The Night Parrot Geopsittacus Occidentalis: Evidence of its Occurrence in North-Western Victoria During the 1950s

1981 ◽  
Vol 81 (4) ◽  
pp. 239-240 ◽  
Author(s):  
P.W. Menkhorst ◽  
A.C. Isles
Keyword(s):  
The 1950S ◽  
Western Victoria ◽  
North Western

Leaf spot and dry rot of lettuce caused by Xanthomonas vitians (Brown) Dowson

1963 ◽  
Vol 14 (6) ◽  
pp. 778 ◽  
Author(s):  
DE Harrison
Keyword(s):  
Leaf Spot ◽  
Early Spring ◽  
Late Winter ◽  
Laboratory Studies ◽  
Dry Rot ◽  
Complete Destruction ◽  
Western Victoria ◽  
Valley Area ◽  
North Western

During the late winter and early spring of 1960, and again to a lesser extent in 1961 and 1962, many lettuce crops in the Murray Valley area of north-western Victoria were seriously affected by a disease characterized by blackening, dry rotting, and collapse of the affected leaves. The incidence of disease varied from about 10% up to practically complete destruction of some plantings. A yellow bacterium was consistently isolated from affected plants and proved to be pathogenic to lettuce. Laboratory studies have shown that the organism agrees closely with the recorded description of Xanthomonas vitians (Brown) Dowson, which has not, apparently, been previously studied in Australia.

Control of Amsinckia spp. by the pastures of north-western Victoria

1965 ◽  
Vol 5 (19) ◽  
pp. 500
Author(s):  
DJ Connor
Keyword(s):  
Seed Production ◽  
Subterranean Clover ◽  
Barrel Medic ◽  
Limited Application ◽  
One Year ◽  
The One ◽  
Western Victoria ◽  
Establishment Phase ◽  
North Western ◽  
Very High

Amsinckia is a serious weed in the wheat growing areas of north-western Victoria. It is successful in the inter-crop pastures, based upon barrel medic, because it grows faster than barrel medic in the cooler months of May to August. In addition, the rapid growth in height associated with the change from rosette to elongating phases ensures a height advantage over the pasture species when the flush of pasture growth does commence. Seed production by each Amsinckia plant is very high, and for this reason any competitive restriction obtained in one year is not necessarily reflected in the establishment phase of the next. Subterranean clover c.v. Clare is more competitive than barrel medic and was able to eliminate Amsinckia from the sward in two years. However it has only limited application in the pastures of north-western Victoria. A mowing treatment was carried out at the commencement of Amsinckia flowering, for this coincides with the beginning of rapid pasture growth. Regrowth produced a reversal of height relationships within the pasture and enabled barrel medic to shade Amsinckia BJ this treatment growth and seed production of Amsinckia were reduced by 99 per cent within the one season.

A Bird-Lover in the Mallee of North-western Victoria

1927 ◽  
Vol 27 (2) ◽  
pp. 69-75
Author(s):  
Charles Sullivan
Keyword(s):  
Western Victoria ◽  
North Western

Diet of the House Mouse, Mus domesticus, in the Mallee Wheatlands of North-Western Victoria

1991 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
CR Tann ◽  
GR Singleton ◽  
BJ Coman
Keyword(s):  
Climatic Factors ◽  
Stomach Contents ◽  
Nutritional Factors ◽  
Annual Peak ◽  
Food Quantity ◽  
Cereal Grain ◽  
Seed Reserves ◽  
Second Year ◽  
Western Victoria ◽  
North Western

