Life Sciences Commons^™

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 …

Algal Growth And The Phosphorus Cycle, Arthur J. Mccomb, K. S. Hamel, A. L. Huber, D. K. Kidby, R. J. Lukatelich

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

Larger algae and microscopic phytoplankton foul the waters of the Peel-Harvey estuarine system, upsetting the fishery and polluting the beaches.

These aquatic plants grow in response to phosphorus runoff from drainage, trapping phosphorus in the estuary and using it in their growth. When they die this phosphorus remains in the system to be recycled for further plant growth.

Algal pollution in the estuary can be lessened by reducing the amount of phosphorus entering the system, increasing phosphorus losses to the ocean, or in some way blocking the trapping and recycling processes.

Alternative Pasture Species For Deep Sands, D A. Nicholas

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

Although the climate of the swan coastal plain between Perth and Bunbury is suitable for growing a range of pasture species, some soil types greatly limit this range.

Pasture species commonly grown in the South-West, such as subteranean clover and annual ryegrass, can only be grown successfully on the better soils of the coastal plain - the loams, yellow sands and Joel sands. On the freely drained, deep, infertile Gavin sands such species rarely persist because of the soil's poor water holding capacity, and its water repellency and its poor ability to retain nutrients.