Life Sciences Commons^™

Adaptability And Reliability Of Yield For Four Bell Pepper Cultivars Across Three Southeastern States, Laurie Hodges, Douglas Sanders, Katharine Perry, Kent M. Eskridge, K.M. Dean Batal, Darbie M. Granberry, Wayne J. Mclaurin, Dennis Decoteau, Robert Dufault, J. Thomas Garrett, Russell Nagata

Department of Agronomy and Horticulture: Faculty Publications

(Capsicum annuum L.) cultivars were evaluated for yield (total weight of marketable fruit) performance over 41 environments as combinations of 3 years, three planting dates, and seven locations across North Carolina, South Carolina, and Georgia. Cultural practices, including trickle irrigation and double rows planted on blackplastic- covered beds, were uniform across all environments, except for fertilization, which was adjusted at each location based on soil tests. Comparing production over 3 years between the mountain location and the Coastal Plain location in North Carolina, yields were lower on the Coastal Plain. Spring plantings provided higher yields than summer plantings at …

Photoperiod Sometimes Influences Common Bacterial Blight Disease Of Common Beans, Mohamed F. Mohamed, Dermot P. Coyne

Department of Agronomy and Horticulture: Faculty Publications

Common bacterial blight, incited by Xanthomonas campestris pv. phaseoli (Smith) Dye (Xcp), is a serious disease of common beans (Phaseolus vulgaris L.). Three experiments were conducted twice in growth chambers at 26 ± 1C under short (10 hours light/14 hours dark) and long (16 hours light/8 hours dark) photoperiods to determine the influence of these photoperiods, flower bud removal, pod development, and pre- and postinoculation photoperiods on the reaction of common beans to Xcp. In one test, ‘PC-50’ (susceptible; S) flowered earlier and was more susceptible to Xcp under the short photoperiod than under the long photoperiod. …

A Radiation-Induced Mutant With Resistance To Common Bacterial Blight Disease In Common Beans, Mohamed F. Mohamed, Dermot P. Coyne, Paul Read

Department of Agronomy and Horticulture: Faculty Publications

The leaf reaction of the Phaseolus vulgaris L. germplasm—UNECA (M6 mutant derived from the cultivar Chimbolito, Costa Rica), ‘Chimbolito’, BAC-6 (Brazil), XAN- 159 (Centro Internacional de Agricultura Tropical, Cali, Colombia), and ‘PC-50’ (Domican Republic)—to Xanthomonas campestris pv. phaseoli strain V₄S₁ (Dominican Republic) were determined in two replicated trials conducted in a greenhouse in Lincoln, Neb. (Feb.– Mar. and July–Aug. 1993). ‘PC-50’ and ‘Chimbolito’ were susceptible to Xcp strain V4S1 in both tests. UNECA, BAC-6, and XAN-159 had similar levels of resistance to Xcp in the July to August trial. However, in the February to March trial, the …

Velvetleaf (Abutilon Theophrasti) Recruitment, Survival,Seed Production, And Interference In Soybean (Glycine Max), John L. Lindquist, Bruce Maxwell, Douglas Buhler, Jeffrey Gunsolus

Department of Agronomy and Horticulture: Faculty Publications

Field studies were conducted at Rosemount, MN, in 1992 and 1993 to quantify the demographic processes regulating the population dynamics of velvetleaf in soybean as part of a corn-soybean rotation. A consistent 6.8 ± .08% of the total velvetleaf seedbank emerged each year. Less than 21% of all velvetleaf seedlings survived each year in mixture with soybean, due in part to Verticilium spp wilt infection. The probability of seedling survival varied across time of emergence Velvetleaf seed production in the absence of crop competition was 125 and 227 seeds plant^-1 in 1992 and 1993, respectively. Velvetleaf plants that emerged …

Brown· Midrib Sorghum Silage For Midlactation Dairy Cows, R. J. Grant, S. G. Haddad, K. J. Moore, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

