scholarly journals Yield reduction caused by a soil-borne disease of naked, dwarf, and conventional oat in Finland

1996 ◽  
Vol 5 (4) ◽  
pp. 475-483
Author(s):  
Pirjo Peltonen-Sainio ◽  
Jari P. T. Valkonen ◽  
Hilkka Koponen
Keyword(s):  
Root Rot ◽  
Severe Disease ◽  
Fusarium Culmorum ◽  
Yield Reduction ◽  
Above Ground Biomass ◽  
Yield Losses ◽  
Fusarium Spp ◽  
Warm Weather ◽  
The University ◽  
Field Plots

A severe disease occurred in the field plots of naked (cv. Salomon), dwarf (cv. Pal), and conventional oat (cvs. Jalostettu maatiainen and Salo) at the Viikki Experimental Farm of the University of Helsinki, Finland, in 1994 and 1995. Symptoms were expressed as grayish-brown necrotic areas on the lower leaves which killed plants from the seedling to heading stage, the effect being cultivar dependent. The proportion of plants killed contributed to the yield losses. The infection also resulted in less grains per panicle and lower weight of both panicle and vegetative above-ground biomass. From a total of 57 fungal isolates obtained from infected leaves, Fusarium culmorum (W.G.Sm.) Sacc. and F. sambucinum Fuck, dominated and subsequently caused infection (particularly foot and root rot) in oat in laboratory tests. These two Fusarium spp. were considered to be the primary causal agents of the symptoms observed in the field, although other pathogens may have been present. The disease was probably soil-borne. The results of this study suggested that the unusually dry and warm weather during late June and in July was the principal factor behind the severe disease outbreak.

STUDIES ON FOOT AND ROOT ROT OF WHEAT: IV. EFFECT OF CROP ROTATION AND CULTURAL PRACTICE ON THE RELATIVE PREVALENCE OF HELMINTHOSPORIUM SATIVUM AND FUSARIUM SPP. AS INDICATED BY ISOLATIONS FROM WHEAT PLANTS

1934 ◽  
Vol 10 (1) ◽  
pp. 115-124 ◽  
Author(s):  
W. C. Broadfoot
Keyword(s):  
Root Rot ◽  
Cultural Practices ◽  
Fusarium Culmorum ◽  
Cultural Practice ◽  
Root Tissue ◽  
Fusarium Spp ◽  
Crown Tissue ◽  
Helminthosporium Sativum ◽  
Relative Prevalence ◽  
Marked Tendency

The crown and root tissue from 43,305 of 47,360 plants examined in this investigation yielded Helminthosporium sativum, Fusarium culmorum and other Fusarium spp., either alone or in combination with these or other fungi and bacteria. It was the exception for any mature plant, the surface tissue of which was disinfected, to be free from fungi or bacteria. None of the various crop sequences or cultural practices used in this study appeared to significantly affect more than another the relative prevalence of either H. sativum or Fusarium spp., as indicated by isolations from the crown tissue of wheat. However, as there was a marked tendency at certain stations each year for H. sativum or Fusarium spp. to predominate, it was concluded that certain factors of the environment were more effective than the crop sequence in modifying the relative prevalence of the two fungi mentioned in the crown and root tissue of wheat plants.

STUDIES ON THE CONTROL OF ROOT-ROT DISEASES OF CEREALS: IV. INFLUENCE OF MECHANICAL SEED INJURY ON INFECTION BY FUSARIUM CULMORUM IN WHEAT

1936 ◽  
Vol 14c (12) ◽  
pp. 438-444 ◽  
Author(s):  
J. E. Machacek ◽  
F. J. Greaney
Keyword(s):  
Root Rot ◽  
Field Experiments ◽  
Fusarium Culmorum ◽  
Western Canada ◽  
Wheat Seed ◽  
Fusarium Root Rot ◽  
Field Plots ◽  
Made In ◽  
Experimentally Induced

The results of field experiments made in 1932, 1933, and 1934, to determine the effect of mechanical seed injury on the incidence of root rot caused by Fusarium culmorum and on yield in wheat are presented.Successful positive attacks of Fusarium root rot were experimentally induced in field plots. The tests showed that reduced emergence, increased root rot, and reduced yield uniformly followed the planting of injured wheat seed; and that the amount of disease increased and the yield decreased with an increase in the degree of seed injury. In these experiments Mindum and Marquis wheat seemed equally affected by seed injury.The investigation suggests that the large annual losses in yield caused by root-rot diseases of cereals in Western Canada may be substantially reduced by sowing clean, vigorous, sound seed.

scholarly journals Reaction of spring barley cultivars grown in Finland to soil-borne infection by Bipolaris sorokiniana and to its toxic metabolites

