The destructive nature of the clover seed chalcid has been known since the latter part of the 19th century. This jet-black Hymenoptera, often called the "chalcis-fly," destroys from 10 to 20 percent of the alfalfa seed in Utah each year. Damage as high as 85 percent has been reported.

One of the limiting factors associated with seed production of alfalfa and certain clovers is a small jet-black wasp commonly known as the clover seed chalcid, Bruchophagus gibbus (Boheman). In alfalfa seed producing areas this insect is often referred to as the alfalfa seed chalcid or the alfalfa seed chalcis-fly. In local areas of Utah, farmers often refer to this insect as simply "the fly."

The studies here reported involve two crosses, one of which was between a pure line of Kanred and a pure line of Martin from a bunt resistant selection. The other was between a pure line of G-149, a rust-resistant segregate from Sevier X Dicklow, and a pure line of Ridit. These were both economic breeding projects made in an effort to combine the good commercial qualities of Kanred and G-149 with the high bunt resistance of Martin and Ridit, respectively. These crosses also furnished, as a by-product, some good genetic data, as in each cross one parent was fully awned and the other awnless, one had red grain and the other white grain.

High quality seed is of first importance in efficient crop production. Seed is one of the major factors affecting yield and quality of the crop. High quality seed is of adapted varieties, has high gemination, and is free of foreign material and weed seeds. Crop seed containing weed seeds may be the means of infesting farm land with weeds. Such seed is expensive at any price.

Due to the commercial importance of barley many hybridization studies have been prosecuted in an effort to produce superior economic strains. While the economic breeding is still important, at present there is considerable scientific interest int he inheritance of the characters and in the location of the genes in the different linkage groups. Barley is rather favorable genetic material for such study. There is a great number of cultivated varieties and strains which differ widely in heritable characters. Barley can be grown under a wide range of climatic conditions and will produce rather large F2 families. The fact that it has only seven chromosomes makes linkage studies more feasible than in wheat or oats with their greater chromosome complements. The characters studied in this paper are: black versus white glume color, long haired versus short haired rachilla, rough versus smooth awns, and branched versus unbranched style.

During the past few years there have been numerous studies made of various characters in wheat. Some characters which were thought at first to be simple in inheritance have since been found to be rather complex. The data in the following pages are the results of an investigation made to study the inheritance of awns in a cross between Hard Federation and Kota varieties of wheat. Until the last few years awn inheritance in wheat has been regarded as extremely simple, that is, as being dependent on a single factor difference. The awns of the F1 plants have nearly always been intermediate in length between the awns of the two parents with the F2 ratios 3:1 or 1:2:1, awnlessness usually being regarded as dominant. Recently, however, it has become apparent that the inheritance of awns is much more complex than the original data indicated. Several workers have found two independent factors and one has found two factors segregating in such a fashion as strongly to suggest linkage between these two factors.

The relationship of artificial heating to the germination of seeds has been a subject of more or less interest for the last 75 years. Like other research work, experimenters first had their attention called to the problem largely as the result of innate curiosity. They were interested in the result as measured by germinative power, of the application to seeds of different amounts of heat for varying periods of time, consequently many divergent and sundry experiments were carried out. Seeds of a large number of plants have been subjected to tests and the results recorded. The investigations include the effect of heating seeds in soil, in water, in atmospheres of different relative humidities, in carbon dioxid, in ether, in carbon disulphid and in dry air. Each specific experiment has been associated with various temperatures and with various periods of tiem. It is of interest to note that the actual methods used in determining results are about as diversified as the time and temperature. This thesis presents data showing only the effects of dry heating seed at high temperatures. Therefore in discussion of the literature only that material will be considered which has a direct bearing upon that phase of the heating problem.

Barley, during the past three decades, has been used considerably for the study of linkage groups and character inheritance. The commercial varieties are diploids, having seven pairs of chromosomes. Six linkage groups have been established. According to studies on interchange by Kramer et al. (1954), two linkage groups, formerly designated as III and VII, may be separate arms of the same chromosome. They are now generally considered as one linkage group.

