Lucerne aphid effects on 18 pasture legumes in southern Queensland: a glasshouse study

1979 ◽  
Vol 19 (96) ◽  
pp. 59 ◽  
Author(s):  
BA Franzmann ◽  
WJ Scattini ◽  
KP Rynne ◽  
B Johnson

The suitability of 18 naturalized or commercial pasture legumes as hosts of the spotted alfalfa aphid (SAA) (Therioaphis trifolii f, maculata (Monell)) and the blue-green aphid (BGA) (Acyrthosiphon kondoi Shinji) and the effects of the aphids on the growth of these legumes were investigated in uncaged pots in a glasshouse trial. The species and cultivars tested were: Medicago sativa cv. Hunter River, M. truncatula var. truncatula cv. Jemalong, M. truncatula var. truncatula cv. Cyprus, M. scutellata cv. Robinson, M. littoralis cv. Harbinger, M. polymorpha, M. minima, M, lupulina, Trifolium repens cv. Ladino, T. repens cv. Grasslands Huia, T, semipilosum var. glabrescens cv. Safari, T, pratense cv. Grasslands Turoa, T, subterraneum cv. Woogenellup, T, glomeratum, Astragalus hamosus cv. loman, Vicia dasycarpa cv. Namoi, Ornithopus compressus cv. Pitman, Macroptilium atropurpureum cv. Siratro. Medicago spp. and Trifolium spp. supported the greatest populations of SAA and BGA, respectively, although high populations of the latter were supported on most legumes. M. scutellata cv. Robinson and M. truncatula cvv. Jemalong and Cyprus supported a low population of SAA while T. semipilosum cv. Safari was the only Trifolium sp. host. BGA developed on all legumes with lowest populations on O. compressus cv. Pitman, M. atropurpureum cv. Siratro and Vicia dasycarpa cv. Namoi. SAA reduced yields of all Medicago spp, except cvv. Jemalong, Cyprus and Robinson ; all M. littoralis cv. Harbinger and most M. polymorpha plants died. BGA reduced yields of all legumes except cv. Robinson, cv. Namoi, cv. Pitman and cv. Siratro; all cv. loman plants died. Treatment with both aphids reduced yields of all legumes except cv. Namoi, cv. Pitman and cv. Siratro and killed all plants of cv. Harbinger, M. polymorpha and cv, loman. Of the legumes examined, V. dasycarpa cv. Namoi, O. compressus cv. Pitman, M. atropurpureum cv. Siratro and perhaps M. scutellata cv. Robinson are the only cultivars of species which may be expected to produce reasonable yields under combined attack

1985 ◽  
Vol 25 (4) ◽  
pp. 850 ◽  
Author(s):  
MJ Barbetti

The effects of inoculum level, and temperature and humidity regimes on the development of Cercospora blackstem disease (caused by Cercospora zebrina) in subterranean clover (Trifolium subterraneum) were investigated. Mycelial fragments were an effective and reliable inoculum. The incidence, severity, and the rate of disease development increased with increasing period of high humidity after inoculation and with increasing concentrations of inoculum. Disease was greatest at 18/13� (12/12 h, day/ night), followed by 21/16�C, and then l5/10�C While all cultivars of T. subterraneum sprayed with hyphal fragments of C. zebrina became infected, Trikkala and Larisa showed some resistance. Of the alternative pasture legumes, lucerne (Medicago sativa), medic (M. littoralis, M. truncatula), drooping-flowered clover (T. cernuum), strawberry clover (T. fragiferum), rose clover (T. hirtum) and white clover (T. repens) were all susceptible; only serradella (Ornithopus compressus) was resistant.


2017 ◽  
Vol 57 (3) ◽  
pp. 539 ◽  
Author(s):  
P. Beck ◽  
T. Hess ◽  
D. Hubbell ◽  
M. S. Gadberry ◽  
J. Jennings ◽  
...  

The objective of this study was to evaluate the effects of including alfalfa (ALF, Medicago sativa L.) or a combination of white (Trifolium repens L.) and red (Trifolium pretense L.) clovers (CLVR) inter-seeded into bermudagrass (Cynodon dactylon L. Pers.) on herbage nutritive value compared with monocultures of bermudagrass fertilised with 0 (0N), 56 (56N), or 112 (112N) kg nitrogen (N)/ha over four grazing seasons. In autumn, at the end of the fourth year and in the spring before the fifth grazing season, alfalfa and clover plants were killed and the carryover N benefit of CLVR or ALF was compared with N fertilisation rates during the fifth year. Across years, N fertilisation rate increased herbage mass and carrying capacity linearly; whereas herbage production from CLVR and ALF swards was equivalent to 56N, were greater than 0N and less than 112N. Herbage mass in CLVR and ALF swards was greater than fertilised bermudagrass swards in the spring and did not differ from fertilised bermudagrass in the early summer. In late summer herbage accumulation of CLVR and ALF swards appeared to decrease, limiting the herbage mass in the legume pastures compared with 56N and 112N. Carrying capacity of CLVR and ALF swards was greater than fertilised bermudagrass in the spring and early summer, but did not differ from fertilised swards in the late summer. The N benefit of including legumes in bermudagrass swards can alleviate the reliance on synthetic N fertilisation with little overall effect on pasture carrying capacity.