1985 ◽  
Vol 57 (2) ◽  
pp. 85-96
Author(s):  
Aarne Kurppa
Keyword(s):  
Root Rot ◽  
Spring Barley ◽  
Severe Disease ◽  
Bipolaris Sorokiniana ◽  
Toxin Production ◽  
Yield Losses ◽  
Disease Symptoms ◽  
Barley Cultivars ◽  
Toxic Metabolites ◽  
The Mean

Soil-borne infection of Bipolaris sorokiniana caused foot and root rot in all spring barley cultivars studied. Significant differences in susceptibility of the cultivars and pathogenicity of the fungus isolates were found. Primary symptoms caused by the fungus were seedling blight, later foot and root rot. Yield losses caused by the fungus varied from 3 % to 33 % the mean being c. 15 %. Yield losses could occur without severe disease symptoms. Toxic metabolites produced by the fungus induced visible foot and root symptoms in all cultivars tested and caused lesions in the leaves of some cultivars. Variability in toxin production of fungus isolates as well as the reaction of a cultivar to toxins was demonstrated. The cultivars most susceptible to soil-borne infection by the fungus also showed the most severe symptoms when exposed to toxic metabolites of the fungus.

scholarly journals Influence of Formononetin and NaCl on Mycorrhizal Colonization and Fusarium Crown and Root Rot of Asparagus

Plant Disease ◽  
2002 ◽  
Vol 86 (12) ◽  
pp. 1318-1324 ◽  
Author(s):  
Wade H. Elmer
Keyword(s):  
Sodium Chloride ◽  
Root Rot ◽  
Arbuscular Mycorrhizae ◽  
Soil Cores ◽  
Fusarium Spp ◽  
Left Behind ◽  
Vesicular Arbuscular ◽  
Vam Colonization ◽  
Crown And Root Rot ◽  
Field Plots

Replanted asparagus fields commonly fail to produce a profitable stand due to alleopathic residues left behind from the previous asparagus crop, elevated densities of pathogenic Fusarium spp., and low densities of vesicular arbuscular mycorrhizae (VAM). Formononetin, a plant isoflavone that stimulates VAM spores to germinate, and sodium chloride (NaCl), a disease-suppressing amendment, were evaluated alone and in combination for their effect on reestablishing asparagus at two locations in abandoned asparagus fields. Greenhouse studies also were conducted with naturally and artificially infested soils. Formononetin was applied as a crown soak or soil drench, and NaCl was applied as a granular treatment. Feeder roots from soil cores sampled from field plots and from greenhouse transplants were assayed for colonization by VAM and for lesions caused by Fusarium oxysporum and F. proliferatum. Formononetin increased the number of VAM vesicles in roots from the field and greenhouse studies and reduced the percent root lesions caused by Fusarium spp. when compared with the nontreated controls. NaCl was more effective than formononetin in reducing the percentage of root lesions in both field and greenhouse experiment when compared with untreated plants but had no effect on VAM colonization. However, there was evidence that NaCl negated the effect of formononentin on VAM colonization. The NaCl treatment increased the May 2001 spear number by 15% and marketable spear weight by 23%. At one site, treatment with formononetin increased mean number of stalks per plant by 29% in 2000 and 14% in 2001. Both formononetin and NaCl improve growth and reduce disease of asparagus in replanted asparagus and may be useful in reestablishing asparagus in abandoned asparagus field.

Multiple infections of subcrown internodes of wheat (Triticum aestivum) by common root rot fungi

1977 ◽  
Vol 55 (1) ◽  
pp. 30-34 ◽  
Author(s):  
R. D. Tinline
Keyword(s):  
Triticum Aestivum ◽  
Root Rot ◽  
Fusarium Culmorum ◽  
Cochliobolus Sativus ◽  
Multiple Infections ◽  
Common Root ◽  
Fusarium Spp ◽  
Common Root Rot ◽  
Fusarium Sp

In the greenhouse, subcrown internodes of wheat plants were inoculated with Cochliobolus sativus (Ito & Kurib.) Drechsler ex Dastur, Fusarium culmorum (W. G. Smith) Sacc., F. acuminatum Ell. & Ev., or F. sulplureum Schlecht. and at various times subsequently with C. sativus; or the internodes were inoculated with C. sativus and subsequently with it or a Fusarium sp. Using isolation of the fungi as the criterion for infection, it was found that prepossession of the internode by C. sativus did not prevent later invasion by it or by the fusaria; however, C. sativus was a relatively unsuccessful challenger to F. culmorum and F. acuminatum. The results suggest that when C. sativus and one of these two Fusarium spp. appear together in isolations from common root rot diseased plants that the initial invader was C. sativus.

