Plant Pathology Commons^™

Carrot Export Growth Depends On Keeping Cavity Spot Under Control, Allan Mckay, Elaine Davison

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

Cavity spot is the most serious disease affecting carrot production in Ly Western Australia. With carrots now being the State's most important horticultural export, Agriculture Western Australia has undertaken extensive research to ensure the export market continues to grow.

Clubroot, Rachel Lancaster, Caroline Donald, Ian Porter

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

Rachel Lancaster, Caroline Donald and Ian Palmer, outline some control measures for clubroot, one of the most serious diseases of crucifers world wide.

Northern Australia Quarantine Strategy. Weeds Target List, B. M. Waterhouse, A A. Mitchell

Biosecurity published reports

Second edition.

The Northern Australia Quarantine Strategy (NAQS) was established in 1989 as an outcome of a major evaluation of quarantine in Australia (AGPS 1987, 1988). NAQS activities include surveying for weeds,insect pests and diseases of plants; and pests and diseases of animals in northern Australia, Papua New Guinea and Indonesia. The primary goal is to provide early detection and warning of new quarantine threats or incursions.

A targetted approach was adopted for all pests, diseases and weeds. For each category of pest, experts in the discipline compiled lists of organisms not known from Australia but known to occur in …

Coming To Grips With Eradu-Patch Of Lupins, Bill Macleod, Mark Sweetingham

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

Investigations by Bill MacLoud and Mark Sweetingham have confirmed that Eradu-patch of lupins is caused by apreviously undescribed fungal pathogen,\.

They have developed strategies to minimise the spread of patches but choices are limited for control in lupin crops

Cucumber Mosiac Virus In Lupins, Annette Bwye, Roger Jones, Wayne Proudlove

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

Cucumber mosaic virus is a threat to lupin crops from Geraldton to Esperance, particularly to those growing in areas receiving more than 400 mm average annual rainfall. The disease markedly decreases grain yield in narrow-leafed and yellow lupins but doesnot infect albus or sandplain lupins. Worldwide , after bean yellow mosaic virus, cucumber mosaic virus is the second most important virus affecting lupins. Annette Bwye, Roger Jones and Wayne Proudlove outline the symptoms, spread and management of this serious disease.

Pulses : Profitable New Crops For The Wheatbelt, Kadambot Siddique, Stephen Loss, Ian Pritchard

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

Narrow-leafed lupins have beeb produced on sandy acid soils throughout the wheatbelt for more than two decades. However, the wheatbelt contains large areas ofsoilsnot suited to narrow-leafed lupins. For several years reasearchers have been examining alternatives to narrow-leafed lupins for these soils.

Kadambot Siddique, Stephen Loss and Ian Prichard look at production of these new grain legumes, known as pulses.

Bulletin 4294 - Virus Diseases Of Lupins, Roger Jones

Bulletins 4000 -

Two virus diseases pose a serious threat to lupins. These are caused by cucumber mosaic virus (CMV), which induces diseases in narrow-leafed and yellow lupins, and bean yellow mosaic virus (BYMV), which infects all types of cultivated lupins. The effects of the viruses on lupin plants range from subtle colour changes and leaf distortion to leaf shedding, stunting and death. Seed production is decreased or prevented. There is no cure, but lupin crops can be managed to minimise both virus spread and its persistence from year to year.

CMV and BYMV occur within all tissues in the plant, but do …

Biological Control Of Doublegee : Israeli Weevil Could Help Fight Doublegee, John Scott, Paul Yeoh

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

Since its deliberate introduction from South Africa as a salad vegetable in 1830 the doublegee has spread to become a major weed throughout much of Australia.

It is one of the most serious weeds of crops and pastures in Western Australia, smothering other more useful plants while young, and troubling both humans and animals with its sharp spiny seeds when mature.

Using biological control techniques, scientists are now attacking it and related docks in three ways - with an aphid, a weevil and a fungus.