Brown midrib sorghum silage was compared with alfalfa, corn, and normal sorghum silages for its effect on performance, ruminal metabolism, and digestive kinetics of Holstein dairy cows in midlactation. Twelve cows averaging 90 ± 5 DIM were assigned to one of four diets in replicated 4 X 4 Latin squares with 4-wk periods. Additionally, 3 ruminally fistulated cows (95 ± 20 DIM) were assigned to the same diets in a 3x 4 Youden square for measurement of ruminal characteristics. Diets were fed as isonitrogenous TMR that contained 65% silage (OM basis). The DMl was greater for the corn and brown …

The Influence Of Plant Population Spatial Arrangement On Individual Plant Yield, John L. Lindquist, D. Rhode, K. J. Puettmann, B. D. Maxwell

Department of Agronomy and Horticulture: Faculty Publications

Two greenhouse experiments were conducted to evaluate the performance of individual oat (Avena sativa) target plants as influenced by neighbor oat plants with different spatial arrangements. Crop spatial arrangement was separated into three com- ponents: (I) population density, (2) distance between plants (distance dispersion, DD), and (3) angular arrangement of plants about one another (angular dispersion, AD). Distance dispersion was quantified using a weighted mean distance from a target individual to its neighbors. Angular dispersion of neighbors around the target was quantified using a measure of circular variance. DD and AD were combined to create a dispersion index …

Effects Of Antitranspirant And Polyacrylamide Gel On Early Growth Of Muskmelon (Cucumis Melo L Cv. Hiline) [Abstract], Entin Daningsih, Laurie Hodges, James R. Brandle

Department of Agronomy and Horticulture: Faculty Publications

Field experiments were conducted in 1991, 1992, and 1993 to evaluate the effects of antitranspirant (Folicote, Aquatrol Inc.) and polyacrylamide gel (Supersorb, Aquatrol Inc.) on early growth of muskmelon.

Purification Of The Major Soybean Leaf Acid Phosphatase That 1s Increased By Seed-Pod Removal, Paul E. Staswick, Chuck Papa, Jing-Feng Huang, Yoon Rhee

Department of Agronomy and Horticulture: Faculty Publications

Fruit removal for 5 weeks after flowering increased acid phosphatase activity 10-fold in soybean (Glycine max 1. Merr. vai Hobbit) leaves compared with normal seed-pod-bearing plants. The major acid phosphatase activity in leaves was purified over 2700-fold, yielding a single polypeptide of 51 kD with a specific activity of 1353 units/mg protein using p-nitrophenylphosphate as the substrate. lsoelectric focusing demonstrated that the purified protein co-migrated with a majority of the activity that increased in leaves following seed-pod removal. lmmunoblot analysis demonstrated that at least part of the increased activity was dueto an increased abundance of the phosphatase protein. In situ …

Models To Predict Yield Loss Due To Weeds In Rice Ecosystems, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Yield loss models have been developed and evaluated for irrigated rice ecosystems with respect to effects of Echinochloa crusgalli. Simple regression models that give the relation between yield loss and weed density or relative leaf area are discussed with respect to their practical value in weed management in rice. More complex eco-physiological process models have been developed and used for rice ecosystems as well. Such models can be useful as a tool in research, whereas more simple approaches are needed for practical application in weed management.

Rotation And Nitrogen Fertilization Effects On Changes In Soil Carbon And Nitrogen, Gary E. Varvel

Department of Agronomy and Horticulture: Faculty Publications

Long-term effects of cropping systems on soil properties, such as organic soil C and N levels, is necessary so more accurate projections can be made regarding the sequester and emission of CO₂ by agricultural soils. This information can then be used to predict the effects of cropping systems on both soil degradation, maintenance, or improvement and global climate changes. My objective was to evaluate the effects of crop rotation and N fertilizer management on changes in total soil C and N concentrations that have occurred during an 8-yr period in a long-term study in the Western Corn Belt. Seven …

Liight Reflectance Compared With Other Nitrogen Stress Measurements In Corn Leaves, Tracy M. Blackmer, James S. Schepers, Gary E. Varvel

