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Proceedings Of The 8th Annual Meeting, Southern Soybean Disease Workers (March 11-12, 1981, Memphis, Tennessee): Soybeans, The Crop Of The Future

Southern Soybean Disease Workers: Conference Proceedings

General Session

Presidential Address - Glen Whitney

The Influence of Plant Diseases on American Agriculture - Wiley Garrett

Integrated Pest Management: A National Prospective - B. Blair

Development in Brazil, the Future World Supplier of Food: Industry Overview - Ray Smith

Soybean Disease Loss Estimate - R. V. Sturgeon

Soybeans, Seed, Seedling, and Soil-Borne Disease, James Kantzes presiding

Standardized Seed Treatment Research Report - M. C. McDaniel

Soybean Seedling Disease Control and Plant Populations - Norman Horn

Metalaxyl: A New Seed Dressing and Soil Treatment Fungicide - H. V. Morton and D. Houseworth

Soybean Seed Treatment: U. S. Status …

The Physical And Chemical Limnology Of Lake Mcconaughy With Reference To Fisheries Management, Melvin W. Taylor, Kit M. Hams

Nebraska Game and Parks Commission: Publications

Lake McConaughy is an important fishery resource of the state of Nebraska. The estimated fishing pressure in 1975 as determined from a postal creel census was 175,872 angler days (Morris 1977). This estimate is inflated compared to an on-site creel census conducted in 1977-78 which showed a total of 69,500 fishing trips annually (Madsen 1980). Not all fishermen were contacted so this estimate is undoubtedly too low. Regardless of which figure is accepted, the reservoir provides many man-days of fishing opportunity. Conservation and management of the fishery resource is necessary to maintain and/or improve its quality,

An important factor in …

A Generalized Inland Fishery Simulator For Management Biologists, Melvin W. Taylor

Nebraska Game and Parks Commission: Staff Research Publications

Presently available fishery models are either too simplified or too complicated to be useful to inland fishery managers. This research was directed toward developing a simplified but realistic computerized simulator useful to fishery managers. The model developed is basically an ageclass structured simulator with features built in to allow easy but effective use by fishery managers. It includes provisions for input of all important parameters plus provisions for density-dependent relationships where applicable. Examples of model use are given for a put-and-take rainbow trout (Salmo gairdneri) fishery and a self-sustaining walleye (Stizostedion vitreum) population.

Physical And Chemical Limnology Of Lake Mcconaughy, Melvin W. Taylor, Kit M. Hams

Nebraska Game and Parks Commission: White Papers, Conference Presentations, and Manuscripts

Lake McConaughy is an important fishery resource of the state of Nebraska. The estimated fishing pressure in 1975 as determined from a postal creel census was 175,872 angler days (Morris 1977). This estimate is inflated compared to an on-site creel census conducted in 1977-78 which showed a total of 69,500 fishing trips annually (Madsen 1980). Not all fishermen were contacted so this estimate is undoubtedly too low. Regardless of which figure is accepted, the reservoir provides many man-days of fishing opportunity. Conservation and management of the fishery resource is necessary to maintain and/or improve its quality,

An important factor in …

Water Current, Volume 13, No. 1, January/February 1981

Water Current Newsletter

Annual Report, Nebraska Water Resources Center
Water Resources Seminars
Matching Fund Proposals Submitted to OWRT
Nebraska Water Conference
Fischbach Receives Award
Director of DWR Resigns
EPA Announces Groundwater Protection Plan
Five-Year Research Goals and Objectives
Research Review: Estimation of Ground Water Recharge Benefits for Irrigation Use

Natural And Applied Control Of Insects By Protozoa1, J.E. Henry

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Protozoa have been recognized as important factors in the natural regula­tion of the densities of certain insects. However, they have been given little consideration as applied microbial agents because entomophilic species cause chronic or debilitative infections in a narrow range of hosts. From a control standpoint, and ultimately from an economic standpoint, they could not compete with the more rapid, broad spectrum action of chemical insec­ticides or the more virulent pathogens such as bacteria, viruses, and certain fungi. Protozoa appeared useful only when low levels of pests could be tolerated, as in forests.