1999 ◽  
Vol 50 (3) ◽  
pp. 303 ◽  
Author(s):  
A. Loi ◽  
J. G. Howieson ◽  
P. S. Cocks ◽  
S. J. Carr

Genetic variation between and within populations of Biserrula pelecinus L. (biserrula) and Ornithopus compressus L. (yellow serradella) and associated rhizobia was studied using germplasm collected from sites in central-eastern and south-eastern Sardinia (Italy). Pods and root-nodule bacteria were collected on diagonal transects at each site. Plants were characterised in nursery rows and the rhizobia were isolated and tested for their effectiveness. Thirteen morphological traits were recorded and the results were analysed using cluster analysis. Genetic and phenotypic variation of rhizobia were assessed using DNA analysis (PCR, RAPDs) and effectiveness indices, respectively. Genetic variation based on morphological traits was found between and within sites for both species. Pod characteristics and flowering time were the most important traits assisting in discriminating between accessions. Flowering time varied more in serradella than in biserrula, particularly at Cantoniera Cannas. Although all rhizobial strains nodulated all accessions of biserrula, great variability in capacity to fix nitrogen was evident between and within sites. Distinct PCR amplification profiles were generated for individual rhizobial strains, which confirmed the phenotypic variability (effectiveness indices) of the strains. No relationship was found between host and rhizobia variation. The results are discussed in terms of (a) genetic differences for each species within and between sites; (b) differences in behaviour in respect to genetic variation between biserrula, serradella, and other Mediterranean annual legumes; and (c) spatial variability and symbiotic effectiveness of rhizobia.


1995 ◽  
Vol 35 (3) ◽  
pp. 367 ◽  
Author(s):  
DGDe Marco ◽  
CB Li ◽  
PJ Randall ◽  
Marco DG De

This paper describes the tolerance to high concentrations of manganese (Mn) of pasture legumes that are suitable for the >500 mm rainfall zone in southern Australia. The legumes are lucerne (Medicago sativa), burr medic (M. polymorpha), murex medic (M. murex), balansa clover (Trifolium balansae), Persian clover (T. resupinatum), subterranean clover (T: subterraneum), greater lotus (Lotus pedunculatus), and seradella (Ornithopus compressus). Wheat (Triticum aestivum) cv. Egret and subterranean clover cvv. Mt Barker and Karridale were included to place the tolerance of the remaining species in the context of other studies.Symptoms of toxicity differed between species. Species ranking (in descending order) for Mn tolerance, and external threshold Mn concentrations (mmol/L), were subterranean clover (1.0), wheat (0.71), balansa clover (0.54), greater lotus (0.51), serradella (0.50), Persian clover (0.25), murex medic (0.24), burr medic (0.20), and lucerne (0.19). Critical toxicity concentrations derived from the relationships of yields to Mn concentrations in whole shoots for each species were as follows (mg Mn/kg DW): subterranean clover (2010), balansa clover (1330), serradella (1080), greater lotus (760), wheat (570), burr medic (440), murex medic (430), Persian clover (360), lucerne (190).


Author(s):  
J.G. Hampton ◽  
M.J. Hill

Herbage seed lots of the same chronological age, certification class and germination values often differ in performance in the field, in storage, or both. These performance differences are ascribed to another seed quality factor, seed vigour. Vigour differences have been shown to occur in New Zealand seed lots of Trifolium repens, T. pratense, Medicago sativa, Bromus willdenowii, Cynosurus cristatus and Festuca spp., and are highly likely to occur in all other herbage species. This review of vigour in herbage seed lots discusses the concept, its possible causes, the implications for sowing, storage and export of seed, and how seed lot vigour information might be used by the farmer, seed store manager and seed marketer. Keywords seed vigour, field emergence, storage, export, herbage seed, germination


1977 ◽  
Vol 28 (5) ◽  
pp. 807 ◽  
Author(s):  
CS Andrew

Seven tropical and five temperate pasture legume species were grown in pots of three sulphur-deficient soils with varying additions of sulphate. Growth responses and the chemical composition of the plant tops were recorded, and from the latter, tentative critical concentrations of sulphur were established. These were compared with data from two field sites (six species only). Critical concentrations of sulphur in the tops of species sampled at the immediate pre-flowering stage of growth were: Macroptilium lathyroides 0.17%, Macroptilium atropurpureum 0.15%, Desmodium intortum 0.17%, Desmodium uncinatum 0.17%, Stylosanthes humilis 0.14%, Lotononis bainesii 0.15%, Glycine wightii 0.17%, Trifolium repens 0.18%, Trifolium semipilosum 0.17%, Medicago sativa 0.20%, Medicago truncatula 0.20% and Medicago denticulata 0.20%. Sulphate concentration and nitrogen/sulphur ratios were investigated as alternative diagnostic indices, but were not considered as suitable as total sulphur indices for the assessment of sulphur deficiency in legumes. Nitrogen concentrations in the plant tops were increased by sulphate supply, and excellent correlations were established between the nitrogen and sulphur concentrations in the plant tops.


1971 ◽  
Vol 24 (5) ◽  
pp. 1041 ◽  
Author(s):  
CP Way ◽  
GN Richards

Stylosanthes humilis, the predominant pasture legume in North Queensland, has been collected at three different stages of growth, viz. flowering, seeded, and senescence. The plants have been divided into stem, leaf, root, seed, and pod and each fraction has been analysed for the following types of polysaccharide components: water- solubles, pectic substances, hemicelluloses, and cellulose. The absolute monosaccharide composition of each of these fractions has been determined by hydrolysis and gas chromatography. Most of the polysaccharide components are similar in nature to those previously found in temperate pasture legumes (e.g. Medicago sativa), but the seeds are unusual among legumes in containing no galactomannan and there is evidence of the presence of a glucomannan in all parts of the plant.


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