Within a few years it is hoped that while still present, the doublegee will be …

Biological Control Of Doublegee : Doublegee Decline And The Dock Aphid, John Scott, Francoise Berlandier, Kristy Hollis

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

Since 1990 farmers in the Western Australian wheatbelt have been reporting doublegee plants that appear to be diseased, stunted and producing poorly formed fruit (the spiny casing around the single doublegee seed). Often no obvious cause of this decline in plant health is apparent. Experiments carried out in 1990 showed that an aphid, which feeds hidden in the growing tips of doublegee stems and in young distorted leaves, is the most likely cause. This North American aphid, the dock aphid (Brachycaudus rumexicolens), arrived in WA in 1987. It appears to only feed on docks, doublegees and related plants and is …

Developing Improved Varieties Of Subterranean Clover, Phil Nichols, Bill Collins, Dennis Gillespie, Martin Barbetti

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

Subterranean clover is widely recognised as the most important pasture legume species in southern Australia, having been sown over about 20 million hectares.

Together with superphosphate and trace elements, it has been a key factor in improving and maintaining soil fertility, and has resulted in dramatic increases in crop, livestock and wool production.

While the value of subterranean clover is well established, it does have some shortcomings.

Many varieties grown today are not sufficiently adapted to the environments and management systems in use. Others lack sufficient pest and disease resistance.

Improved subterranean clovers are being bred with better adaptation and …

Merging Conservation With Production In Remnant Bush, Anne Morgan, Alison Fuss

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

Exports of cutflowers and foliage from Western Australia are now worth about $17 million a year. A third of this is picked from the bush, either on Crown Land or areas of remnant bush on private property. While the industry's future lies in cultivation, bush picking is likely to remain important for some years. This can provide both extra income for farmers and benefit the environment - as long as care is taken

Biological Control Of Doublegee : Fungi May Be Another Weapon, Roger Shivas, John Scott

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

A fungus has been assessed both in Australia and South Africa since 1989 for its potential to control doublegee.

Under optimal environmental conditions it causes a severe stem blight which ultimately kills the plant. It also infects seeds, and caused up to 30 per cent mortality at a field site near Badgingarra.

Hopes to develop the fungus as a mycoherbicide (fungal killer of plants) have had to be dropped because it produces a potent toxin but it is still contributing to control in the field.

Barley Yellow Dwarf Virus In Cereals, Simon Mckirdy, Roger Jones

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

Worldwide, barley yellow dwarf virus (BYDV) is the most widespread and damaging virus disease of cereals. It infects wheat, barley, oats and grasses and is transmitted by several aphid species. The virus is not seed-borne and to persist from one growing season to the next it must survive in over-summering grasses.

Barley yellow dwarf virus decreases grain yield and also causes shrivelled grain. Yield loss is greatest from infection early in the growing season.

Eradication Of Apple Scab, John Cripps, Ralph Doepel

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

The detection of apple scab in two orchards at Pemberton and New/ands in December 1989 ended Western Australia's 41-year, scab-free span for apple growers .

Without eradication orchardists would have had to apply up to 20 fungicidal sprays a year, at an annual cost of $1-2 million, to be able to market a high proportion of scab-free fruit. The industry chose eradication as the cheaper alternative, but the location of infected orchards at Pemberton in particular, with its high rainfall, suggested that it would be difficult .

Scab, or black spot, is the most serious fungal disease of apples in …

Stubble Retention And Leaf Disease In Lupin And Cereal Crops, Mark Sweetingham, Robert Loughman, Ron Jarvis

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

Retention of cereal stubbles can reduce leaf disease in lupins but increase leaf disease in cereals. The extent of cereal disease carry-over in stubbles depends on the locality and whether multiple cropping or crop rotation is practised

Paddock Sampling For Management Of Annual Ryegrass Toxicity, Ian Riley

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

Annual ryegrass (Lolium rigidumJ seedheads containing corynetoxins, a group of bacterially produced antibiotics, are poisonous to livestock. Animals that eat affected ryegrass develop annual ryegrass toxicity (ARGT), suffer convulsive staggers and die within a few days of eating a lethal dose. ARGT is characterised by high death rates, especially where pastures are not known to be affected and where stock-owners are not expecting the problem. Fortunately, there are commercial tests that determine the levels of ARGT organisms in the paddock and the risk of getting the disease. These tests will help farmers plan their cropping and pasture programs for the …

