Pathogenicity of fungi associated with seedling disease of cotton

1993 ◽  
Vol 33 (7) ◽  
pp. 923 ◽  
Author(s):  
HJ Ogle ◽  
AM Stirling ◽  
PJ Dart
Keyword(s):  
Seedling Survival ◽  
New South ◽  
Seedling Emergence ◽  
Pythium Ultimum ◽  
Fusarium Spp ◽  
Trichoderma Spp ◽  
Seedling Disease ◽  
Soil P ◽  
South Wales ◽  
Penicillium Spp

Fungi associated with cotton seedling disease were isolated directly from a vertisol at Narrabri, New South Wales, in which cotton had failed to establish, and from cotton seedlings grown in the same soil and seedlings grown in 7 Queensland cotton-growing soils (also Vertisols). Fusarium spp., Penicillium spp., Trichoderma spp., Rhizoctonia solani, Pythium vexans, I unidentified pythiaceous fungi, and a number of miscellaneous unidentified fungi were isolated from soil or soilborne plant debris. Pythium ultimum, R. solani, Fusarium spp., and unidentified pythiaceous fungi were isolated from lesions on seedling hypocotyls. The pathogenicity of the fungi was investigated using cotton seedlings grown in steamed potting mix; 93% of seedlings survived in the absence of fungal inoculum. Of the fungi isolated from the Narrabri soil, P. ultimum and R. solani were most pathogenic, reducing seedling survival at 14 days after inoculation to 33%. Isolates of P. vexans and Fusarium spp. reduced seedling survival to 64% and 73-87%, respectively. Isolates of R. solani or P. ultirnum from the Queensland soils completely prevented seedling emergence in most cases, while isolates of Fusarium spp. were not pathogenic. Isolates of both R. solani and P. ultimum varied significantly in pathogenicity.

Ecology of Nassella neesiana, Chilean needle grass, in pastures on the Northern Tablelands of New South Wales. II. Seedbank dynamics, seed germination, and seedling recruitment

2003 ◽  
Vol 54 (6) ◽  
pp. 621 ◽  
Author(s):  
M. R. Gardener ◽  
R. D. B. Whalley ◽  
B. M. Sindel
Keyword(s):  
Seed Production ◽  
Seedling Recruitment ◽  
Seedling Survival ◽  
New South ◽  
Seedling Emergence ◽  
New South Wales ◽  
Separate Experiment ◽  
Bare Ground ◽  
Total Percentage ◽  
South Wales

This is the second in a series of papers investigating the ecology of Nassella neesiana (Trin. & Rupr.) Barkworth (Chilean needle grass) in pastures on the Northern Tablelands of New South Wales. The reasons for its success as a pasture weed are discussed. Nassella neesiana has a large and persistent soil seedbank. After 3 years without seed input, the seedbank declined from 4676 to 1323 seeds/m2. When an exponential decay curve was fitted to the data it was predicted that the seedbank would reach 10 seeds/m2 after 12.4 years. When seed production was large in 1996, 41.6% of seeds produced were incorporated into the seedbank, whereas in 1995 and 1997 the smaller seed production was only sufficient to maintain seedbank numbers. Furthermore, it is likely that the seedbank numbers were underestimated because they did not include basal cleistogenes. In a separate experiment, basal cleistogenes were found to contribute a further 20% to the seedbank.A small proportion of the viable seeds in a natural seedbank emerged from bare ground over 2 years. Seedling survival was high, with 78% of those germinating from bare ground surviving for at least 20 months. Several experiments were designed to investigate the mechanisms of this germination and survival. It appears that the seeds of N. neesiana have an after-ripening requirement of between 3 months and 1 year for maximum germination. Lemma removal from seeds stored for 8 months increased germination from 49 to 82%. The rate of germination and the total percentage of seeds germinating also increased with time of burial in the ground. Of seeds that had been buried for 2 years, 90% germinated after laboratory incubation compared with 48% of seeds stored in the laboratory as controls. Depth of seed burial appears to affect seedling emergence and survival. A smaller number of seedlings emerged from 0–10 mm and they had lower survival than those from seed buried at 10–20 mm.

