bluuebunny/crossref_metadata_2025 huggingface dataset:
Yield and Stability of Yield of Barley Populations1
Authors: Rasmusson D. C.
Published: July 2010

Yield and stability of yield were studied in two sets of barley (Hordeum vulgare L.) populations. Each set consisted of three distinct levels of genetic diversity: homogeneous varieties, simple mechanical mixtures, and complex mixtures (bulk hybrids). Both sets were grown in rod‐row trials at two locations for 5 years. As a group, the simple mixtures were slightly higher yielding than varieties or complex mixtures. Varieties yielded more than complex mixtures in set 1, but not in set 2. The highest yielding entry in set 1 was Traill, and in set 2 the high entries were Liberty and a mixture involving Liberty. In general, the mean of component lines and the mean of parental varieties provided a good estimate of the yields of the simple and complex mixtures, respectively.

Varieties and simple mixtures were judged to be similar in stability and both were somewhat less stable than complex mixtures. However, differences among entries within each of the diversity groups were relatively large and preclude definite conclusions regarding the relationship between level of genetic diversity and stability.
Relative Importance of Stem and Root Genotype in Determining Differences in Percent Protein and Oil of Soybean Seed1
Authors: Caldwell B. E. , Hanson W. D.
Published: July 2010

Reciprocal grafts were made among soybean genotypes varying in protein and oil percentage of the seed to determine the importance of root and stem in protein and oil accumulation. Results from two years indicate that the control sites for protein and oil synthesis are located in the aboveground portion of the plant. Differences in root genotype did not affect the protein and oil content of the seed.
Photosynthesis of Alfalfa Leaves as Influenced by Age and Environment1
Authors: Pearce R. B. , Brown R. H. , Blaser R. E.
Published: July 2010

Net photosynthesis (Pn) was measured on alfalfa, Medicago saliva L., leaves of different ages from a growth chamber and from normal and thinned field plots. Pn declined with leaf age after full expansion. The mean Pn for young leaves was 52 mg CO2 dm$#x2212;2 hr−1 when grown in the field and 35 mg CO2 dm−2 hr−1 when grown in the growth chamber. However, when photosynthesis was expressed on a dry weight basis this difference no longer existed. Leaves remained alive more than 60 days in the growth chamber but lived only half as long in the field. Thinning field plots delayed senescence.

Specific leaf weight (SLW = leaf dry weight/leaf area) was influenced by the light intensity and its change within the environment. SLW for young leaves was 5 mg cm2 when grown in the field and 3 mg cm−2 when grown in the growth chamber. SLW increased with leaf age in the growth chamber but decreased with leaf age in unthinned field plots.
Heritability of Cold Hardness in Flax (Linum usitatissinum L.)1
Authors: Omran Abbas O. , Atkins I. M. , Gilmore E. C.
Published: July 2010

Two hundred F2 families from each of two crosses, ‘DeOro’ ✕ ‘Dillman’ and ‘Linore’ ✕ ‘B‐5128,’ were studied in the F3 and F4 generations for reaction to low temperatures at two locations. Each generation was grown in a different year. During the first season, the plants were subjected to severe low temperatures, as low as —23C (—9F) at Chillicothe, Texas, but snow cover protected the plants so that cold injury was mild to moderate. The second season, temperatures dropped as low as —17C (2F) at Denton, Texas, without snow cover, and cold injury was moderate to severe. A cold hardiness index (CHI) was calculated from the degree of injury and the percentage of plants injured in each row. Dominance deviations could not be detected in the F3 or F4 generations. Due to the seasonal differences, genetic variances of families in the F4 were often higher than variances in the F3. Heritability estimates of CHI calculated from components of variance were .35 in the F3 and .59 in the F4 of the second cross. Heritability was estimated also by the regression of F4 on F3 which was .75 ± .15 for the first cross, and .56 ± .04 for the second cross. The regression estimates were unbiased by genotype‐ year and genotype‐location interactions. The expected genetic advance in F4, by selecting the top 5% in F3, was 12 CHI units in both crosses. The observed gain in F4 was the same as predicted in the first cross, but it was much less than expected in the second cross. Estimates of genetic variance in the F4 increased as the season progressed indicating that selection near the end of the season would be much more efficient than selection after the first period of freezing. Growth habit appeared to be closely associated with cold hardiness. Cold hardy lines all formed a rosette of branches during the winter contrasted to the upright growth of the cold sensitive lines
Inter‐Genotypic Competition in Soybeans II. Predicted and Observed Performance of Multiline Mixtures1
Authors: Brim C. A. , Schutz W. M.
Published: July 2010

