RECENT OBSERVATIONS ON STRAWBERRY ROOT ROT IN THE NIAGARA PENINSULA

1934 ◽  
Vol 11 (1) ◽  
pp. 18-31 ◽  
Author(s):  
A. A. Hildebrand
Keyword(s):  
Root Rot ◽  
Mycorrhizal Fungi ◽  
Lateral Roots ◽  
Root Systems ◽  
The Other ◽  
Cultivated Plants ◽  
Frequency Of Occurrence ◽  
The Moment ◽  
Apparently Healthy

The investigations reported here have centred largely around isolations from, and critical microscopic examination of, the roots of affected plants. Isolations from 684 young, adventitious and lateral roots showing definite lesions bordered by turgid, healthy tissue, yielded representatives of approximately 20 different genera of fungi, ranging in frequency of occurrence from 0.4% in the case of Gliocladium to 32.7% in the case of Fusarium. Next to Fusarium, isolates of Ramularia and Pythium appeared most frequently and consistently in culture, the former in 28.5%, and the latter in 10.8%, of the plantings. Results of infection experiments involving these as well as other genera, including Penicillium, Rhizoctonia, Hainesia, Cylindrocladium, Coniothyrium and Helminthosporium, are not yet available and it is impossible at the moment to evaluate the significance of their association with the diseased condition of the roots from which they were isolated. Isolations from 125 apparently healthy rootlets occurring on root systems, other parts of which were more or less severely diseased, yielded representatives of nine different genera of fungi, ranging in frequency of occurrence from 1.6% in the case of Alternaria to 5.6% in the case of Ramularia. Isolates of Fusarium appeared in 4.0% of the plantings.Microscopic examination of 550 adventitious and lateral roots of wild and cultivated plants has revealed the almost universal occurrence in their tissues of two of the so-called "endotrophic mycorrhizal fungi." One of these is of the characteristic phycomycetoid type, producing arbuscules and vesicles, the other, of the Rhizoctonia type familiar in orchids. The former type has been observed much more consistently than the latter. In a number of instances both types have been found in the tissues of the same rootlet. At least three strains of the Rhizoctonia type have been isolated but so far all efforts to culture the other organism have been unsuccessful. Resting spores of Olpidiaster (Asterocystis) and the spherical, smooth-walled spores of some member of the Plasmodiophoraceae were observed in diseased rootlets in the early part of the growing season. Pythium was noted in abundance occurring on diseased roots obtained in the field during September and November.Nematodes have been encountered in association with diseased roots in numbers and frequency sufficient to suggest a possible causal relationship to strawberry root rot.

THE MICROBIOLOGICAL BALANCE OF STRAWBERRY ROOT ROT SOIL AS RELATED TO THE RHIZOSPHERE AND DECOMPOSITION EFFECTS OF CERTAIN COVER CROPS

1941 ◽  
Vol 19c (6) ◽  
pp. 199-210 ◽  
Author(s):  
P. M. West ◽  
A. A. Hildebrand
Keyword(s):  
Cover Crops ◽  
Root Rot ◽  
Red Clover ◽  
Root Systems ◽  
The Other ◽  
Leguminous Plants ◽  
Other Hand ◽  
Living State ◽  
Rhizosphere Effects ◽  
Severity Of The Disease

Soybean and red clover, grown as cover crops and incorporated into strawberry root rot soil, showed a marked difference in ability to control the disease on variety Premier. Soybean caused a striking reduction in the incidence of root rot and a drastic shift in the bacterial equilibrium of the soil. Red clover had little effect on the severity of the disease or the general microflora of the soil.A study of "rhizosphere effects" reveals that the characteristic differences between the resultant bacterial equilibrium of the soils in which the two leguminous plants were grown, could not be attributed to influences exerted by the latter in the living state. However, the bacterial types favoured during decomposition in experimental cultures of tissues of red clover and of soybean, each inoculated with root rot soil, were identical with those isolated from root rot soil with which red clover and soybean, respectively, had been incorporated. In contrast to the putrefactive decomposition of red clover, soybeans apparently underwent a carbohydrate breakdown that could be reproduced essentially in culture by the substitution of glucose for soybean tissues. Beneficial changes in the bacteriology of actual root rot soils could be induced by the decomposition of pure carbohydrate in place of soybean. The favourable alteration in the bacterial equilibrium was accompanied by a corresponding modification of the fungous flora such that potentially pathogenic forms were replaced by presumably innocuous ones. These carbohydrate treated soils were capable of producing strawberry plants with well developed healthy root systems. The ability of soybean to control strawberry root rot therefore seems to depend primarily on a carbohydrate type of breakdown in diseased soil, causing a highly favourable shift in the microbiological equilibrium. The decomposition of red clover, on the other hand, did not under the same conditions induce these salutary effects.

