Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 7 of 7
Full-Text Articles in Life Sciences
Winter Wheat Growth In Artificially Compacted Soil, Wallace Wilhelm, L. N. Mielke
Winter Wheat Growth In Artificially Compacted Soil, Wallace Wilhelm, L. N. Mielke
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
Dense soil tillage pans can develop from the improper use of tillage tools. The influence of compacted layers or pans on plant growth and development, although much studied, is not clearly understood. This greenhouse experiment evaluated the influence of uniformly compacted soil and thin layers of compacted soil placed at various depths on early growth of winter wheat (Triticum aestivum L.). Artificially compacted soil [Alliance silt loam, Aridic Argiustoll (Eluviated Brown Chernozem); A horizon] profiles were constructed in polyvinyl chloride tubes of 150-mm diameter by 350 mm long. Treatments were: (1) uniformly noncompacted (bulk density 1.30 Mg m-3) …
Duration Of Fertility Of Turkeys Inseminated At Different Times After The Onset Of Photostimulation, M. R. Bakst
Duration Of Fertility Of Turkeys Inseminated At Different Times After The Onset Of Photostimulation, M. R. Bakst
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
To investigate the relationship between photostimulation, ovary and oviduct weights, and oviducal sperm-storage tubule (SST) development and functional capacity, 33-week-old turkey hens were placed in four groups of 15 hens each. Each group was inseminated three times in 30 min with 50 × 106 spermatozoa (a total of 150 × 106 spermatozoa) on the day of photostimulation, or on Days 7, 14, or 21 after the onset of photostimulation (Groups A, B, C and D, respectively). From weeks 4 to 8 after photostimulation, 5 additional hens were inseminated each week and then killed 24 h later to determine …
Suggestions Regarding Alcoholic Bird Collections, Peter F. Cannell, Murray R. Bakst, Cheryl S. Asa
Suggestions Regarding Alcoholic Bird Collections, Peter F. Cannell, Murray R. Bakst, Cheryl S. Asa
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
One third of the known species of birds are unrepresented in alcoholic collections and nearly 70% of the rest are represented by 10 or fewer specimens (Wood et al. 1982, Zusi et al. 1982). Simply put, "existing anatomical specimens do not meet present and future research needs and . .. the situation must be corrected" (Jenkinson and Wood 1985:587). Actually, current alcoholic specimen resources may be even worse than indicated by Wood et al. (1982), despite commendable recent improvements. Here, we argue the urgent need for additional alcoholic specimens, stressing in particular quality of fixation, the importance of series, documentation …
Turkey Hen Fertility And Egg Production After Artificial Insemination And Multiple Oviduct Eversion During The Pre-Laying Period, M. R. Bakst
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
The onset of egg production (mean 18 · 3 days after the onset of photostimulation) and the rate of egg production (flock averaged 4 · 9 eggs per bird per week for the first 8 weeks of egg production) were not affected by 5 days of twice daily oviduct eversion ('venting') in the pre-laying period when compared to unvented controls. After the onset of photostimulation, pre-laying hens were inseminated twice daily on Days 12 to 16 with 3 μl semen containing 15 × 106 spermatozoa, and compared with groups of hens inseminated once daily on Days 15 and 16 with …
Male Sterility In Soybean-An Overview, Robert Graybosch, Reid G. Palmer
Male Sterility In Soybean-An Overview, Robert Graybosch, Reid G. Palmer
United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications
The most common type of reproductive mutations observed in the soybean [Glycine max (L.) Merr.]are those that induce male sterility.The high frequency of occurrence of male-sterile mutations indicates that a number of genes influence the processes of microgametogenesis and microsporogenesis. The current knowledge of these mutations is summarized. The origins of male-sterile mutations, their inheritance patterns, and known linkage relationships are detailed. The phenotypic expression of male-sterile mutations, including their effects on both male and female reproduction, is discussed. The influence of environment on the expressivity of male sterile mutations, and the effects of male-sterile mutations on physiological processes …
Considerations In Breeding Endophyte-Free Tall Fescue Forage Cultivars, Jeffrey F. Pedersen, D. A. Sleper
Considerations In Breeding Endophyte-Free Tall Fescue Forage Cultivars, Jeffrey F. Pedersen, D. A. Sleper
Department of Agronomy and Horticulture: Faculty Publications
Breeding tall fescue (Festuca arundinacea Schreb.) cultivars that are free of the endophytic fungus Acremonium coenophialum Morgan-Jones and Gams [previously identified and referred to as Epichloe typhina (Fries) Tulasne] is necessary to improve animal performance. The techniques used in developing new cultivars are not greatly different from those used previously, with one exception. Prior to the evaluation of new tall fescue lines or populations, the endophyte needs to be eliminated from the seed or the plants. Several techniques utilizing aging, heat, or chemical treatment are being used to effectively accomplish this in the seed. Methods for permanently eliminating the endophyte …
Levels And Timing Of Nitrogen Fertilizer Applications For Tall Fescue In Central Alabama, J. W. Odom, Jeffrey F. Pedersen
Levels And Timing Of Nitrogen Fertilizer Applications For Tall Fescue In Central Alabama, J. W. Odom, Jeffrey F. Pedersen
Department of Agronomy and Horticulture: Faculty Publications
Tall fescue (Festuca arundinacea Schreb.), the most important cool season perennial pasture grass in the United States, is generally well adapted to the northern two-thirds of Alabama. Unfortunately, the most commonly grown tall fescue cultivar, Kentucky 31, is of northern origin and is dormant during the winter. To reduce this problem, AU Triumph was selected from Mediterranean germplasm. The Alabama Agricultural Experiment Station released this cultivar to growers in 1981. Compared to Kentucky 31, AU Triumph produces about 80 percent more forage during the winter and produces mature seed about 2 weeks earlier in the spring. Total annual forage production …