AH of the 10 possible two‐ and three‐line mixtures of four soybean (Glycine max L. Merrill) lines exceeded the yield of component means. Seven of the mixtures were superior, although not significantly, to the best component of the respective mixtures. Mixtures were seldom more efficient (seed yield per unit of straw) than expected on the basis of component mean performance. The increased productivity was closely associated with the magnitude of net competitive effects. A model which utilized estimates of within‐ and between‐row competition effects for predicting the yield of mixtures was extremely reliable. The sum of the deviations of predicted from observed was essentially zero for the yield of two‐ and threeline mixtures. This result indicated that the deviations were a result of random error rather than bias in the model. Competitive effects obtained in hill plots appeared to be reliable estimates of within‐row competition despite the disparity in plant densities for the two planting configurations. Effects due to between‐row competition contributed very little to the agreement between predicted and observed performance. The results suggest that a nine‐hill plot is an effective field design for determining pair‐wise competitive effects in soybeans, and that it may be useful for determining these effects in other crop species.
Genetic Male Sterility in Barley. II. Available Spring and Winter Stocks>1
Authors: Hockett E. A. , Eslick R. F. , Reid D. A. , Wiebe G. A.
Published: July 2010

Genetic male sterile stocks of 101 spring and 115 winter barley (Hordeum vulgate and Hordenm distichum) stocks are available on order from Bozeman, Mont., and Beltsville, Md., respectively. We described a system of temporary symbols for designation of new mutants until allelism tests are completed.
Developing Alfalfa Resistant to Alfalfa Weevil Oviposition1
Authors: Busbice T. H. , Campbell W. V. , Rawlings J. O. , Barnes D. K. , Ratcliffe R. H. , Hanson C. H.
Published: July 2010

Alfalfa, Medicago sativa L., populations differed significantly in suceptibility to oviposition by the alfalfa weevil Hypera postica (Gyllenhal) in laboratory preference tests. Factors responsible for oviposition preference were strongly influenced by changes in environment. Low oviposition was associated with small stem diameter. Selection for resistance to oviposition appeared to be effective. Methods of testing alfalfa for resistance to oviposition were described.
Handling of Oat Chromosomes1
Authors: Sun Nai‐Chau , Sadanaga K.
Published: July 2010

A procedure and schedule for germinating oat seeds and preparing root tip chromosomes is presented. Control of environmental factors that affect germination and growth produced root tips with many metaphase cells. The main features of the procedure are: 1) use of plastic petri dishes and filter paper, 2) 2.65 ml distilled water per petri dish with seven seeds, 3) cold treatment (0‐4 C) of seeds in petri dish for 48 hours, 4) incubation of seeds in 27 C incubator for 44 hours, and 5) pretreatment of root tips in 0.002 M 8‐hydroxyquinoIine at 12‐13 C for 3.67 to 4 hours. Root tips are fixed in Farmer's fluid and kept in a 37 C oven for 48 hours before hydrolysis and staining with Feulgen.
Recurrent Selection in Self‐Pollinated Crops without Extensive Crossing
Authors: Compton W. A.
Published: July 2010

A procedure is presented which will allow breeders of self‐pollinated crops to conduct selection recurrently in a population without large numbers of pollinations. The procedure is based on the use of the ‘single‐seed descent’ method, but with each derived line being a descendent of a different F1 rather than from different F2 plants within an F1.
Epistasis in Maize (Zea mays L.) I. F1 Hybrids and Their S1 Progeny1
Authors: Stuber C. W. , Moll R. H.
Published: July 2010

Interpopulation single crosses (F1's) and the progenies from one generation of selfing (S1's) arising from 128 unselected lines (64 from the maize variety ‘Jarvis Golden Prolific’ and 64 from the variety ‘Indian Chief’) were evaluated to determine the importance of epistasis. Significant epistatic effects were detected in some specific sets of crosses. However, the amount of the total variability that could be attributed to epistasis was, on the average, less than 10%. These and earlier results suggest that epistasis may be important in unique genetic combinations but these combinations occur either too infrequently or with such limited effect that they are not detectable in random mating equilibrium populations.
Response of Flax to Postemergence Herbicides1
Authors: Nalewaja John D. , Bothun R. E.
Published: July 2010

