Subterranean clover stunt, a virus disease of pasture legumes

1959 ◽  
Vol 10 (2) ◽  
pp. 145 ◽  
Author(s):  
NE Grylls ◽  
FC Butler
Keyword(s):  
Experimental Data ◽  
Myzus Persicae ◽  
Virus Disease ◽  
Subterranean Clover ◽  
Field Observations ◽  
Pasture Legumes ◽  
Aphis Craccivora Koch ◽  
Insect Transmission ◽  
Perennial Legumes ◽  
Subtropical Species

A study has been made of a recently recognized virus disease, subterranean clover stunt. Field observations of its occurrence, distribution, and symptoms, and experimental data on insect transmission are recorded. Attempts to transmit the disease by mechanical means and by leafhoppers were unsuccessful. It was transmitted by two species of aphids, efficiently by Aphis craccivora Koch and less efficiently by Myzus persicae (Sulz.), but not by four other species of aphids tested. The virus was transmitted to a series of indicator plants by aphids and, since it carried over a moult of A. cruccivora, it belongs to the "persistent" type. The host range covers a wide variety of legumes, including some subtropical species. The means by which the disease is carried over from season to season was not determined but the virus probably persists in summer-growing annual and perennial legumes.

The transference of nitrogen from pasture legumes to an associated grass under several systems of management in pot culture

1965 ◽  
Vol 16 (6) ◽  
pp. 915 ◽  
Author(s):  
JR Simpson
Keyword(s):  
White Clover ◽  
Subterranean Clover ◽  
Experimental Period ◽  
The Other ◽  
Temporary Increase ◽  
Winter Period ◽  
Pasture Legumes ◽  
Perennial Legumes ◽  
Intact Root ◽  
Pot Culture

The extent of underground transference of nitrogen from three pasture legumes, each growing in association with a grass, has been studied in pot culture under several systems of management during the first 12–18 months after sowing. The three legumes performed quite differently. Subterranean clover did not release any nitrogen until senescence and then produced a rapid transference. White clover was competitive for nitrogen until the autumn-winter period. Lucerne released nitrogen gradually over the whole experimental period. Frequent defoliation of the legumes reduced competition for nitrogen by white clover but also reduced transference from the other legumes. Killing the perennial legumes produced only a small temporary increase in transference. Wilting and temporary drying treatments also reduced the transference. Thus there was no evidence that the nitrogen transference from lucerne was due to a shedding or decay of nodules induced by defoliation; it could equally well be due to direct excretion of nitrogen from the intact root system. The significance of the results in pasture establishment in infertile areas is discussed.

INSECT TRANSMISSION OF THE VIRUS CAUSING LITTLE CHERRY DISEASE

1960 ◽  
Vol 40 (4) ◽  
pp. 707-712 ◽  
Author(s):  
W. H. A. Wilde
Keyword(s):  
Sweet Cherry ◽  
Prunus Avium ◽  
Virus Disease ◽  
Insect Transmission ◽  
Prunus Avium L ◽  
Cherry Trees

Little cherry virus disease of sweet cherry (Prunus avium L.) was transmitted under screenhouse conditions by 3 species of leafhoppers (Homoptera: Cicadellidae) out of 24 species tested. Macrosteles fascifrons (Stal), the 6-spotted leafhopper, transmitted the disease in seven tests; Scaphytopius acutus (Say), the sharp-nosed leafhopper, transmitted it once; and Psammotettix lividellus (Zett.) transmitted it once. The transmissions were made from diseased sweet cherry trees of the variety Lambert to indicators of the varieties Star or Sam. With the exception of 1 transmission, 2 to 4 years were necessary following inoculation for unmistakable expression of symptoms in the indicators. M. fascifrons was also implicated in 18 successful transmissions to mature sweet cherry trees grown in the open.

Evaluation of pasture legumes sown into a prepared seedbed at Tamworth, New South Wales. 2. Seed production and seed reserves

1993 ◽  
Vol 33 (3) ◽  
pp. 299 ◽  
Author(s):  
GM Lodge
Keyword(s):  
Seed Production ◽  
New South ◽  
New South Wales ◽  
Pasture Legumes ◽  
South Wales ◽  
Medicago Scutellata ◽  
Seed Reserves ◽  
Annual Medics ◽  
Perennial Legumes ◽  
Seed Yields