Gradually, interest in protozoa as potential biological …

Insecticides And Pheromones Used In The Midwest. A Short Review, Evelyn Osbourne, Paul Schwartz

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The Midwest produces most of the food and feed grains and oilseeds grown in the US. as well as a substantial proportion of a variety of other crops, but corn accounts for at least 75% of insecticide use in the region. The total amount of insecticides used on crops could be greatly reduced if economic losses from insects could be predicted accurately. We will examine the current status of chemical controls for insects of economic importance to this region, indicating some areas where new developments are needed or are likely to occur.

Determination Of Selenium In Biological Materials By Stable Isotope Dilution Gas Chromatography-Mass Spectrometry, Donald C. Reamer, Claude Veillon

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Selenium can be determined quantitatively in biological samples after digestion using nitric acid, orthophosphoric acid, and hydrogen peroxide and the formation of 5-nitropiazselenol. Samples are spiked with enriched ⁸²Se and lsotoplc ratio of ⁸⁰Se to ⁸²Se is measured by combined gas chromatographymass spectrometry using dual ion monitoring. Precise determination at the parts-per-billion level is possible. The accuracy of the method Is verlfied by using standard reference materials.

Housing And Management To Reduce Climactic Impacts On Livestock, G. Leroy Hahn

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Weather is a constraint on efficient livestock production systems. Evaluation of the degree of constraint is a difficult, but necessary task before selection of appropriate modifications in management or environments can be made. The basis for rational selection from available alternatives for the limitation of climatic stress in livestock has continued to improve, particularly with the development of rudimentary functional relationships between animal performance and weather parameters. Such relationships, when combined with probabilistic knowledge of the weather parameters, permit prediction of the reduction in animal performance under natural conditions, or of the benefits to be derived from proposed housing or …

A Feeding Deterrent Effect Of A Water Extract Of Tansy (Tanacetum Vulgare L., Compositae) On Three Lepidopterous Larvae, Gary Brewer, Harold J. Ball

Department of Entomology: Faculty Publications

A tansy (Tanacetum vulgare L.) extract was made by grinding fresh tansy leaves in distilled water. The extract, when "painted" on broccoli leaf discs, was found to deter feeding of two of three lepidopterous larvae studied. When the tansy extract was "painted" on the entire body surfaces of the larvae of three lepi dopterous species, no deleterious reactions were observed.

Comparative Water Relations And Photosynthesis Of Mycorrhizal And Non-Mycorrhizal Bouteloua Gracilis H.B.K. Lag Ex Steud., Michael F. Allen, William K. Smith, Thomas S. Moore Jr., Martha Christensen

Department of Plant Pathology: Faculty Publications

The rangeland grass, Bouteloua gracilis was inoculated with its mycorrhizal symbiont, Glomus fasciculatus, to determine the influence of vesicular-arhuscular mycorrhizae on water status, stomatal behaviour and photosynthesis as well as gross plant morphology, biomass and phosphorus content. Mycorrhizal infection increased transpiration rates by over 100% with 50 to 70% lower leaf resistances to water vapour diffusion. Leaf xylem pressure was not different between mycorrhizal and non-mycorrhizal plants indicating that whole-plant resistance to water transport was reduced by more than 50%. Photosynthetic rates under saturating light conditions increased 68% with infection as a consequence of a 33% reduction in stomatal …

Spatial Memory And The Performance Of Rats And Pigeons In The Radial-Arm Maze, Alan B. Bond, Robert G. Cook, Marvin R. Lamb

Papers in Behavior in Biological Sciences

The resource-distribution hypothesis states that the ability of an animal to remember the spatial location of past events is related to the typical distribution of food resources for the species. It appears to predict that Norway rats would perform better than domestic pigeons in tasks requiring spatial event memory. Pigeons, tested in an eight-arm radial maze, exhibited no more than half of the memory capacity observed in rats in the same apparatus and may not have used spatial memory at all. The results were interpreted as supporting the hypothesis.