A flax (Linum usitatissimum L.) variety, ‘Newbud,’ known to be susceptible to 2‐methyl‐4‐chlorophenoxyacetic acid (MCPA) and a variety, ‘Bolley,’ known to be resistant to MCPA were treated for response to 2‐methoxyo 3,6‐dichlorobenzoic acid (dicamba), 4‐amino‐3,5,6‐trichloropicolinic acid (picloram), 3,5‐dibromo‐4‐hydroxybenzonitrile (bromoxynil), and 2,2‐dichloropropionic acid (dalapon) under field conditions at Fargo, N. D. Although all herbicides reduced the flaxseed yield of Newbud more than that of Bolley, the greatest difference between the varieties occurred with MCPA. Injury to both varieties was influenced by the herbicide and application rate. The herbicides delayed flowering and maturity dates, generally reduced seed weight and germination, and reduced or did not affect oil percentage and iodine value.
Genetic Variability in In Vitro Dry Matter Digestibility of Fall‐Saved Reed Canarygrass, Phalaris arundinacea L.1
Authors: Carlson I. T. , Asay K. H. , Wedin W. F. , Vetter R. L.
Published: July 2010

Variation in percentage of in vitro digestible dry matter (IVDDM) in fall‐saved forage from 20 reed canarygrass (Phalaris arundinacea L.) clones and their topcross progenies was studied under two clipping managements. Significant differences were found among parent clones in all tests and among their progenies (at .01 and .10 probability levels) in two of three tests. Broad‐sense heritabilities ranged from 51 to 80% among clonal means and from 6 to 66% among progeny means. Significant parent‐progeny correlations also indicated the presence of heritable variation in IVDDM. The correlation between parent and progeny means over years and clipping managements was .69. Average percentage IVDDM decreased from 65 to 55% with an increase from two to three months in length of regrowth period in 1964. The interaction of clones or progenies with length of regrowth period was not significant. A highly significant clone ✕ year interaction indicated that selection should be based oil more than one year's results.

Correlations between IVDDM and yield of dry matter, percentage dry matter, percentage crude protein, and palatability score were low and not significant. All correlations with yield were negative and those with percentage crude protein were positive.
Behavior, Transmission, and Morphological Effects of Accessory Chromosomes in Panicum coloratum L.1
Authors: Burson B. L. , Bashaw E. C.
Published: July 2010

Accessory chromosomes in Panicum coloratum L. were approximately half the size of a univalent and resembled the normal chromosomes in general appearance, stain reaction, and typical distribution at the metaphase plate. Accessory chromosomes did not pair with each other but were frequently associated with members of the normal complement. Occasionally the accessories underwent precocious and continued division during meiosis I, resulting in a large accumulation by anaphase I. Accessory chromosomes were transmitted in limited numbers through male and female gametes. Few progeny received more than one accessory and none had more than two. The results suggested some type of gametic selection favoring gametes with few or no accessories. Accessory chromosomes had no appreciable influence on fertility or morphology. Apparently, they are either inert or sub‐inert, or they were not present in sufficient quantity to exert a major influence.
Microsporogenesis and Embryogenesis in Pennisetum flaccidum Griseb1
Authors: Chatterji Asoke K. , Timothy D. H.
Published: July 2010

The chromosome number, 2n = 36, of the Himalayan forage grass Pennisetum flaccidum Griseb. was reported for the first time. Chromosomes formed 12 to 14 bivalents and two to three quadrivalents at diakinesis. The species was considered to be tetraploid with x = 9 as the basic number. Meiosis was generally regular with some early disjunction, laggards, and micronuclei. Pollen sterility was 22.8%. Embryo development was aposporous. Normal megaspores degenerated following formation of several four‐nucleate nucellar sacs. Ultimately, one nucellar embryo sac survived and gave rise to a single embryo. Endosperm development and division was presumed to stimulate embryo differentiation and development.
Relative Performance of Normal and Modified Protein (Opaque‐2) Maize Hybrids1
Authors: Lambert R. J. , Alexander D. E. , Dudley J. W.
Published: July 2010