Department of Agronomy and Horticulture: Faculty Publications

New tools that can rapidly quantify the N status of corn could be valuable in N fertilizer management practices. This study was conducted to compare light reflectance from corn leaves with other parameters used to detect N deficiencies. Light reflectance (400-700 nm) as measured from corn leaves in the laboratory with a Hunter tristimulus colorimeter was compared with Minolta SPAD 502 chlorophyll meter readings (light transmittance at 650 and 940 nm), leaf N concentrations, and specific leaf N (h' content per unit area). Measurements were made on individual ear leaves collected from an irrigated corn N response trial with four …

Cdna Sequence For The Ribulose 1,5 Bisphosphate Carboxylase/Oxygenase Complex Protein A Protein That Accumulates In Soybean Leaves In Response To Fruit Removal, Paul E. Staswick, Steven J. Crafts-Brandner

Department of Agronomy and Horticulture: Faculty Publications

Soybean (Glycine max L.) transiently accumulates two abundant vegetative storage proteins, VSP A and VSP B, in vacuoles of above-ground vegetative tissues (Wittenbach, 1983; Staswick, 1990). As older leaves and stems become a source of exported metabolites for developing sinks, the VSPs are preferentially degraded and the resulting metabolites are presumably mobilized in the xylem and phloem stream. A striking feature of these proteins is that VSP gene expression is dramatically increased in mature leaves following the remova1 of reproductive sinks (seed pods) and the amount of these proteins increases accordingly (for review, see Staswick, 1994). Other changes …

'Chase' Pinto Dry Bean, Dermot P. Coyne, D.S. Nuland, Dale T. Lindgren, James R. Steadman

Department of Agronomy and Horticulture: Faculty Publications

The release of ‘Chase’ fulfills a need in southwestern Nebraska for a Pinto dry bean cultivar (Phaseolus vulgaris L.) with resistance to rust [Uromyces appendiculatus (Pers.) Unger] and several bacterial diseases. Rust, common bacterial blight [Xanthomonas campestris pv. phaseoli (Smith) Dye], and bacterial brown spot (Pseudomonas syringae pv. syringae van Hall) diseases have recently reduced bean yields and seed quality of Pinto dry beans in that region and northeastern Colorado. ‘Chase’ is the first Pinto cultivar that combines resistance to rust(races of rust prevalent in recent years in Nebraska and Colorado), bacterial brown spot, halo blight …

Heritability Estimates Of Turf-Type Characteristics In Buffalograss, S.J. Browning, Terrance P. Riordan, Rodger K. Johnson, Julie Johnson-Cicalese

Department of Agronomy and Horticulture: Faculty Publications

Buffalograss [Buchloë dactyloides (Nutt.) Engelm] is a drought-resistant, dioecious species, native to the Central Great Plains, which shows excellent potential as a low maintenance turfgrass. Although buffalograss can be propagated vegetatively, there is a need for seeded turf-type cultivars. To assist in developing seeded cultivars, heritabilities of turf characteristics were estimated. Heritabilities from maternal half-sib analyses ranged from h² = 0.04 ± 0.03 for the 1988 uniformity rating to h² = 0.62 ± 0.26 for the 1989 spring color rating. Heritability estimates calculated from offspring-parent regression were also variable and generally lower than maternal half-sib analysis. The …

An Improved Measure Of Angular Dispersion In Plant Neighborhoods, Klaus J. Puettmann, Dan Rhode, Bruce D. Maxwell, John L. Lindquist

Department of Agronomy and Horticulture: Faculty Publications

Spatial distribution is an important factor determining the intensity and outcome of plant competition. The commonly used measure of angular distributions of plants around a target plant (1 - r) is shown to be limited to unimodal distributions. We present a new index which is based on the variance of the differences between the azimuth of neighboring plants. The new index is an improvement as it characterizes the angular dispersion in both unimodal and multimodal distributions.