Microfungi of crowns and roots of apparently healthy dormant strawberry plants

1969 ◽  
Vol 47 (6) ◽  
pp. 945-949 ◽  
Author(s):  
C. O. Gourley
Keyword(s):  
Root Rot ◽  
The Other ◽  
Fusarium Spp ◽  
Fungal Flora ◽  
Black Root Rot ◽  
Fruit Pathogens ◽  
Apparently Healthy

The crowns and roots of 100 cold-stored, apparently healthy strawberry plants of each of the varieties Acadia, Catskill, Cavalier, Gorella, Guardsman, Midway, Redcoat, Sparkle, and Surecrop were examined for their fungal content. Crowns contained representatives of 43 genera; roots contained 38, of which 36 were in both crowns and roots. Strawberry foliar and fruit pathogens were present in a relatively small number of the crowns and roots. In general, Chaetomium spp. and Fusarium spp. were the most prevalent. Chaetomium cochliodes was more prevalent in Cavalier and Redcoat, the varieties most susceptible to root rot in the field, than in the other varieties. The crowns and roots of apparently healthy, dormant strawberry plants contained a fungal flora similar to that associated with the black root rot complex.One fungus, Varicosporium elodeae, isolated from strawberry plants has not previously been reported in Canada.

scholarly journals Visual and Infrared Assessment of Root Colonization of Apple Trees by Phymatotrichopsis omnivora

Plant Disease ◽  
2000 ◽  
Vol 84 (5) ◽  
pp. 539-543 ◽  
Author(s):  
W. T. Watson ◽  
C. M. Kenerley ◽  
D. N. Appel
Keyword(s):  
Root Colonization ◽  
Lateral Roots ◽  
Canopy Temperature ◽  
Root Systems ◽  
Root Diameter ◽  
The Other ◽  
Apple Trees ◽  
Malus Domestica Borkh ◽  
Central Texas ◽  
Phymatotrichopsis Omnivora

Root systems of 5-year-old, trellised apple trees (Malus domestica Borkh) on cv. M.7a root-stocks were assessed for the presence of fungal strands of Phymatotrichopsis omnivora (Duggar) Hennebert in two orchards in central Texas. Fungal advance within each orchard was assessed in five directions. Pathogen growth (P < 0.01) occurred beyond symptomatic trees along and perpendicularly across rows. In one orchard, 80% of the first asymptomatic trees were infected along rows, followed by 60% infection perpendicularly across rows. In the other orchard, there was 100% infection of the first asymptomatic trees along rows and 60% infection perpendicularly across rows. No growth was observed diagonally across rows in either orchard. Infrared readings of canopy temperature and differences between canopy temperature and air temperature were significant (P < 0.01) for predicting infection of asymptomatic, infected trees in one orchard. Trees were shown to have extensive taproot decay and infection of lateral roots before canopy symptoms began to develop. Root diameter appeared to have no effect on the growth of the fungus.

TEM studies of tweed microstructures in annealed amelia albite

1990 ◽  
Vol 48 (4) ◽  
pp. 1064-1065
Author(s):  
Y. J. Kim ◽  
D. M. Henderson
Keyword(s):  
Annealing Time ◽  
The Other ◽  
Frequency Of Occurrence ◽  
Systematic Trend ◽  
Tweed Structure

Natural Amelia albite (Ab99.3An0.1Or0.6) annealed at 1073° and 924°C for various periods up to 140 days has been studied by NMR. TEM studies of the same sample revealed a distinct tweed microstructure in some samples annealed at both 1073°C and 924°C. On the whole, the quasi-regular tweed has a periodicity of 100 - 200 Å in both directions, one nearly normal to b* and the other approximately parallel to b*, which gives rise to two-directional streaking in SADP’s (Fig. 1 and 2). However, there are some differences in the tweed structure developed on annealing at 1073°C and at 924°C in albite.Albite samples annealed at 1073° show a systematic trend in their development of tweed structures: the regularity, periodicity, and frequency of occurrence increase with annealing time during the first 3 days, and then decrease gradually until no tweed microstructures are seen in samples annealed for more than 15 days. The tweed structure proceeds locally to form one-directional twin-like microstructures.