Performance of early backcross generation opaque‐2 and normal three‐way maize (Zea mays L.) hybrids was compared at two locations. The opaque‐2 hybrids were lower in grain yield and weight per 100 kernels but higher in grain moisture, cracked kernels, and total oil content. Differences for whole kernel lysine values were found for the comparisons opaque‐2 vs. normal between locations and among opaque‐2 hybrids.
Quantitative Genetic Estimates for Brown Spot Resistance in Corn1
Authors: Thompson D. L.
Published: July 2010

Fifteen populations of corn (Zea mays L.), each with six generations (P1, P2, F1, F2, B1, and B2), were inoculated with Physoderma maydis Miyabe and rated for brown spot symptoms. Parents for each population were a susceptible inbred and an isogenic resistant line. Pooled additive effects were the most important and were significant in all 15 populations. Pooled dominance effects were significant for five populations and epistasis for four populations.
Lysine Content of Opaque‐2 Maize Kernels having Different Phenotypes1
Authors: Paez A. V. , Helm J. L. , Zuber M. S.
Published: July 2010

Classification of homozygous opaque‐2 kernels of maize (Zea mays L.) in segregating progenies has been done on the assumption that the phenotype of these kernels is completely opaque. Certain lines in the S2 generation derived from opaque appearing S1 parents produced two phenotypic classes: (1) entirely opaque, and (2) modified opaque‐1/2 opaque : 1/2 translucent.

Lysine content of 1/2 : 1/2 kernels was not different from opaque kernels on the same ear. Likewise the lysine content of translucent and opaque fractions of the endosperm from the 1/2 : 1/2 class was not different.

High lysine corn with a high test weight and other desirable kernel characteristics may be produced by taking advantage of this opaque‐2 phenotypic expression.
Some Photo‐Dependent Responses in Pisum. I. Physiological Behavior1
Authors: Marx G. A.
Published: July 2010

Two new (G‐ and G2) and two previously known (K and I) photo‐dependent response types of Pisum were compared in a phytotron after having been distinguished earlier under greenhouse conditions. In the first of two experiments the four response types were exposed to three photoperiods, 9, 12, and 15 hours, at a constant growth temperature of 17 C. Plants of the K‐type exhibited a quantitative increase in nodes and days to flower in response to decreasing length of photoperiod, whereas I‐type plants were day‐neutral or insensitive to length of photoperiod. Flowering in G‐type plants was either completely inhibited or sharply delayed at all three photoperiods. G2‐type plants, like the I‐type, were insensitive to daylength with respect to nodes to flower but, unlike the I‐type, they exhibited a protracted period of apical growth, again at all photoperiods. The behavior of the G‐ and G2‐types at the 15 hour photoperiod was atypical since under long day conditions in the field or greenhouse these types ordinarily do not show a response.

The response types were not discriminated under the conditions of a second experiment which included two levels of light intensity and two levels of growth temperature and a long (18‐hour) photoperiod. Growth temperature had no influence on the number of nodes to flower but it had a marked influence on the number of days to flower.
Fiber Elongation Rates in Five Varieties of Cotton (Gossypium hirsutum L.) as Influenced by Night Temperature1
Authors: Gipson J. R. , Ray L. L.
Published: July 2010

Five cotton varieties were grown in the field under four different night temperature regimes (10, 15, 20, and 25 C). The influence of temperature on the rate and extent of fiber elongation was studied. Temperatures below 20 C reduced fiber length; and generally, the reduction was greater in varieties having the longer fibers. Lowering night temperature increased the fiber elongation period and slowed the fiber growth rate. The temperature coefficients of elongation indicated the rate of elongation for all varieties was extremely temperature‐sensitive up to 15 days age. Beyond 15 days age, however, the coefficlents of elongation quickly approached one, indicating temperature independence.
Laboratory Selection of Alfalfa for Resistance to Anthracnose, Colletotrichum trifolii1
Authors: Ostazeski S. A. , Barnes D. K. , Hanson C. H.
Published: July 2010

