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.

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.

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.

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.

A Nutrient Culture Technique to Measure Lettuce,Lactuca sativa, Sensitivity to Thiobencarb

1988 ◽  
Vol 2 (3) ◽  
pp. 291-293
Author(s):  
Stephen Reiners ◽  
Stanley F. Gorski
Keyword(s):  
Nutrient Solution ◽  
Dry Weight ◽  
Culture Technique ◽  
Abnormal Growth ◽  
Nutrient Culture ◽  
Lettuce Growth ◽  
Dark Green ◽  
Lettuce Cultivar ◽  
Leaf Dry Weight ◽  
Nutrient Solutions

A modified nutrient solution, used to study lettuce cultivar response to thiobencarb, provided an excellent medium for lettuce growth and is an alternative to other nutrient solutions. Leaf dry weight was inhibited 50% by 3- and 5-μM thiobencarb in ‘Dark Green Boston’ and ‘Great Lakes 366’, respectively, while ‘Bibb’, ‘Slobolt’ and ‘Valmaine’ responded intermediately. Growth inhibitions and herbicide injury symptoms, which included abnormal growth and stunted secondary leaves, were similar in both nutrient solution and soil assays. Due to its ease of preparation and elimination of the variability associated with soil assays, the nutrient solution may be considered a superior alternative to soil assays.

EFFECTS OF INOCULATING WHEAT SEEDLINGS WITH HELMINTHOSPORIUM SATIVUM AND SPREAD OF THE FUNGUS TO AN EXTERNAL SUBSTRATE

1961 ◽  
Vol 41 (4) ◽  
pp. 791-798 ◽  
Author(s):  
P. M. Simmonds
Keyword(s):  
Nutrient Solution ◽  
Nitrate Solution ◽  
Potassium Nitrate ◽  
Field Conditions ◽  
Severe Injury ◽  
Wheat Seedlings ◽  
Root Diseases ◽  
Leaf Chlorosis ◽  
Potassium Nitrate Solution ◽  
Helminthosporium Sativum

Studies were conducted with wheat seedlings inoculated with Helminthosporium sativum and observations were made on the spread of this fungus from lesions or other sources into an external substrate. Infections caused severe injury as measured by leaf chlorosis. Injury was reduced when the seedlings were supplied with potassium nitrate solution in place of water. There was greater injury and more extensive colonization of the fungus when the nutrient solution was enriched by adding sucrose. The fungus was observed to spread readily from lesions and other sources into the adjacent environment. Soil masses around a root lesion did not inhibit the spread. The results of these studies are discussed in relation to root diseases under field conditions.

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.

NITROGEN NUTRITION OF CITRUS NURSERY STOCK IN PINE BARK SUBSTRATES.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1161f-1161
Author(s):  
John D. Lea-Cox ◽  
Irwin E. Smith
Keyword(s):  
Nutrient Solution ◽  
Nitrogen Nutrition ◽  
Dry Mass ◽  
Pine Bark ◽  
Growing Period ◽  
Rough Lemon ◽  
Nursery Stock ◽  
Citrus Rootstock ◽  
Cleopatra Mandarin ◽  
Nutrient Solutions

Pine bark is utilized as a substrate in citrus nurseries in South Africa. The Nitrogen (N) content of pine bark is inherently low, and due to the volubility of N, must be supplied on a continual basis to ensure optimum growth rates of young citrus nursery stock. Three citrus rootstock (rough lemon, carrizo citrange and cleopatra mandarin) showed no difference in stem diameter or total dry mass (TDM) when supplied N at concentrations between 25 and 200 mg ·l-1 N in the nutrient solution over a 12 month growing period. Free leaf arginine increased when N was supplied at 400 mg·l-1 N. The form of N affected the growth of rough lemon. High NH4-N:NO3-N (75:25) ratios decreased TDM when Sulfur (S) was absent from the nutrient solution, but not if S was present. Free arginine increased in leaves at high NH4-N (No S) ratios, but not at high NH4-N (S supplied) ratios. Free leaf arginine was correlated with free leaf ammonia. These results have important implications for reducing the concentration of N in nutrient solutions used in citrus nurseries and may indicate that higher NH4-N ratios can be used when adequate S is also supplied.

