Fungi associated with root and hypocotyl diseases of seedling lupins in Western Australia

1989 ◽  
Vol 40 (4) ◽  
pp. 781 ◽  
Author(s):  
MW Sweetingham
Keyword(s):  
Field Experiment ◽  
Western Australia ◽  
Root Rot ◽  
Fusarium Spp ◽  
Pythium Irregulare ◽  
Root Pathogen ◽  
Isolation Frequency ◽  
South West ◽  
Pot Experiments ◽  
Pathogenicity Tests

Pleiochaeta setosa, Pythium irregulare, Fusarium spp. and Rhizoctonia spp. were frequently isolated from root lesions on lupin seedlings growing at 18 locations in the temperate south-west of Western Australia. P. setosa was isolated from all 13 sites where lupins had previously been grown (average isolation frequency 90%) but from none of the 5 sites with no lupin history. P. setosa was pathogenic in pot experiments using colonized millet or conidia as inoculum. Certain isolates of P. irregulare and Rhizoctonia spp. were pathogenic, but all Fusarium isolates appeared very weak or non-pathogenic. In a fungicide drench field experiment Rovral� reduced the isolation of P, setosa from roots by 97% and reduced root rot by 42%, providing complementary evidence for the importance of P. setosa as a root pathogen in Western Australia.Rhizoctonia solani was isolated from characteristic reddish-brown hypocotyl lesions and reproduced these symptoms in pathogenicity tests.

Fungi associated with root rot of subterranean clover in Western Australia

1985 ◽  
Vol 25 (3) ◽  
pp. 574 ◽  
Author(s):  
DH Wong ◽  
MJ Barbetti ◽  
K Sivasithamparam
Keyword(s):  
Fusarium Oxysporum ◽  
Western Australia ◽  
Root Rot ◽  
Seedling Emergence ◽  
Subterranean Clover ◽  
First Record ◽  
Field Trials ◽  
Pythium Irregulare ◽  
Highly Pathogenic ◽  
South West

Field trials were conducted during 1982-84 to determine the severity of root rot, and the identity and pathogenicity of the fungi associated with root rot of subterranean clover at five locations in the south-west of Western Australia. At all sites, there was moderate to severe root rot and seedling emergence was greatly reduced. Pythium irregulare and Fusarium oxysporum were the fungi most frequently isolated from diseased roots. F. avenaceum, P. irregulare, P. spinosum and R. solani were highly pathogenic to subterranean clover seedlings. F. oxysporum and P. medicaginis were less pathogenic and F. acuminatum, F. culmorum, F. equiseti, one isolate of M. phaseoli, and W. circinata were only weakly pathogenic. Ceratobasidium sp. (AG K), F. sulphureum, one isolate of M. phaseoli, P. coloratum, and R. cereale were non-pathogenic. This is the first record of pathogenicity of F. acuminatum, F. culmorum, F. equiseti, M. phaseoli and P. spinosum on subterranean clover in Western Australia. P. clandestina was detected at all sites.

High phosphorus concentrations in seed of wheat and annual medic are related to higher rates of dry matter production of seedlings and plants

1988 ◽  
Vol 28 (6) ◽  
pp. 765 ◽  
Author(s):  
MDA Bolland ◽  
MJ Baker
Keyword(s):  
Triticum Aestivum ◽  
Field Experiment ◽  
Western Australia ◽  
Dry Matter ◽  
Field Experiments ◽  
Medicago Polymorpha ◽  
P Concentration ◽  
Pot Experiments ◽  
Matter Production ◽  
Burr Medic

Seed of 2 cultivars of wheat (Triticum aestivum) and 1 burr medic (Medicago polymorpha) with increasing phosphorus (P) concentrations (wheat 1.4-3.7 g P/kg dry matter, medic 3.3-7.9 g P/kg dry matter) were collected from field experiments with variable levels of applied superphosphate (wheat 0- 577 kg P/ha, medic 0-364 kg P/ha) in south-western Australia. These seeds were used in further experiments to examine the effect of seed P concentration on the subsequent dry matter (DM) production of seedlings and plants in 3 glasshouse pot experiments and 1 field experiment. Seed of the same size (wheat, 35 mg/seed; medic, 3.6 mg/seed) but with increasing P concentration produced substantially higher DM yields in the absence or presence of freshly applied superphosphate P up to 28-35 days after sowing in the pot experiments and 67 days after sowing in the field experiment.