Peptidohydrolases Of Soybean Root Nodules, Nasir S. A. Malik, N. E. Pfeiffer, D. R. Williams, Fred W. Wagner

Department of Biochemistry: Faculty Publications

Nodule extracts prepared from Glycine max var Woodworth possessed endopeptidase, aminoptidase, and carboxypeptidase actiities. Three distinct endopeptidase activities could be resolved by disc-gel electrophoresis at pH 8.8. According to their order of increasing electrophoretic mobility, the first of these enzymes hydrolyzed azocasein and n-benzoyl-LLeu-β-naphthylamide, while the second hydrolyzed n-benzoyl-L-Arg-/8- naphthylamine (Bz-L-Arg-/βNA), n-benzoyl-L-Arg-β-nitroanilide (Bz-L-Arg-βNA), and azocasein. The third endopeptidase hydrolyzed Bz-L-Arg-βNA, Bz-L-Arg-βNA, and hemoglobin. Fractions of these enzymes extracted from electrophoresis gels were shown to have pH optima from 7.5 to 9.8. AU of the endopeptidases were completely inhibited by diisopropylphosphorofluoridate, demonstrating that they were serine proteases.

Lavender, A Chick Melanocyte Mutant With Defective Melanosome Translocation: A Possible Role For 10 Nm Filaments And Microfilaments But Not Microtubules, Paula Mayerson, John Brumbaugh

School of Biological Sciences: Faculty Publications

Lavender is a mutation of chick neural-crest-derived melanocytes showing dilute feather pigmentation. This defect, previously attributed to a lack or attenuation of dendrites, was found to be due to a defect in melanosome translocation. The mutant phenotype, of melanin-congested perikarya and pigmentless dendrites is expressed both in vivo and in vitro. Studies with colcemid and cytochalasin B suggest that the avian melanocyte resembles a dispersing amphibian melanophore in its requirement for microfilaments but not microtubules.

Ultrastructural analysis revealed a normal complement of intracellular filaments. Microtubules, however, are scarce. Intermediate (10 nm) filaments surround and are closely associated with intracellular organelles, …

Intercellular Communication In Plants: Evidence For A Rapidly Generated, Bidirectionally Transmitted Wound Signal, Eric Davies, Anne Schuster

School of Biological Sciences: Faculty Publications

Wounding (whether by excision, abrasion, or puncture) elicited rapid, massive, and enduring formation of polysomes in aged pea stems and other mature tissues. The response depended on temperature and severity of wounding but not on water uptake, and it occurred in tissues adjacent to, distant from, above, and below the site of injury. The kinetics of polysome formation were similar in tissues adjacent to or up to 150 mm distant from the point of injury. The wound-induced increases in proteinsynthesizing capacity of the polysomes both in vivo and in vitro were much greater than the increases in rRNA and poly(A) …

Lavender, A Chick Melanocyte Mutant With Defective Melanosome Translocation: A Possible Role For 10 Nm Filaments And Microfilaments But Not Microtubules, Paula L. Mayerson, John A. Brumbaugh

School of Biological Sciences: Faculty Publications

Lavender is a mutation of chick neural-crest-derived melanocytes showing dilute feather pigmentation. This defect, previously attributed to a lack or attenuation of dendrites, was found to be due to a defect in melanosome translocation. The mutant phenotype, of melanincongested perikarya and pigmentless dendrites is expressed both in vivo and in vitro. Studies with colcemid and cytochalasin B suggest that the avian melanocyte resembles a dispersing amphibian melanophore in its requirement for microfilaments but not microtubules.

