Disorders of Environmental Origin Commons^™

Leaf Diseases Of Wheat And Time Of Sowing, J M. Wilson

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

Leaf diseases of wheat can be avoided by delaying the planting of a crop, but this often leads to reduced yield because the benefits of early sowing usually outweigh anylosses caused by leaf disease.

However, it is only in exceptional circumstances that farmers need to consider leaf disease when making decisions about planting date, as this article shows. Most examples are taken from department of Agriculture trials in its northern advisory region, but the principals apply to other agricultural 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.

Annual Ryegrass Toxicity Research Update, A G P Brown, P. Vogal

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

Annual ryegrass toxicity (ARGT) is a complex disease that kills sheep and cattle grazing pastures which contain infected ryegrass. The disease results when a nematode (Anguina agrostis) and a batcerium (Corynebacterium sp.) invade annual ryegrass and cause the seed heads to become toxic as the grass dries off.

The bacterium produces a complex toxin of 18 glycolipid compounds or corynetoxins which have been found to be virtually identical to the antibiotic tunicamycin.

Reproductive Wastage In Sheep On Clover Areas, Department Of Agriculture, Western Australia

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

Western Australia's 67 per cent lambing for 1970 compares poorly with that of other Australian States, and other countries. From the 12.3 million ewes mated in this State's agricultural areas in 1970, only 8.2 million lambs were marked.

This low 77.7 per cent conception rate sparked the present series of reproductive wastage investigations by the Department's Sheep and Wool Branch.

This report describes the first year's results of the project in W.A.'s "clover disease" areas.

Oat Diseases In Western Australia, W R. Tweedie, W. A. Shipton

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

OVER ONE MILLION acres of oats are grown yearly in this State, making the crop next in importance to wheat.

Pathogenic organisms are responsible for considerable reductions in yield, yet losses can be minimized if control measures are taken.

Choking Of Milking Machine Pulsators, G R. Olney

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

THE value of applying the teat cup squeezing action more slowly, by "choking", has been well demonstrated for a number of years.

Leslie and Whittlestone (1938) suggested that brutal teat cups and snappy pulsators could be undesirable because of the trauma caused.

Choking was recommended by them to overcome this.

Fatique In Caged Layers, P Smetana

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

Pullets found immobilised on the floors of their laying cages may only be suffering from the easily-treated "cage layer fatigue" and should be checked for this before being disposed of as affected with the incurable fowl paralysis.