Plant Biology Commons^™

Clearwing Moths Are Key To Dock Control, Kingsley Fisher

Journal of the Department of Agriculture, Western Australia, Series 4

Two clearwing moths imported from Morocco and France could be the key to controlling dock (Rumex pulcher) - one of the worst weeds of high rainfall pastures in southern Australia

Monitoring Western Australia's Rangelands, Ron Hacker, David Beurle, George Gardiner

Journal of the Department of Agriculture, Western Australia, Series 4

Rangelands, native pastures used for grazing domestic livestock, occupy about 100 million hectares or 40 per cent of Western Australia, extending from the tropical grasslands of the Kimberley to the arid shrub steppe of the Nullarbor Plain.

The rangelands are characterized by highly variable seasonal conditions. Carrying capacity can fluctuate dramatically from year to year. Grazing management requires a tactical approach from one season to the next because of the great variation in the capacity of the land to support stock.

Rangeland monitoring provides pastoralists with objective information on these changes to assist their management decision making. The Western Australian …

Maine's Endangered And Threatened Plants, Maine State Planning Office

Maine Collection

Maine's Endangered and Threatened Plants

Executive Department, Maine State Planning Office, Critical Areas Program, 1990.

Biological Control Of Doublegee, Dane Panetta

Journal of the Department of Agriculture, Western Australia, Series 4

Doublegee (Emex australis) is one of the worst agricultural weeds in Western Australia. To date, however, biological control of this weed has proved elusive. Multiple releases of two weevils which attack doublegee have not led to insect establishment. For one of these species, further research has shown that doublegee control would probably not be achieved in the wheatbelt even if insect establishment were enhanced by growing its host during the summer months. A joint Western Australian Department of Agriculture/ CSIRO project is investigating the virulence and host specificity of an undescribed South African species o/Phomopsis fungus. Should this pathogen prove …

Noteworthy Collections: Virginia, W. John Hayden

Biology Faculty Publications

The above collections represent the second record for the state of Virginia, and may well establish the northernmost station for the species in the eastern United States. According to B.L. Lipscomb (Sida 8:320-327. 1980), this Old World weed is spreading throughout the warmer regions of North America. The only previous record of the species from the state is a Fernald specimen from Owl Creek in Virginia Beach. R.W. Tyndall, who found the species in northeastern North Carolina, was unable in 1978 to locate the plant at Fernald's Virginia Beach locality (Castanea 48:277-280. 1983). The Amelia County plants occur in two …

Ontogeny Of The Cotyledonary Region Of Chamaesyce Maculata (Euphorbiaceae), W. John Hayden

Biology Faculty Publications

Development of the cotyledonary region in Chamaesyce maculata is described from germination of the seed through formation of the dense mat of branches which characterize this common weed. The cotyledonary node is trilacunar with split-lateral traces. Epicotyl development is limited to a pair ofleaves ("V-leaves") inserted directly above and decussate to the cotyledons. The two V-leaves are also vascularized by three traces and insertion of these traces relative to the vasculature at the immediately subjacent cotyledonary node is asymmetrical; four of the six V-leaf traces arise on one side of the intercotyledonary plane and two arise on the opposite side. …

Looking At Lupins - Lupin Management In The South Eastern Wheatbelt, W. L. Smart, M. M. Ralph, J. M. Liddle, R.. D. Ramm, C. J. Robinson, E. W. Armstrong

Grain and other field crops research reports

In the past couple of years research into lupins has increased substantially particularly in the fields of weed control, seeding rates, and control of diseases such as brown leaf spot and pleiochaeta root rot. This report is a summary of the lupin trials in the Lake Grace advisory area as well as a guide to better lupin farming.

The Potential For Skeleton Weed, John Dodd, F. D. Panetta

Journal of the Department of Agriculture, Western Australia, Series 4

Since its introduction into Australia during the 900s skeleton weed has become one of the most economically significant weeds. Its presence in cereal crops in south-eastern Australia has caused suvere yield reductions and harvesting problems.

Skeleton weed was first found on a Western Australian farm in 963. Since then it has been the subject of an intensive eradication campaign organised by the Agricultural Protection Board and funded by an annual levy on wheat growers. Such campaigns, which rely mainly on volunteer searchers, do not exist in eastern Australia because the weed is so widespread it would be impossible to eradicate. …

The Pollen Exostructure Of Striga (Scrophulariaceae), Mark A. Deleonardis

Biological Sciences Theses & Dissertations

In this survey, the pollen exostructure of 13 Striga species was examined using light microscopy and scanning electron microscopy. Two of the 13 species were also observed by transmission electron microscopy to assess major differences in exine composition. Striga pollen is consistently spherical to oblate, isopolar, tectate, and three or four colpate. Sculpturing may be psilate, psilate-perforate, finely rugulate, or coarsely rugulate. The equatorial width of the species surveyed ranged from 15 to 30 micrometers. It is concluded that variation in Striga pollen sculpturing, aperture structure, and size support the current taxonomy of the genus.