Ultrastructural analysis revealed a normal complement of intracellular filaments. Microtubules, however, are scarce. Intermediate (10 nm) filaments surround and are closely associated with intracellular …

Cover Of Plants With Extrafloral Nectaries At Four Northern California Sites, Kathleen H. Keeler

School of Biological Sciences: Faculty Publications

Percent cover of plants with extrafloral nectaries was investigated in three California habitats with the same physiognomy as habitats previously studied in Nebraska (perennial native grassland, riparian forest, deciduous forest). In contrast to Nebraska where cover of plants with extrafloral nectaries reached 14 percent, no plants with extrafloral nectaries were found in any California transect. Chaparral was also studied; no plants with extrafloral nectaries were found.

Analysis Of A Controlling-Element Mutation At The Adh Locus Of Maize, John Osterman, Drew Schwartz

School of Biological Sciences: Faculty Publications

A Ds-suppressed Adh mutant was isolated by the allyl alcohol pollen selection

technique. The mutant produces a reduced level of an altered thermolabile

enzyme suggesting that the Ds element is inserted in the Adh structural gene.

The mutant protein is enzymatically active and does not differ detectably in

size from the progenitor protein. A number of possible explanations for the data

are presented.

Genetic Structure Of Two Species Of Waterstriders (Gerridae: Hemiptera) With Differing Degrees Of Winglessness, Anthony J. Zera

Anthony Zera Publications

The Gerridae (Hemiptera: Insecta) is a worldwide family whose constituent species exhibit dramatic inter- and intra-specific variation in the degree of winglessness (Brinkhurst, 1960; Vepsäläinen, 1978; Calabrese, 1979). At one extreme, the family contains species which are fully winged in all populations and during all seasons, while several species consist almost exclusively of wingless morphs over large geographical ranges and during all seasons. Many species exhibit the intermediate case of wingpolymorphism: the occurrence of various combinations of fully winged, partially winged and/ or wingless morphs in the same population at the same time. Various wing-polymorphic species show differing patterns of …

Review Of Observations Of Wildlife, Paul A. Johnsgard

Papers in Ornithology

Nearly everybody has a childhood hero, but only rarely do those heros survive the test of time to stand even taller in the mind's eye when approaching a halfcentury of one's own lifetime. Sir Peter Scott is a man of such stuff; his enormous artistic abilities and capacity for converting those talents into the environmental education of several generations of Britons, and toward the conservation of the earth's natural resources, cause him to stand uniquely alone in the international environmental scene. His book is an informal retrospective look at his own life, his artwork, and his concerns for conservation and …

Pseudogymnophallus Alcae Gen. N. Et Sp. N. (Trematoda: Gymnophallidae) From Alcids (Charadriiformes) In Subarctic Seas, Eric P. Hoberg

Harold W. Manter Laboratory of Parasitology: Faculty Publications

Pseudogymnophallus alcae gen. n. et sp. n. is described for trematodes from alcids (Charadriiformes: Alcidae) from the North Pacific region (Gulf of Alaska, Bering Sea, and Chukchi Sea): horned puffin, Fratercula corniculuta; tufted puffin, Lunda cirrhuta; parakeet auklet, Cvclorrhvnchus psittacula, and least auklet, Aethia pusilla; and from the western North Atlantic Ocean, (Gulf of St. Lawrence): razorbill, Alca torda. Pseudogymnophallus is distinguished from other genera of Gymnophallidae by the intertesticular position of the ovary; a cylindrical, undivided seminal vesicle; and by an intestinal diverticulum dorsal to the arch of each cecum.

