INTERRELATIONSHIPS BETWEEN PLANT AGE, ROOT-ROT INFECTION, AND COLD HARDINESS IN WINTER WHEAT

1960 ◽  
Vol 38 (4) ◽  
pp. 601-611 ◽  
Author(s):  
J. E. Andrews ◽  
J. S. Horricks ◽  
D. W. A. Roberts

The effect of plant age and root rot caused by Bipolaris sorokiniana and Fusarium culmorum on the cold hardiness of winter wheat and the effect of cold injury on root-rot infection were studied during 3 years at Lethbridge, Alberta. The oldest and youngest plants were less cold hardy than those of an intermediate age. Root-rot damage predisposed plants to cold injury and, in turn, cold injury predisposed plants to root-rot damage. Winter wheat inoculated with B. sorokiniana and F. culmorum and seeded at the earliest dates had recovered from infection before exposure to the freezing treatment and, apparently because of delayed development, was more cold hardy than uninoculated wheat seeded on the same date. Results from cold-chamber and field studies indicated that the severe root-rot damage often observed in nearly mature winter wheat seeded early the previous year is not a direct result of heavy infection at or near the time of seeding but is secondary to winter injury that often occurs in early-seeded winter wheat.

Author(s):  
М. В. Тищенко ◽  
В. М. Смірних ◽  
С. В. Філоненко ◽  
В. В. Ляшенко

У результаті польових досліджень було встановлено вплив попередників, системи удобрення і способів основного обробітку ґрунту на ураження рослин пшениці озимої кореневими гнилями в короткоротаційних сівозмінах зони недостатнього зволоження. Найбільше уражених рослин пшениці озимої кореневими гнилями виявилось в зернопросапній сівозміні, де попередником була сама пшениця, а також в зернопаропросапній сівозміні, де попередником був чорний пар. Найменше уражених кореневими гнилями рослин пшениці озимої (15,3–20,0 %) за найнижчої інтенсивності розвитку хвороби (5,8–7,3 %) спостерігали після кукурудзи на силос. Проведення поверхневого обробітку ґрунту на глибину 10–12 см під зернові культури, в тім числі й під пшеницю озиму, на фоні 6,25 т гною + N33,8Р45,0К33,8 + солома + гичка в просапній сівозміні після кукурудзи на силос спричинило найбільше ураження рослин пшениці кореневими гнилями (24,4 %) з підвищенням інтенсивності розвитку хвороби до величини 10,5 %. Проведення оранки під усі культури в просапній сівозміні за внесення за ротацію сівозміни з розрахунку на 1 га ріллі 6,25 т гною + N33,8Р45,0К33,8 + солома + гичка забезпечило найвищу урожайність зерна пшениці озимої – 4,39 т/га. As a result of field studies, the effect of predecessors, fertilizer systems and methods of basic tillage on the damage of winter wheat plants by root rot in short-rotation crop rotations in the zone of inadequate moisture was established. The most affected wheat plants of winter rot was found in grain sown crop rotation, where the forerunner was the wheat itself, as well as in the grain-para-breeding crop rotation, where the black pairs were the precursor. The least affected by root rot of winter wheat plants (15.3–20.0 %) at the lowest intensity of disease (5.8–7.3 %) was observed after corn silage. Conducting surface cultivation of soil at a depth of 10–12 cm under grain crops, including under winter wheat, against the background of 6.25 t of manure + N33.8R45.0K33.8 + straw + gill in the crop rotation after corn on silage caused most defeat of wheat plants by root rot (24.4 %) with an increase in the intensity of the disease to a value of 10.5 %. Providing plowing for all crops in the fertile crop rotation for rotation of crop rotation per hectare of arable land of 6.25 tons of manure + N33.8R45.0K33.8 + straw + lace ensured the highest yield of wheat of winter wheat – 4.39 tons/ha.


1984 ◽  
Vol 62 (4) ◽  
pp. 818-822 ◽  
Author(s):  
D. W. A. Roberts

Young plants of the cold-hardy winter wheat (Triticum aestivum L. emend. Thell.) Kharkov 22 MC did not develop atypical prostrate or rosette growth habit unless light supply exceeded 350 klux∙h∙day−1. Prostrate habit developed under both short (10-h) and long (16-h or 24-h) photoperiods. Under a given photoperiod, expression of this trait intensified as light intensities increased. This finding was demonstrated in both field and growth-cabinet experiments. The degree of development of the rosette growth habit may be assessed by plotting plant height against plant age. Plants that develop typical rosettes decline in height when the rosettes develop whereas plants that remain erect show a continuous increase in height.