This paper describes a highly efficient procedure for screening alfalfa populations for resistance to anthracnose, Colletotrichum trifolii. Seedlings 2, 4, and 6 weeks old were inoculated with C. trifolii by spraying plants in a moist chamber with a suspension of conidia and comminuted mycelia. Plants differed for types of lesions and degree of resistance. Less than 556 of seedlings selected as resistant were found to be escapes when retested as mature plants. Alfalfa varieties developed by field recurrent selection in southern areas where anthracnose is endemic were significantly more resistant than northern varieties. All varieties tested had at least a few plants with some degree of anthracnose resistance. In an experimental synthetic, one cycle of selection increased the frequency of highly resistant plants from 18 to 7556. Development of an anthracnose‐resistant alfalfa is expected to prolong stand longevity and increase alfalfa productivity in the Middle Atlantic and Southeastern United States.
Variation and Covariation of Agronomic Traits in Durum Wheat1
Authors: Lebsock K. L. , Amaya Arnoldo
Published: July 2010

Experience has shown that large kernels and high test weight have been associated in inheritance with tallness and lateness in the breeding of durum wheat, Triticum durum Desf. To determine if these unfavorable associations were genetic, F2, F3, and F4 generations of four crosses were studied in the field. Phenotypic and genotypic correlation coefficients did show that selection for short, early‐maturing plants might result in lines with lower kernel weight and test weight in some segregating populations. However, the selection of short, early, large seeded lines appeared to be possible. Significant positive correlations occurred for kernel weight with grain yield and test weight and grain yield with test weight.

Average heritabilities for kernel weight, test weight, and number of kernels per spike were 72, 67, and 69% respectively. Expected and actual gains due to selection agreed well for maturity, height, kernel weight, test weight, and number of kernels per spike.

The data showed that kernel weight might be used effectively for rapid indirect selection of high test weight and, possibly, higher yield in large F2 and F3 populations.
In Vitro Germination of Kentucky Bluegrass Pollen (Poa Pratensis L. ‘Newport’)1
Authors: Maun M. Anwar , Teare I. D. , Canode C. L.
Published: July 2010

The germination of Kentucky bluegrass pollen, Poa pratensis L., ‘Newport’, was studied in artificial cultures containing variable concentrations of sucrose, calcium nitrate and boric acid. The germinations were made in an incubator in the dark at 21 ± 1 C. Good germination and growth were obtained with 13% sucrose, 0.75% agar agar, and 10 ppm of calcium nitrate and 5 ppm of boric acid.
Temperature Effects on the Development of Hair Groups and Stalk Coloration in Saccharum L.1
Authors: Bull T. A.
Published: July 2010

High temperatures (34 C) completely repress the development of two of three hair groups investigated and markedly reduce the degree of stalk coloration in Saccharum. Hair group 67, previously considered to occur only in S. robustum Brandes and Jeswiet ex Grassl, was induced in several clones of S. spontaneum L. and S. officinarum L. grown at low temperatures (16 C). Low temperature induction of hair groups was simulated in a commercial sugarcane variety grown at high temperatures by treatment with benzyladenine.

Although unreliable for taxonomic purposes hair group induction may prove useful for evolutionary studies within Saccharum.
Use of Cytoplasmic Male Sterility, Compared to Hand Emasculation, and Translocations for Chromosome Analysis in Sorghum vulgare Pers1
Authors: Papathanasiou G. A. , Lessman K. J.
Published: July 2010

Results obtained after use of a cytoplasmic male‐sterile restorer gene system in testcrosses with translocations for chromosome analysis were compared with those from testcrosses after hand emasculation. The use of male‐sterile cytoplasm was relatively easy and less time consuming, thus allowing production of large numbers of progeny and an accurate estimate of linkage intensity.

This variation in methodology may have application with other self‐pollinated crops where cytoplasmic male‐sterile restorer gene systems and transloeation stocks exist.

Using this scheme the linkage groups T231(13.06±l.1)‐ Dd and T396(5.0±0.6)‐Yy were found, and the possible location of these markers was discussed. The establishment of the chromosome complement and male sterility of MSCK60 as a standard for chromosome analyses in sorghum was proposed.
Effect of Tassel Removal on Grain Yield of Corn (Zea mays L.)1
Authors: Hunter R. B. , Daynard T. B. , Hume D. J. , Tanner J. W. , Curtis J. D. , Kannenberg L. W.
Published: July 2010