The quality and/or quantity of food available to mice at key times may be important in generating plagues. This study examined the diet and breeding performance of mice over two years in the mallee wheatlands of Victoria. Mice were trapped approximately every 6th week and their stomach contents examined for seven categories of food. Indices of occurrence and estimates of percentage volumes of each category indicated that cereal seeds were the staple food of mice. They bred earlier in the second year, but in both years there was a pulse of invertebrates and fresh grass seeds in the diet before the onset of breeding. These pulses occurred when seed reserves ['mature' (>3 months) cereal and dicotyledon seeds] were low. Mice, however, were highly responsive to changes in the availability of different food classes throughout the study. Thus the relative influences of nutritional factors (food quality) and availability of food (food quantity) on the onset of breeding were difficult to determine. The annual peak in female breeding coincided with the availability of fresh cereal grain. Breeding ceased in autumn each year despite the presence of ample 'mature' cereal seeds. Investigations of the effect of climatic factors on timing and abundance of nutrients in the environment is essential for an understanding of their influence on the population dynamics of mice.

Parasitism by Aphytis chrysomphali, Mercet and A. melinus Debach of Californian red scale, Aonidiella aurantoo (Maskell), in relation to seasonal availability of suitable stages of the scale

1973 ◽  
Vol 21 (1) ◽  
pp. 111 ◽  
Author(s):  
IW McLaren ◽  
GA Buchanan
Keyword(s):  
Reproductive Potential ◽  
Host Population ◽  
Early Summer ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
Western Victoria ◽  
Host Parasite ◽  
Relationship Of ◽  
Scale Control ◽  
North Western

A field study was undertaken to investigate the host-parasite relationship of A. aurantii and two species of Aphytis in north-western Victoria, and to suggest methods for improving and extending the biological control of A. aurantii in Victoria. Monthly samples of scale-infested Valencia oranges from five unsprayed biocontrol properties at Mildura provided information which showed a positive correlation between the percentage of available stages in the host population and the efficiency of parasitism by the Aphytis. This was thought to result from the seemingly inefficient method employed by the Aphytis in selecting a suitable host in which to oviposit; a postulate reinforced by the results of earlier work. The scarcity of suitable hosts at certain times of the year is thought to limit the efficiency of the Aphytis by reducing the chances of the parasite to achieve its reproductive potential. On the basis of this study an improved approach to red scale control is proffered, namely that attempts be made to augment the effectiveness of the established Aphytis by devising methods for increasing the proportion of available stages in red scale populations during late spring and early summer. Field and laboratory evidence indicates that parasitism by Aphytis, rather than variation in weather, is responsible for the considerable seasonal fluctuations in percentage of scales available for parasitism.

A Postfire Chronosequence of Cone, Follicle and Seed Production in Banksia ornata

1986 ◽  
Vol 34 (4) ◽  
pp. 425 ◽  
Author(s):  
AM Gill ◽  
A Mcmahon
Keyword(s):  
Seed Production ◽  
Seedling Establishment ◽  
Quantitative Research ◽  
Weather Conditions ◽  
Fire Intensity ◽  
Stand Age ◽  
Laboratory Conditions ◽  
Western Victoria ◽  
North Western ◽  
Seasonal Weather

The fire-sensitive shrub Banksia ornata relies on seed stored in serotinous 'cones' for its regeneration. Seed release takes place largely as a result of fire but a very small percentage of fruits may open spontaneously. In a chronosequence studied in heaths of the Little Desert of north-western Victoria, we found no seedling establishment in the absence of fire except in the oldest stand, dated at 50+ years since fire. Seed quantity was low in stands 6-7 years old but rose to a peak in the 38-year-old stand. The decline of seed quantity in the 50+ year-old stand was due to dieback and death of bushes. There was no evidence for an increase in the proportion of seeds predated with age of stand. An average of about 70% of the seed was regarded as 'intact' (no sign of damage) and about 80% of these seeds germinated under ideal laboratory conditions. It was estimated that the amount of seed available for regeneration increased with stand age up to 38 years but declined by 50+ years. It was suggested that a period of 16 years without fire could be needed to achieve stand replacement of populations of this species. The age at which full replacement can be achieved will vary, however, according to fire intensity and seasonal weather conditions. Further quantitative research is needed.