Sources Of Variation In The Spectrophotomteric Assay Of Hydrocyanic Potential In Sorghum Seedlings, R. D. Lee, B. E. Johnson, J. F. Pedersen, Francis A. Haskins, Herman J. Gorz

Department of Agronomy and Horticulture: Faculty Publications

Spectrophotometry is a useful assay for hydrocyanic acid potential (HCN-p) in sorghum and sudangrass [both Sorghum bicolor (L.) Moench] seedlings, but no systematic study of sources of variation in the procedure has been reported. Selfed seed was harvested from each of 12 ramets (two each from two sister plants from three low-HCN-p sudangrass parents), and seedlings for sampling were grown ina growth chamber, in two rows from each ramet, Seven-day-old seedlings were harvested and divided into two samples per row for extraction; two aliquots per extract were assayed spectrophotometrically for HCN-p. The experiment was replicated three times. The three parents …

Big Bluestem And Switchgrass Establishment As Influenced By Seed Priming, Jana J. Beckman, Lowell E. Moser, Keith Kubik, Steven S. Waller

Department of Agronomy and Horticulture: Faculty Publications

Seed dormancy and slow seedling development often limit establishment of warm-season grass stands. Establishment of seedlings with two solid matrix seed priming (SMP) treatments [2-d moistened (17°C) and 14-d wet-chill (4°C)] was compared with untreated seed of 'Kaw' and 'Pawnee' big bluestem (Andropogon gerardii Vitman) and 'Pathfinder' and 'Cave-in-Rock' switchgrass (Panicurn virgaturn L.) in greenhouse and field experiments. In two greenhouse studies, seedling emergence was monitored from 7 to 26 d after planting and number of adventitious roots were monitored from 2 to 5 wk after planting. Field experiments were initiated on 19 Apr. 1988, 3 June 1988, …

Water Deficit Effects On Osmotic Potential, Cell Wall Elasticity, And Proline In Five Forage Grasses, D. J. Barker, C. Y. Sullivan, Lowell E. Moser

Department of Agronomy and Horticulture: Faculty Publications

Physiological responses of forage grasses to water deficit are not well documented, but may be important in determining drought resistance. The objective of this study was to determine the response of osmotic potential, leaf proline concentration, and cell wall elasticity to water deficit for the C₄ (warm-season) grasses 'Nebraska 54' indiangrass [Sorghastrum nutans (L.) Nash], 'Pathfinder' switchgrass (Panicum virgutum L.), and 'Pawnee' big bluestem (Andropogon gerardii Vitman), and the C₃ (cool-season) grasses, 'Ioreed' reed canarygrass (Phalaris arundinacea L.), and 'Lincoln' smooth bromegrass (Bromus inermis Leyss.). Other measurements included leaf water potential, soil water …

Dependence Of 3 Nebraska Sandhills Warm-Season Grasses On Vesicular-Arbuscular Mycorrhizae, John J. Brejda, D. H. Yocom, Lowell E. Moser, Steven S. Waller

Department of Agronomy and Horticulture: Faculty Publications

Vesicular-arbuscular mycorrhizae (VAM) are rare or absent in actively eroding soils of the Sandhills. The objective of this study was to determine if 3 major Sandhills warm-season grasses used in reseeding eroded Sandhills sites are highly mycorrhizal dependent, and evaluate the response of VAM at different phosphorus (P) levels. In 2 greenhouse experiments, sand bluestem [Andropogon gerardii var. paucipilus (Nash) Fern.], switchgrass, (Panicum virgatum L.), and prairie sandreed [Calamovilfa longifolio (Hook) Scribn.] were grown in steam-sterilized sand in pots and inoculated with either indigenous Sandhills VAM, Glomus deserticola, or noninoculated. In the second experiment, VAM inoculated …