Assessment of tolerance for reducing yield losses in field pea caused by Aphanomyces root rot

2013 ◽  
Vol 93 (3) ◽  
pp. 473-482 ◽  
Author(s):  
R. L. Conner ◽  
K. F. Chang ◽  
S. F. Hwang ◽  
T. D. Warkentin ◽  
K. B. McRae
Keyword(s):  
Disease Severity ◽  
Root Rot ◽  
Weight Ratio ◽  
Field Pea ◽  
Control Measures ◽  
Effective Control ◽  
Yield Losses ◽  
Plant Vigour ◽  
Shoot Weight ◽  
High Yields

Conner, R. L., Chang, K. F., Hwang, S. F., Warkentin, T. D. and McRae, K. B. 2013. Assessment of tolerance for reducing yield losses in field pea caused by Aphanomyces root rot. Can. J. Plant Sci. 93: 473–482. Aphanomyces root rot, caused by Aphanomyces euteiches Drechs., is a serious disease of peas (Pisum sativum) that can severely reduce seed yield, and few effective control measures are available. The development of pea cultivars with tolerance or partial resistance to Aphanomyces root rot is generally considered to be one of the best options to reduce yield loss. A 4-yr field study was conducted at disease-free sites and at an Aphanomyces root rot site to compare the responses of cultivars and lines in the presence and absence of Aphanomyces root rot, identify breeding lines with tolerance and to evaluate the effects of tolerance on plant growth, disease severity and yield. At the Aphanomyces root rot site, a second test was established in which the phosphite fungicide Phostrol™ was applied as a soil drench treatment to the pea cultivars and lines. Aphanomyces root rot reduced seedling emergence, biomass production and yield in the susceptible pea genotypes. However, line 00-2067 consistently produced relatively high yields at all the field sites. At the Aphanomyces root rot site, yield was closely associated with plant vigour and shoot weight. Small, but significant, differences (P<0.05) in disease severity were observed between susceptible cultivars and tolerant lines indicating that the lines producing high yields at the Aphanomyces root rot site are tolerant rather than partially resistant. The root/shoot weight ratio was very low in the tolerant lines, indicating that even though their root systems were reduced and severely damaged by root rot, they were still able to produce high yields under favourable conditions for the disease. Drench application of the fungicide Phostrol™ did not significantly reduce root rot severity or improve the performance of any of the pea cultivars or lines.

scholarly journals Integrated radar and lidar analysis reveals extensive loss of remaining intact forest on Sumatra 2007–2010

2015 ◽  
Vol 12 (22) ◽  
pp. 6637-6653 ◽  
Author(s):  
M. B. Collins ◽  
E. T. A. Mitchard
Keyword(s):  
Average Rate ◽  
Forest Biomass ◽  
Forest Monitoring ◽  
Synthetic Aperture ◽  
Lidar Data ◽  
Above Ground Biomass ◽  
Swamp Forest ◽  
L Band ◽  
Field Plots ◽  
Change Map

Abstract. Forests with high above-ground biomass (AGB), including those growing on peat swamps, have historically not been thought suitable for biomass mapping and change detection using synthetic aperture radar (SAR). However, by integrating L-band (λ = 0.23 m) SAR from the ALOS and lidar from the ICESat Earth-Observing satellites with 56 field plots, we were able to create a forest biomass and change map for a 10.7 Mha section of eastern Sumatra that still contains high AGB peat swamp forest. Using a time series of SAR data we estimated changes in both forest area and AGB. We estimate that there was 274 ± 68 Tg AGB remaining in natural forest (&amp;geq; 20 m height) in the study area in 2007, with this stock reducing by approximately 11.4 % over the subsequent 3 years. A total of 137.4 kha of the study area was deforested between 2007 and 2010, an average rate of 3.8 % yr−1. The ability to attribute forest loss to different initial biomass values allows for far more effective monitoring and baseline modelling for avoided deforestation projects than traditional, optical-based remote sensing. Furthermore, given SAR's ability to penetrate the smoke and cloud which normally obscure land cover change in this region, SAR-based forest monitoring can be relied on to provide frequent imagery. This study demonstrates that, even at L-band, which typically saturates at medium biomass levels (ca. 150 Mg ha−1), in conjunction with lidar data, it is possible to make reliable estimates of not just the area but also the carbon emissions resulting from land use change.