Effects of depth and time of sowing on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth

1993 ◽  
Vol 44 (6) ◽  
pp. 1311 ◽  
Author(s):  
GM Lodge ◽  
AJ Schipp
Keyword(s):  
New South ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Maximum Temperature ◽  
Sowing Time ◽  
Sand Mixture ◽  
South Wales ◽  
Seed Field ◽  
Dry Conditions ◽  
Soil Temperatures

Two experiments examined the effects of sowing time and depth (surface and 10, 25, 50 mm) on emergence of Danthonia richardsonii Cashmore and Danthonia linkii Kunth. Experiment 1 was conducted from January to December 1990 on a loam/sand mixture in boxes. Emergence was highest in both species for seeds sown onto the soil surface in summer and autumn (P < 0.05). Sowing at any depth at any time of the year, or surface sowing in winter and spring, markedly reduced emergence. Experiment 2 was conducted in the field at Tamworth, northern New South Wales from September 1991 to August 1992, on a red brown earth and a black earth. This study confirmed that emergence in both species was highest from surface sown seed. Field emergence was lowest in winter, but in contrast to experiment 1, it was higher in spring, particularly on the black earth. Seedling emergence appeared to be related to mean maximum temperature, decreasing in winter as it declined below 20�C, and increasing in spring when it was greater than 23�C. Differences in seed weight were reflected in emergence of D. richardsonii and D. linkii in experiment 1. Similar emergence was recorded for the loamlsand mixture and sand, indicating that there was little effect of texture. Phalaris aquatica L. cv. Sirosa surface sown in December had lower emergence ( P < 0.05) than both Danthonia spp., but emergence of this larger seeded cultivar was higher at depths of 10 and 25 mm. Laboratory studies to determine reasons for the low emergence of D. richardsonii and D. linkii from depth, indicated that neither had an obligate light requirement for germination. Depth, however, reduced germination (P < 0.05) compared with surface sowing of seed. Seedlings at depth also were observed to have slower rates of shoot and root elongation. In the field, the most successful establishments of D. richardsonii and D. linkii seedlings are likely to occur from surface sowings in April and May. Sowing in spring may also be possible if mean maximum soil temperatures exceed 23�C, and seedlings can establish before the onset of hot, dry conditions in summer.

scholarly journals The population dynamics of perennial chenopod shrubs in semi-arid western New South Wales.

1990 ◽  
Vol 12 (1) ◽  
pp. 29 ◽  
Author(s):  
DJ Eldridge
Keyword(s):  
Population Dynamics ◽  
Population Ecology ◽  
Arid Zone ◽  
Seedling Survival ◽  
New South ◽  
New South Wales ◽  
South Wales ◽  
Semi Arid

This thesis deals with some aspects of the population ecology of arid zone perennial chenopod shrubs. It examined the effects of grazing on the population dynamics of Atriplex vesicaria, Maireana astrotricha and Maireana pyramidata, the influence of weather on recruitment and survival of Atriplex vesicaria and the effects of various microtopographical features on seedling survival of Atriplex vesicaria.

scholarly journals Avaliação das comunidades fúngicas encontradas em amostras de solo: uma revisão sistemática da literatura

2019 ◽  
Vol 10 (6) ◽  
pp. 67-76
Author(s):  
Fabíola Dresch ◽  
Daiane Flores Dalla Lana ◽  
Mônica Jachetti Maciel
Keyword(s):  
Fusarium Spp ◽  
Trichoderma Spp ◽  
Penicillium Spp

