Life Sciences Commons^™

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

Department of Agronomy and Horticulture: Faculty Publications

Four bell pepper (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 black plastic-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 …

Weed Suppression With Grazing Or Atrazine During Big Bluestem Establishment, B. Keith Lawrence, Steven S. Waller, Lowell E. Moser, Bruce Anderson, Larry L. Larson

Department of Agronomy and Horticulture: Faculty Publications

Weed competition is a major factor causing warm-season grass seeding failures in rangeland and cropland. With a limited number of herbicides available for weed control, grazing may reduce competing vegetation in seedings and serve as an alternative to herbicides. Many immature needy forbs and grasses are palatable to cattle and contain high nutrient levels. Research was conducted (RCBD, 4 reps) comparing grazing by yearling cattle with chemical suppression [atrazine (6-chloro-N-ethyl-N’- (methylethyl)-1, 3, 5-triazine-2, 4-diamine)] for weed control in big bluestem (Andropogon gerardii var. gerardii Vitman) seedlings at Mead, Nebr. on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic …

Ruminal Degradation Of Switchgrass, Big Bluestem, And Smooth Bromegrass Leaf Proteins, Daren D. Redfearn, Lowell E. Moser, Steven S. Waller, Terry J. Klopfenstein

Department of Agronomy and Horticulture: Faculty Publications

Two in situ protein disappearance experiments were conducted to determine disappearance rates of leaf protein fractions and characterize individual leaf protein fractions that escaped ruminal degradation. Fresh leaf blades of two warm-season grasses, switchgrass (Panicum uirgatum L. 1 and big bluestem (Andropogon gerardii Vitman), and one cool-season grass, smooth bromegrass (Bromus inermis Leyss.), were included in Exp. 1. Only warm season grasses were used in Exp. 2. Leaves were harvested from greenhouse-grown plants, placed in polyester bags, and incubated up to 48 h in situ in three ruminally fistulated steers fed diets of warm season grass hay. …

Quantifying Developmental Morphology Of Perennial Grasses, K. J. Moore, Lowell E. Moser

Department of Agronomy and Horticulture: Faculty Publications

Perennial forage grasses can be viewed as modular organisms. The phytomer is usually considered the basic unit of the grass plant and consists of a leaf blade and sheath, the internode, the node, and the associated axillary bud below the point of sheath attachment. The tiller is a collection of phytomers differentiated from a single apical meristem. The grass plant is a group of tillers that ultimately arise from a single zygote and are of the same genotype. A grass sward is a population of individual plants, often genetically related, but usually of unique genotypes. The developmental morphology of perennial …

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 …

In Vitro Starch Disappearance Procedure Modifications, C. J. Richards, Jeffrey F. Pedersen, R. A. Britton, R. A. Stock, C. R. Krehbiel

Department of Agronomy and Horticulture: Faculty Publications

Four in vitro experiments evaluated the effects of ruminal fluid inoculum:artificial saliva ratios,

grinder type, grind size, and diet of ruminal fluid donor on in vitro starch disappearance. Experiment 1 examined rates of starch disappearance and coefficients of determination obtained by linear regression of starch disappearance using five grain sorghum (Sorghum bicolur (L.) Moench) lines, a corn (Zeu muys L.) control, and a wheat (Triticum aestivum L.) control. Grains were incubated for 4, 8, 12, 16, and 20 h with inoculum varying in proportion of ruminal fluid and artificial saliva ( l:l, 1:2, 1:3, and 1:4). In …

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 …

A Modified Stimpmeter For Small-Plot Turfgrass Research, Roch E. Gaussoin, Jeff Nus, Larry Leuthold

Department of Agronomy and Horticulture: Faculty Publications

Golf ball roll is measured with a United States Golf Association (USGA) Stimpmeter. Three Stimpmeters were fabricated identically to the USGA Stimpmeter, except for the location of the ball release notch. The modified Stimpmeters had ball release notches located at 57, 38, and 19 cm, rather than at 76 cm from the beveled end. The modified Stimpmeters were tested on a creeping bentgrass green located at Mead, Neb., at three mowing heights (4.8, 4.0, and 3.2 mm). The Stimpmeters were effective in measuring golf ball roll distance and provided reasonable and consistent estimates of friction. Modified Stimpmeters are relatively inexpensive …

Modeling The Population Dynamics And Economics Of Velvet Leaf (Abutilon Theophrasti) Control In A Corn (Zea Mays)-Soybean (Glycine Max) Rotation, John L. Lindquist, Bruce D. Maxwell, Douglas D. Buhler, Jeffrey L. Gunsolus

Department of Agronomy and Horticulture: Faculty Publications

A simulation model was developed to predict the population dynamics and economics of velvetleaf control in a corn-soy bean rotation. Data compiled from the literature were used to parameterize the model f or two situations, one in which velvetleaf was infected by a Verticillium spp. wilt and one without infection. Verticillium was assumed to have no effect on corn or soybean yield. In the absence of control, simulated seed bank densities of a Verticillium-infected velvetleaf population were 5 to 50 times lower than for an uninfected velvetleaf population. The model was used to evaluate a threshold weed management strategy …