scholarly journals Silicon attenuates calcium deficiency by increasing ascorbic acid content, growth and quality of cabbage leaves

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dalila Lopes da Silva ◽  
Renato de Mello Prado ◽  
Luis Felipe Lata Tenesaca ◽  
José Lucas Farias da Silva ◽  
Ben-Hur Mattiuz
Keyword(s):  
Ascorbic Acid ◽  
Nutrient Solution ◽  
Acid Content ◽  
Dry Matter ◽  
Ascorbic Acid Content ◽  
Calcium Deficiency ◽  
Ca Deficiency ◽  
Leaf Water Loss ◽  
Nutrient Solutions

AbstractCalcium (Ca) deficiency in cabbage plants induces oxidative damage, hampering growth and decreasing quality, however, it is hypothesized that silicon (Si) added to the nutrient solution may alleviate crop losses. Therefore, this study aims at evaluating whether silicon supplied in the nutrient solution reduces, in fact, the calcium deficiency effects on cabbage plants. In a greenhouse, cabbage plants were grown using nutrient solutions with Ca sufficiency and Ca deficiency (5 mM) without and with added silicon (2.5 mM), arranged as a 2 × 2 factorial in randomized blocks, with five replications. At 91 days after transplanting, the plants were harvested for biological evaluations. In the treatment without added Si, Ca deficiency promoted oxidative stress, low antioxidant content, decreased dry matter, and lower quality leaf. On the other hand, added Si attenuated Ca deficiency in cabbage by decreasing cell extravasation while increasing both ascorbic acid content and fresh and dry matter, providing firmer leaves due to diminished leaf water loss after harvesting. We highlighted the agronomic importance of Si added to the nutrient solution, especially in crops at risk of Ca deficiency.

scholarly journals Temperature and pH of the nutrient solution on wheat primary root growth

2004 ◽  
Vol 61 (3) ◽  
pp. 313-318 ◽  
Author(s):  
Carlos Eduardo de Oliveira Camargo ◽  
Antonio Wilson Penteado Ferreira Filho ◽  
Marcus Vinicius Salomon
Keyword(s):  
Root Growth ◽  
Nutrient Solution ◽  
Primary Root ◽  
Growth Period ◽  
Triticum Aestivum L ◽  
Solution Temperature ◽  
Stages Of Development ◽  
Primary Root Growth ◽  
Temperature And Growth ◽  
Nutrient Solutions

Primary root growth is very important for wheat (Triticum aestivum L.) crop in upland conditions in the State of São Paulo. Fourteen wheat genotypes (mutant lines and cultivars) were evaluated for primary root growth during 7 and 15 days of development in complete and aerated nutrient solutions, in the laboratory. In the first experiment, solutions with three pH values (4.0, 5.0 and 6.0) at constant temperature (24 ± 1°C), and in the second experiment, solutions with the same pH (4.0) but with three temperatures (18°C ± 1°C, 24°C ± 1°C and 30°C ± 1°C) were used. High genetic variability was observed among the evaluated genotypes in relation to primary root growth in the first stages of development in nutrient solutions independent of pH, temperature and growth period. Genotypes 6 (BH-1146) and 13 (IAC-17), tolerant to Al3+ showed genetic potential for root growth in the first stages of development (7 and 15 days), regardless of nutrient solution temperature and pH. Genotypes 14 (IAC-24 M), 15 (IAC-24), 17 (MON"S" / ALD "S") ´ IAC-24 M2, 18 (MON"S" / ALD "S") ´ IAC-24 M3 and 24 (KAUZ"S" / IAC-24 M3), tolerant to Al3+, showed reduced root growth under the same conditions.

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