Agronomy and Crop Sciences Commons^™

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.

Miscellaneous Publication 42/93 - Development And Dissemination Of Design Methods For Rangeland Paddocks Which Maximise Animal Production And Minimise Land Degradation, Shane Cridland, Mark Stafford Smith

Animal production and livestock published reports

Surveys of rangeland resources in Western Australia to date have shown that 23% of the area surveyed is in poor range condition. Poor condition is characterised by the loss of perennial vegetation allowing wind and water erosion. Approximately another 37% is in only fair range condition (Curry and Hacker 1990).

The loss of range condition is partly due to uneven use of paddocks by sheep and cattle. The areas close to water and the preferred pasture types are often over-utilised, while areas well away from water and less preferred pasture types are under-utilised. The result is that rangeland in good, …

Establishment Of Lupin Seedlings, Miles Dracup

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

Good seedbed conditions lead to high and rapid seedling emergence and vigorous seedlings best equipped to avoid disease, weed competition and sand-blasting. Good establishment is needed for a high yielding crop.

In Western Australia, seedbed moisture and temperature are most likely to limit successful emergence of lupins, especially with the trend toward early sowing.

Research by the Department of Agriculture is helping to define seedbed temperature and moisture requirements for successful lupin establishment that will help future research for improving seedbed conditions.

Production Of High-Value Wheats : One Sustainable Answer To The Cost:Price Squeeze, Wal Anderson, Alan Peggs, Doug Sawkins

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

Farmers and scientists alike over the past decade have sought to address the declining terms of farm trade (the cost.price squeeze) by increasing wheat yields in ways that will ensure both their economic and ecological survival. Nevertheless, costs have continued to increase as a proportion of the value of the product.

Many farmers have increased their wheat yields substantially and the industry as a whole is more conscious of the quality of its product.

Over the past 10 years or more there has been intense interest in, and considerable adoption of. conservation farming techniques such as minimum tillage, residue retention, …

Effect Of Light, Nitrogen, And Water Management On Rice (Oryza Sativa) Tolerance To Fenoxaprop, Roy J. Smith Jr., Aurora M. Baltazar, Paolo Nastasi

Journal of the Arkansas Academy of Science

The effect of light intensity, nitrogen (N), and water management on rice (Oryza sativa cv. 'Newbonnet' and 'Lemont') tolerance to fenoxaprop {(+)-2-[4[(6-chloro-2-benzoxazolyl)oxy]phenoxy]propanoic acid} was determined in two field studies at the Rice Research and Extension Center, Stuttgart, AR, in 1988 and 1989. In one study, 'Newbonnet' rice was treated with 0.22 kgai ha-1fenoxaprop at 0, 1, 3, 5, 7, 10, 14, and 28 days after N application and flooding. Moderate to severe foliar chlorosis, stunting, and stand and yield reductions occurred when fenoxaprop was applied within 7 days after N application and flooding. None to slight injury or yield reduction …

Developmental Morphology Of Tropical Sorghum And Sorghum X Sudangrass, R. B. Mitchell, K. J. Moore, Jeffrey F. Pedersen, T. A. Peterson, L. E. Moser, D. D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Tropical sorghum and sorghum x sudangrass are known to be efficient scavengers of soil nitrogen and are important forage crops in the U.S. Nitrate contamination of groundwater due to disposal of organic wastes and excessive fertilization is a major concern in the Central Great Plains. A common disposal method of municipal wastes is application to fallow cropland. Quantification of the developmental morphology of tropical sorghum and sorghum x sudangrass is important to developing management strategies that allow multiple applications of organic wastes to optimize nitrogen removal and dry matter production. The objective of this study was to quantify the developmental …

Genetic Manipulation Of Tall Fescue, Jeffrey F. Pedersen, D. A. Sleper

Department of Agronomy and Horticulture: Faculty Publications

Genetic manipulation of tall fescue (Festuca arnndinacea Schreb.) has not been altered by the discovery of the Acremonium coenophialum (Morgan-Jones and Gams) / grass interaction. However, tall fescue breeding programs have been affected greatly. The basic methods for genetically manipulating the grass have remained static. Tall fescue is an obligate out-crossing species, and most improvements are, therefore, captured in the form of an improved population developed through some form of mass or recurrent selection. What has changed is the breeder's ability to recognize genetic differences in the grass because of the confounding effect of A. coenophialum on plant phenotype. It …