Plots sown in 1983 were used to examine the seed production and reserves (residual hardseeds) of 15 annual legumes over 5 years at Tamworth in northern New South Wales. Seed production characteristics were measured in 1983 for these annuals, and for 6 perennial legumes. After the annuals had set seed in 1983, an area of the plots was sprayed to prevent flowering in subsequent years, and the rates of decline in seed reserves were compared with those from areas that seeded annually. Seed yields of the perennials were often significantly lower than those of the annuals except Trifolium glomeratum. Seed yields of T. subterraneum var. subterraneum cvv. Seaton Park and Woogenellup were significantly higher than those of cv. Nungarin and T. subterrarzeum var. brachycalycinum cv. Clare. Seed numbers were lowest for Medicago scutellata cv. Sava among the annual medics, and for Nungarin among subterranean clovers. There was little relationship between the mean number of seeds produced from 1983-86 and maturity grading, and between seed numbers and relative dry matter yield. Seed reserves decreased over 5 years by more than 90% in the sprayed treatments of all species. This decrease was not continuous, with the largest declines occurring from December 1983 to August 1984. In the sprayed treatments of Seaton Park, Woogenellup, and Clare, and in both treatments of Astragalus hamosus cv. Ioman, Vicia dasycarpa var. villosa cv. Namoi, and T. hirtum cv. Hykon, none of the original 1983 seed was recovered in 1987. For the annual medics and Nungarin, the number of residual hardseeds in the sprayed treatments in 1987 was about 3-5% of the seed produced in 1983. From 1983 to 1987, seed numbers in the unsprayed treatments declined by 7040% for the annual medics and by 85-95% for Seaton Park, Woogenellup, and Clare. Long-term persistence of annual medics and Nungarin depended on seed production in most years and the maintenance of a high number of residual hardseeds in the soil. In contrast, the mid- and late-maturing subterranean clovers Woogenellup and Clare had low seed reserves and were dependent on seed production in most years for their continued regeneration.

Variability of in vitro ruminal fermentation and methanogenic potential in the pasture legume biserrula (Biserrula pelecinus L.)

2013 ◽  
Vol 64 (4) ◽  
pp. 409 ◽  
Author(s):  
Bidhyut Kumar Banik ◽  
Zoey Durmic ◽  
William Erskine ◽  
Phillip Nichols ◽  
Kioumars Ghamkhar ◽  
...  
Keyword(s):  
Core Collection ◽  
Volatile Fatty Acids ◽  
Germplasm Collection ◽  
Red Clover ◽  
Subterranean Clover ◽  
Ruminal Fermentation ◽  
Rumen Microbes ◽  
Pasture Legumes ◽  
Pasture Legume

Biserrula (Biserrula pelecinus L.) is an important annual pasture legume for the wheatbelt of southern Australia and has been found to have lower levels of methane output than other pasture legumes when fermented by rumen microbes. Thirty accessions of the biserrula core germplasm collection were grown in the glasshouse to examine intra-specific variability in in vitro rumen fermentation, including methane output. One biserrula cultivar (Casbah) was also grown at two field locations to confirm that low methanogenic potential was present in field-grown samples. All of the biserrula accessions had significantly reduced methane [range 0.5–8.4 mL/g dry matter (DM)] output compared with subterranean clover (28.4 mL/g DM) and red clover (36.1 mL/g DM). There was also significant variation in fermentability profiles (except for volatile fatty acids) among accessions of the core collection. Methanogenic potential exhibited 86% broad-sense heritability within the biserrula core collection. The anti-methanogenic and gas-suppressing effect of biserrula was also confirmed in samples grown in the field. In conclusion, biserrula showed variability in in vitro fermentation traits including reduced methane production compared with controls. This bioactivity of biserrula also persists in the field, indicating scope for further selection of biserrula as an elite methane-mitigating pasture.

Tobacco rosette: a complex virus disease

Parasitology ◽  
1946 ◽  
Vol 37 (1-2) ◽  
pp. 21-24 ◽  
Author(s):  
Kenneth M. Smith
Keyword(s):  
Myzus Persicae ◽  
Complex Disease ◽  
Virus Disease ◽  
Tobacco Plant ◽  
Giant Cells ◽  
Mottle Virus ◽  
Insect Vector ◽  
Two Component ◽  
Set Up ◽  
Abnormal Tissue

An account is given of a composite virus disease of tobacco for which the name tobacco rosette has been suggested.The two component viruses, named the mottle and vein-distorting viruses respectively, have been separated, and their symptomatology and methods of transmission described. The mottle virus is both sap and aphis-transmitted, but the vein-distorting virus is aphis-borne only.The symptoms and histopathology of the complex disease in the tobacco plant are dealt with in some detail. There are three main types of symptoms: (1) intense rosetting, (2) splitting of the tissues, (3) formation of enations on the under-surface of the leaves.The splitting of the tissues has been examined microscopically, and a number of photomicrographs are given illustrating the formation of the fissures. It is suggested that there is a concentration of virus in the cambium which prevents the formation of the normal xylem. Abnormal tissue and giant cells are formed in the cortex and pith. This appears to set up stresses which cause the splitting.The insect vector of the complex disease is the aphis Myzus persicae Sulz. Another aphis, M. pseudosolani Theob., is also a vector but is less efficient than M. persicae.The writer's thanks are due to Prof. F. T. Brooks, F.R.S., with whom he discussed the histopathology of the rosette disease, to Dr Roy Markham for taking the photographs illustrating Pl. I, figs. 2–5, and to Mr Charles Harpley of the Molteno Institute for his assistance in taking' the photomicrographs.