No solo os microrganismos possuem diversas funções, sendo responsáveis por inúmeras reações bioquímicas, não só relacionados com a transformação da matéria-orgânica, mas também com o intemperismo das rochas, desempenhando papel importantíssimo na gênese do solo. Decompõem a matéria-orgânica, realizam a ciclagem de nutrientes e de energia, interferindo no crescimento de plantas. Produzem compostos complexos que agregam o solo, fazem a decomposição de xenobióticos, atuando na biorremediação de poluentes e de agrotóxicos, na formação de associações micorrízicas, na fixação biológica do nitrogênio, no controle de pragas, e, além disso tudo, causam doenças. O conhecimento dos microrganismos do solo é fundamental para o levantamento taxonômico das populações que estão ali, podendo levar ao descobrimento de processos metabólicos utilizados por estes organismos, tornando-se importantes para as interações ambientais e aplicações biotecnológicas. Assim, o presente trabalho teve como objetivo identificar, por meio de pesquisas já publicadas, a diversidade de fungos presentes em diferentes tipos de solo, avaliando a influência das características do solo sobre as comunidades fúngicas. Os solos analisados variaram de amostras urbanas a solos de áreas nativas, argilosos, arenosos ou orgânicos (compostagem). Quanto aos microrganismos, os gêneros citados com mais frequência nos estudos foram Penicillium spp., seguido de Fusarium spp., Aspergillus spp., Trichoderma spp., e Verticillium spp. Concluiu-se que grande parte dos microrganismos mencionados nos trabalhos já são ou podem ser utilizados para fins biotecnológicos, sendo fontes de diversas enzimas e produtores de compostos importantes. Aspectos generalistas referentes à umidade, à temperatura, à posição e à composição orgânica do solo mostraram influenciar no desenvolvimento dos fungos, nos quais solos mais úmidos, superficiais e como maior oferta de material orgânico aumentam a presença e o crescimento destes indivíduos.

Seedling emergence and survival of annual pasture legumes in northern New South Wales

1996 ◽  
Vol 47 (4) ◽  
pp. 559 ◽  
Author(s):  
GM Lodge
Keyword(s):  
New South ◽  
Seedling Emergence ◽  
New South Wales ◽  
Survival Rates ◽  
Trifolium Subterraneum ◽  
Survival Curves ◽  
Vicia Villosa ◽  
Pasture Legumes ◽  
South Wales ◽  
Seedling Emergence And Survival

Seedling emergence and survival of 15 annual pasture legumes was studied in the field at Tamworth, northern New South Wales. Emergence was measured in permanent quadrats (0.09 m2) in covered and uncovered areas approximately every 15 days from 30 November 1983 to 30 November 1984. Survival of seedlings was estimated from 15 December 1983 to 31 August 1984, before plants senesced. Emergence was generally highest in summer and autumn following seed set and lowest in winter and spring. Two legumes, Medicago scutellata cv. Sava and Trifolium subterraneum cv. Seaton Park, had high emergence in winter (mid July). Total seedling emergence was highest ( P < 0.05) in covered areas of cv. Seaton Park and uncovered areas of T. hirtum cv. Hykon. All T. subterraneum cultivars, M. minima, Astragalus hamosus cv. Ioman, Vicia villosa cv. Namoi, and M. truncatula cv. Paraggio had higher total emergence in covered compared with uncovered areas. In contrast, total emergence of M. aculeata, M. truncatula cv. Jemalong, Sava, and Hykon was lowest in covered areas. Cover had little effect on the total emergence of M. truncatula cv. Sephi and T. glomeratum. Of the 7700 individual seedlings marked from November 1983 to August 1984, a mean of only 31% (covered) and 41% (uncovered) survived until 31 August 1984. For each emergence time, highest ( P < 0.05) survival rate coincided with the highest (P < 0.05) number of emerged seedlings in 4 of the legumes in covered areas (cv. Namoi, 31 January; cv. Ioman, 31 March; cv. Hykon, 15 April; cv. Sava, 15 July; Table 4) and 9 in uncovered areas (cvv. Nungarin, Seaton Park, and Namoi, 31 January; M. aculeata and cv. Sephi, 28 February; cvv. Jemalong and Ioman, 31 March; T. glomeratum, 15 April; cv. Sava, 15 July). In all other legumes there was no optimum time for emergence, since the highest (P < 0.05) survival rates were associated with seedling survivals <50%. Generally, survival curves with a mortality constant rather than a mortality rate were a better fit ( P < 0.05) for most legumes and times. This implied that these survival curves were determined at the time of recruitment, and declined at a constant rate, despite below-average post-emergence rainfall in May-June. Low rates of survival at times of highest ( P < 0.05) emergence indicated that there may have been some density-dependent regulation in some of the legumes.

