bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relative Grazing Preference of Panicum Germplasm from Three Taxa
Authors: Burns J. C. , Timothy D. H. , Mochrie R. D. , Fisher D. S. 
Published: July 2010

AbstractSwitchgrass (Panicum virgatum L.) has shown potential in the humid United States for being a valuable livestock feed. Its contribution would be enhanced, however, by improved quality and palatability. The objective of this study was to determine if relative preference differences existed within germplasm of the Panicum taxa. Twenty‐four accessions representing three Panicum taxa [Panicum amarum Elliot var. amarum, P. amarum var. amarulum (Hitch. and Chase) P.G. Palmer, and P. virgatum L.] were selected from a collection of 92 naturally occurring accessions based on desirable morphological and quality traits. These accessions represented grazing (G), hay (H), and intermediate (I) morphological types. The eight accessions selected to represent each type varied considerably in morphology. The G and I types evaluated in one experiment and the H types in a second, were established in four replicates on a Cecil clay loam (clayey, kaolinitic, thermic Typic Hapludult) soil. Relative preference scores (1 = least preferred and 10 = most preferred) achieved by defoliation with yearling steers (>BOS taurus) showed a consistent preference difference among accessions within types. The strongest differential in palatability was noted within the G types. Entry #16, the most preferred with a mean rating of 8.1, scored 7 to 10 for 45 out of 48 defoliation opportunities. Entry #13, the least preferred with a mean rating of 3.4, scored 1 to 3 for 31 out of 48 opportunities. Preference was not taxon related. Animal defoliation scores (preference) were not highly correlated (r < 0.60) with in vitro dry matter disappearance, considered the best laboratory index of quality, nor with fiber fraction concentrations or agronomic measurements (canopy height and percent stand). Those entries identified with highest preference in each of the G, I, and H types offer potentially valuable germplasm sources for incorporating desirable traits into switchgrass cultivars. The presence of relatively unpalatable naturally occurring germplasm in the Panicum taxa cautions against indiscriminate use of wild types for agronomic improvement of present cultivars.
Genotypic Sensitivity to Drought and Yield Potential of Peanut
Authors: Rao R. C. Nageswara , Williams J. H. , Singh Murari 
Published: July 2010

AbstractIt is important to understand genotype ✕ drought pattern (timing, duration) interactions in peanut (Arachis hypogaea L.) to develop managerial and breeding strategies for improving and stabilizing yields in drought‐prone areas or in environments with limited water resources. This study investigated genotypic sensitivity to various patterns of drought (yield decrease per unit of water deficit) and its relationship with yield potential (yield under nonstressed conditions) in a range of peanut genotypes grown on a medium deep Alfisol at ICRISAT center, Patancheru, A.P. India. In the first experiment, 22 peanut genotypes of similar maturity were evaluted in 12 drought patterns. Single and multiple periods of water deficits were created during various crop growth phases. In the second and third experiments, 60 and 64 genotypes were subjected to droughts during pod set and seed filling stages, respectively. When water deficit occurred during seed filling phase, genotypic yield potential accounted for approximately 90% of the variation in pod yield sensitivity to water deficits. It is unlikely, therefore, that breeders will be able to combine high yield potential with low sensitivity to drought spanning the seed‐filling phase, therefore other improvement strategies are necessary. Pod yield potential accounted for less of the variation in drought sensitivity (15 to 64%) in early and midseason droughts. For these circumstances it may be possible to identify genotypes with both high yield potential and relatively low drought sensitivity.
Design and Evaluation of a Neutron Access Tube Extractor
Authors: Weaver Barry A. , Morgan Jack A. , Whitt Douglas E. 
Published: July 2010

AbstractThe labor and material costs associated with extracting neutron access tubes used for neutron probe soil water determinations can be substantial. Present commercially available access tube extractors are clumsy to use, and can ruin tubes that are being extracted from high clay content soils. To remedy these problems, a new access tube extractor was designed. The extractor slips over the tube to be removed and is secured in place by a threaded collar that provides the initial pressure to hold it in place until the extraction force is applied. As the extractor pulls on the access tube during removal, conically‐tapered jaws exert additional clamping pressure on the tube in greater proportion than the pulling force required to remove the tube. The device easily extracts access tubes against a resistance of up to 13.7 kN (3086 lb.) with no damage to the tubes. Either a mechanical jack or a hydraulic lift on a tractor may be used to extract access tubes.
Foliar Feeding of Cotton: Evaluating Potassium Sources, Potassium Solution Buffering, and Boron
Authors: Howard Donald D. , Gwathmey C. Owen , Sams Carl E. 
Published: July 2010