Genetic Manipulation Of Tall Fescue, Jeffrey F. Pedersen, D. A. Sleper

Department of Agronomy and Horticulture: Faculty Publications

Genetic manipulation of tall fescue (Festuca arnndinacea Schreb.) has not been altered by the discovery of the Acremonium coenophialum (Morgan-Jones and Gams) / grass interaction. However, tall fescue breeding programs have been affected greatly. The basic methods for genetically manipulating the grass have remained static. Tall fescue is an obligate out-crossing species, and most improvements are, therefore, captured in the form of an improved population developed through some form of mass or recurrent selection. What has changed is the breeder's ability to recognize genetic differences in the grass because of the confounding effect of A. coenophialum on plant phenotype. It …

Comparison Of Sorghum And Indiangrass Chloroplast Genomes Using Rflps, Jeffrey F. Pedersen, R. D. Lee, D. J. Lee, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

Sorghum (Sorghum bicolor (L.) Moench) and indiangrass (Sorghastrum nutans (L.) Nash) appear closely related based on morphological and chemotaxonomic characters. Each species could potentially provide desirable traits to the other. However, traditional breeding techniques have been unsuccessful in hybridizing these two species. The objective of this study was to determine the relatedness of sorghum and indiangrass chloroplast DNA using RFLPs. Eleven sorghum lines in several cytoplasms, two indiangrass popu1ations, and a corn line were studied using 60 proberestriction enzyme combinations. Principal component analysis of the results showed sorghum to be as closely related to corn as to indiangrass, with no …

Developmental Morphology Of Tropical Sorghum And Sorghum X Sudangrass, R. B. Mitchell, K. J. Moore, Jeffrey F. Pedersen, T. A. Peterson, L. E. Moser, D. D. Redfearn

Department of Agronomy and Horticulture: Faculty Publications

Tropical sorghum and sorghum x sudangrass are known to be efficient scavengers of soil nitrogen and are important forage crops in the U.S. Nitrate contamination of groundwater due to disposal of organic wastes and excessive fertilization is a major concern in the Central Great Plains. A common disposal method of municipal wastes is application to fallow cropland. Quantification of the developmental morphology of tropical sorghum and sorghum x sudangrass is important to developing management strategies that allow multiple applications of organic wastes to optimize nitrogen removal and dry matter production. The objective of this study was to quantify the developmental …

Breeding Systems For Cross-Pollinated Perennial Grasses, K. P. Vogel, Jeffrey F. Pedersen

Department of Agronomy and Horticulture: Faculty Publications

I. Introduction

II. Reproductive and Breeding Characteristics

III. Breeding Systems

A. Ecotype Selection

B. Recurrent, RestricteclPhenotypic Selection

C. Half-sib Progeny Test

D. Between and Within Family Selection

E. Recurrent Multistep Family Selection

IV. Gains From Selection

A. Time Interval per Cycle

B. Potential Gain per Cycle .

C. Potential Inbreeding per Cycle

V. Polycrossing

VI. Hybrid Cultivars

VII. Conclusions

Literature Cited

Sources Of Resistance To Common Bacterial Blight And Rust In Elite Phaseolus Vulgaris L. Germplasm, E. Arnaud-Santana, M.T. Mmbaga, Dermot P. Coyne, James R. Steadman

Department of Agronomy and Horticulture: Faculty Publications

We studied leaf and pod reactions of 18 Phaseolus vulgaris germplasm lines (three temperate and 15 tropical) to four Xanthomonas campestris pv. phaseoli (XCP) (Smith) Dye strains and seven Uromyces appendiculatus (UA) (Pers.) Unger races. Line × XCP interaction was significant for leaf and pod reactions. The common bean lines XAN-159, BAC-6, and XAN-112 had the best combined leaf and pod resistance to XCP. Line × UA race interactions were significant ( P = 0.05). Lines IAPAR-14 and BAC-6 had the best combined resistance to XCP and UA.

