  
Fungal Pathogens ◽  
Plant Pathogens ◽  
Higher Plants ◽  
Fusarium Culmorum ◽  
Suppressive Effect ◽  
Plant Production ◽  
Shoot Biomass ◽  
Organic Substrates

The use of biological control is becoming a common practice in plant production. One overlooked group of organisms potentially suitable for biological control are Rhizoctonia-like (Rh-like) fungi. Some of them are capable of forming endophytic associations with a large group of higher plants as well as mycorrhizal symbioses. Various benefits of endophytic associations were proved, including amelioration of devastating effects of pathogens such as Fusarium culmorum. The advantage of Rh-like endophytes over strictly biotrophic mycorrhizal organisms is the possibility of their cultivation on organic substrates, which makes their use more suitable for production. We focused on abilities of five Rh-like fungi isolated from orchid mycorrhizas, endophytic fungi Serendipita indica, Microdochium bolleyi and pathogenic Ceratobasidium cereale to inhibit the growth of pathogenic F. culmorum or Pyrenophora teres in vitro. We also analysed their suppressive effect on wheat infection by F. culmorum in a growth chamber, as well as an effect on barley under field conditions. Some of the Rh-like fungi affected the growth of plant pathogens in vitro, then the interaction with plants was tested. Beneficial effect was especially noted in the pot experiments, where wheat plants were negatively influenced by F. culmorum. Inoculation with S. indica caused higher dry shoot biomass in comparison to plants treated with fungicide. Prospective for future work are the effects of these endophytes on plant signalling pathways, factors affecting the level of colonization and surviving of infectious particles.

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