2018 ◽  
Vol 245 ◽  
pp. 11006 ◽  
Author(s):  
Nadezhda Grebenikova ◽  
Alexander Korshunov ◽  
Vasily Rud’ ◽  
Ivan Savchenko ◽  
Marcia Marques

Researching the special and infraspecial structure in causative agent populations of the most dangerous diseases root rots of cereals in various regions of the Russjan Federation has been carried out. The defeat of cereals root rots old in Russia causes in the a complex patogenic. More often meet Fusarium culmorum (W.G.Sm.) Sacc., F. oxysporum (Schlecht.) Snyd.et Hans., F. heterosporum Nees., F. sporotrichiella nom.nov. Bilai F. gibbosum App.et Wr.emend Bilai., F. avenaceum (Fr.) Sacc. and Bipolaris sorokiniana (Sacc.) Shoem., Alternaria spp.


HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 541e-541
Author(s):  
Gregory L. Reighard ◽  
David R. Ouellette

Large fluctuations in annual peach production is a chronic problem in the southeastern United States. Winter and spring cold injury to flowers reduces the potential peach crop almost every year in the Southeast. A bloom delaying peach interstem has consistently delayed phenology in the Southeast, but its effect on bud hardiness is unknown. Nine varieties (650–1050 chill hours) budded to `Ta Tao 5' (P.I. 101667) interstems on Lovell rootstock or budded to only Lovell rootstock (i.e., controls) were sampled monthly from November or December to late February in 1996–97 and 1997–98 from an interstem test established in 1993 near Clemson, S.C. High-chill varieties such as `Contender', `Encore', and `Redhaven' were 1 to 2 °C more cold-hardy on interstem trees in late winter. General trends showed that varieties were slightly more cold-hardy on interstems in 1996–97, but no differences were observed from Nov.1997 through early Jan. 1998. Significant varietal differences in cold-hardiness were found on each sampling date, but no trends were observed.


1990 ◽  
Vol 68 (5) ◽  
pp. 830-835 ◽  
Author(s):  
W. J. Turnock ◽  
P. M. Reader ◽  
G. K. Bracken

The Canadian population of Delia radicum is more cold hardy than the English population in that the supercooling point is slightly lower and overwintering pupae are less sensitive to lower temperatures and longer exposure times. However, the Canadian population is slightly less cold hardy at higher temperatures within the cold injury zone. Female D. radicum were more susceptible to cold-induced mortality than males among the Canadian population, but this sex difference was not significant in the English population. The proportion of malformed adults and the rate of postdiapause development were not related to cold injury in either population. The bounds of the cold injury zone for species or populations of freezing susceptible, diapausing insects plus the sensitivity of the species to cold injury within this zone can provide an ecologically sound method of describing cold hardiness. Sensitivity, measured by the slope of a regression describing the relationship between survival and the duration of exposure at a low temperature, can also be used to calculate the rate at which cold injury occurs at any temperature within the cold injury zone. This slope may reflect the overwintering conditions of a species or population because Canadian populations of both D. radicum and Mamestra configurata (Noctuidae) have similar coefficients, but these are very different from the coefficient of the English population of D. radicum. The supercooling point did not provide a useful indication of the susceptibility of these cold-hardy diapausing insects to cold injury.


Plant Disease ◽  
2008 ◽  
Vol 92 (9) ◽  
pp. 1299-1306 ◽  
Author(s):  
Berna Tunali ◽  
Julie M. Nicol ◽  
David Hodson ◽  
Zafer Uçkun ◽  
Orhan Büyük ◽  
...  

The objective of this study was to determine the distribution frequency of the fungi associated with wheat (Triticum aestivum) crowns and roots in cereal producing areas of Turkey through a targeted survey of 518 commercial fields over a 2-year period. More than 26% of the fields had one or more of the fungal species commonly reported as part of the dryland root rot complex, Fusarium culmorum (14%) > Bipolaris sorokiniana (10%) > F. pseudograminearum (2%). The fungi considered to be part of the high rainfall root rot complex were found at very low frequencies: 2% for Gaeumannomyces graminis and 3% for Pythium spp. Species of Rhizoctonia were found in 22% of the fields. Several Fusarium species considered to be less or nonpathogenic to cereals were also found in high frequencies at 11% (F. oxysporum, F. chlamydosporum), 10% (F. sporotrichioides), and 8% (F. avenaceum and F. solani). The mostly random distribution of cereal root-rotting species across the survey area suggests the fungi are not distributed in any distinct agroecological relationship. As a result, the relative economic importance of a given species on wheat will be determined by a number of factors, such as their fungal pathogenicity, host susceptibility/tolerance, and the seasonal conditions. Results from this study suggest that there are a wide range of fungal species associated with root and crown tissues of wheat.