AbstractFoliar applications of K may be used to supplement soil applications to maximize yields of cotton (Gossypium hirsutum L.). Response to foliar K applications may be improved by choice of K source, buffering the spray solution, or applying K with B. Research was conducted on a Collins silt loam (coarse‐silty, mixed, acid, thermic Aquic Udifluvents) and on a Memphis silt loam (fine‐silty, mixed, active, thermic Typic Hapludalfs) to evaluate KNO3, K2SO4 K2S2O3, and KCl as K sources. A second study evaluated foliar KNO3 and K2SO4 solutions applied unbuffered and buffered to pH 6 and 4 on cotton K nutrition and yield. Foliar K in both studies was applied at 4.1 kg K ha−1 per application. A third study evaluated combinations of soil‐applied and foliar‐applied B and K. Foliar treatments were applied in 93.5 L ha−1 water at early flower or 2 wk after and repeated on a 9‐ to 14‐d interval between the four applications. Yields from the four K sources averaged 10% higher than the untreated check and yields with KNO3 were 4% higher than the other K sources. Buffering two K source solutions to pH 4 resulted in 10% higher yields than the check or unbuffered K solutions. Adding a surfactant (ethoxylated alkyl aryl phosphate esters) to KNO3 resulted in 5% higher yields then the check. Compared with untreated check yields, soil‐applied B at 0.56 kg B ha−1 increased yields by 6%, four foliar applications of 0.11 kg B ha−1 increased yields by 8%, and four foliar applications of 0.11 kg B plus 4.1 kg K ha−1 increased yields by 13%. Foliar K solution buffering and/or the inclusion of foliar B are relatively inexpensive ways of improving yield response. Based on yield increases in this study, these treatments should return 8 to 10 times the product costs.
Effects of Self‐Compatibility on Chance Crossing in Medicago sativa L.1
Authors: Gartner Alvaro , Davis Ralph L. 
Published: July 2010

Nineteen M. sativa clones were evaluated for percent pod set, seeds/pod, seeds/100 flowers tripped and ovules/‐ovary. Pod set was significantly correlated with seeds/pod (r = +0.96). Ovules/ovary was not significantly correlated with either seeds/pod or pod set.Eight of the 19 clones ranging in pod set from 6.9 to 91.2% averaged over 2 self‐pollinations were selected to study the effects of self‐incompatibility on chance crossing without emasculation. These 8 clones were used as females and hand crossed with and without emasculation to 2 different yellow‐flowered clones as males. When the emasculated progenies were compared to the unemasculated progenies, only 1 of the 16 comparisons was significantly different with either the "t" test or X2 of the frequency distribution.The data suggested no relationship between percent self compatibility and selfing when hand crosses were made without emasculation.
Activity of Chloroplasts Isolated from Maize Inbreds and Their F1 Hybrids1
Authors: Miflin B. J. , Hageman R. H. 
Published: July 2010

An investigation into the genetic basis of possible differences in the activity of isloated chloroplasts was conducted with 5 maize inbreds (WF9, R151, R177, R181, and Oh43) and 7 hybrids (WF9 ✕ Oh43, WF9 ✕ Rl51, WF9 ✕ R181, R151 ✕ R177 and reciprocals of the last 3). The ability of the chloroplasts of the various inbreds and hybrids to carry out the Hill, cyclic and noncyclic photophosphorylation recations was demonstrated. These reactions were found to vary in the same manner from genotype to genotype; thus one reaction could serve as an indicator for all three. After establishment of this relationship, the cyclic photophosphorylation reaction was used as the criterion for chloroplast activity.Of the inbreds tested, chloroplasts isolated from R151 had the highest, and those from WF9, the lowest activity. In most instances the chloroplasts from the F1 hybrids had activities intermediate between those of their respective inbred parents. No case of heterosis with respect to activity was observed, although one F1 cross (R151 ✕ R177) was significantly lower in activity than the mean of its parental inbreds. There were no significant differences between the reciprocal crosses.
Selection Value of Phenotypic Attributes in Soybeans1
Authors: Caldwell B. E. , Weber C. R. , Byth D. E. 
Published: July 2010