Nannizzia gypsea. [Descriptions of Fungi and Bacteria].

1965 ◽  
Author(s):  
P. M. Stockdale
Keyword(s):  
Great Britain ◽  
Geographical Distribution ◽  
Tinea Capitis ◽  
New South ◽  
Skin Lesions ◽  
Wide Distribution ◽  
Soil P ◽  
Cook Island ◽  
South Wales ◽  
Infected Skin

Abstract A description is provided for Nannizzia gypsea. Information is included on the disease caused by the organism, its transmission, geographical distribution, and hosts. HOSTS: Recorded only from man (but see NOTES). Guinea-pigs have been experimentally infected. DISEASE: Ringworm (dermatophytosis, tinea). Nannizzia gypsea is apparently widespread in soil and only rarely pathogenic. The scalp (tinea capitis) and glabrous skin (tinea corporis) may be infected. Skin lesions are inflammatory, but details of only two scalp infections are known. In both the lesions were inflammatory; in one favus-like crusts were also found and in the other hair invasion was of the large-spored ectothrix type. In experimental inoculations of guineapigs (Rdzanek, pers. comm.) N. gypsea was slightly more virulent than N. incurvata and N. fulva, the reaction varying from negative to strongly inflammatory, a few ectothrix hyphae breaking up into arthrospores were seen on some hairs, and infected hairs did not fluoresce under Wood's light. GEOGRAPHICAL DISTRIBUTION: Asia (Japan), Australasia and Oceania (Australia (New South Wales), New Zealand, Raratonga, Cook Island), Europe (France, Great Britain, Italy); North America (Tenn.). Probably of world-wide distribution in the soil.

Comparison of bicarbonate-extractable soil phosphorus measured by ICP-AES and colourimetry in soils of south-eastern New South Wales

Soil Research ◽  
2009 ◽  
Vol 47 (7) ◽  
pp. 742 ◽  
Author(s):  
M. R. Hart ◽  
P. S. Cornish
Keyword(s):  
Inductively Coupled Plasma ◽  
New South ◽  
Soil Phosphorus ◽  
New South Wales ◽  
Soil Samples ◽  
Available Phosphorus ◽  
Soil P ◽  
Inductively Coupled ◽  
South Wales ◽  
The Difference

Soil testing for plant-available phosphorus (P) in Australia is most commonly conducted using alkaline sodium bicarbonate extraction (Olsen or Colwell tests), followed by a colourimetric assay to measure the concentration of P in solution. Analysis by inductively coupled plasma (ICP) spectroscopy has become increasingly popular internationally for other soil P tests, especially Mehlich 3, due to its efficiency and ability to measure multiple elements in the one extract. The use of ICP in place of colourimetry has been used in some Australian laboratories for bicarbonate-extractable P. However, the method is known to measure forms of P (organic) that are not measured by the colourimetric assay. This study presents data comparing soil Colwell P measured by the 2 methods for 714 soil samples from pastoral sites in south-east New South Wales. Measurement by ICP consistently yielded significantly higher P concentrations than the colourimetric method (ICP-P = 1.122Col-P + 57.0, r2 = 0.95, P < 0.001). Differences between the 2 techniques were more marked in 0–20 mm than 0–100 mm depth soil samples, and in soils with greater clay contents, suggesting that the difference was related to soil organic matter, and thereby organic P contents. Relative differences were greatest in soils with lower P concentrations, i.e. within the agronomic optimum range of most interest to farmers. ICP analysis cannot be directly correlated with colourimetrically measured P in bicarbonate extracts, and would need to be developed and calibrated as a separate, new soil P test.