Genetic consistency within varieties is essential to quality assurance for any agricultural product. While the Australian coffee industry targets high quality coffee, there is observed morphological variation within coffee varieties in New South Wales plantations. This variability may result from environmental, genetic and/or management factors. Genetic factors can be tested by molecular markers which can also shed light on the questions concerning crop quality management. A review of the literature showed low genetic variation in C. arabica. Hence four different molecular marker systems were used in this study to detect possible genetic variation within and between varieties of local coffee grown in Northern New South Wales (NNSW), Australia. Genetic variation in eighty-four seed propagated coffee (C. arabica) accessions, mainly from two commercial varieties (K7 and CRB) in NNSW, were tested using various PCR-based marker systems (RAPDs, ISSRs, SSRs and AFLPs). Eleven accessions from Central Highland, Vietnam, were used as reference material. While RAPD and ISSR did not distinguish intra-varietal molecular variation, SSR and AFLP data revealed the degree of genetic variability and the relationship among individuals within and between coffee varieties. Despite observed morphological variation within supposedly single variety plantations in NNSW, the genetic variation, measured by genetic distance, revealed in this study was very low (K7: 0.193; CRB: 0.205). There exists genetic variation between different farms sharing the same cultivar (K7) which suggests differences in the management of plantation establishment and sourcing of trees. The genetic variability is not aligned with off-type individuals observed in K7, but is with off-type CRB plants which is probably due to inter-varietal hybrids from unintentional outcrossing. The mean level of genetic identity between cultivars derived from the two distinct types of C. arabica is moderate (0.641). Although genetic variation within and among arabica cultivars is low, sufficient DNA polymorphism was found among some C. arabica accessions to allow differentiation. The results in this study suggested that even the elite cultivars, which have been exposed to intensive selection, still show a certain degree of genetic variation amongst individuals within each cultivar even though C. arabica is a predominantly selfing species and has a narrow genetic foundation. The congruence between AFLP and SSR data sets suggests that either method individually, or a combination, is applicable to genetic studies of coffee. SSR alone clearly distinguished and revealed inter-varietal heterogeneity but were more powerful when combined with AFLP.

Farmers are always looking for ways to increase yields and profits and no-tillage may be a way to achieve this goal. However, a comprehensive study of the performance of no-tillage yields relative to conventional tillage yields and their net returns is lacking. This study evaluated the potential factors that influence differences in conventional tillage and no-tillage yields and net returns as explained by such factors as time, crop, precipitation, soil texture and geographic region. Data were collected from 442 paired tillage experiments growing corn, soybeans, cotton, oats, wheat and sorghum published in three refereed journals. Data were evaluated using a mixed model and logit model respectively, to evaluate differences in mean yields and downside risk with no-tillage compared to tillage. Sorghum and wheat were found to have higher no-tillage yields relative to tillage. No-tillage was also found to outperform conventional tillage in the southern United States with just the opposite occurring in the northern U.S. A silty soil was also found to reduce no-tillage yields. Several factors were found to decrease the chance of downside risk with no-tillage, they were sorghum, sandy soil, Northern Crescent, Northern Great Plains, Prairie Gateway and Southern Seaboard regions. Two factors that increased the chance of lowered no-tillage yields were increased rainfall and length of use of no-tillage. Differences in mean net returns and downside risk were evaluated using a mixed model and logit model. Results showed that no-tillage was more profitable than conventional tillage in the Mississippi Portal region, but less profitable in the Prairie Gateway. Net returns were lower for no-tillage wheat and soybeans when produced in a clay soil. Cotton grown in sand had higher no-till net returns, but increased rainfall decreased cotton net returns. A logit model showed certain factors decreased the probability of lower no-tillage net returns. There was less downside risk with wheat grown under no-tillage as well as less downside risk in the Southern Seaboard region and when no-tillage was used on a clay soil. There were factors that increased the probability of lower no-tillage net returns; increased precipitation, Northern Great Plains, Prairie Gateway and Basin & Range regions.