The Final ‘Thank You’

Derrida Today ◽  
2010 ◽  
Vol 3 (1) ◽  
pp. 21-36
Author(s):  
Grant Farred
Keyword(s):  
South Africa ◽  
South African ◽  
Jacques Derrida ◽  
Political Transition ◽  
The Other ◽  
World Cup ◽  
The Core ◽  
Nelson Mandela ◽  
Black President ◽  
The Moment

‘The Final “Thank You”’ uses the work of Jacques Derrida and Friedrich Nietzsche to think the occasion of the 1995 rugby World Cup, hosted by the newly democratic South Africa. This paper deploys Nietzsche's Zarathustra to critique how a figure such as Nelson Mandela is understood as a ‘Superman’ or an ‘Overhuman’ in the moment of political transition. The philosophical focus of the paper, however, turns on the ‘thank yous’ exchanged by the white South African rugby captain, François Pienaar, and the black president at the event of the Springbok victory. It is the value, and the proximity and negation, of the ‘thank yous’ – the relation of one to the other – that constitutes the core of the article. 1

Macaronics as What Eludes Translation

Paragraph ◽  
2015 ◽  
Vol 38 (2) ◽  
pp. 214-230
Author(s):  
Haun Saussy
Keyword(s):  
Print Culture ◽  
The Other ◽  
Digital Code ◽  
Avant Garde ◽  
The Moment

‘Translation’ is one of our all-purpose metaphors for almost any kind of mediation or connection: we ask of a principle how it ‘translates’ into practice, we announce initiatives to ‘translate’ the genome into predictions, and so forth. But the metaphor of translation — of the discovery of equivalents and their mutual substitution — so attracts our attention that we forget the other kinds of inter-linguistic contact, such as transcription, mimicry, borrowing or calque. In a curious echo of the macaronic writings of the era of the dawn of print, the twentieth century's avant-garde, already foreseeing the end of print culture, experimented with hybrid languages. Their untranslatability under the usual definitions of ‘translation’ suggests a revival of this avant-garde practice, as the mainstream aesthetic of the moment invests in ‘convergence’ and the subsumption of all media into digital code.

Computational and experimental studies of the strength of full-scale samples of pipes with defects "metal loss" and "dent with groove"

2020 ◽  
Vol 10 (3) ◽  
pp. 226-233
Author(s):  
Dmitry A. Neganov ◽  
◽  
Victor M. Varshitsky ◽  
Andrey A. Belkin ◽  
◽  
...  
Keyword(s):  
Internal Pressure ◽  
Experimental Studies ◽  
Full Scale ◽  
The Other ◽  
Metal Loss ◽  
Calculation Methods ◽  
Reliable Operation ◽  
Sufficient Stability ◽  
Comparative Results ◽  
The Moment

The article contains the comparative results of the experimental and calculated research of the strength of a pipeline with such defects as “metal loss” and “dent with groove”. Two coils with diameter of 820 mm and the thickness of 9 mm of 19G steel were used for full-scale pipe sample production. One of the coils was intentionally damaged by machining, which resulted in “metal loss” defect, the other one was dented (by press machine) and got groove mark (by chisel). The testing of pipe samples was performed by applying static internal pressure to the moment of collapse. The calculation of deterioration pressure was carried out with the use of national and foreign methodical approaches. The calculated values of collapsing pressure for the pipe with loss of metal mainly coincided with the calculation experiment results based on Russian method and ASME B31G. In case of pipe with dent and groove the calculated value of collapsing pressure demonstrated greater coincidence with Russian method and to a lesser extent with API 579/ASME FFS-1. In whole, all calculation methods demonstrate sufficient stability of results, which provides reliable operation of pipelines with defects.

Eksplorasi Keragaman FMA yang Bersimbiosis dengan Beberapa Tanaman Budidaya Pada Deposit Fosfat Alam Ayamaru

Agrotek ◽  
2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Antonius Suparno ◽  
Dwiana Wasgito Purnomo ◽  
Karyoto Sardi Amat
Keyword(s):  
Arbuscular Mycorrhiza ◽  
The Other ◽  
Cultivated Plants ◽  
Rock Phosphates ◽  
Other Hand ◽  
Arbuscular Mycorrhiza Fungi

The research was conducted at Soroan, Ayamaru District, South Sorong, Papua. �The objective of the study was to observe the diversity of Arbuscular Mycorrhiza Fungi (AMF) that symbiosis with cultivated plants at the Ayamaru rock phosphates deposit. Based on the observation, there were four AMF associated with nine cultivated plants at the Ayamaru rock phosphates deposit, namely genus Glomus, Acaulospora, Sclerocystis and Gigaspora. Genus Glomus had the greatest diversity (13 types) followed by Acaulospora which comprised of seven types.� On the other hand, the diversity of genus Sclerocystis and Gigaspora only consisted of two types and one type, respectively.