Plant Disease ◽  
2016 ◽  
Vol 100 (8) ◽  
pp. 1692-1708 ◽  
Author(s):  
Richard W. Smiley ◽  
Stephen Machado ◽  
Karl E. L. Rhinhart ◽  
Catherine L. Reardon ◽  
Stewart B. Wuest

Rainfed experiments operated continuously for up to 84 years in semiarid eastern Oregon are among the oldest agronomic trials in North America. Disease incidence and severity had been quantified visually but quantification of inoculum density had not been attempted. Natural inoculum of 17 fungal and nematode pathogens were quantified for each of 2 years on eight trials using DNA extracts from soil. Crop type, tillage, rotation, soil fertility, year, and their interactions had large effects on the pathogens. Fusarium culmorum and Pratylenchus thornei were more dominant than F. pseudograminearum and P. neglectus where spring crops were grown, and the opposite species dominances occurred where winter wheat was the only crop. Bipolaris sorokiniana and Phoma pinodella were restricted to the presence of spring cereals and pulse crops, respectively. Helgardia spp. occurred in winter wheat-fallow rotations but not in annual winter wheat. Gaeumannomyces graminis var. tritici was more prevalent in cultivated than noncultivated soils and the opposite generally occurred for Rhizoctonia solani AG-8. Densities of Pythium spp. clade F were high but were also influenced by treatments. Significant treatment effects and interactions were more prevalent in two long-standing (>50-year) annually cropped experiments (29%) than two long-standing 2-year wheat-fallow rotations (14%). Associations among pathogens occurred mostly in an 84-year-old annual cereals experiment. This survey provided guidance for research on dynamics of root-infecting pathogens of rainfed field crops and identified two pathogens (Drechslera tritici-repentis and P. pinodella) not previously identified at the location.


1983 ◽  
Vol 63 (4) ◽  
pp. 879-888 ◽  
Author(s):  
W. G. LEGGE ◽  
D. B. FOWLER ◽  
L. V. GUSTA

The cold hardiness of tillers separated from the plant immediately before freezing (CTM) or left intact on the crown (ICM) was determined by artificial freeze tests on two sampling dates for four winter wheat (Triticum aestivum L.) cultivars acclimated in the field. Plants with 9 and 13 tillers excluding coleoptile tillers were selected in mid-October and at the end of October, respectively. No differences in lethal dose temperature (LT50) were detected among CTM or ICM tillers sampled in mid-October. The three youngest CTM tillers sampled at the end of October were less cold hardy than older tillers. However, younger CTM tillers did not survive the unfrozen control treatment as well as older tillers. ICM tillers sampled at the end of October had the same LT50 except for one of the older tillers. No correlation was found between either the moisture content or dry weight and the LT50 of tillers. Winter survival of tillers was evaluated for two cultivars in the spring. Tillers of intermediate age and two of the youngest tillers had the highest survival rates. Tiller regeneration from axillary buds rather than the apical meristem occurred following cold stress and was negatively correlated to tiller emergence date. It was concluded that differences in cold hardiness among tillers must be taken into consideration if tillers are utilized to estimate the LT50 of a plant.Key words: Cold hardiness, tillers, winter wheat, Triticum aestivum L., developmental stage, moisture content


Plant Disease ◽  
2020 ◽  
Vol 104 (8) ◽  
pp. 2149-2157
Author(s):  
Göksel Özer ◽  
Timothy C. Paulitz ◽  
Mustafa Imren ◽  
Mehtap Alkan ◽  
Hafiz Muminjanov ◽  
...  

A comprehensive survey was performed to assess fungal populations associated with crown and root rot of wheat throughout the main wheat-growing areas of Azerbaijan. Samples were taken from 76 fields; 630 fungal strains were isolated, identified, and evaluated for pathogenicity. The identification was conducted with morphological and molecular tools such as species-specific PCR and DNA sequencing of the internal transcribed spacer (ITS) and translation elongation factor 1-α (EF1-α) loci. The fungus found in the greatest number of fields (44) was Fusarium culmorum with 192 isolates, followed by F. acuminatum. Other Fusarium spp. isolates were identified: F. equiseti, F. pseudograminearum, F. graminearum, F. incarnatum, F. avenaceum, F. hostae, F. oxysporum, F. proliferatum, F. algeriense, and F. brachygibbosum. Bipolaris sorokiniana, Curvularia spicifera, Exserohilum pedicellatum, Nigrospora oryzae, and Rhizoctonia spp. isolates were also identified, associated with underground parts of wheat. Phylogenetic analyses based on ITS and EF1-α sequences of the isolates showed that the isolates belonging to the same species were clearly separated in the dendrogram. Pathogenicity assays revealed that F. culmorum, F. pseudograminearum, and F. graminearum were most aggressive; F. avenaceum, F. hostae, F. algeriense, B. sorokiniana, C. spicifera, and R. solani isolates were moderately aggressive; C. inaequalis, E. pedicellatum, and N. oryzae were weakly aggressive; and others were nonpathogenic. The result of this study exhibited the existence of a wide range of species associated with crown and root rot of wheat in Azerbaijan. Additionally, this is the first report of F. hostae, F. algeriense, C. spicifera, C. inaequalis, and N. oryzae as pathogens on wheat in Azerbaijan. Azerbaijan is the second country after Algeria in which F. algeriense was detected.


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