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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 …

Pit And Scald Of Granny Smiths, Department Of Agriculture, Western Australia

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

Trials investigating storage and shipping disorders of fruit, mainly apples and pears, are conducted annually in cool rooms made available to the Department by the W.A. Meat Export Works.

Powdery Mildew Of Apples, Department Of Agriculture, Western Australia

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

Powdery mildew (Podosphaera leucotricha) markedly affects the growth and vigour of susceptible apple varieties, particularly Jonathan and Cleopatra.

The fungus survives the winter as mycelial threads in dormant buds on spurs and laterals infected the previous season. At bud-burst the mycelium grows onto the developing leaves and blossom clusters to form white patches.

Spores produced on these patches are spread by the wind onto the healthy growth.

Better Rootstocks For Apple Trees, Frank Melville, J. E. L. Cripps

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

Mailing Merton rootstocks have given the best results in ten years' trials with apple rootstocks on Stoneville Research Station and on growers' properties.

THE type of rootstock used imparts important characteristics to an apple tree. Tree size and stability, cropping characteristics, susceptibility to soil-borne pests and diseases and, to some extent, fruit quality are all affected by the choice of rootstock.

The Elimination Of Cultivation In Apple Orchards : A New Approach To Orchard Soil Management, S E. Hardisty

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

THE idea of eliminating cultivation in orchards suggests a reversal of accepted local practice in orchard soil management—but there is plenty of evidence to show that a noncultivation system has much in its favour.

In this article the advantages and disadvantages of the three main forms of orchard soil management are discussed and experimental evidence is presented in support of noncultivation.

An alternative method, "winter sod" culture, is proposed for irrigated orchards.

Root Growth Of Apple Trees, J E L Cripps

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

IT will surprise even experienced growers to know that an apple tree in W.A. needs twice the quantity of roots the same tree would need in a more temperate climate such as England's.

Apple Dieback In Western Australia, Frank Melville

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

Dieback of apple trees has been a serious and persistent problem in Western Australian orchards for many years.

Field observations and trials suggest that it can be greatly reduced or avoided by spray thinning to control cropping, summer irrigation, light pruning, and avoidance of root damage by cultivation.

The Control Of Bitter Pit In Apples, Frank Melville, S. E. Hardisty, N. S. Shorter

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

Bitter pit is a physiological disorder of apples which causes considerable wastage of otherwise sound fruit .

It is a problem of world-wide occurrence and in Western Australia growing conditions appear particularly favourable for its development.

In recent years a practical means of control by calcium sprays has been developed.

Guard Against Bitter Pit, Department Of Agriculture, Western Australia

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

Two seasons ago bitter pit' caused heavy rejections of apples for export overseas and bad trade publicity.

To avoid a repetition of this, precautions should be taken against bitter pit on all susceptible varieties.

Powdery Mildew Of Apples : Results Of Recent Spray Trials, R F. Doepel, S. E. Hardisty

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

Powdery mildew of apples is found in orchard districts throughout the South-West.

recent years a rapid build-up of the disease has occurred in some plantings as a result of changes in orchard practice.

Satisfactory control can be achieved by pruning out infected shoots and spraying with Karathane or Morocide

Storage Of Yates Apples In Polythene Lined Boxes, Frank Melville

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

Yates apples are subject to shrivelling and must be carefully stored to prevent undue loss of moisture.

Trials conducted in 1955 demonstrated that wilting can be prevented by cold storage in polythene lined boxes and this is now common practice in this State.

Wood-Rotting Fungi Associated With Dieback In Apple Trees : Progress Report : Orchard Surveys And Laboratory Studies, R F. Doepel

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

DIEBACK, or decline, of apple trees has been a serious problem for many years in orchards throughout the South-West of Western Australia.

Wood-rotting fungi are commonly associated with this condition and often bring about collapse of affected trees.

Chemical Thinning Of Apples, S E. Hardisty, N. H. Shorter

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

TWO important related problems of apple-growing in this State are biennial bearing and poor fruit size.

Early thinning by chemical means, is providing a valuable and practical means of tackling these problems.

With every prospect of heavy crops in most districts this year, many growers will be interested in the possibility of spray thinning.

Bitter Pit : A Progress Report On The Use Of Calcium Nitrate Sprays For Its Control, Frank Melville, S. E. Hardisty

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

FREEDOM from serious pests and diseases such as Black Spot and Codling Moth and relative immunity from storage rots has greatly simplified apple growing in Western Australia.

However, what has been gained in this respect is often countered by pre-harvest and post-harvest physiological troubles which are rather common to apple growing in this State.