The occurrence of root-infecting fungi and parasitic nematodes in annual Medicago spp. in Western Australian pastures

2000 ◽  
Vol 51 (4) ◽  
pp. 435 ◽  
Author(s):  
M. P. You ◽  
K. Sivasithamparam ◽  
I. T. Riley ◽  
M. J. Barbetti
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
Pathogenic Fungi ◽  
Parasitic Nematodes ◽  
Fungal Isolates ◽  
As Species ◽  
Significant Damage ◽  
Pathogenicity Tests ◽  
Annual Medicago

Asurvey of 30 medic pastures for root-rots was undertaken in Western Australia and pathogenicity tests of representative fungal isolates from roots sampled were conducted to determine the main factors contributing to medic decline and the association between those factors. In particular, the contribution of pathogenic fungi and nematodes to medic root-rot in Western Australia was studied. From a total of 30 000 pieces of root plated, 3836 fungal isolates were obtained and identified at least to genus level. Four hundred and seventy-two representative isolates were tested for in vitro pathogenicity in Medicago sphaerocarpos cv. Orion. Of these, 32 were further tested in the glasshouse. The pathogenicity tests indicated that 56% of isolates were capable of causing significant damage to the root system and it is likely that pathogenic fungi are largely responsible for medic root-rot in the field. In contrast, the number of Pratylenchus spp. in the roots was not found to relate to disease symptoms. It is concluded that soil-borne pathogenic fungi such as species of Pythium, Fusarium, and Phoma contribute significantly to medic pasture decline in Western Australia.

scholarly journals Control of Soilborne Pathogenic Fungi in Fields of Sweet Onion

Plant Disease ◽  
1997 ◽  
Vol 81 (8) ◽  
pp. 885-891 ◽  
Author(s):  
Donald R. Sumner ◽  
Ronald D. Gitaitis ◽  
J. Danny Gay ◽  
Doyle A. Smittle ◽  
Bryan W. Maw ◽  
...  
Keyword(s):  
Methyl Bromide ◽  
Soil Fungi ◽  
Field Experiments ◽  
Pathogenic Fungi ◽  
Fusarium Spp ◽  
Pythium Irregulare ◽  
Metam Sodium ◽  
Selective Media ◽  
Pathogenicity Tests ◽  
Direct Seeded

Populations of soil fungi from fields planted to sweet onion were assayed on selective media. In pathogenicity tests, Rhizoctonia solani AG-4, Pythium irregulare, and Phoma terrestris were the fungi most virulent on onion seedlings. Plots were fumigated with methyl bromide (MBR), chloropicrin (CP), MBR + CP (67% + 33%), metam sodium, 1,3,-dichloropropene (1,3-D), or 1,3-D + 17% CP in four field experiments in 2 years. Sweet onion was transplanted or direct seeded in October or November and harvested in April or May. MBR + CP and CP were effective in reducing populations of Phoma terrestris, Pythium spp., Fusarium spp., and R. solani AG-4 in soil. Metam-sodium and 1,3-D + 17% CP were less efficacious, and MBR and 1,3-D were ineffective. There were no differences in the percentage of bulbs with decay at harvest or after curing among treatments. Increased yield of marketable bulbs was associated with control of soilborne pathogenic fungi. In fields continuously cropped to onion, decreased yield was primarily associated with control of pink-root induced by Phoma terrestris, and P. terrestris was identified in soil from 74% of the fields assayed.

