Agronomy and Crop Sciences Commons^™

Genetics Of Flower Abortion And Pod Type In Soybean, Krishna P. Sharma

Electronic Theses and Dissertations

Field studies were conducted in 1982, 1983 and 1984 in ten soybean (Glycine max (L.) Merrill) genotypes of maturity group 00 to III, to evaluate the effects of genotype and year on flower abortion (FA), flowers/raceme (FPR), raceme length (RL), pod types (PT), seeds/raceme (SPR), seed weight (SW), and yield/raceme (YPR). Reproductive efficiency index (REI) was calculated for parental genotypes and their segregating populations. The effects of main stem node position and raceme flower position on FA and PT were also studied. Genetic studies were on F₂'s of 13 crosses plus F₃ and F₄ generations of …

The Effect Of Soil Storage Methods And Soil Microbes On Carbofuran And Terbufos Degradation, Muriel Monteleone Runholt

Electronic Theses and Dissertations

The purpose of this research was to determine optimal soil storage methods for soils used in carbofuran and terbufos degradation studies. The effect of soil microbes on degradation was also observed. An LD₅₀ study, using 22 day old crickets (Acheta domestica), was undertaken to establish the appropriate LC dose for carbofuran in the soil storage studies. A carbofuran use history failure soil and a noninsecticide use history soil of the same type were collected from the SDSU experimental farm in Centerville, South Dakota. After initial degradation and microbial analysis, the soils were stored air-dried and with a moisture level …

Growth And Development Of Oat (Avena Sativa L.) Cultivars In Response To Water Stress, Abdel-Fattah H. Belal

Electronic Theses and Dissertations

Water stress occurs frequently in the North Central Plains and causes significant reductions in plant growth, development and grain yield. These effects of water stress apparently are dependent on the ability of plants to adapt to less than optimal environments. Plant water potential is dynamic, changing not only with the soil water content and atmospheric conditions, but also with the stage of growth. When plant water potentials become limiting, various physiological processes associated with plant growth, development and final yield are affected. The reduction in productivity in semi- arid environments is directly related to the inability of crop plants to …

Yellow Spot Of Wheat, R Loughman, J. M. Wilson, R. E. Wilson

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

Yellow spot is a serious leaf disease of wheat in Western Australia. It also occurs in Queensland, New South Wales and South Australia. Yellow spot can appear as a severe leaf blight but generally the disease does not have the rapid epidemic development of wheat rust diseases. It builds up more slowly and is not as obvious in the crop, while caising appreciable yield loss.

Protein Enrichment Of Cereal Grains For Livestock, Andrew C. Dunlop, C. L. Mcdonald

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

Every year Western Australian farmers feed about 759,000 tonnes of cereal grain to livestock, mostly to sheep but also to dairy and beef cattle. These grains are fed as drought feeds, as supplements to augment poor quality or scarce paddock feed or in growth rations to attain higher levels of production. Many grains fed, however, have a low protien content and are therefore used inefficiently by animals.

Several methods of improving the low protien content of feed grains have been tested. They include the addition of lupin seed, spraying oats with urea and gassing oats with ammonia.

Predicted Response To S1 Selection For Agronomic And Disease Resistance Traits In Two Sunflower Populations, Syed Sadaqat Mehdi

Electronic Theses and Dissertations

Variances, heritabilities, genetic and phenotypic correlations, and predicted gains were computed for quantitative disease resistance and agronomic traits from pooled S1 family data of Gene Pool II and ND 761 Helianthus annuus L. populations. Broad-sense heritability estimates for all traits were significant in both populations. Observed genotypic correlation coefficients were larger than their corresponding estimates of phenotypic correlation coefficients. Significant positive genetic correlations between resistance to Alternaria blight and Septoria leaf spot; and non-significant genetic correlations between Sclerotinia wilt disease reaction and agronomic traits were observed in both populations. Resistance to Phoma black stem was not significantly correlated with resistance …

Summary Of Rhizobium Experiments., J. G. Howieson

Experimental Summaries - Plant Research

Rotation trials, 84ME32, 84ME24, 84N18, 84M18, 85KA58. Cross row trials, 85M28. One year trials, 86M41, 86M42. On-going trials, 86M58, 85KA64, 86V3, 86AL. 84WH24.

Barley Trials, Lupin Trials, Wheat Trials, Rob Delane, John Hamblyn

Experimental Summaries - Plant Research

This report examines the results of a number of research projects being conducted throughout the Geraldton region trials were conducted throughout the Geraldton region. Trials were conducted at twelve sites within the northern and central parts of the wheatbelt.