scholarly journals Qualidade sanitária de sementes de aveia preta cv. brs 139 (Avena strigosa SCHREB) submetidas ao envelhecimento acelerado

2013 ◽  
Vol 13 (13) ◽  
pp. 2828-2836
Author(s):  
Marciele Barbieri ◽  
Viviane Schons De Ávila ◽  
Caciara Gonzatto Maciel ◽  
Gisele Noal ◽  
Marlove Fátima Brião Muniz ◽  
...  
Keyword(s):  
Fusarium Spp ◽  
Trichoderma Spp ◽  
Avena Strigosa ◽  
Penicillium Spp

O trabalho objetivou estudar os efeitos de diferentes tratamentos na sanidade de sementes de aveia preta cv. BRS 139. As sementes foram submetidas aos seguintes tratamentos: Vincit®50SC, Vincit®50SC+Trichodel®, Trichodel® e Testemunha sem tratamento. Em seguinda, foram acondicionadas, em caixas do tipo gerbox, com substrato papel-filtro umedecido em água destilada e esterilizada e permaneceram em câmaras B.O.D. na temperatura de 25ºC, com fotoperíodo de 12 horas, até a avaliação. Os fungos associados às sementes foram identificados com o auxílio de microscópios estereoscópico e óptico, após sete dias de incubação. O delineamento estatístico utilizado foi inteiramente casualizado com quatro tratamentos e oito repetições de 50 sementes cada. Os fungos Aspergillus spp, Fusarium spp., Penicillium spp., Rhizoctonia spp., Rhizopus spp. e Trichoderma spp. foram identificados nas sementes. Os resultados mostraram que o produto químico (Vincit®50SC), isolado ou associado com Trichodel®, foi eficaz para o controle de fungos potencialmente patogênicos para as sementes de aveia preta. Conclui-se que os tratamentos mais eficientes para o controle dos fungos presentes consistem no produto químico Vincit® 50SC utilizado isoladamente e quando associado ao produto biológico Trichodel®.

SGS Nutrient Theme: environmental assessment of nutrient application to extensive pastures in the high rainfall zone of southern Australia

2003 ◽  
Vol 43 (8) ◽  
pp. 927 ◽  
Author(s):  
M. R. McCaskill ◽  
A. M. Ridley ◽  
A. Okom ◽  
R. E. White ◽  
M. H. Andrew ◽  
...  
Keyword(s):  
Nitrate Leaching ◽  
Surface Runoff ◽  
New South ◽  
Stream Water ◽  
New South Wales ◽  
Surface Flow ◽  
Stream Water Quality ◽  
Soil P ◽  
South Wales ◽  
Stocking Rates

To assess the risks and benefits of more intensive pasture management, 2 or 3 treatments with contrasting fertiliser regimes were selected from each site of the Sustainable Grazing Systems national experiment. The assessment used soil coring data, modelling and runoff nutrient concentration data.Soil acidification rates were estimated from the simulated nitrate leaching and product removal estimated from the stocking rates at each site. Much higher acidification rates were estimated at sites in Victoria and southern Western Australia than in northern New South Wales. This was because of a lower level of nitrate leaching in summer-dominant rainfall environments coupled with lower stocking rates. Simulations showed highest nitrate leaching on annual pastures, but that a phalaris pasture could reduce this, and a kikuyu pasture could almost fully control leaching.The concentration of P in surface runoff was related to soil P status at the 4 southern sites, indicating that greater use of P fertiliser would increase P movement into waterways. There was no relationship between soil P status and P in surface runoff at the northern New South Wales sites, and across all sites there were no relationships between P fertility and runoff N levels. Concentrations of P and N in runoff greatly exceeded stream water quality guidelines, even on treatments where only minimal P had been applied as fertiliser. There was also evidence of high spatial variation in surface runoff generation, with surface runoff from some plots less than 5% of the streamflow in nearby reference streams. There is therefore scope to control P concentrations in streams by retiring from production the parts of the landscape that generate high quantities of surface flow, but to intensify production on areas that produce little runoff.

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