Root rot caused by Pythium irregulare Buisman, an important factor in the decline of established subterranean clover pastures

1974 ◽  
Vol 25 (4) ◽  
pp. 537 ◽  
Author(s):  
GE Stovold
Keyword(s):  
Root Rot ◽  
Subterranean Clover ◽  
Common Disease ◽  
Crop Species ◽  
Pythium Irregulare ◽  
Factors Affecting ◽  
South Wales ◽  
Matter Production ◽  
Pathogenicity Tests

The problem of poor re-establishment and poor seasonal production in long-term subterranean clover pastures has been recognized for some time, particularly on the Southern Tableland and Slopes regions of New South Wales. Field and laboratory investigations showed that rotting of the lateral feeder roots was a common disease of subterranean clover during the cool part of the growing season. Isolations made from diseased roots yielded a predominance of Pythium spp. of which Pythiurn irregulare was the most common. Pathogenicity tests demonstrated that P. irregulare consistently caused damping-off of germinating subterranean clover. This fungus also infected established plants and at low temperatures caused severe reduction of dry matter production. Symptoms produced on artificially inoculated plants were identical with those observed on plants infected in the field. Soil moisture and the level of fungal inoculum added did not have a critical effect on the severity of root disease. A range of other important pasture and crop species were also artificially infected with P. irregulare, with resulting necrosis of feeder roots. In vitro studies of factors affecting the growth of P. irregulare showed that this pathogen was well adapted to survive and cause disease in cold wet soils, the conditions most favourable for root rot in the field. The importance of P. irregulare as a pathogen of established plants and possible means of reducing its effect on the growth of subterranean clover are discussed.

Root rot of subterranean clover in the irrigation areas of south-western Western Australia

1978 ◽  
Vol 18 (92) ◽  
pp. 426 ◽  
Author(s):  
MJ Barbetti ◽  
GC MacNish
Keyword(s):  
Western Australia ◽  
Root Rot ◽  
Lateral Root ◽  
Disease Incidence ◽  
Seedling Emergence ◽  
Soil Water Potential ◽  
Subterranean Clover ◽  
Pythium Irregulare ◽  
Plant Emergence ◽  
Apparently Healthy

Investigations in 1974 identified the fungi associated with the roots of subterranean clover at four irrigated sites at Wagerup, Western Australia. Two of these sites had previously had a disease problem, two were apparently healthy. A range of fungi were isolated, including Pythium irregulare, P. debaryanum, P. acanthicum, P. middletonii, Fusarium oxysporum, and Rhizoctonia spp. There was a more rapid buildup of Pythium spp. population following the initial irrigation, and an overall lower incidence of Fusarium spp., at the diseased sites. The incidence of Rhizoctonia spp. was usually low and variable at all sites. Disease index ratings rose more rapidly for diseased sites. No association was proven between disease incidence and soil water potential. The three most frequently isolated fungi; viz. P. irregulare, P. acanthicum, and F. oxysporum, were all shown to be capable, under the conditions of this investigation, of producing high levels of tap and lateral root rot, and of causing reductions in seedling emergence. In some cases the levels of both tap and lateral root rot were increased, and the plant emergence decreased, by the application of two or more fungi in combination in comparison with application of a single fungus. Overall P. irregulare was the most pathogenic of the fungi tested.

scholarly journals Pathogenicity of fungi colonising the soil after the cultivation of cover crops towards the seedlings of salsify Tragopogon porrifolius var. sativus (Gaterau) Br.