Barley trials, 86C54, 86C55, 86C56, 86C90, 86C91, 86GE26, 86GE44, 86GE45, 86GE46, 86TS27, 86WH37, 86ME66.

Lupin trials, 86C57, 86C58, 86C59, 86C60, 86C72, 86C73, 86C74, 86C97.

Wheat trials, 86C61, 86C62, WEUNI, 86GE48.

Annual Ryegrass Toxicity Research Summary Of Experiment Results., V. Nieman, A. G. P. Brown, R. Madin

Experimental Summaries - Plant Research

Experiments were set up to screen a range of herbicides which might give improved control of Anguina agrostis over the currently recommended paraquat. Two experiments examined Roundup, Fusilade and Sertin at two rates and two experiments screened eight herbicides at five rates from two x "label recommendation" to 0. 99 x Standard treatment was paraquat at 550 ml. Plots were 3 m x 30 m in the first two experiments and 3 x 5 m (per dilution) in the second. The herbicides were applied on 4/9, 17/9, 24/9, 1/10 and 9/10 (Zadoks stages 32 - 58). There were three replications …

Tolerance Of Cereal Crops To Herbicides, D G. Bowran

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

Herbicides have come to play an important role in the control of weeds in Western Australian cereal crops, with some estimates showing that sufficient herbicide was applied to treat every hectare of cereal grown in 1984.

While the use of herbicides reduces competition from weeds, they may have a hidden cost. As chemicals which affect plants, herbicides may also affect plants, herbicides may also affect and damage the crop which they are protecting. The crop may possibly fail, and some or all of the economic benefits obtained from the chemical control of weeds may not be realised.

Continuous Cereal Cropping With Alternative Tillage Systems In Western Australia, R J. Jarvis, N D. Delroy, A P. Hamblin

Technical Bulletins

In 1977, a ten year series of continuous cropping trials was commenced to compare the effect of four farm tillage systems. This bulletin reports the grain yield results for the first six years of these trials.

Growth And Magnesium Uptake Of Tall Fescue Lines At High And Low Potassium Levels, J. H. Edwards, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Five tall fescue (Festuca arundinacea Schreb.) clonal lines with diverse root and xylem diameters were grown in nutrient solutions with magnesium (Mg) concentrations of 42, 125 and 250 µm and potassium K concentrations of 133 and 333 µm. Leaf Mg concentrations increased with increasing Mg rates at both low and high K concentrations. The tall fescue line with the largest root and xylem diameters had low leaf Mg concentrations, indicating a possible increased Mg tetany potential when consumed by cattle. The response of the K/(Mg+Ca) ratio in the plant, an indicator of tetany potential, to varying solution Mg at low …

Atrazine And Cyanazine Interception And Retention On Crop Residue, Mark A. Wrucke

Electronic Theses and Dissertations

The effect of several variables on herbicide interception and retention by crop residue was investigated. Variables considered include residue type and amount, amount of rain, time of rainfall occurrence, and herbicide formulation. Experiments were conducted in the greenhouse using corn (Zea mays), soybean (glycine max), and wheat (Triticum aestivum) residue. Simulated rainfall was applied using a modified potsprayer. Herbicide concentration in washoff water was determined using the pyridine-alkali colorimeteric technique for chloro-s-triazine herbicides. As the percent ground cover increased, the amount of herbicide reaching the soil surface at application decreased. With normal residue levels attained in South Dakota, 60% or …

Modeling Of Soil Water Flow And Root Uptake, V. Rasiah

Electronic Theses and Dissertations

The soil water pressure head, h, versus soil water content, 9, and the hydraulic conductivity, K, versus θ, relationships appear as functional coefficients in the non-linear partial differential water flow model. Before the flow equation can be used to simulate the flow of water through soils, the h versus θ and K versus θ relationships must be established. This requires the estimation of the parameters that describe the h versus θ and K versus θ functional relationships. In-situ water retention and hydraulic conductivity measurements were determined from the knowledge of initial and boundary conditions and water content profiles during drainage. …

The Effect Of A Bacteriophage On The Competition Of Rhizobium Japonicum Strains For Nodulation Of Glycine Max (L.) Merr, Lori Kelley

Masters Theses

The symbiotic relationship between Rhizobium japonicum (Kir.) Buch. and Glycine max (L.) Merr. was the concern of this thesis. This relationship occurs naturally in soybean fields. In the field there are many different strains of Rhizobium. Some of these strains fix atmospheric nitrogen more efficiently than others resulting in a higher crop yield. The problem is the more efficient nitrogen fixers are out-competed by less efficient nitrogen fixers. In order to solve this problem the more competitive strains have to be controlled. There are two main ways to do this. One is to increase the number of the desired …