The growth of Easter lily (Lilium longiflorum) as influenced by vesicular–arbuscular mycorrhizal fungi, Fusarium oxysporum, and fertility level

1978 ◽  
Vol 56 (21) ◽  
pp. 2773-2780 ◽  
Author(s):  
R. N. Ames ◽  
R. G. Linderman
Keyword(s):  
Fusarium Oxysporum ◽  
Root Rot ◽  
Mycorrhizal Fungi ◽  
Control Plant ◽  
Fertilizer Treatment ◽  
Fertility Level ◽  
High Inoculum ◽  
Easter Lily ◽  
Vesicular Arbuscular ◽  
Pot Culture

Easter lily bulbs were inoculated in the greenhouse with pot-culture inoculum containing a mixture of four vesicular–arbuscular (VA) mycorrhizal fungi as well as other fungi and bacteria, including pathogens. These organisms had multiplied in association with roots of lily, onion, and clover in pot cultures inoculated with sievings from lily field soils. Growth, as measured by bulb weight gain, root volume, and total leaf area, was determined on lily bulb plants inoculated at two inoculum levels and grown under three fertilizer regimes. Growth of plants inoculated with pot-culture inoculum was less than that of controls, especially in plants given the high inoculum (which included pot-culture plant roots) and the high rate of fertilization. The growth reduction apparently was due to the combined effect of greater incidence of Fusarium oxysporum root rot infections, damage to roots from fertilizer, and lower incidence of VA mycorrhizal infections. More mycorrhizal infections occurred in the low-fertilizer treatment than in the high- or no-fertilizer treatments at both high and low inoculum levels, but more F. oxysporum root rot occurred in the high-inoculum, high-fertilizer treatment.In a second experiment, lily seedlings that lacked bulb nutrient reserves were grown at a low fertilizer level and inoculated with Acaulospora trappei without any pathogens. Mycorrhizal plants were significantly larger than nonmycorrhizal control plants, and their tissues contained more N, P, K, Ca, and Mg than control plant tissues.

Planting Betula pendula on pine sites infested by Heterobasidion annosum: disease transfer, silvicultural evaluation, and community of wood-inhabiting fungi

2004 ◽  
Vol 34 (1) ◽  
pp. 120-130 ◽  
Author(s):  
Vaidotas Lygis ◽  
Rimvydas Vasiliauskas ◽  
Jan Stenlid
Keyword(s):  
Root Rot ◽  
Forest Regeneration ◽  
Betula Pendula ◽  
Root Systems ◽  
Fungal Species ◽  
Heterobasidion Annosum ◽  
Strong Impact ◽  
Fungal Isolation ◽  
Somatic Incompatibility ◽  
Forest Sites

Persistence of the root rot pathogen Heterobasidion annosum (Fr.) Bref. s.s. on infested areas and its transfer to a forest regeneration was studied in three forest sites in eastern Lithuania. The sites represented H. annosum disease centres in Pinus sylvestris L. stands, which were clear-felled and replanted with Betula pendula Roth 25 years prior to our study. Fungal isolation from trees and stumps on each site was performed on both replanted B. pendula and surrounding P. sylvestris from the previous generation. Low productivity of B. pendula stands (45.0–76.1 m3·ha–1), high mortality rates, and comparatively low vigor of trees (measured as crown densities) indicated a strong impact of root rot. Based on somatic incompatibility tests, we detected large spreading areas of clones of H. annosum (up to 48 m across) and old (35- to 40-year-old) clonal individuals. Territorial clones covered areas that encompassed both previous stands of P. sylvestris and current stands of B. pendula. Our results showed that H. annosum is able to persist in root systems of diseased trees for decades and readily attack birch replanted on infested sites. In addition, a total of 83 fungal species (out of 398 isolates) was found as a result of sampling 508 B. pendula, 49 P. sylvestris, 21 Juniperus communis L., and 1 Salix cinerea L. trees.

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