Relay-Intercropping Muskmelons With Scotch Pine Christmas Trees Using Plastic Mulch And Drip Irrigation, W.J. Lamont, D.L. Hensley, S. Wiest, Roch E. Gaussoin

Department of Agronomy and Horticulture: Faculty Publications

Two systems of relay-intercropping muskmelons (Cucumis melo L.) with Scotch pine (Pinus sylvestris L.) Christmas trees using black plastic mulch and drip irrigation were evaluated for their potential to improve cash return. Returns ranged from a high of $26,200/ha for plastic mulch-drip irrigation and a selling price of $1.00/melon to a low of $6900/ha for bare ground-drip irrigation and a selling price of $0.40/melon. The benefitcost index ranged from 24 to 3.4, depending on the system evaluated. Pine growth apparently was impeded by plastic mulch; however, increased yields of melons grown under plastic mulch may offset the slight …

‘Concetta’ Rose, Ellen T. Paparozzi

Department of Agronomy and Horticulture: Faculty Publications

‘Concetta’ is a fluorescent, orange-colored rose suitable for pot forcing, landscape planting, and fresh or dried commercial cut flowers (Fig. 1). It produces few thorns and can be propagated from three-eye softwood stem cuttings or through tissue culture.

Origin
‘Concetta’ (Papconc; originator or breeder, can be used for a trademark) arose as a sport (chimera) on the floribunda rose ‘Gabriella’ (Berggren), which was a mutation of ‘Mercedes’ (R. Kordes) (Krussmann, 1981). ‘Mercedes’ is a floribunda rose from a cross of an unnamed seedling with ‘Anabell’ (Kordes) (Krussmann, 1981).

Culture
Initial propagation was from three-eye softwood stem cuttings, which rooted readily …

Performance Of Green And Blanched Asparagus Cultivars In Nebraska [Abstract], Laurie Hodges, Roger Uhlinger, Ernesto Brovelli, Susan Cuppett, Anne Parkhurst

Department of Agronomy and Horticulture: Faculty Publications

Fourteen asparagus cultivars were established in 1988 in eastern Nebraska on a heavy silty clay soil to determine suitability for Nebraska production.

Registration Of N27 Sweetclover Germplasm, Herman J. Gorz, Francis A. Haskins, G. R. Manglitz, R. R. Smith, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

N27 Sweetclover [Melilotus officinalis (L.) Lam.] (Reg. no. GP-l, PI 552552) is a biennial, yellow-flowered, high-coumarin strain that was selected for large seed size and for resistance to the sweetclover aphid [,i>Therioaphis riehmi (Bornerj]. N27 was developed cooperatively by the USDA-ARS and the Nebraska Agricultural Research Division and was released in February 1991.

Registration Of N28 And N29 Sweetclover Germplasms, Herman J. Gorz, Francis A. Haskins, G. R. Manglitz, R. R. Smith, K. P. Vogel

Department of Agronomy and Horticulture: Faculty Publications

Two sweetclover [Melilotus officinalis (L.) Lam.] germplasms, N28 (Reg. no. GP-2, PI 552553) and N29 (Reg. no. GP-3, PI 552554), are improved biennial, yellow-flowered strains selected for low coumarin content (or, more accurately, for low content of o-hydroxycinnamic acid β-D-glucoside; [1]) and for resistance to the sweetclover aphid (Therioaphis riehmi Bomer). N28 and N29 were developed cooperatively by the USDA-ARS and the Nebraska Agricultural Research Division and were released in February 1991.

In Situ Ruminal Protein Degradation Of Switchgrass And Smooth Bromegrass, J. J. Mullahey, Steven S. Waller, K. J. Moore, Lowell E. Moser, Terry J. Klopfenstein

Department of Agronomy and Horticulture: Faculty Publications

Performance of livestock grazing warm-season, perennial grasses is generally greater than would be expected given their relatively low protein concentrations. Two experiments were conducted to assess ruminal escape protein using an in situ rumen technique for switchgrass (Panicum virgatum L.) and smooth bromegrass (Bromus inennis Leyss.). Whole-plant, leaf, and stem samples were harvested at specific stages of maturity in 1987. Duplicate samples of each grass were incubated for 12 h in situ. Escape protein values were expressed as concentration [grams escape protein per kilogram dry matter (DM) adjusted for acid detergent insoluble nitrogen (ADIN)] and as a percentage …