2008 ◽  
Vol 20 (2) ◽  
pp. 75-84
Author(s):  
Elżbieta Patkowska ◽  
Mirosław Konopiński
Keyword(s):  
Sclerotinia Sclerotiorum ◽  
Cover Crops ◽  
Root Rot ◽  
Plant Pathogens ◽  
Fusarium Culmorum ◽  
Disease Index ◽  
Soil Environment ◽  
Common Vetch ◽  
Pythium Irregulare ◽  
Pathogenicity Tests

Abstract The purpose of the present study was to conduct pathogenicity tests for salsify seedlings in a soil environment colonised by selected fungi species, after the cultivation of cover crops such as oats, common vetch and tancy phacelia. A growth chamber experiment used the seeds of ‘Mamut’ salsify and soil overgrown with Altenaria alternata, Fusarium culmorum, F. oxysporum, Pythium irregulare, Rhizoctonia solani and Sclerotinia sclerotiorum. The pathogenicity of these microorganisms towards salsify seedlings was established on the basis of the grown plants, their health and a disease index calculated on the basis of a fivedegree scale. The examined isolates considerably weakened the emergence and health of salsify. Based on pathogenicity tests, such species as R. solani, S. sclerotiorum and P. irregulare were considered as the major cause of seedling necrosis and root rot of the plants of the Tragopogon porrifolius var. sativus. Among the studied soil-borne plant pathogens, the most pathogenic ones towards salsify seedlings proved to be the isolates of R. solani, S. sclerotiorum and P. irregulare, whereas the least harmful included A. alternata and F. culmorum.

scholarly journals Isolation, Identification and Biomanagement of Root Rot of Black Cumin (Nigella sativa) Using Selected Bacterial Antagonists

2017 ◽  
Vol 6 (3) ◽  
pp. 47-56 ◽  
Author(s):  
Al-Sman K. Mohamed ◽  
Abo-El-yousr A. M. Kamal ◽  
Eraky Amal ◽  
El-Zawahry Aida
Keyword(s):  
Root Rot ◽  
Nigella Sativa ◽  
Fusarium Spp ◽  
Black Cumin ◽  
Genus Fusarium ◽  
Fungal Isolates ◽  
Fusarium Lateritium ◽  
Pathogenicity Tests ◽  
Causal Pathogen

The study deal with potentiality of some bioagents for controlling the root rot of black cumin under greenhouse conditions, caused by Fusarium spp. Eight fungal isolates were obtained from diseased of back cumin plants collected from Assiut Governorate. These isolates were belonged to the genus Fusarium spp. They were identified as, four isolates of F. comptoceras, three isolates of F. solani and one isolate Fusarium lateritium. Pathogenicity tests indicated that all tested fungal isolates were able to infect black cumin plants causing symptoms of root rot resulted in dwarfism and death before the capsules mature. They varied in their pathogenicity, Fusarium comptoceras No.1 gave the highest percentage of disease severity and percentage of infection on black cumin plants (53 and 50% respectively), while isolates F. comptoceras Nos. 3 and F. solani No. 6 gave the lowest percentage of infection (15 and 17% respectively) the rest of isolates showed moderate of percentage of infection. Antagonistic capability of 15 isolates (PGPR) was tested in vitro against growth of three isolates of Fusarium spp. the causal pathogen of root rot of black cumin. Seeds black cumin plant treated with all bioagents as a suspension significantly increased the root dry weigh and foliar dry weigh compared to infected control. In conclusion, our study confirmed that used of bioagents may be applied as future ecofriendly alternatives to synthetic fungicides for controlling the disease of black cumin.

Survey of feral honey bee (Apis mellifera) colonies for Nosema apis in Western Australia

2007 ◽  
Vol 47 (7) ◽  
pp. 883 ◽  
Author(s):  
Rob Manning ◽  
Kate Lancaster ◽  
April Rutkay ◽  
Linda Eaton
Keyword(s):  
Apis Mellifera ◽  
Honey Bee ◽  
Western Australia ◽  
Honey Bees ◽  
Nosema Apis ◽  
The South ◽  
South West ◽  
Feral Populations ◽  
Significant Difference

The parasite, Nosema apis, was found to be widespread among feral populations of honey bees (Apis mellifera) in the south-west of Western Australia. The location, month of collection and whether the feral colony was enclosed in an object or exposed to the environment, all affected the presence and severity of infection. There was no significant difference in the probability of infection between managed and feral bees. However, when infected by N. apis, managed bees appeared to have a greater severity of the infection.

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