Comparison Of Sorghum And Indiangrass Chloroplast Genomes Using Rflps, Jeffrey F. Pedersen, R. D. Lee, D. J. Lee, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

Sorghum (Sorghum bicolor (L.) Moench) and indiangrass (Sorghastrum nutans (L.) Nash) appear closely related based on morphological and chemotaxonomic characters. Each species could potentially provide desirable traits to the other. However, traditional breeding techniques have been unsuccessful in hybridizing these two species. The objective of this study was to determine the relatedness of sorghum and indiangrass chloroplast DNA using RFLPs. Eleven sorghum lines in several cytoplasms, two indiangrass popu1ations, and a corn line were studied using 60 proberestriction enzyme combinations. Principal component analysis of the results showed sorghum to be as closely related to corn as to indiangrass, with no …

Breeding Systems For Cross-Pollinated Perennial Grasses, K. P. Vogel, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

I. Introduction

II. Reproductive and Breeding Characteristics

III. Breeding Systems

A. Ecotype Selection

B. Recurrent, RestricteclPhenotypic Selection

C. Half-sib Progeny Test

D. Between and Within Family Selection

E. Recurrent Multistep Family Selection

IV. Gains From Selection

A. Time Interval per Cycle

B. Potential Gain per Cycle .

C. Potential Inbreeding per Cycle

V. Polycrossing

VI. Hybrid Cultivars

VII. Conclusions

Literature Cited

Opportunity Knocks : Sowing Wheat Early In The North-Eastern Wheatbelt, Nicole Kerr, Doug Abrecht

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

Farmers consider many factors in deciding whether to start sowing wheat, but the most important are the amount of rain and time of year. In this study we assessed the chances of farmers in the north-eastern wheatbelt (less than 325 mm rainfall) receiving enough rain to sow wheat early. In low rainfall areas such as this, where an early finish to the season is likely, it is especially important that farmers take advantage of all early sowing opportunities. The potential benefits of sowing wheat early generally outweigh the associated risks, particularly in lower rainfall areas. However, early sowing depends on …

Jasmonate, Genes, And Fragrant Signals, Paul E. Staswick

Department of Agronomy and Horticulture: Faculty Publications

Although first recognized for its growth-inhibiting activity about 20 years ago, JA² and its fragrant methyl ester MeJA (referred to here collectively as jasmonate) are receiving renewed interest as potentially important signaling molecules in plants. This is because jasmonate markedly increases the expression of specific plant genes, some of which are wound responsive. Similarities with fatty acid-derived stress signaling molecules in animals (1) make jasmonate of general biological interest.

A Review Of Plant Introductions To The Kimberley 1955 To 1987, R Mccartney

Grain and other field crops published reports

This report summarizes the work done by the Department of Agriculture, Western Australia, in the west and north Kimberley in introducing plant species during 1955-1987.

For the purposes of this repor1the following areas are defined thus:

• West Kimberley- lies between latitude 17°5 and 19°5 and longitude 121°E and 127°E, with an extension to the north of 1° between 121°E and I 24°20'E. The area is 118,000 km".

• North Kimberley - lies north of latitude 17°5 and between longitude 124°20'E and 127°30'E. The area is 85,000 km'.

• East Kimberley-lies north of latitude 19°5 and between longitude 127°30'E and …

1991 Catalogue Of The Australian Lupin Collection Including Field Evaluation Data For Wild, Semi-Domesticated And Fully Domesticated Accessions, J. C. Clements, W. A. Cowling

Grain and other field crops research reports

This report lists all wild, semi-domesticated and fully domesticated accessions in the Australian Lupin Collection to 1991. The Collection is composed of 2,264 accessions (Perth Numbers between 20629 and 27067) introduced to Australia or from naturalized populations and breeding programmes within Australia. Several accessions are selections from variable populations which were identified during field trials in South Perth, Western Australia. This catalogue lists the characteristics and field evaluation data for every accession where available. Plant breeders and crop scientists will find this information useful for the selection of lupin genotypes with desired characteristics.