Classical And Molecular Approaches To Breeding Horticultural Plants For Disease Resistance: Introduction To The Colloquium, Dermot P. Coyne

Department of Agronomy and Horticulture: Faculty Publications

Diseases of horticultural crops have always been a concern of crop producers, processors, merchandisers, and consumers because of reductions in yield and product quality. Excessive chemical application to control diseases of some crops has been a health concern in some countries. Some diseases pose a major constraint, or even a threat, to the production of a crop in a region. Plant breeders, in association with plant pathologists, have had notable successes in breeding disease-resistant varieties, thus ensuring the economic production of a crop. There is now an increased need to breed for disease resistance of horticultural crops because of a …

‘Lakota’ Winter Squash, A Cultivar Derived From Native American Sources In Nebraska, Dermot P. Coyne, J.M. Reiser, Lisa Sutton, Alice Graham

Department of Agronomy and Horticulture: Faculty Publications

‘Lakota’ is a novel, smooth- and thinskinned, small-fruited, early maturing, ovoidshaped winter squash [Cucurbita maxima (Duch.)] (Fig.1). Plants produce fruit exhibiting various degrees of green and orange variegated patterns, along with some solid green and orange fruit. ‘Lakota’ was released because of its novel decorative value and good baking quality. A similar winter squash is not available commercially.

Origin

Seeds of the winter squash population from which ‘Lakota’ was selected were donated to the Univ. of Nebraska, Lincoln, by A.G., who originally received the seed from the late Martha Newman, Alliance, Neb. By examining the Quarter Master Reports (1820), …

Statistical Analysis Of Disease Reaction Data Using Nonparametric Methods, Kent M. Eskridge

Department of Agronomy and Horticulture: Faculty Publications

Plant breeders developing disease-resistant horticultural crops need flexible and powerful statistical methods to compare treatments efficiently. The most commonly used statistical methods are those based on analysis of variance (ANOVA), regression, and correlation. The valid use of these methods requires that the data have 1) normally distributed responses, 2) constant error variance, 3) independently distributed errors, and 4) a correctly specified model. However, many plant disease experiments yield data that do not adhere to these standard assumptions. For example, in an experiment involving population levels of a pathogen, rarely will population levels be normally distributed. Field counts of the number …

Influences Of Trees On Abundance Of Natural Enemies Of Insect Pests: A Review, Mary Ellen Dix, R. J. Johnson, Mark O. Harrell, Ronald M. Case, Robert J. Wright, Laurie Hodges, James R. Brandle, Michelle M. Schoeneberger, N. J. Sunderman, R. L. Fitzmaurice, Linda J. Young, Kenneth G. Hubbard

Department of Agronomy and Horticulture: Faculty Publications

In this article we review the use of natural enemies in crop pest management and describe research needed to better meet information needs for practical applications. Endemic natural enemies (predators and parasites) offer a potential but understudied approach to controlling insect pests in agricultural systems. With the current high interest in environmental stewardship, such an approach has special appeal as a method to reduce the need for pesticides while maintaining agricultural profitability. Habitat for sustaining populations of natural enemies occurs primarily at field edges where crops and edge vegetation meet. Conservation and enhancement of natural enemies might include manipulation of …

An Automated Plot Harvest System For Use With A Commercial Forage Harvester, Jeffrey F. Pedersen, Kenneth J. Moore

Department of Agronomy and Horticulture: Faculty Publications

This automated harvest system is based on minimal modification of currently available commercial forage harvesters. Using 6.8 m plots separated by 0.75 m alleys, a single operator can harvest, finely chop, and collect wet plot weights of forage sorghum [Sorghum bicolor (L.) Moench] or pearl millet [Pennisetum glaucum (L.) R. Hr.] in <1 min per plot. Harvested material is deposited in a pile in the center of each plot. Subsamples for moisture and quality analysis can easily and safely be obtained from the pile.

Trees On The Great Plains: Agro-Ecosystem Diversity, Laurie Hodges, Mary Ellen Dix, James R. Brandle, Mark O. Harrell, Robert J. Wright, Ron J. Johnson, Ronald M. Case, Kenneth G. Hubbard, Linda J. Young, Rebecca L. Fitzmaurice, Nathalie J. Sunderman, Michele M. Schoeneberger

Department of Agronomy and Horticulture: Faculty Publications

Agriculture in the Great Plains faces increasing pressure for environmental stewardship and for more economical farming and pest management practices. The concept of sustainable agriculture was developed to address these needs. A sustainable agricultural system is one that consistently enhances environmental quality and the resource bases, provides basic human food and fiber needs, is economically viable, and enhances the quality of life for farmers and society. In the Great Plains, we define agroforestry as the use of trees to help make agricultural production systems more sustainable. The trees function to conserve soil, water, wildlife, and other natural resources. They also …

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 …