The average selection index was used to evaluate the contribution of various phenotypic attributes in selection gain for yield, protein, and oil — individually, and in various combinations.Selection gain for yield was maximum hen all attributes were used and selection was for yield alone. Deleting any attribute other than yield did not affect selection gain.Maximum gain for protein and oil (pounds per acre) was obtained from the indices constructed to advance yield; yield and protein; yield and oil; and yield, protein, and oil. Maximum change in percent protein and percent oil was obtained by selecting for these attributes individually, but the total production of oil and protein expressed as pounds per acre was decreased.
Thrips Injury to Upland Cotton (Gossypium hirsutum L.) Varieties1
Authors: Hawkins B. S. , Peacock H. A. , Steele T. E. 
Published: July 2010

The purpose of this study was to obtain thrips injury data on Upland cotton varieties currently planted in the Southeast and to associate the effects of the injury with yield. Yield and thrips injury data were obtained on 16 varieties at Experiment, Georgia, in 1960, and thrips injury data on 12 varieties at Jackson, Georgia, in 1961. In 1960, a highly significant (P=.01) negative correlation (0.52) between yield and injury‐index was obtained. The linear regression showed a decrease of 392 pounds seed cotton per acre for each unit increase in thrips injury‐index. A highly significant correlation (0.73) between the 1960 and 1961 thrips injury‐index data was obtained.The order of rank of thrips resistance for varieties tested was ‘Empire,’ ‘DeKalb 108,’ ‘Dixie King,’ ‘Rex,’ ‘Auburn 56,’ ‘Plains,’ ‘Stoneville 7,’ ‘Coker 100A,’ and ‘Deltapine 15.’Empire and varieties having Empire in their genetic background exhibited more resistance to thrips injury than did other varieties.The value of Empire genes in a cotton breeding program for thrips resistance is pointed out.
Inheritance of Resistance to Bacterial Blight (Pseudomonas glycinea Coerper) in Soybeans ( Glycine max L. )1
Authors: Mukherjee Debabrata , Lambert J. W. , Cooper R. L. , Kennedy B. W. 
Published: July 2010

Parents and F3 families of seven soybean crosses were studied for reaction to the bacterial blight organism, Pseudomonas glycinea Coerper. Six of the crosses were tested in both the field and the greenhouse to a single colony isolate of the organism obtained at St. Paul, Minnesota, and four were tested under similar conditions to an isolate from Morris, Minnesota.The two isolates gave distinctly different reactions on the populations studied, indicating the presence of pathogenic races. Also, varietal reactions varied somewhat with the environments used in testing.Resistance to the St. Paul isolate, designated race 1, was attributed to a single dominant gene, possessed by the varieties ‘Norchief,’ ‘Harosoy,’ and P.I. 132,207. The proposed symbol for this gene is Rpg1. The inheritance of resistance to the Morris isolate, race 2, appeared to involve more than one gene. Delineation of detail, however, must await further study.
Respiration of Leaves in Light and Darkness1
Authors: Moss Dale N. 
Published: July 2010

Leaves of six species were placed in a plexiglass chamber. CO2‐free air was admitted to the chamber and the CO2 concentration in the egress air determined in both light and darkness.The rate of CO2 evolution from the leaves of five species decreased when they were first lighted, passed through a minimum (“dip”), then increased to a higher rate than the original dark rate (“illumination plateau”). Upon darkening, the rate of CO2 evolution rapidly increased to a rate higher than the illumination plateau (“dark surge”), then gradually decayed to the original steady state dark respiration rate. Thus, light enhances a reaction which leads to additional CO2 evolution above normal dark respiration for many species when the CO2 concentration in the atmosphere is low.Maize did not have this light‐stimulated CO2 evolution.
Evaluation of Synthetic Varieties of Maize for Yield1
Authors: Hallauer Arnel R. , Eberhart S. A. 
Published: July 2010