Section A of this catalogue should be …

Review Of The Wild Oat Inflorescence And Seed: Anatomy, Development And Morphology, M. V. S. Raju, David M. Sutherland

Biology Faculty Publications

This slim volume describes a detailed study of the reproductive parts of Avena fatua, the wild oat plant-a common weed in the northern plains and the probable ancestor of the cultivated oat. The book integrates the author's own work with information from available literature and includes lengthy technical descriptions of the structure and the growth of the inflorescence, the floret, the ovule, the pollen grain, the embryo, the seed, and the young seedling. Throughout the work, the author relates the wild oat's structure and development to other grasses, other monocotyledons, and other seed plants, offering evolutionary interpretations of many of …

Propagation Of Yellow Bells (Geleznowia Verrucosa Turcz., Rutaceae) From Seed, Blakely Paynter, Kingsley Dixon

Grain and Other Field Crops Research Articles

Geleznowia verrucosa Turcz. (Rutaceae) is a commercially important, bush-picked wildflower that has no known commercial means of propagation. This study examined factors influencing seed dormancy and likely to restrict germination of the species. Germination of entire, untreated seed was low (less than 2%), but removal of a small portion of the testa at or near the radicle end of the seed improved germination. This response was affected by the temperature under which the seed germinated, but was unaffected by exposure of the seed to light while germinating. The percentage germination of nicked seeds 52 days after sowing increased from 8% …

Bulletin No 4220 - Growing High Yielding Wheat Crops In The Central Wheatbelt, Michael Perry

Bulletins 4000 -

In this Bulletin we hope to provide you with what we believe is the best and most up-to-date information about growing wheat in your particular environment.

It is now more important than ever for producers to get the most out of their resources of land, labour and capital. The key to doing that is the knowledge to do even better what you probably do well already-growing wheat.

Inheritance Of Acid-Soil Tolerance In Sorghum (Sorghum Bicolor) Grown On An Ultisol, C. I. Flores, L. M. Gourley, Jeffrey F. Pedersen, R. B. Clark

Department of Agronomy and Horticulture: Faculty Publications

Inheritance of acid-soil tolerance (generally considered AI-toxicity tolerance) i.n sorghum [Sorghum bicolor (L.) Moench] is not clear. Forty F₁ sorghum hybrids and their 14 parents were grown two seasons in the field at relatively high (67 and 71%) and low (43 and 42%) Al saturations on an acid Ultisol in Colombia, South America to evaluate the effects of acid soil on agronomic component traits and to better understand inheritance of acid-soil tolerance of sorghum. For plants grown at the high Al saturation levels, hybrids from acid-soil tolerant [AS-T] x acid soil-sensitive [AS-S] crosses were as tolerant as hybrids from …

Fertility And Forage Yield Of Sorghum X Sudangrass Hybrids In A1 And A3 Cytoplasm, J. J. Toy, Jeffrey F. Pedersen, K. J. Moore

Department of Agronomy and Horticulture: Faculty Publications

Most sorghum x sudangrass hybrids are currently produced in Al male-sterile cytoplasm. Availability of alternative cytoplasmic sterility systems allows production of sorghum x sudangrass hybrids that may have superior forage characteristics. A study was conducted to compare the agronomic performance of Al and A3 sorghum x sudangrass hybrids. A bulk of eight sudangrass populations was used to pollinate four grain sorghum inbreds normally used as females that had been sterilized in both Al and A3 cytoplasm, and two inbreds normally used as males that had been sterilized in A3 cytoplasm. The hybrids were evaluated in 1990. Results indicate that male-sterile …

Notes: Interpretive Analysis For Forage Yield Trial Data, Jeffrey F. Pedersen, K. J. Moore, Edzard Van Santen