Parasites And Diseases Of Mullets (Mugilidae), I. Paperna, Robin M. Overstreet

Harold W. Manter Laboratory of Parasitology: Faculty Publications

The following treatment of parasites, diseases and conditions affecting mullet hopefully serves several functions. It acquaints someone involved in rearing mullets with problems he can face and topics he should investigate. We cannot go into extensive illustrative detail on every species or group, but do provide a listing of most parasites reported or known from mullet and some pertinent general information on them. Because of these enumerations, the paper should also act as a review for anyone interested in mullet parasites or the use of such parasites as indicators about a mullet's diet and migratory behavior. Unfortunately, limited space prohibits …

Late Quaternary Environmental History Of Lake Valencia, Venezuela, J. Platt Bradbury, B. Leyden, M. Salgado-Labouriau, W. M. Lewis Jr., C. Schubert, M. W. Binford, D. G. Frey, D. R. Whitehead, F. H. Weibezahn

United States Geological Survey: Staff Publications

Chemical, paleontological, and mineralogical analyses of a 7.5-meter core from the middle of Lake Valencia, Venezuela, have provided information on the paleoclimatic history of this low-elevation, low-latitude site for the last 13,000 years. The data show that dry climates existed in this region from 13,000 years before present (B.P.) until about 10,000 years B.P. The Lake Valencia Basin was occupied by intermittent saline marshes at that time. About 10,000 years B.P., a permanent lake of fluctuating salinity formed and arboreal plant communities replaced the earlier dominant xeric herbaceous vegetation and marsh plants. By 8500 years B.P., Lake Valencia reached moderate …

Blood Flow To The Corpus Luteum-Bearing Ovary And Ipsilateral Uterine Horn Of Cows During The Oestrous Cycle And Early Pregnancy, S. P. Ford, J. R. Chenault

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Total ovarian blood flow of cows (sum of flows through the ovarian artery and uterine branch of the ovarian artery), measured by electromagnetic flow probes, followed a consistent cyclic pattern, being highest from Day 10 of the oestrous cycle (oestrus = Day 0) until 4 days before the subsequent oestrus. During this period of high ovarian blood flow, blood of uterine origin flowed to the ovary through the uterine branch of the ovarian artery and was found to comprise 20-40% of the ovarian blood flow. Between Days -4 and -3, ovarian blood flow dropped (P < 0·01)from 3·2 ± 0·5 to 1·0 ± 0·4 ml/min, coincident with a reversal of flow through this anastomosis. Uterine arterial blood flow was highest (P < 0·05)from 1 day before oestrus to the day of oestrus when compared to the remaining days of the oestrous cycle. Throughout the oestrous cycle, ovarian blood flow was positively correlated with systemic concentrations of progesterone (r = 0·55, P < 0·01)and negatively correlated with systemic concentrations of oestradiol-17β (r = -0·42, P < 0·01). In contrast, uterine arterial blood flow was negatively correlated with systemic progesterone (r =-0·25, P < 0·05) and positively correlated with systemic oestradiol (r = 0·45, P < 0·05). These data provide direct evidence in the cow that a portion of the blood flowing to the ovary containing a fully functional corpus luteum is contributed by the ipsilateral uterine artery.

A Water Quality Survey Of The Big Blue River, Nebraska, Terry R. Maret, Curtis C. Christiansen

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Physiochemical and bacteriological conditions along with the macroinvertebrate community structure were studied to evaluate water quality of the Big Blue River, in southeastern Nebraska. Samples were taken between November 7, 1978, and December 19, 1979, at six stations from the headwaters to lower reaches of the river. Some sample sites were below specific municipal and industrial effluents to evaluate better their impact on water quality. Parameters measured included pH, temperature, dissolved oxygen, suspended solids, conductivity, biochemical oxygen demand, nitrate, ammonia, and fecal coliforms. Dissolved oxygen and nitrate were significantly different (p<0.05) between stations, with the headwaters station exhibiting the greatest difference in water quality. Fecal coliforms were substantially higher at stations below Crete. The macroinvertebrate fauna comprised 42 and 66 taxa collected with Ekman grabs and multiplate artificial substrates, respectively. Average diversity values, using the Shannon-Weaver index, indicated all stations would be categorized as moderately polluted. Taxa collected at the stations showed a great deal of homogeneity. An exception was the headwaters site where pollution-associated taxa were found in abundance. Seasonal changes were an apparent factor affecting diversity of the macro invertebrates. The results collected provide useful baseline information for future evaluation of water quality trends of the Big Blue River.