Using The Zadoks Growth Scale, M W. Perry, D. G. Bowran, G. Brown

Journal of the Department of Agriculture, Western Australia, Series 4

The Zadoks growth scale, which is already used overseas as an aid to better crop management, is gradually being adopted in crop production in Western Australia.

By using the scale grain growers are able to identify the various stages of crop development, particularily those growth stages that are closely related to practices such as crop spraying where treatment too early or too late may be ineffective or damaging.

Beating The Blackberry, J H. Moore, E. B. Hoskins

Journal of the Department of Agriculture, Western Australia, Series 4

The blackberry is an aggressive, strongly-growing plant that has spread throughout parts of the south-west of Western Australia.

Although most blackberry infestations on agricultural land have been dramatically reduced since compulsory control measures were introduced 30 years ago, about 3,600 hectares are still infested today.

Recent research has shown that three new herbicides are highly effective against blackberry, and much safer to use than the older ones.

Effective biological control of blackberry may also be possible.

Research On Declared Plants And Other Weeds, G. A. Pearce

Journal of the Department of Agriculture, Western Australia, Series 4

Knowledge about weeds is necessary to assess their significance, devise control measures and to select those which are to be declared for the purposes of the Agricultural and Related Resources Protection Act.

Once a plant has been declared in Western Australia, all landowners must control and prevent its spread to new areas and work towards eradicating known infestations. The Act also declares plants which are prohibited from entering the State.

It is becoming more and more important to provide specific reasons for the declaration of a weed and its placement in a certain category. Such decisions require appropriate action to …

Rare Vascular Plants Of Maine : A Critical Areas Program Report, Susan C. Gawler, L. M. Eastman

Maine Collection

Rare Vascular Plants of Maine : A Critical Areas Program Report

Based on Rare Vascular Maine Plants (1978) with Additional Herbarium Data and Rare Plants Information by L.M. Eastman.

Introduction, Criteria, Annotated Rare Plant List, Species Accounts, Additional Herbarium Data, County & Town Index Editing by Susan C. Gawler.

Executive Department, State Planning Office, 189 State Street, Augusta, Maine, 04333 (June 1981).

Contents: Acknowledgements / List of Tables / List of Figures / Part One: Introduction / Part Two: List of the Rare Vascular Plants of Maine / Part Three: Species Accounts / Part Four: Subspecific Taxa / Appendices / …

Perennial Pasture Measures Up, D A. Nicholas

Journal of the Department of Agriculture, Western Australia, Series 4

In a trial at Manjimup, a pasture based on the perennial grass, Currie cocksfoot, gave substantially more production than a comparable annual pasture.

Bulletin No 3993 - The Control Of Saffron Thistle, G. A. Pearce

Bulletins - 3000 - 3999

Saffron thistle is a primary noxious weed and is widespread throughout the drier parts of Western Australia. When growing in pasture its prickly growth habit discourages animals from grazing amongst it so that its presence results in the loss of feed. In crops it reduces yield and results in dockage when seed is found in harvested grain.

Wild Oats In W.A, J G. Paterson

Journal of the Department of Agriculture, Western Australia, Series 4

A summary of background information, recent research findings and current recommendations for the control of wild oats in Western Australia.

The Doublegee Problem In Western Australia, D J. Gilbey

Journal of the Department of Agriculture, Western Australia, Series 4

Doublegee is native to South Africa and is now naturalised as a serious weed of crops and pastures throughout the temperate areas of Australia.

Doublegee was introduced for cultivation as a vegetable by English migrants to the Swan River Colony in 1830, and a bed of doublegees is known to have been sown at Mr. J. Phillips' property on the Canning River in 1833. However, the plant soon became a troublesome weed and its name was changed from Cape spinach to Tanner's curse and later to doublegee.

More than 180 doublegee seedlings per square metre have been counted in a …

Docks In Western Australia, J M. Allen

Journal of the Department of Agriculture, Western Australia, Series 4

A survey carried out by the Department of Agriculture has shown that docks are the most serious weed of the higher rainfall areas of Western Australia. They are estimated to cost farmers $400 000 annually in lost production. One of the main reasons why they are important weeds is that they regenerate rapidly from tubers and compete with desirable annual pasture species. Also the upright dock flowering stems are woody and unpalatable. Individual plants become intertwined and deter stock from grazing summer pastures.