Department of Agronomy and Horticulture: Faculty Publications

Forage cultivar evaluation is often done in small plots with multiple harvests throughout the growing season. Data is often summarized by presenting a yearly total yield for each cultivar in addition to the mean for each harvest date. Data summarization often becomes burdensome and difficult to interpret. Regressing yield against a growth index associated with harvest dates can be utilized to describe forage performance in a concise and easily interpreted format. Subsets of data from tall fescue (Festuca amndinacea Schreb.) yield trials conducted in Alabama and Kentucky were used to demonstrate the technique. The analysis involves regressing yield of a …

Nitrogen And Methyl Jasmonate Induction Of Soybean Vegetative Storage Protein Genes, Paul E. Staswick, Jing-Feng Huang, Yoon Rhee

Department of Agronomy and Horticulture: Faculty Publications

Vegetative storage protein (VSP) and VSP mRNA levels in soybean (Glycine max) leaves correlated with the amount of NH₄NO₃ provided to nonnodulated plants. The mRNA level declined as leaves matured, but high levels of N delayed the decline. This is consistent with the proposed role for VSP in the temporary storage of N. Wounding, petiole girdling, and treatment with methyijasmonate (MeJA) increased VSP mRNA in leaves 24 hours after treatment. The magnitude of the response depended on leaf age and N availability. N deficiency essentially eliminated the response to wounding and petiole girdling. MeJA was …

Sterol Composition Of The Corn Root Lesion Nematode, Pratylenchus Agilis, And Corn Root Cultures, David J. Chitwood, William R. Lusby

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Sterols from mixed stages of the com root lesion nematode, Pratylenchus agilis, and uninfected corn root cultures were analyzed by gas chromatography-mass spectrometry. Twenty-eight sterols were identified in P. agilis, including nine not previously detected in nematodes. The major sterols were 24-ethylcholest-22-enol, 24-ethylcholesta-5,22-dienol, 24-methy1cholestanol, 24-ethylcholestanol, isofucostanol, and 24-ethylcholesterol. The principal corn root sterols were 24-ethylcholesta-5,22-dienol, 24-methylcholesterol, 24-ethylcholesterol, isofucosterol, and cycloartenol. Therefore, the major metabolic transformation of sterols by P. agilis was saturation of the sterol nucleus. In addition, very small amounts of 4α-methylsterols were biosynthesized by P. agilis. The 4-methylation pathway is unique to nematodes and was …

Origin And Evolution Of Defective Interfering Rnas Of Tomato Bushy Stunt Virus, David A. Knorr, Thomas Jack Morris

School of Biological Sciences: Faculty Publications

Viruses with defective genomes have been identified in association with virtually every major family of viruses and have been widely utilized as tools for investigating virus functions in animal cell culture systems (Perrault, 1981). It is generally thought that defective interfering viruses (DIs) arise through deletion, rearrangement, or recombination of a competent viral genome. DIs tack the ability for independent existence relying on their parental helper viruses to supply factors required for replication, maturation, and/or encapsidation (Huang and Baltimore, 1977). The interference attributed to DIs is thought to result from competition with the helper virus for factors required in trans …

Waterlogging : How It Reduces Plant Growth And How Plants Can Overcome Its Effects, Tim Setter, Bob Belford

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

Lack of oxygen is the major cause of limited plant growth in waterlogged soils. When soils become waterlogged less gas diffuses to and from the roots through the soil pores; there are changes in concentrations of mineral elements in soil solutions; and toxic products of roots and soil microorganisms begin to accumulate. These changes adversely affect germination, growth and development of plants.

Evaluation Of Seeding Rates Of Au Triumph And Endophyte-Infected Kentucky 31 Tall Fescue, Jeffrey F. Pedersen, D. M. Ball

Department of Agronomy and Horticulture: Faculty Publications

Increased difficulty in stand establishment of tall fescue (Festuca arundinacea Schreb.) has been reported by producers since the introduction of endophyte (Acremonium coenophialum Morgan Jones and Gams)-free tall fescue seed into the market place. This has encouraged the use of higher seeding rates for endophyte-free tall fescue without scientific basis. The objective of this study was to determine whether ‘AU Triumph’, and endophyte-free cultivar, and endophyte-infected ‘Kentucky 31’ differ in minimum seeding rates for successful establishment. Experiments were established at two locations in each of two years, using a randomized complete block with four replications. Soils at the two locations …

