Life Sciences Commons^™

Weeds Can Poison Crops, Aik Hock Cheam

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

Weeds can interfere with the growth of a crop simply by competing with the crop for nutrients, moisture and light. But some weeds also release chemicals that inhibit the germination and growth of crop plants; the technical term for this is allelopathy. Aik Cheam outlines the problems caused by two common weeds and the discusses preventative measures.

Canola : Golden Oil For Farmers And Consumers, Paul Carmody

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

It is feasible that canola could become Western Australia's fourth largest crop after wheat, barley and lupins by the turn of the century.

Without the stigma attached to its parent crop, rapeseed, canola has also become one of the most successful international agricultural product launches, proving itself not only a useful cropping alternative but a healthy oil for consumers. State Oilseeds Adviser PAUL CARMODY sets the scene.

Fast Tracking Barley Varieties Using Anther Culture, Sue Broughton, Penny Priest

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

Breeding new varieties of barley or other cereal crops usually takes between 12 and 15 years. five years of that time may be needed to stabalise the new varieties so that they breed trueto type, but anther culture can reduce this delay to only eight months. This technology will allow the Department of Agriculture's barley breeding programme to respond more rapidly to changes in goals set by industry and to meet market demands.

Production Of High-Value Wheats : One Sustainable Answer To The Cost:Price Squeeze, Wal Anderson, Alan Peggs, Doug Sawkins

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

Farmers and scientists alike over the past decade have sought to address the declining terms of farm trade (the cost.price squeeze) by increasing wheat yields in ways that will ensure both their economic and ecological survival. Nevertheless, costs have continued to increase as a proportion of the value of the product.

Many farmers have increased their wheat yields substantially and the industry as a whole is more conscious of the quality of its product.

Over the past 10 years or more there has been intense interest in, and considerable adoption of. conservation farming techniques such as minimum tillage, residue retention, …

Establishment Of Lupin Seedlings, Miles Dracup

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

Good seedbed conditions lead to high and rapid seedling emergence and vigorous seedlings best equipped to avoid disease, weed competition and sand-blasting. Good establishment is needed for a high yielding crop.

In Western Australia, seedbed moisture and temperature are most likely to limit successful emergence of lupins, especially with the trend toward early sowing.

Research by the Department of Agriculture is helping to define seedbed temperature and moisture requirements for successful lupin establishment that will help future research for improving seedbed conditions.

Opportunity Knocks : Sowing Wheat Early In The North-Eastern Wheatbelt, Nicole Kerr, Doug Abrecht

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

Farmers consider many factors in deciding whether to start sowing wheat, but the most important are the amount of rain and time of year. In this study we assessed the chances of farmers in the north-eastern wheatbelt (less than 325 mm rainfall) receiving enough rain to sow wheat early. In low rainfall areas such as this, where an early finish to the season is likely, it is especially important that farmers take advantage of all early sowing opportunities. The potential benefits of sowing wheat early generally outweigh the associated risks, particularly in lower rainfall areas. However, early sowing depends on …

New Yellow Serradella Varieties For Low Rainfall Pastures, Clinton Revell

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

Large areas of acidic, sandy soils in Western Australia's low and medium rainfall, wheatsheep areas are suited to the pasture legume, yellow serradella.

In the past, a lack of varieties with suitable maturity has limited the use of this species.

New varieties developed in Western Australia and significantly earlier in maturity than traditional types can now extend the use of yellow serradella into these regions.

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

The Impact Of Red Kangaroos On The Rangelands, Grant Norbury, Dale Norbury

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

Kangaroos and other native animals should be maintained across their natural range, including areas set aside for pastoral use. But the added grazing pressure on native vegetation from sheep, cattle and feral animals, together with unnaturally high numbers of kangaroos, has seriously degraded much of our rangelands. Cattle and sheep numbers are relatively easy to control. The same cannot be said for kangaroos. Access to widespread man-made watering points has allowed kangaroos to continue breeding when normally a shortage of water would suppress reproduction.

Pastoralists complain that commercial kangaroo shooting is not always effective in preventing damage caused by kangaroos. …

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 …

Waterlogging : How It Reduces Plant Growth And How Plants Can Overcome Its Effects, Tim Setter, Bob Belford

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

Lack of oxygen is the major cause of limited plant growth in waterlogged soils. When soils become waterlogged less gas diffuses to and from the roots through the soil pores; there are changes in concentrations of mineral elements in soil solutions; and toxic products of roots and soil microorganisms begin to accumulate. These changes adversely affect germination, growth and development of plants.

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 …

Increased Returns From Agronomic Inputs In Early Sown Cereal Crops, W K. Anderson

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

When crop variety and soeing dae are matched so that flowering occurs in the 'window' for a particular site, grain yields are increased and yield response to inputs such as nitrogen fertilizer and seeding rate is magnified.