Sister Chromatid Exchanges In A Male With A Y/Y Translocation, Merlin G. Butler

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Sister chromatid exhanges (SCE) are considered indicators of genetic damage and early chromosome changes. The SCE frequency from an infertile 27-year-old, white male with tall stature and a non-dicentric Y/Y translocation consisting of one short arm and two long arms of the Y chromosome was determined. The SCE frequency was 7.9 ± SD 1.4 while to SCE frequency from ten control subjects was 8.4 ± SD 0.51. A two-tailed t-test was applied to the SCE data and no significant difference was found between the individual with the Y/Y translocation and control subjects. Apparently, this altered chromosomes does not interfere …

Preliminary Report On The 1979 Excavations At The Clary Ranch Site, Thomas P. Myers, Richard G. Corner, Lloyd G. Tanner

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

During the summer of 1979 excavations at the Clary Ranch Site (Ash Hollow, Garden County, Nebraska) demonstrated the presence of a Late Paleoindian bison-butchering site. Bison tooth-eruption patterns indicate that the kill took place in late spring to early summer. Turtle and canid bones were also recovered. The presence of Frederick and Meserve points suggests an antiquity of more than 8,500 yr for the site.

Transactions Of The Nebraska Academy Of Sciences And Affiliated Societies Volume Ix (1981): Table Of Contents

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Nebraska Academy of Sciences, Officers, Policy Committee .......... ii

Editorial Board, Instructions to Contributors .......... v

Membership Objectives and Friends of the Academy .......... vi

Anthropology

Preliminary report on the 1979 excavations at the Clary Ranch Site (Myers, Corner, and Tanner) .......... 1

Biological and Medical Sciences

Sister chromatid exchanges in a male with a Y /Y translocation (M. G. Butler) .......... 9

Further observations on polymegaly in species of the Drosophila affinis subgroup (Ho-Chi Chang and D. D. Miller) .......... 13

Pruduction rates of aquatic insects in a turbid reservoir (J. C. Lund and E. J. Peters) .......... 23 …

Production Rates Of Aquatic Insects In A Turbid Reservoir, John C. Lund, Edward J. Peters

Transactions of the Nebraska Academy of Sciences and Affiliated Societies

Buckley Creek 3F is a turbid 13 ha reservoir in southeastern Nebraska. The quality of the environment was assessed in 1977 with an annual production estimate of the benthic insects.

Monthly bottom samples were taken using a 15 cm (6 in.) Ekman dredge. To observe any correlation between production and other factors, chemical and physical parameters consisting of total alkalinity, hardness, pH, conductivity, salinity, temperature, dissolved oxygen, and suspended solids were monitored.

Total benthis production was 0.156 g/m²/yr (dry weight). Individual genera produced between 0.001 (Chaoborus sp.) and 0.057 g/m²/yr (Hexagenia sp.). Published studies …

Karyology And Morphometrics Of Three Species Of Akodon (Mammalia: Muridae) From Northwestern Argentina, Rubén M. Barquez, Daniel F. Williams, Michael A. Mares, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Chromosomal and morphometric studies were conducted on a sample from an assemblage of Akodon spp. occurring in various patterns of sympatry from the provinces of Catamarca, Jujuy, Salta, and Tucumán, Argentina. Results showed three distinct morphometric groups based upon size. Size also varied with age, but there were no significant differences in measurements of males and females. The three morphometric groups have distinct karyotypes. Akodon caenosus Thomas is the smallest of the three, and has a karyotype of 2n = 34, FN = 40. A. boliviensis tucumanensis J. A. Allen is intermediate in size and has 2n = 40, FN …