Heritability Of Root Characteristics Affecting Mineral Uptake In Tall Fescue, J. H. Edwards, Jeffrey F. Pedersen, R. C. Kingery

Department of Agronomy and Horticulture: Faculty Publications

Modification of plant roots can potentially increase the area. of adaptation of tall fescue (Festuca arundinacea Schreb.). Limited information is available on the heritability of root diameter and root volume in tall fescue. A greenhouse experiment was conducted with'50 random 'Kentucky 31' (Ky-31) tall fescue parents and their progeny grown in aerated nutrient solution during four separate time intervals. Measurements of root volume, root diameter, shoot Mg concentration, and shoot K/(Mg + Ca) ratio were made six weeks after clonal material was transplanted in nutrient solution. Heritability estimates for root volume, root diameter, shoot Mg concentration, and shoot K/(Mg …

A Review Of The Agronomic Characteristics Of Endophyte-Free And Endophyte-Infected Tall Fescue, Jeffrey F. Pedersen, G. D. Lacefield, D. M. Ball

Department of Agronomy and Horticulture: Faculty Publications

Agronomic differences between endophyte- (Acremonium coenophialum Morgan Jones and Gams) free and endophyte-infected tall fescue (Festuca arundinacea Schreb.) exist, and should be considered when implementing a management strategy. Although dry matter yield of tall fescue does not generally appear to be influenced by endophyte infection status, endophyte infection has been shown to improve seedling performance and survival, is associated with insect and nematode resistance, drought resistance, improved nitrogen assimilation, and higher seed set. Considering all biologically valuable characters of the endophyte-tall fescue relationship, survival of endophyte-infected tall fescue is probably better than that of endophyte-free tall fescue, especially in drought- …

Fescues With Large Roots Are Drought Tolerant, H. A. Torbert, J. H. Edwards, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Consideration of root/soil interactions is essential in, adapting tall fescue (Festuca arundinacea Schreb.) to soil and climatic conditions of the Coastal Plain region of the southeast. Sandy soils of the region are very susceptible to the formation of hardpans. These compacted layers often restrict plant root development to the plow layer (0 to 6 in.) and prevent plant roots from reaching available moisture and nutrients in the subsoil horizons. Plants grown under these conditions are shallow rooted and will be subjected to water stress up to 50% of the time during the growing season. Although implements are available to penetrate …

Bulletin 4133 - Fungal Diseases Of Pasture Legumes In Western Australia, M. J. Barbetti

Bulletins 4000 -

Subterranean clover (Trifolium subterraneum L.) is the most important annual pasture legume in Western Australia, forming the basis of some 6.5 million ha of annual pastures. The success of subterranean clover may be attributed to its ability to increase soil fertility as a consequence of nitrogen fixed, to withstand heavy grazing, to control soil erosion and, with some cultivars, to tolerate waterlogging. Fungal diseases have been a major limitation to the productivity of subterranean clover, affecting both the amount of plant matter and the quantity of seed produced.

Annual medic (Medicago spp., in particular M. polymorpha L.) is also an …

Bulletin No 4146 - Commercial Production Of Pawpaws In Western Australia, J. R. Burt, B. L. Toohill

Bulletins 4000 -

The papaw (Carica papaya L.) is a native plant of Central America. It produces its highest yields of good quality fruit in tropical regions.

The tree is short-lived and rarely produces crops for more than two or three years. It is quick growing and soon reaches a maximum height of 5 to 7 m. It is usually unbranched, but may branch after either injury to the top or cutting back.

Flower : Predicting Flowering Times Of Cereal Crops, G A B Elliott, Stephen Loss

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

FLOWER is a computer program which predicts the flowering date of a given wheat or barley variety at a specified location and sowing date. Department of Agriculture agronomists, breeders and advisers are using the program to provide useful information on how the development of cereals responds to different environments across Western Australia's cereal growing areas.