This response occurs because the srop's potential for setting and filling grains is much improved by sowing at the optimum time. However varieties differ in their yield potential because they have different lenghts of growing season, which probably affects grain numbers, and because they have different inherent grain sizes. These differences affect the way varieties react to sowing date. Figure 1 shows how …

Early Sowing : One Key To Improved Yields Of Cereal Crops, M W. Perry, Wal Anderson, Rob Delane

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

Early sowing of cereal crops is one of the most important management practices through which Western Australian cereal growers can increase yields.

Researchers have long known that in theory early sowing should mean improved growth and water use efficiency - which both contribuite to increased yields. Application of this knowledge has had to await new tillage and herbicide technology, but recent research in the northan and central wheatbelt has now demonstrated the advantages of early sowing in practice. And more exciting yet, there is evidence that yield responses to weed control and applied fertilizers may also be greater in early …

Flower : Predicting Flowering Times Of Cereal Crops, G A B Elliott, Stephen Loss

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

FLOWER is a computer program which predicts the flowering date of a given wheat or barley variety at a specified location and sowing date. Department of Agriculture agronomists, breeders and advisers are using the program to provide useful information on how the development of cereals responds to different environments across Western Australia's cereal growing areas.

Frost Injury To Wheat, S P. Loss

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

Frost injury has not been a major concern to the Western Australian wheat industry despite causing spectacular but irregular crop losses on some farms.

The development of suitable herbicides, direct drilling technology and the adoption of early flowering varieties in the late 1970s and early 1980s led to wheat crops being sown and flowering earlier than previously. This resulted in an increase in the incidence of frost damage.

Research into frost indicates that most wheat producers face low to moderate risks of yield loss caused by frost. However, individual farms in particular years can suffer devestating widespread losses. Grost injury …

Early Sowing Of Ceral Crops In Low Rainfall Areas, R J. Delane, John Hamblin

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

One of the objectives of the Department of Agriculture's crop research in the low rainfall, northern wheatbelt is to develop crop varieties and management practices that will make best use of stored water on both sandplain and fine textured soils. Sowing a crop early will improve its water use efficiency and yiel in low rainfall areas.

Clover Infertility Of Sheep : Continuing Problem, N R. Adams, Keith Croker

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

Some varieties of subterranean clover, notably Dinninup, Dwalganup and Yarloop, contain compounds which act like the female sex hormone oestrogen. These plant oestrogens, or "phyto-oestrogens", interfere with the fertility of sheep and depress the percentage of lambs born.

Over the past 10 years our understanding of clover infertility has increased, and we can now gauge the extent of this residual problem. In fact, there is a widespread but low-level incidence of infertility which does not greatly affect individial farms but which has an important impact on the State's sheep production.

Trends In Wheat Protein/Yield Relationships, G B. Crosbie, Harry Fisher, Bryan Whan

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

The major concern of wheat breeders in WesternAustralia has been to increase grain yield while maintaining quality at an acceptable level. There has been no concious effort to select for protein content. It is of interrest, therefore, to compare the relationship between yield and protein of varieties which have been prominent in Western Australia at various times, to see what effects yield increases have had on protein content and the extent of any variation which might exist.

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. …

Variation In Wheat Protein Content : The Effect Of Environment, G B. Crosbie, Harry Fisher

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

Over the past 20 years, the average protein content of WesternAustralian wheat has ranged from 9.3 to 12.0 per cent, with a mean level of 10.4 per cent. At most grain receival points, in any one season, individual loads can often vary in protein content by as much as 5 per cent protein or more. Rainfall and soil fertility account for much of this variation.

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.

Serena And Circle Valley Medic Establishment, M A B Ewing

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

Since the commercial release of the burr medics Serens in 1983, and Circle Valley ayearlater, much has been learnt about the establishment and management of these pasture legumes. When sown on suitable soils and with appropriate establishment and management techniques, these medics have the potential to dramatically change farm profitability. This results from both increased production from livestock and from improved cereal crops grown in rotation.

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.

Soil Acidity And Legume Nodulation, J G. Howieson, M. A. Ewing

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

Nitrogen is a basic constituent of protien and is essential to all forms of life. Many agricultural plants are legumes - a group of plants which, in co-operation with specialised soil bacteria, fix their own nitrogen from the air. When the legume dies, the organic matter breaks down anf the nitrogen becomes available to the following crops.

Soil acidity is a major factor limitimg the successful association between legumes and their beneficial soil bacteria in Western Australia.

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 …

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.

Ryegrass Toxicity Organism Found On Other Grasses, D L. Chatel, J. L. Wise, A. G. Marfleet

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

Yellow slime disease caused by Corynebacterium sp. has recently been found in three grass species.

The diseased grasses were found in the field growing with each other and with affected toxic annual ryegrass.

Trials Indicate Best Lupin Seeding Rates, G H. Walton

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

Trials on the seeding rate of lupins have shown that for most crops, at least 80kg of seed per hectare gives best yields. However the yields varied considerably, and in higher yielding situations, lower seeding rates were better.

Plants As Pumps, E A N Greenwood

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

Native species vary greatly in their ability to pump ground water.

CSIRO studies are measuring water use by different plants to plan revegetation strategies.