Physical Sciences and Mathematics Commons^™

Continued Ddt Persistence In Mississippi River Delta Streams: A Case Study, Stephen A. Sewell, Luther A. Knight Jr.

Journal of the Arkansas Academy of Science

Fish samples representative of several trophic levels were taken from the Wolf and Loosahatchie Rivers of western Tennessee during the early 1980s. Results indicate that DDT, with metabolites DDD and DDE, remains common in fish tissues in these areas and approaches the levels recommended as maxima for human consumption by the U.S. Food and Drug Administration. Samples of top carnivores and forage fishes, particularly the gizzard shad, Dorosoma cepedlanum, commonly exceeded 500 ppb DDE. The results are discussed in light of sediment disturbing activities.

Serradella Prospects At Esperance, Michael D A Bolland

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

Yellow serradells is a promising introduced annual legume suitable for some of Western Australia's well drained sandy acid soils where other pasture legumes failto persist.

In the Esperance area serradella grows siccessfully on some sandy soils more than 0.5 metres deep. I develops deep roots rapidly - up to three times deeper than subterranean clover - and this is probably the main reason for its persistance.

At present only two late maturing, registered serradella cultivars are available to farmers in southern Australia. This article describes research at Esperance to delect earlier flowering cultivars for persistence in areas with less than …

Row Spacing And Cereal Crop Yield, R N. Burch, M. W. Perry

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

Cereal growers in western Australia have, traditionally, burned cereal stubbles. Burning stubble residues reduces weed seed populations and fungal pathogens, but its main purpose has been to eliminate straw which might cause blockages od seeding machinery and por see-bed preparation in the time critical seeding operation.

In 982, the Department of Agriculture began a project to determine whether wider spaced rows also depressed cereal yields in Western Australia. This article summarises some of the important results from that work.

Agricultural Progress On The Ord, D A. Mcghie

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

This is the first of occasional articles describing the experimental and commercial activity on the Ord River Irrigation Area (ORIA) in Western Australia's Kimberley region.

Against a background of extensive recources of land and water, a sometimes cimatic advantage and a complementary disadvantage of a remote location, agriculture on the Ord has swung from various monocultures to a broadly based and diversified production. In 1986, the value of agricultural production on the Ord will approach values equivalent to those of the cotton era for the first time since the demise of that industry 12 years ago.

Survey Of 1985 Periodical Cicada (Homoptera: Magicicada) Emergence Sites In Washington County, Arkansas, With Reference To Ecological Implications, Douglas A. James, Kathy S. Williams, Kimberly G. Smith

Journal of the Arkansas Academy of Science

Systematic roadside surveys were conducted in June 1985 in Washington County, Arkansas, to locate areas where 13-year periodical cicadas had emerged during May. Although cicadas were found in a variety of upland and bottom land forest habitats, the present cicada distribution reflects the original forest and prairie pattern in the county, even though those boundaries are now largely lost. This suggests a high degree of philopatry whereby emergency areas have remained in the same area for the last 100 years. All present day emergence areas are within the White River drainage, suggesting that it was the main cicada dispersal route …

Grazing And Management Of Saltland Shrubs, C V. Malcolm, J. E. Pol

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

areas of bare saltland on farms need not be unproductive etesores. Many Western Australian farmers are now successfully growing salt-tolerant or halophytic shrubs such as bluebush (Maireana brevifolia), saltbushes (Atriplex spp.) and samphires (Halosarcia spp.) on these areas.

Department of agriculture trials and farmers' experience indicate that if saltland is planted with recommended shrubs, it can provide two months' valuable grazing for sheep during autumn and early winter, a time when paddock feed is scarce. Research by the Department has also identified a range of salt-tolerant shrubs suited to the various types of saltland.

Grazing trials to …

Biological Control Of Parkinsonia, W M. Woods

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

One of the most troublesome weeds in northern Australia'a lastoral country is Parkinsonia aculeata, commonly called Parkinsonia, Jerusalem Thorn, Palo Verde or Retama. In 983 Western Australia, ueensland and the Northern Territory started a joint biological control programme against this perst by sending the author overseas to search for its natural predators in southern USA, Mexico and Central America. A few insects show promise and one, a bruchid beetle Mimosetes ulkei, is being tested under Quarantine in Queensland.

Wheat Growth On Saline Waterlogged Soils, E G. Barrett-Lennard

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

Studies of the growth of plants on salt-affected soils have focused maily on the effects of salt. However, many salt-affected soils are also subject to waterlogging. Glasshouse experiments conducted by the Department of Agriculture have shown that although wheat growth is not greatly reduced by low levels of salt under well drained conditions, under waterlogged conditions such levels of salt can have a severe effect.