Other Plant Sciences Commons^™

How Sustainable Is Grazing Sheep On Annual Pastures In The Woolbelt?, Don Mcfarlane, Richard George

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

Low wool prices have reduced the profitability of producing wool from clover-based annual pastures in the south-western woo/belt. The heavy reliance on one commodity is economically unsustainable for many farmers. But we should also consider how ecologically sustainable the practice is.

Shallow-rooted annual pastures contribute to widespread salinity in the area, annual legumes are acidifying the soils and making them water repellent, and bare, detached soils from heavy grazing cause sheet and rill erosion during autumn storms. In addition, stock are degrading remnant vegetation and destroying the soil's structure.

To counteract this degradation, the woo/belt needs more perennial pastures and …

Virus Diseases Of Subterranean Clover Pastures And Their Management, David Ferris, Roger Jones

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

In Western Australia and southern Australia generally, subterranean clover mottle (SCMV) and bean yellow mosaic (BYMV) are the most damaging virus diseases of subterranean clover pastures.

Although infected plants cannot be cured of virus infection, pastures can be managed to reduce both virus spread and persistence from year to year. Management options depend on which virus is present and include reseeding with resistant varieties; changing the pasture composition so that non-host species predominate; altering grazing practices to limit spread; and application of pesticide sprays to kill aphids.

Diversity Of Vascular Plants And Intensity Of Plant Collecting In Nebraska, Robert B. Kaul, Steven B. Rolfsmeier

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

A computerized database of Nebraska's flora has been made from specimens in 20 herbaria. Almost 1,900 species of native and escaped-alien vascular plants have been collected in the state since the mid-1800s. The flora of some counties is very well known but that of many counties, especially southwestern and Sandhills counties, is poorly collected. More than 800 species (nearly 100% of the species that are likely to occur) have been collected from each of Cherry, Douglas, Lancaster, and Richardson counties, but fewer than 150 species are known from Fillmore and McPherson counties, less than 25% of the potential number species …

Crops In The Woolbelt : Current Options And Emerging Prospects, Wal Anderson, Ross Gilmour, Robyn Mclean, Peter Nelson, K H.M Siddique, Paul Carmody, Ian Prtichard

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

It has traditionally been more profitable to grow sheep for wool in the medium rainfall parts of the south-west of Western Australia than to grow crops . Crop production has been difficult owing to the hilly terrain, the frequency of waterlogging, the high incidence of damaging frosts in some areas, the frequency of losses from diseases, difficulties with wet weather at harvest, and a lack of adapted crop varieties.

Advances over the past decade have made cropping on a limited scale potentially profitable in the woo/belt.

This article is intended to bring the various options for crop production to the …

Purification Of The Major Soybean Leaf Acid Phosphatase That 1s Increased By Seed-Pod Removal, Paul E. Staswick, Chuck Papa, Jing-Feng Huang, Yoon Rhee

Department of Agronomy and Horticulture: Faculty Publications

Fruit removal for 5 weeks after flowering increased acid phosphatase activity 10-fold in soybean (Glycine max 1. Merr. vai Hobbit) leaves compared with normal seed-pod-bearing plants. The major acid phosphatase activity in leaves was purified over 2700-fold, yielding a single polypeptide of 51 kD with a specific activity of 1353 units/mg protein using p-nitrophenylphosphate as the substrate. lsoelectric focusing demonstrated that the purified protein co-migrated with a majority of the activity that increased in leaves following seed-pod removal. lmmunoblot analysis demonstrated that at least part of the increased activity was dueto an increased abundance of the phosphatase protein. In situ …

Using Saltland In Pakistan : An Australian Connection, Ed Barrett-Lennard, Riaz Qureshi

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

Pakistan and Australia have a common enemy in salt. In each country millions of hectares of previously productive land have been affected by salt (or have the potential to become saline) because of inappropriate agricultural development. Since 1989 the Western Australian Department of Agriculture has participated in a research project in Pakistan which involves revegetation of salt land using Australian shrubs. Early results are very promising.

Cdna Sequence For The Ribulose 1,5 Bisphosphate Carboxylase/Oxygenase Complex Protein A Protein That Accumulates In Soybean Leaves In Response To Fruit Removal, Paul E. Staswick, Steven J. Crafts-Brandner

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max L.) transiently accumulates two abundant vegetative storage proteins, VSP A and VSP B, in vacuoles of above-ground vegetative tissues (Wittenbach, 1983; Staswick, 1990). As older leaves and stems become a source of exported metabolites for developing sinks, the VSPs are preferentially degraded and the resulting metabolites are presumably mobilized in the xylem and phloem stream. A striking feature of these proteins is that VSP gene expression is dramatically increased in mature leaves following the remova1 of reproductive sinks (seed pods) and the amount of these proteins increases accordingly (for review, see Staswick, 1994). Other changes …

Models To Predict Yield Loss Due To Weeds In Rice Ecosystems, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Yield loss models have been developed and evaluated for irrigated rice ecosystems with respect to effects of Echinochloa crusgalli. Simple regression models that give the relation between yield loss and weed density or relative leaf area are discussed with respect to their practical value in weed management in rice. More complex eco-physiological process models have been developed and used for rice ecosystems as well. Such models can be useful as a tool in research, whereas more simple approaches are needed for practical application in weed management.

Systematic Anatomy Of Euphorbiaceae Subfamily Oldfieldioideae I. Overview, W. John Hayden

Biology Faculty Publications

The biovulate subfamily Oldfieldioideae of Euphorbiaceae, characterized by spiny pollen, is an otherwise apparently diverse assemblage of mostly Southern Hemisphere trees and shrubs that traditionally have been allied with genera of Phyllanthoideae and Porantheroideae sensu Pax and Hoffmann. Although fairly diverse anatomically, the following structures characterize the subfamily with only a few exceptions: pinnate brochidodromous venation with generally randomly organized tertiary and higher order venation; foliar and petiolar glands absent; unicellular or unbranched uniseriate trichomes; latex absent; mucilaginous epidermis or hypodermis; brachyparacytic stomata; vessel elements with simple perforation plates and alternate, often very small, intervascular pits; thick-walled nonseptate imperforate tracheary …

Stem Development, Medullary Bundles, And Wood Anatomy Of Croton Glandulosus Var. Septentrionalis (Euphorbiaceae), Sheila M. Hayden, W. John Hayden

Biology Faculty Publications

Anatomy and development of vascular tissues in the annual stems of Croton glandulosus var. septentrionalis are described. In primary stages of growth the stem possesses a eustele of bicollateral bundles; international phloem is notably more extensive than the external. In addition to a vascular cambium and secondary xylem that form in the usual fashion, additional cambia add cells to the internal phloem portion of the bicollateral bundles, forming well-marked medullary bundles at the perimeter of the pith. At first, the perimedullary cambial strands produce only internal secondary phloem; later, internal secondary xylem is present, the medullary bundles have an inverted …