In three of five cases, tassel removal from corn (Zea mays L.) at or near tassel emergence increased grain yields. The increase was larger and more consistent at higher populations. When leaf tissue was removed with the tassel, yields were decreased, although this effect was smaller at higher populations. A large portion of the yield response from detasseling resulted from the elimination of tassel light interception. Simulated small tassel size (produced by tassel side branch removal) resulted in increased grain yields.
Factors Influencing Persistence and Depletion in Buried Seed Populations. I. A Model for Analysis of Parameters of Buried Seed Persistence and Depletion.1
Authors: Schafer D. E. , Chilcote D. O.
Published: July 2010

A model describing the parameters of persistence and depletion within buried seed populations is presented. This model provides a conceptual framework for problems involving buried seed persistence and depletion which are often encountered in weed control and crop seed certification. Them model may also find use in studies where the ecology, physiology and genetics of buried seed persistence and depletion are being evaluated.
Alfalfa Yield Components in Solid Seedings1
Authors: Miller D. A. , Shrivastava J. P. , Jackobs J. A.
Published: July 2010

Prediction of yield and two components of yield of alfalfa, (Medicago saliva L.), in solid‐seeded stands at Urbana, Ill. revealed the following: (1) On the basis of five independent variables studied, spring crown area of the plant (X1), dry weight of the previous harvest (X2), distance of the nearest neighbor (X3), potential area of the plant (X4), and number of steins of the nearest neighbor (X5), one could predict more reliably the total dry matter yield of a plant (Y1), and its number of stems (Y2) than the weight per stem (Y3). (2) The effect of the independent variables was not of the same magnitude for different harvests of a variety nor for different varieties. (3) Crown area and yield of the previous harvest were the most important variables influencing the yield and two components of yield. (4) Potential area of the plant was not an important predictor of yield in individual harvests, but was significant when considered on a seasonal basis. (5) The number of stems of the nearest neighbor was a better predictor of plant yield and its components than distance of this neighbor.
Analysis of a Negative Response to Selection for High Yield in Winter Barley, Hordeum vulgare L.1
Authors: Nickell C. D. , Grafius J. E.
Published: July 2010

A winter barley population composed of 387 lines in the F5 generation was grown in 1966 from which 136 strains were selected with a mean yield of 123.3% of the cheek variety. In the following generation the same 136 selected strains were grown in 1967 producing a mean yield of 90.7% of the same check variety.

The “apparent” negative response to selection was analyzed with respect to yield components: heads per unit area (X), kernels per head (Y), and kernel weight (Z). Twice as many heads were produced in 1967 as 1966, but fewer kernels per head and smaller kernels were produced in 1967 than in 1966. The inverse relationship between the components is explained by “component compensation.”

The inter‐annual correlations for the yield components were slightly negative. The overriding effect of the environment on the genetic processes and extreme compensation between yield components were postulated to cause the low inter‐annual correlations.

Evidence was presented that optima exist in any given gene pool for yield components and their inter‐relationship in order that maximumy ields can be reached for a given environment. Selection in one environment for these optima does not mean necessarily that under another environment the same production performance will be obtained. This in turn suggests that the plant breeder should consider the joint manipulation of genotype and environment to get the maximumg ain from a given gene pool. He must either do this or accept compromises which fail to achieve maximum results.
Boron Deficiency and Amino Acid and Protein Contents of Peanut Leaves1
Authors: Shiralipour Aziz , Harris Henry C. , West S. H.
Published: July 2010

Total nitrogen, total protein, and individual free amino acids were compared in peanut leaves (Arachis hypogaea L.) grown with two levels of boron. The boron‐deficient treatment decreased the fresh and dry weight of the plants compared to that of the boron‐sufficient treatment. On a per cell (rag DNA) basis, however, total amino acids and nitrogen increased, but protein remained unchanged in boron‐deficient leaves. The increase in amino acids was restricted to arginine, aspartate, glutamate, proline and serine. It was concluded that the increase in level of amino acids can be partially or perhaps completely accounted for by the excess nitrogen found in the leaves of the boron deficient plants.
Phenotypic and Genotypic Variation and Covariation of Some Quantitative Turf Characters of Poa pratensis L.1
Authors: Berry C. D. , Glover D. V. , Daniel W. H.
Published: July 2010

Fifteen seed sources (accessions) of Kentucky bluegrass (Poa pratensis L.) constituting a rather broad based, random sample of bluegrass turf types, were grown to study several turf characteristics. Individual plants were transplanted into pots on two dates and ultimately space planted to the field.

