Life Sciences Commons^™

Model Building To Measure Impact Of Weather On Crop Yields, Arlin M. Feyerherm, Gary M. Paulsen

Conference on Applied Statistics in Agriculture

The object of this research was to identify and evaluate alternatives when building mathematical models to measure the impact of weather on crop yields. Alternatives exist relative to selection of: (1) observational units with attention to size and coverage (areal and temporal), (2) observational periods for defining weather variables, and (3) mathematical forms and types of weather variables to measure impacts of moisture and temperature. The study involved an analysis of four weather-yield functions for winter wheat. The functions represented combinations of levels of two factors: (1) size and coverage of the observational units (plot yields from a multi-state area …

Increased Returns From Agronomic Inputs In Early Sown Cereal Crops, W K. Anderson

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

When crop variety and soeing dae are matched so that flowering occurs in the 'window' for a particular site, grain yields are increased and yield response to inputs such as nitrogen fertilizer and seeding rate is magnified.

This response occurs because the srop's potential for setting and filling grains is much improved by sowing at the optimum time. However varieties differ in their yield potential because they have different lenghts of growing season, which probably affects grain numbers, and because they have different inherent grain sizes. These differences affect the way varieties react to sowing date. Figure 1 shows how …

Long-Term Rotation Trials., I Rowland, W Hawkins

Experimental Summaries - Plant Research

Paddock 5AE on Merredin research station, 66M29, 67C13, 67N4, 68E5, 68SG5, 73SG16, 88EB2.

Vacuole Formation In Wheat Starchy Endosperm, D. B. Bechtel, A. Frend, L. A. Kaleikau, J. D. Wilson, P. R. Shewry

Food Structure

The formation of vacuoles in wheat (Triticum aestivum cv. Highbury) starchy endosperm cells was studied using electron microscopy. Some vacuoles were always present, even in the coenocytic cytoplasm. The first formed endosperm cells were highly vacuolated, but became filled with cytoplasm as they grew older. Various-sized pieces of cytoplasm were found in vacuoles of developing endosperm cells, probably as a result of autophagic sequestration. The membranes of the autographic vacuoles appeared to originate from the rough endoplasmic reticulum and from extensions of already-formed vacuoles. Autographic activity was confirmed by localizing the hydrolytic enzyme acid phosphatase within the vacuoles. The rough …

Use Of Image Analysis To Predict Milling Extraction Rates Of Wheats, A. D. Evers, R. P. Withey

Food Structure

Image analysis of grain morphological characteristics was examined as a possible means of predicting extraction rates of a wide variety of wheat types.

Two elevations of grain were examined and measured for the top view whole grains were used, while for the lateral view grains were sagittally bisected in the plane of the crease. Extraction rate was assessed on laboratory mills and expressed as flour yield.

Milling extraction rate correlated with one shape factor with a coefficient of 0.78. Inclusion of a second factor in a stepwise regression increased the correlation coefficient to 0.925.

No satisfactory predictor of extraction rate …

Long Season Wheat Production On The South Coast Of Western Australia., W R. Smith, A P. Webster

Experimental Summaries - Plant Research

Fungicide, time of sowing, wheat variety. Time of sowing, wheat variety, 89AL3, 89ES3, 89JE1, 89KO3. Wheat phenology, 89E5, 89MT8. Aphid control, time of sowing, wheat variety, 89E3, 89MT5.

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.

Cereal Structure And Its Relationship To Nutritional Quality, S. H. Yiu

Food Structure

Factors that determine the digestibility of carbohydrates and minerals in cereals are examined . Most carbohydrates and minerals in cereals are structurally bound, either surrounded by or associated with cell wall components not easily digested by non-ruminant animals and humans. Treatments such as mechanical grinding and heat improve the digestibility of nutrient s . Further processing and cooking result in structural and physeochemical changes of cereal starch, phytate, and dietary fiber. Such changes greatly Influence the physiological and metabolic effects in animals and humans. The digestive breakdown of most nutrient components is also dependent on the activities of enzymes in …

Early Sowing Of Ceral Crops In Low Rainfall Areas, R J. Delane, John Hamblin

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

One of the objectives of the Department of Agriculture's crop research in the low rainfall, northern wheatbelt is to develop crop varieties and management practices that will make best use of stored water on both sandplain and fine textured soils. Sowing a crop early will improve its water use efficiency and yiel in low rainfall areas.