Three New Late-Midseason Subterranean Clovers Released For High Rainfall Pastures, Phil Nichols, Donald Nicholas

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

Three new subterranean clovers - Denmark, Gou/bum and Leura - have been released in 1992 by the National Subterranean Clover Improvement Program. These subterranean clovers are black-seeded, have low oestrogen levels and improved disease resistance. Their release offers the potential for substantial improvements in pasture productivity in areas of southern Australia that have long growing seasons.

This article outlines some of the testing procedures and subsequent selection of these varieties and describes their characteristics and potential role in Western Australia.

Australian Genetic Resources Of Trifolium And Ornithopus Species, Richard Snowball, Kevin Foster, Bill Collins

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

The introduction of improved pasture legumes into the cereal growing areas of southern Australia changed the face of our agricultural systems.

Subterranean clover was the first pasture legume to have a major impact, and the first varieties were available commercially in the 1930s. Since then, many varieties have been released, leading to the most recent release of Denmark, Gou/bum and Leura in 1992.

The development of burr, barrel and murex medics also had an impact on the pasture production of less acid heavy soils. Yellow serradella is still being developed for the more acid sandy soils.

This development of improved …

New Leaf Rust Helps To Control Blackberry, Jonathon Dodd, Sandy Lloyd

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

The release of spores of the blackbeny leaf rust in spring 1991 marked the second attempt in Western Australia at controlling weedy blackberries with a biological agent. The strain of rust now being used is expected to be more effective than the one released in the 1980s.

This article describes the techniques used for rearing and releasing the fungus and illustrates the effects of the rust on blackbeny.

Coping With Brown Spot And Root Rots Of Lupins, Mark Sweetingham

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

There is increasing concern that brown spot and root diseases may limit the long term viability of lupin cultivation in close rotations in the agricultural areas of Western Australia. Research has found several useful strategies to reduce the impact of brown spot and Pleiochaeta root rot so that losses can be kept to a minimum. Rhizoctonia has proved more difficult to combat. Although less widespread than Pleiochaeta, it has caused severe losses and appears to be increasing in incidence, particularly in the northern wheatbelt. Research has vastly expanded our knowledge of the strains of Rhizoctonia present in our soils and …

Bulletin 4133 - Fungal Diseases Of Pasture Legumes In Western Australia, M. J. Barbetti

Bulletins 4000 -

Subterranean clover (Trifolium subterraneum L.) is the most important annual pasture legume in Western Australia, forming the basis of some 6.5 million ha of annual pastures. The success of subterranean clover may be attributed to its ability to increase soil fertility as a consequence of nitrogen fixed, to withstand heavy grazing, to control soil erosion and, with some cultivars, to tolerate waterlogging. Fungal diseases have been a major limitation to the productivity of subterranean clover, affecting both the amount of plant matter and the quantity of seed produced.

Annual medic (Medicago spp., in particular M. polymorpha L.) is also an …

Breeding Phomopsis-Resistant Lupins, John Sylvester Gladstones

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

The release of Gungurru and Yorrel lupins marks the coming of age of the narrow-leafed lupin as a crop plantt. These are the first cultivars of the species th have substantial resistance to Phomopsis stem blight, which will make the stubbles much safer for grazing stock.

This article describes the new lupins, their background, and how they were bred. It also acknowledges the contributions of colleagues who helped in important ways.

Erosion Potential Of Phomopsis-Resistant Lupins, D J. Carter, Paul Findlater

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

During lupin harvesting, up to 20 per cent of the grain remains on the ground. This non-harvested or pilt grain is a valuable feed for sheep during early summer because the pods, leaf and stem generally provide little nutrient in the stubnbles. In addition, the more efficient the weed control, the less valuable are the stubbles.

The disease lupinosis caused by Phomopsis leptostromiformis restricts the amount of grazing from the lupin stubbles, and hence the risk of wind-erosion of stubble paddocks.