Measurements on six characteristics were made: (1) leaf width, (2) growth habit, (3) leaf angle, (4) rust resistance, (5) total spread and (6) sod spread. All characters were found to be highly significant for the accessions genetic mean square.

Broad sense heritability and genetic coefficients of variation were calculated as estimates of the genetic variability among these accessions. Phenotypic and genotypic correlation coefficients were also computed, and indicated that simultaneous selection may be possible for important characters in the development of superior turf types.
Sesame Variety Comparisons and Breeding Objectives in the Sandy Soils of the Central Sudan1
Authors: Gerakis P. A. , Tsangarakis C. Z.
Published: July 2010

Nine introduced and the predominant local land variety of sesame (Sesame indicum L.) were compared in observation plots and trials in the Pediplain and Sand Sheet soils of Kordofan during 1963–1965. The effect of added nitrogen and phosphorus on each variety was also investigated. All varieties did better on the Pediplain than on the Sand Sheet soll due to the better moisture retention characteristics of the former. The amount of seasonal rainfall affected greatly the yields and the magnitude of the response to fertilizers. Yields were extremely low in 1965 especially at Umm Higlig as a result of the protracted period of drought during seed formation. Few significant differences between varieties were found. The local land variety was inferior to a number of introduced ones when grown in the Pediplain soil under conditions of adequate rainfall. Significant responses to fertilizers were noted for all varieties, however, fertilizer application would appear economically justifiable only under sufficient rainfall. The suitability of each variety as breeding material was evaluated and the special importance of drought resistance and earliness as breeding objectives was pointed out.
Cross‐Compatibility of Birdsfoot Trefoil, Lotus corniculatus L.1
Authors: Miller John D.
Published: July 2010

All possible crosses, including reciprocals, were made among four clones of birdsfoot trefoil, Lotus comiculatus L. Objectives were to determine cross‐compatibilities of the clones, to detect reciprocal effects, to study some components of seed yield and determine effect of different dates on crossing. Reciprocal differences were noted for number of pods, number of seed, and percentage successful crosses. Crosses were made on three dates to determine effect of varying day lengths on seed yield and related characters. In mid‐winter, successful crosses were difficult to make and seed yields were poor. Diallel analyses disclosed that seed weight and percentage successful crosses were influenced by general combining ability effects. No specific combining ability effects were noted. Differences in cross‐compatibility were found.
Seed Dormancy in Two Species of Digitaria from Africa1
Authors: Baskin Jerry M. , Schank S. C. , West S. H.
Published: July 2010

Dormancy in seeds of Digitaria milanjiana (Rendle) Stapf and D. pentzii Stent was investigated by germination tests in the laboratory over a 12‐month period. By using intact, dehulled, clipped and chemically treated seeds, dormancy was found to be due to the need for a period of after‐ripening in dry storage and to effects exerted by palea aml lemma. The caryopsis itself after‐ripens upon storage for 4 to 5 months, and removal of palea and lenmm from 4‐ to 5‐month‐old caryopses results in almost complete germination. Good germination can be obtained in seeds stored for shorter periods of time either by removing the seed coat, pericarp and endosperm or by treating dehulled seeds with gibberellic acid.
Inbreeding in Synthetic Varieties1
Authors: Busbice Thad H.
Published: July 2010

A method for computing inbreeding in advanced generations of synthetic varieties was demonstrated. With a knowledge of the effect of inbreeding on the productivity of a particular crop species, a plant breeder, by applying the formulae derived in this paper, can determine the effect of varying the number of parents used to produce a synthetic variety, the amount of inbreeding of parents, if any, that is desirable, and the synthetic generation that should be utilized for agronomic production.
Differential Physiological Response of Sugarcane Varieties to Osmotic Pressures of Saline Media1
Authors: Tanimoto Tyrus T.
Published: July 2010

Exposure of sugarcane varieties to different levels of osmotic pressure in nutrient solution (by adding NaC1) emphasizes varietal differences in response to this pressure. Working with varieties H 37‐1933 (known to be sensitive to drought) and H 49‐3533 (known to be tolerant to drought), physiological responses to added amounts of osmotic pressure were measured. Differential responses between these two varieties were shown in growth, flowering (tasseling), formation of joints, uptake of phosphorus, uptake of sodium, and storage of sucrose. These experiments showed that, above a certain pressure, there is a withdrawal of sugars from the basal or older joints. Provided that they have not been exposed to osmotic pressure great enough to cause death, after removal of the added pressure the plants start returning sugar to those joints from which it was withdrawn during the period of osmotic stress.
Two Rapid Assays for Saponin in Individual Alfalfa Plants1
Authors: Jones Merlyn , Elliott Fred C.
Published: July 2010