Effects of intersowing with beans on the spread of groundnut rosette virus by Aphis craccivora Koch (Hemiptera, Aphididae) in Malawi

1976 ◽  
Vol 66 (2) ◽  
pp. 331-333 ◽  
Author(s):  
J. A. K. Farrell
Keyword(s):  
Phaseolus Vulgaris ◽  
Arachis Hypogaea ◽  
Virus Disease ◽  
High Density ◽  
Aphis Craccivora ◽  
Plant Populations ◽  
Bean Plants ◽  
Aphis Craccivora Koch ◽  
Field Beans

AbstractIn two trials, at Chitedze, Malawi, in 1966–1967, the spread of rosette virus disease in groundnuts (Arachis hypogaea) intersown with field beans (Phaseolus vulgaris) was less than the spread in groundnut monocultures comprising plant populations equivalent to the number of groundnut plants and to the total number of plants in the intersown crop. In one trial, numbers of early rosette transmissions were related to numbers of alate Aphis craccivora Koch, the vector of the virus, found on groundnut plants. Immigrant alate A. craccivora settling on the intersown crop were trapped by the hooked epidermal hairs of the bean plants and the observed reduction of rosette infection in the intersown crop was attributed to this effect. Inter-sowing with beans is considered less effective than early-sown, high-density monoculture as a method of reducing groundnut rosette infections and yields of groundnuts from inter-sown crops may be lower than those obtained from high-density monoculture.

Performance and weed-suppressive potential of selected pasture legumes against annual weeds in south-eastern Australia

2019 ◽  
Vol 70 (2) ◽  
pp. 147 ◽  
Author(s):  
Sajid Latif ◽  
Saliya Gurusinghe ◽  
Paul A. Weston ◽  
William B. Brown ◽  
Jane C. Quinn ◽  
...  
Keyword(s):  
Subterranean Clover ◽  
Weed Suppression ◽  
Weed Species ◽  
Mixed Stands ◽  
South Eastern ◽  
Pasture Legumes ◽  
Eastern Australia ◽  
Weed Suppressive Ability ◽  
Weed Infestation ◽  
South Eastern Australia

Mixed farming systems have traditionally incorporated subterranean clover (Trifolium subterraneum L.) and lucerne (Medicago sativa L.) as key components of the pasture phase across south-eastern Australia. However, poor adaptation of subterranean clover to acidic soils, insufficient and inconsistent rainfall, high input costs, soil acidification and the emergence of herbicide-resistant weeds have reduced efficacy of some traditional clover species in recent years. To overcome these challenges, numerous novel pasture species have been selectively improved and released for establishment in Australia. Despite their suitability to Australian climate and soils, limited knowledge exists regarding their weed-suppressive ability in relation to establishment and regeneration. Field trials were therefore conducted over 3 years in New South Wales to evaluate the suppressive potential of selected pasture legume species and cultivars as monocultures and in mixed stands against dominant annual pasture weeds. Pasture and weed biomass varied significantly between pasture species when sown as monocultures, but mixtures of several species did not differ with regard to establishment and subsequent weed infestation. Arrowleaf clover (T. vesiculosum Savi.) and biserrula (Biserrula pelecinus L.) cv. Casbah showed improved stand establishment, with higher biomass and reduced weed infestation compared with other pasture species. Generally, weed suppression was positively correlated with pasture biomass; however, yellow serradella (Ornithopus compressus L.) cv. Santorini exhibited greater weed suppression than other pasture legumes while producing lower biomass, thereby suggesting a mechanism other than competition for resources affecting weed-suppressive ability. Over the period 2015–17, arrowleaf clover and biserrula cv. Casbah were generally the most consistent annual pasture legumes with respect to yearly regeneration and suppression of annual pasture weed species.

scholarly journals Transmission of Chickpea chlorotic dwarf virus in Chickpea by the leafhopper Orosius albicinctus (Distant) in Pakistan – Short communication

2011 ◽  
Vol 47 (No. 1) ◽  
pp. 1-4 ◽  
Author(s):  
K.P. Akhtar ◽  
M. Ahmad ◽  
T.M. Shah ◽  
B.M. Atta
Keyword(s):  
Myzus Persicae ◽  
Short Communication ◽  
Polyclonal Antibodies ◽  
Viral Disease ◽  
Elisa Test ◽  
Dwarf Virus ◽  
Aphis Craccivora Koch ◽  
Orosius Albicinctus ◽  
Transmission Studies ◽  
Das Elisa

Chickpea chlorotic dwarf virus (CpCDV, genus Mastervirus, family Geminiviridae) is the most common viral disease of chickpea in Pakistan. Two aphid [Aphis craccivora Koch, Myzus persicae (Sulzer)], two leafhopper [Empoasca devastans Distant, Orosius albicinctus (Distant)] species and an unidentified brown leafhopper were collected in a chickpea field by hand and sweep nets for transmission studies of CpCDV. Transmission results showed that only the leafhopper O. albicinctus successfully transmitted the CpCDV from diseased to healthy chickpea plants. The presence of CpCDV in inoculated plants and the vector O. albicinctus were confirmed by DAS-ELISA test using specific polyclonal antibodies.

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