Seed production and seed germination of Amsinckia hispida

1965 ◽  
Vol 5 (19) ◽  
pp. 495 ◽  
Author(s):  
DJ Connor
Keyword(s):  
Seed Germination ◽  
Environmental Factors ◽  
Seed Production ◽  
Constant Temperature ◽  
Cold Treatment ◽  
North West ◽  
Seed Maturity ◽  
Germination Behaviour ◽  
Western Victoria ◽  
North Western

Amsinckia hispida is a serious annual weed of cereal culture in north-western Victoria. Individual plants produce seed for up to two months in the spring and this provides a range of seed maturity that is reflected by a gradual build-up of germinability in the following autumn. In addition the seed has an optimum constant temperature for germination of 13�C (48�F) and responds markedly to a period of cold treatment. These three features act together to produce the series of Amsinckia populations which are characteristic of its autumn germination behaviour in north-west Victoria. Seeds which germinate early are responsible for infestations in the pasture phase and those which germinate later are not controlled by pre-sowing cultivation and remain to germinate within crops. The response of Amsinckia to environmental factors is such that these plants which germinate late within wheat crops have an extended rosette period and are highly competitive.

The effect of excluding insect pollinators on seediness of Imperial mandarin fruits

1992 ◽  
Vol 32 (3) ◽  
pp. 409 ◽  
Author(s):  
SR Sykes ◽  
JV Possingham
Keyword(s):  
Major Effect ◽  
Fruit Weight ◽  
Soluble Solids ◽  
Parthenocarpic Fruit ◽  
Insect Pollinators ◽  
Western Victoria ◽  
Insect Visitors ◽  
North Western ◽  
Number Of Seeds

The effect of caging trees to exclude insect visitors on the fruit density, seediness, and quality of Imperial mandarin in north-western Victoria was investigated during 1990-91.The major effect of caging was a reduction in fruit seediness, with open trees having 5-16% of fruit seedless and caged trees 80-95%. The number of seeds per fruit ranged from 0-18 and 0-5 for open and caged trees, respectively. Caging trees had no effect on mean fruit density, mean fruit weight, fruit juiciness, soluble solids and percentage citric acid. These results provided further evidence for parthenocarpic fruit development by Imperial mandarin.

Variation in Phebalium glandulosum subsp. glandulosum: morphometric and anatomical evidence (Rutaceae)

2008 ◽  
Vol 21 (4) ◽  
pp. 271 ◽  
Author(s):  
Robyn L. Giles ◽  
Andrew N. Drinnan ◽  
Neville G. Walsh
Keyword(s):  
New South ◽  
Anatomical Variation ◽  
New South Wales ◽  
South Australia ◽  
Geographic Range ◽  
New Subspecies ◽  
South Wales ◽  
Climate Analysis ◽  
Western Victoria ◽  
North Western

Specimens of Phebalium glandulosum Hook. subsp. glandulosum representing the entire geographic range of the subspecies were examined for morphological and anatomical variation. Phenetic patterns were identified with the pattern analysis package PATN, and three distinct groups were identified. One group consists of plants from inland areas of New South Wales, north-western Victoria, and the Yorke and Eyre Peninsulas of South Australia; a second group consists of plants collected from alongside the Snowy River in eastern Victoria and south-eastern New South Wales; and a third group consists of plants from Queensland and northern New South Wales. The climate analysis program BIOCLIM was used to compare climate variables across the geographic range, and showed clear climatic separation in support of the phenetic analysis. The three groups are formally recognised here as distinct subspecies. Plants from Queensland and the Bourke region of northern New South Wales belong to the typical subspecies; plants from north-western Victoria, central New South Wales, and the Yorke and Eyre Peninsulas of South Australia form a cohesive assemblage and are recognised as a new subspecies P. glandulosum subsp. macrocalyx; and plants from the Snowy River in far eastern Victoria and the Southern Tablelands of New South Wales form a distinct and isolated group recognised as a new subspecies P. glandulosum subsp. riparium. These new subspecies are formally described, and an identification key and summaries distinguishing all six subspecies of P. glandulosum are presented.

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