However, the introduction of lupin varieties moderately resistant to Phomopsis and with reduced potential to cause lupinosis means that …

Breeding Field Peas : Screening Pea Lines, G H. Walton

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

The early use of field peas in Western Australia was as a green manure crop or to feed stock be grazing the mature crop. Varieties which produced a large bulk of green material were sown. There was no control over insects or diseases.

In 1985, the Feseral Government recognised that to realize the potential of grain legumes grown throughout Australia, more research was needed.

One of the Grain Legume Research Council's (GLRC) priorities is species evaluation and variety improvement.

Since 1983, the Western Australian Department of Agriculture has screened advanced crossbred lines from the South Australian breeding programme for its …

Quarantine Disinfestation A Bibliography With Relevance To Ornamental Plant Material, Kevin Seaton, Daryl Joyce

Biosecurity published reports

This bibliography has been compiled as part of a programme to develop new and improved techniques for the insect disinfestation of export cut-flowers and cut-foliage. The objective of the programme is to identify the most effective disinfestation treatments. Suitable treatments should kill insects in the flowers without directly injuring the flowers or reducing their postharvest life.

The bibliography presents references relating to the disinfestation of ornamental material (i.e. cut-flowers, cut-foliage, and potted plants). However, it also includes references on disinfestation of fruit, vegetables, and stored grain where this information has some relevance to the disinfestation of ornamental materials. The bibliography …

Selection And Development Of Early Maturing Varieties Of Murex Medic., D. J. Gillespie

Experimental Summaries - Plant Research

Trial 88A25, 88MO44, 88NA83, 88AL15

Location: Avondale, New Norcia, Darkan, Cranbrook, Arthur River, Kellerberrin North Quairdading, Gabalong, Merredin, Badgebup and Pingrup.

Over 300 recent overseas introductions of murex medic were evaluated in rows at South Perth in 1988. Of these 15 selections were identified with acceptable spinniness that flower in 100 days or less. Four years ago there was only one selection flowering in under 110 days and that was spiny!

These selections will be evaluated in small plot trials in several country sites in 1989.

This programme aims to identify superior varieties to Zodiac which was released in 1988.

Seed-Bourne Virus Diseases In Annual Pasture Legumes, R A C Jones

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

No abstract provided.

Diseases Of Native Flowers, Peter Mcr Wood

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

The native flora of Australia has evolved in such a way as to render it resistant to many of the fungi and bacteria that commonly infect exotic cultivated flower crops. Many of our native plants have tough sclerophyllous foliage which makes it difficult for pathogenic organisms to gain access, particularly in their natural undisturbed habitats. Root tissue of these plants also tends to be woodier than that of exotic plants, thus making it less accessible as a food source for common rootattacking fungi such as Rhizoctonia and Pythium.

Potato Cyst Nematode, J M. Stanton

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

For many years, Australia has been the only large land mass in the world in which potato cyst nematode has not been found. However, in 1986, potato cyst nematode was found on four properties at Munster 10km south of Perth, Western Australia.

Potato cyst nematode is a minute worm like organism which attacks the roots of several plant species including potatos, causing very high yield losses. It is a very serious pest of potatoes throughout the world and strict quarantine controls are enforced in countries and potato-growing areas froo of nematode.

Root Disease Of Cereals, G C. Macnish, Chang Sha Fang, Karen Mcroberts

Experimental Summaries - Plant Research

Effects of nitrogen source on take-all, 82N34, 77E4. Take-all, cultivar, fertilizer, fungicide interactions, 87MT47, 87MT48, 87MT49. Take –all decline, 86MT7. Rhizoctonia root rot. Rhizoctonia patch and soil compaction, 87E28. Rhizoctonia patch and short chemical fallow, 87E3, 87E38. Rhizoctonia strains and paddock history, 87E31. Rhizoctonia root rot - host effects on strains, 87BA4, 86E30. Fusarium crown rot. Fusarium crown rot and cultivars, 87ME2, 87ME4, 87ME3 ( abandoned ).