Results from the survey of the dock problem are given in this article. The findings show that …

A Mode Of Action Of Herbicides: Inhibition Of The Normal Process Of Nitrite Reduction, Lowell Klepper

Nebraska Agricultural Experiment Station: Historical Research Bulletins

Herbicides were shown to interfere in the normal process of enzymatic nitrite reduction by the plant in photosynthetic and nonphotosynthetic plant tissues with little effect on nitrate reduction. This preferential inhibition caused nitrite to accumulate. The occurrence of free nitrite within the plant can help to explain the toxicity symptoms, nastic growth reactions, abnormal metabolism and rapid death due to herbicide action. This blockage of nitrite reduction was shown with all photosynthetic inhibitor herbicides tested and with numerous other herbicides. The effect was demonstrated using an in vivo assay, intact green plants and germinating seedlings. A basic in vivo method …

Faster Weed Germination With Early Cultivation, Geoffrey A. Pearce

Journal of the Department of Agriculture, Western Australia, Series 4

The key to cultural control of weeds in cereal crops is an understanding of the factors which govern germination of the weed seeds.

Covering the seed with soil keeps out light, provides a stable moisture supply and makes germination faster than if the seed is left on the soil surface.

Shallow cultivation at the start of the growing season provides the soil cover needed for fast, even germination of weed seeds.

Smooth-Stemmed Turnip, B J. Quinlivan, A. C. Devitt

Journal of the Department of Agriculture, Western Australia, Series 4

Cruciferous weeds are common throughout the agricultural areas of Western Australia. They include wild turnip, wild mustard, wild radish, charlock and raphistrum weed or short fruited turnip.

Another one—tentatively named smooth-stemmed turnip—has recently been sighted. Its exact weed potential will not be known for some years, but it is likely to spread through the south coastal districts where the climate and sandy surfaced soils favour its growth.

Annual Pasture And Weed Plant Ecology, B J. Quinlivan

Journal of the Department of Agriculture, Western Australia, Series 4

The purpose of this article is to outline a few basic principles of pasture and weed ecology with particular reference to seed dormancy mechanisms.

These principles apply to many pasture plants and weeds, although their relative importance varies with the particular plants under study.

Management Of Dry Land Lucerne In The South-West, R Sprivulis

Journal of the Department of Agriculture, Western Australia, Series 4

MANY dry land lucerne stands have been successfully established in the dairying areas of the South-West.

With good management these can remain productive for many years; poor management can greatly reduce their productive life.

Cotton Bush (Asclepias Fruticosa L.) : Garden Plant Now A Noxious Weed, G R W Meadly

Journal of the Department of Agriculture, Western Australia, Series 4

THE cotton bush is native to South Africa but is now naturalised in most tropical and sub-tropical countries of the world. Its spread is, in no small measure, due to being grown frequently as a garden subject.

Calotropis Or Rubber Tree (Calctropis Procera (Linn.) Dryand), G R W Meadly

Journal of the Department of Agriculture, Western Australia, Series 4

TWO SPECIES of Calotropis have been introduced to the northern parts of Western Australia. They are closely related in most respects but differ in one fundamental feature which decides their significance as undesirable plants.

The Control Of Annual (Wimmera) Ryegrass In Cereal Crops, Geoffrey A. Pearce, B. J. Quinlivan

Journal of the Department of Agriculture, Western Australia, Series 4

The annual ryegrasses are valuable pasture plants in Western Australia, yet have become one of the major weed problems in cereal crops.

The key to cultural control of annual ryegrasses in cereal crops is an understanding of the factors which govern germination of the seed.

Covering the seed with soil keeps out light and provides a more stable moisture supply, bringing about a faster rate of germination. This is the basis of control programmes recommended in this article.

Recommendations for chemical control are also included.

The Control Of Weeds In Linseed And Rape, Geoffrey A. Pearce

Journal of the Department of Agriculture, Western Australia, Series 4

Like all crops linseed and rapeseed can suffer from weed competition.

Linseed is highly susceptible to weed competition, while rape is susceptible to the chemicals used to kill broad-leaved weeds, so both crops pose special problems.

As in other broad-acre crops, cultural methods usually provide the best means of weed control.

Weed Control Research Pays Dividends, G R W Meadly

Journal of the Department of Agriculture, Western Australia, Series 4

On my bookshelf is a handbook entitled "War on Weeds" or "How to Double our Food Supply."

In many of these countries experiments have been made to ascertain as far as possible the exact damage done by weeds to crops.

Result: In all the experiments, whether made in England or abroad, the mean loss was over 50 per cent.

The level of loss is equally true today, but the methods at our disposal for handling weeds have improved tremendously.

Dormancy And Life Span Of Saffron Thistle Seeds, B J. Quinlivan, J. R. Pierce

Journal of the Department of Agriculture, Western Australia, Series 4

RESEARCH in the Geraldton area has indicated that seeds of the saffron thistle (Carthamus lanatus) spread their germination over some seven years but most germinate in the first two years.

Factors influencing the rate of germination and the survival of seeds are the depth of burial and the presence of termites in the soil.

Control Of Cape Tulip, Geoffrey A. Pearce

Journal of the Department of Agriculture, Western Australia, Series 4

CAPE TULIP is the worst weed in the Avon Valley and northern areas of the Great Southern districts.

It occurs elsewhere to a limited extent but even then it is regarded as a serious weed.