Biology and Control of Black Nightshade (Solanum nigrum) in Cotton (Gossypium hirsutum)

1991 ◽  
Vol 5 (4) ◽  
pp. 713-722 ◽  
Author(s):  
Paul E. Keeley ◽  
Robert J. Thullen
Keyword(s):  
Soil Moisture ◽  
Sprinkler Irrigation ◽  
Yield Losses ◽  
Accelerated Degradation ◽  
Black Nightshade ◽  
Excellent Control ◽  
Late Application ◽  
And Control ◽  
Field Plots ◽  
Weed Resistance

A 4-yr study (1985, 1987, 1988, 1989) was conducted on the same field plots at Shafter, CA to evaluate the efficacy of prometryn in controlling black nightshade on planting beds of cotton. Two rates (1.7 and 2.2 kg ai ha–1) were applied at two times (mid March before the preplant irrigation and early April at cotton planting) each year. Incorporation of prometryn into moist planting beds with a powered rotary tiller operated at 10 cm deeper resulted in excellent control of black nightshade under low to moderate weed pressure in 1985 and 1987. Control of nightshade with early and late applications of 1.7 kg ha–1of prometryn under high weed pressure in 1988 was only 70% at harvest, and yield losses of cotton averaged 25%. Yields of cotton treated with 2.2 kg ha–1of prometryn in 1988 were not significantly different from weed-free plots. Only the late application of 2.2 kg ha–1of prometryn prevented significant cotton losses under extreme weed pressure in 1989. Cotton yield losses with the other prometryn treatments ranged from 78 to 100%. Losses of cotton in weedy-check plots that received only cultivation ranged from 22% in the absence of rain or irrigation at cotton planting in 1987 to as much as 100% when rain fell in 1988 or plots were irrigated at planting in 1989. Plots hoed one time 4 wk after cotton planting yielded an average of 84% as much seed cotton as weed-free plots. In an attempt to determine why the efficacy of prometryn declined between 1985 and 1989, several experiments were conducted in 1988 to 1990 to discover reasons for this poor control of nightshade. Because efforts failed to provide evidence for the movement of the herbicide with water, the development of weed resistance to prometryn, or accelerated degradation of this herbicide in soil, increasing weed seed populations in soil were believed to have contributed greatly to the declining nightshade control from prometryn. The fact that prometryn applied and incorporated into flat soil provided excellent control of nightshade in 1990 under sprinkler irrigation indicated that both soil moisture and incorporation techniques limited activity of prometryn in planting beds in 1988 and 1989. Incomplete control of nightshade plus good soil moisture at planting contributed to the high weed populations in 1988 and 1989.

scholarly journals Taxonomic composition and incidence of phytopathogenic fungi on the roots of soft spring wheat in the Kansk-Krasnoyarsk forest-steppe

2021 ◽  
Vol 2 (44) ◽  
pp. 22-22
Author(s):  
Alexander Saakian ◽  
◽  
Keyword(s):  
Spring Wheat ◽  
Root Rot ◽  
Bipolaris Sorokiniana ◽  
Triticum Aestivum L ◽  
Wheat Root ◽  
Phytopathogenic Fungi ◽  
Taxonomic Composition ◽  
Forest Steppe ◽  
Root Infection ◽  
Fusarium Spp

The taxonomic composition and incidence of phytopathogenic fungi on the roots of soft spring wheat Triticum aestivum L. of nine varieties of Siberian origin (Altayskaya 70, Altayskaya 75, Krasnoyarskaya 12, Novosibirskaya 15, Novosibirskaya 16, Novosibirskaya 29, Novosibirskaya 31, Novosibirskaya 41 and Svirel) cultivated using wheat and fallow as a predecessor, was studied in the area of Kansk-Krasnoyarsk forest-steppe. Average incidence of fungal root infection was 24%. In plants grown using wheat as a predecessor, the incidence was statistically significantly (p <0.05) higher than in plants grown using fallow as a predecessor (27.3 versus 20.6%). Statistically significant (p <0.05) differences in the prevalence of root infection were revealed between cultivars. The maximal prevalence (33.3 and 32.3%, respectively) on average for the wheat predecessor and fallow was found for the varieties Svirel and Altayskaya 75, the minimal (16.7%) for the varieties Novosibirskaya 16 and Altayskaya 70. The complex of phytopathogenic fungi on the roots is represented by Fusarium spp., Bipolaris sorokiniana and Alternaria spp. (31.4, 44.9 and 23.7% of the pathogenic complex on average for varieties and variants, respectively). The composition of pathogens statistically significantly (p <0.01) depends on the predecessor. In the plants cultivated using wheat as a predecessor, the proportion of Alternaria spp. was higher whereas proportions of Fusarium spp. and Bipolaris sorokiniana were lower. No differences in prevalence and taxonomic composition of root infection between varieties originated from Novosibirsk territory, Krasnoyarsk territory and Altay territory were found. Keywords: SPRING WHEAT, ROOT ROT, KRASNOYARSK TERRITORY, FUSARIUM SPP., BIPOLARIS SOROKINIANA, ALTERNARIA SPP

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