G89-936 Russian Wheat Aphid, Gary L. Hein, Frederick P. Baxendale, John B. Campbell, Arthur F. Hagen, James A. Kalisch

University of Nebraska-Lincoln Extension: Historical Materials

The Russian wheat aphid is a serious insect threat to small grains. Its description, damage and control are discussed here.

The Russian wheat aphid (RWA) is a serious insect threat to wheat and other small grains. Growers should examine small grain fields regularly for this pest throughout the fall. In the spring, weekly examinations are needed from the time wheat resumes growth through the late heading stages.

Farmers are encouraged to collect samples of unknown aphids on small grains and have them identified by the Cooperative Extension Service. Proper identification of the aphid is critical in determining the need for …

G89-906 Barley Yellow Dwarf Disease Of Barley, Oats, And Wheat, John E. Watkins, Leslie C. Lane

University of Nebraska-Lincoln Extension: Historical Materials

The symptoms of barley yellow dwarf are covered here, as are disease occurrence and spread, and control.

Barley yellow dwarf (BYD) is distributed worldwide. It is the most economically important disease of barley and oats in North America. Barley yellow dwarf, wheat streak mosaic (WSM) and soil-borne wheat mosaic (SBWM), are three virus diseases that caused serious cereal grain yield losses in Nebraska during the last decade.

Since the mid-1980s barley yellow dwarf has become increasingly widespread in Nebraska, and now is a serious concern to oat and wheat producers. Outbreaks occasionally reach epidemic proportions as occurred in wheat in …

Microstructural Changes In Wheat Starch Dispersions During Heating And Cooling, M. Langton, A. M. Hermansson

Food Structure

Microstructural changes in 8-11% wheat starch dispersions during heating, cooling and cold storage have been evaluated by light microscopy and scanning electron microscopy.

Heat treatment of wheat starch dispersions gives rise to two stages of swelling and solubilization. During the first phase of swelling, solubilized amylose was observed ln the centre of the granules and, to some extent, outside the granules. Further swelling deformed the granules and more amylose was released. When the temperature treatment took place under shear, the outer layer of the swo llen granules fra ctured at 94°C and above, and amylopectin fragments were dispersed into the …

The Nitrogen Response Of Wheat Crops Following Lupins, I C. Rowland, Mel Mason, John Hamblin

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

One of the many benefitsof growing narrow-leaved lupins in a crop rotation (Rowland et al 1988) in the increased yield of the following cereal crop as a result of the improved nitrogen level of the soil.

This article reports the results from 41 wheat/lupin rotation trials involving a range of nitrogen rates throughout the Western Australian agricultural area between 1978 and 1987. These trials allowed scientists to assess the interaction of nitrogen fertilization with previous cropping history and to estimate some of the contribution of the nitrogen and other effects of lupins within the crop rotations. The results provide some …

Early Sowing : One Key To Improved Yields Of Cereal Crops, M W. Perry, Wal Anderson, Rob Delane

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

Early sowing of cereal crops is one of the most important management practices through which Western Australian cereal growers can increase yields.

Researchers have long known that in theory early sowing should mean improved growth and water use efficiency - which both contribuite to increased yields. Application of this knowledge has had to await new tillage and herbicide technology, but recent research in the northan and central wheatbelt has now demonstrated the advantages of early sowing in practice. And more exciting yet, there is evidence that yield responses to weed control and applied fertilizers may also be greater in early …

Frost Injury To Wheat, S P. Loss

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

Frost injury has not been a major concern to the Western Australian wheat industry despite causing spectacular but irregular crop losses on some farms.

The development of suitable herbicides, direct drilling technology and the adoption of early flowering varieties in the late 1970s and early 1980s led to wheat crops being sown and flowering earlier than previously. This resulted in an increase in the incidence of frost damage.

Research into frost indicates that most wheat producers face low to moderate risks of yield loss caused by frost. However, individual farms in particular years can suffer devestating widespread losses. Grost injury …

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.

1989 Agricultural Research, Southeast Kansas Branch Station, L. W. Lomas, K. P. Coffey, J. L. Moyer, D. W. Sweeney, G. V. Granade, T. Walter, K. W. Kelley

Kansas Agricultural Experiment Station Research Reports

Research on beef cattle and crops at Southeast Kansas Branch Station.