Nine maize synthetic varieties were crossed in a diallel series and evaluated for yield performance per se and in crosses. The synthetic varieties and crosses were grown at 3 locations in each of 2 years, and, on the basis of the combined analysis over locations and years, the 6 experiments were considered as representative of 6 random enviromnents.A nonorthogonal partition of the entry sum of squares obtained estimates of average, variety, and specific heterosis. F‐tests indicated that average heterosis was significant at the 1% level in 5 of the 6 experiments and for the combined analysis over experiments. Of the total sum of squares due to heterosis, 73% was attributed to average heterosis. Variety heterosis was significant in the combined analysis, but the proportion of the heterosis sum of squares due to variety heterosis was only 11%. Specific heterosis was nonsignificant.Estimated and observed heterosis were obtained for each of the synthetic varieties. Average observed heterosis on the basis of constant, mid‐parent, and high parent was 12, 11, and 6%, respectively. Estimated heterosis, obtained as average heterosis (h̄) plus variety heterosis (hj) for each variety, ranged from 6% for C.B. Syn. #1 to 14% for Ind. Syn. A. Average estimated heterosis (h̄) was 11%.Estimates of synthetic variety effects (vj), obtained for each variety by least squares analysis, included the performance of a variety per se and in variety crosses. The estimates of variety effects ranged from −5.7 for Ind. Syn. A to 5.2 for L.E. Syn., and formed three distinct groups. The relatively large, positive vj group included C.B. Syn. #3, S.S. Syn., and L.E. Syn. Pa. Int. Syn. had essentially zero variety effects. C.B. Syn. #1 and #2 and Ind. Syn. A. and B had relatively large, negative effects.The correlation between the predicted (Ŷj = μv + vj) and observed yield performance of the nine synthetic varieties was significant (r = .92**), as was the correlation between predicted [Cjj = μv + 1/2 (vj + vj) + h̄] and observed variety cross performance (r = .74**).
A Serological Study of Medicago sativa L. Varieties1
Authors: Esposito V. M. , Ulrich V. , Burrell R. G. 
Published: July 2010

Certified seed of Medicago sativa L. ‘Atlantic,’ ‘Cayuga,’ ‘Culver,’ ‘DuPuits,’ ‘Haymor,’ ‘Narragansett,’ ‘Orchies,’ ‘Vernal,’ and ‘Warrior’ were utilized in this study to investigate the possibility of employing serological methods for the identification of M. sativa varieties.Specific serological tests appear to be sufficiently definite for the identification of seed protein phenotypes. The results indicate that it is possible to identify nine varieties and to distinguish one from another. At this time, the basis of this intervarietal variation cannot be entirely ascribed to either genetic or environmental components, since both have been shown to influence protein content in other plants and animals; thus, a combination of genetic and environmental components may also be responsible for the diversifications displayed by Medicago sativa varieties. This method of seed identification, if proven to hold over the entire spectra of varietal seed, will offer a relatively fast and inexpensive means for identifying seed. The extreme economy of materials and time is of real advantage in any analysis, but especially so in this type of testing for varietal purity.
Preliminary Groupings of Plant Introductions of Alfalfa (Medicago sativa, L.) for Heterosis Studies1
Authors: Dudley John W. , Davis R. L. 
Published: July 2010

In preparation for a study of between and within group crosses as sources of heterotic combinations we classified 144 plant introductions into eight groups. Three replications of five plant plots of each introduction were grown from original seed in North Carolina and Indiana and evaluated for a number of characters. Based on origin, winter‐hardiness, leafhopper yellowing score, growth index in North Carolina and growth index in Indiana we classified 7 introductions of M. sativa var. gaetula as gaetula; 5 introductions as gaetula‐like; 50 as Chilean; 20 as Chilean‐like; 90 as Flemish; 19 as Afghan; 9 as Afghan‐like; and 14 as non‐hardy. When the groups with the suffix “‐like” were combined with groups having the same name, five major groups were formed. Countries considered to be in the center of origin of alfalfa contributed entries to all but the Chilean major groups.Ways of using the proposed groups for increased efficiency in the search for heterotic combinations and for more precise preliminary classification of new plant introductions are proposed.
Heterosis in Oats1
Authors: Petr F. C. , Frey K. J. 
Published: July 2010

Several attributes were studied in the F1 and F2 generations of oat crosses grown in space‐planted nurseries in 1955. The F1's of 15 oat crosses and their parents were sown in a randomized complete‐block design with 3 replicates. The plots, spaced 30 cm apart, each contained 5 competitive plants (sown 30 cm apart) upon which measurements were taken for heading date, number of panicles per plant, number of spikelets per primary panicle, plant height and grain yield. In 1957, the F2 and parent plants were spaced 10 cm apart and measured for the same attributes as the F1's.The grain yields of each F1 exceeded the higher yielding parent. Grain yields in the F1 ranged from 101 to 130% of the higher parent with a mean for all crosses of 112%. The parent, Victory, produced consistently low yielding crosses. The yields of some crosses in the F2 exceeded the higher yielding parent and the mean F2 yields, relative to the higher yielding parent, was 99%. For one cross, the relative yield of the F2 was 120% of the higher parent.Positive heterosis was expressed for number of panicles per plant, and for each cross the heading date of the F1 was earlier than the midparent. Except in a few crosses, plant height and number of spikelets per panicle in the F1's and F2's closely approximated the midparents.The correlations of midparental values with Ft and F2 cross means for number of spikelets per panicle, plant height and heading date were all highly significant and above 0.89. For yield, similar correlations were 0.60.
Thermal Stability of Malic Dehydrogenase from Heat‐Hardened Phaseolus acutifolius ‘Tepary Buff’1
Authors: Kinbacher E. J. , Sullivan Charles Y. , Knull H. R. 
Published: July 2010

Malic dehydrogenase was extracted from high temperature hardened and unhardened leaves of 4‐ to 5‐weekold, greenhouse grown, 'Tepary Buff beans. Purified fractions of malic dehydrogenase were exposed to temperatures that ranged from 30 to 62 C for 15 minutes. The specific activity of the enzyme was markedly reduced by temperatures above 50 C. Malic dehydrogenase extracted from hardened plants was significantly more thermostable than the extracts from unhardened tissue. The extracts from hardened tissue also exhibited a significantly higher specific activity over a wider pH range than the extracts from unhardened tissue.The results from heat tolerance tests with intact leaf discs correlated well with the reduction in activity of the extracted malic dehydrogenase. These data indicate that enzyme denaturation is an important factor in heat tolerance. One way that high temperature hardening may increase the heat tolerance of higher plants is by increasing the thermal stability of enzymes.
Seedling Growth of a Hypogeal Legume, Vicia dasycarpa, in Relation to Seed Weight1
Authors: Williams William A. 
Published: July 2010

Increasing seed weight resulted in increased seedling dry weight and increased leaf area but did not affect the relative growth rate of Vicia dasycarpa. Varying the depth of planting did not significantly affect seedling dry weight or leaf area during time intervals measured from emergence. The inference was drawn that cotyledonary reserves do not have a major influence on the size of the photosynthetic organs of this hypogeal species.Since these results are similar to those reported by others for epigeal legumes, it is suggested that the positioning of the cotyledons in either the aerial or the subterranean enviroment has no marked effect on the growth in dry weight or leaf area of forage legumes.
Estimates of Genetic and Environmental Variability in Barley1
Authors: Rasmusson D. C. , Glass R. L. 
Published: July 2010

Two populations of F3 derived lines of barley were studied in the F5, F6, and F7 generations. Variance components and heritability were estimated and genetic advance predicted for each of seven traits. The genotype ✕ environment interaction components of variance were smaller than the genotype and plot error components for all traits, except percent nitrogen in one population. Estimates of the second order interaction, σ2gly, were generally larger than those of the first order interactions, σ2gl, and σ3gy Heritability estimates were highest for heading date and diastatic power, intermediate for kernel plumpness, height, and extract, and lowest for yield, for percent nitrogen, heritability was relatively high in population 1 and low in population 2.Under the conditions of this study, a single trial with 3 replicates gave sufficient information for each of the seven traits to provide favorable odds of including the elite lines if the top 25% were selected.Data from triplicate determinations of percent nitrogen, percent extract, and diastatic power indicated that replication in our laboratory testing is unnecessary.
Development of Single‐Cross Hybrids from Two‐Eared Maize Populations1
Authors: Hallauer Arnel R. 
Published: July 2010

A procedure for the development of single‐cross hybrids from two‐eared maize populations was outlined. Selections are made among individual plant crosses in each generation of inbreeding. Selection among individual plant genotypes is continued until the plants are relatively homozygous, at which time one should have a group of selected single‐cross hybrids that have been tested at each level of inbreeding. The procedure is designed to maximize selection for nonadditive genetic effects.Two generations of individual plant selection for yield have been completed. A mild selection intensity (approximately 36%) was used in each generation. Relative to six common hybrid checks, selection was effective in the first generation.