Two assays were developed for screening individual alfalfa (Medicago saliva) plants for crude saponin. Twenty alfalfa leaf samples, selected on the basis of erythrocyte assay results, were evaluated by the fish assay and secondly by a chemical determination for saponins. The correlation coefficients of these assay results were ∝erythrocyte vs. chemical (r = .90), √fish vs. √erythrocyte (r = −.91), and √fish vs. chemical (r = −.81). Results indicate that the two assays may provide rapid and accurate estimates of crude saponin in alfalfa plants.
Effects of Fineness of Grind and Periodic Agitation on Total Available Carbohydrate Values Obtained by Enzyme Saccharification1
Authors: Greub L. J. , Wedin W. F.
Published: July 2010

Grinding alfalfa and birdsfoot trefoil root samples to pass through 18‐, 40‐, or 80‐mesh screens had no effect on TAC values except for late summer and autumn samples wherein TAC levels were high and starch was a major constituent. Periodic agitation during enzyme saccharification usually did not increase TAC values.
Screening for Photosynthetic Efficiency1
Authors: Menz Kenneth M. , Moss Dale N. , Cannell Robert Q. , Brun Wllliam A.
Published: July 2010

Maize (Zea mays L.), sorghum (Sorghum vulgare L.) and several other plants have maximum rates of photosynthesis of 50 to 60 mg CO2 dm−2 hr−1 and have CO2 compensation concentrations (Γ) near 0 ppm. In contrast, small grains and many other plants have maximum rates of photosynthesis of 20 to 30 mg CO2 dm−2 hr−1 and Γ values near 60 ppm. By growing a mixture of these high and low Γ plants together in a closed chamber, a CO2 concentration below that necessary for survival of the high Γ plants was obtained. Only low Γ plants remained alive after 5 to 8 days in the chamber. This is a rapid and simple method for screening populations of plants for high photosynthetic rates.
Effects of Okra Leaf Shape on Boll Rot, Yield, and Other Important Characters of Upland Cotton, Gossypium hirsutum L.1
Authors: Andries J. A. , Jones J. E. , Sloane L. W. , Marshall J. G.
Published: July 2010

The effects of okra leaf shape on boll rot, yield, and other important characters of Upland cotton (Gossypium hirsutum L.), were investigated at three locations in Louisiana and on three varietal backgrounds. Varieties responded in a similar manner to the leaf shape treatments for all characters studied, but the location ✕ leaf shape interaction was significant in some cases.

The okra leaf shape character, as an average of varieties and locations, caused a significant reduction in the incidence of boll rot in comparison with normal leaf cotton. It was associated with a significant increase in yield, earliness, lint percentage and micronaire value, and a substantial increase in fruiting rate. Okra leaf shape had no effect on boll weight, fiber length, fiber length uniformity, or fiber strength, but caused a reduction in fiber elongation and total leaf area.

A mixed population of okra leaf and normal leaf plants in a 1:1 ratio was investigated. The mixed population was found to have no advantage over the pure populations of the contrasting leaf shapes.
Carbohydrate Reserve Trends in Orchardgrass (Dactylis glomerata L.) Grown under Different Cutting Frequencies and Nitrogen Fertilization Levels1
Authors: Reynolds John H.
Published: July 2010

Carbohydrate reserve trends in ‘Boone’ orchardgrass (Dactylis glomerata L.) were compared for 2 years (1965 and 1966) at Knoxville, Tenn., under four cutting frequencies (9 cuts, 7 cuts, 5 cuts, and 4 cuts per year) and two nitrogen fertilization levels (112 kg/ha and 224 kg/ha). Carbohydrate reserves, as evaluated by percentage of fructose in the stubble, usually reached their highest lewfls of each year during the fall. A definite pattern of depletion and replenishment of carbohydrates was most evident in the 4‐cut and 5‐cut treatments during 1965. Carbohydrate levels were generally lower during 1965 in the more frequently cut treatments. Carbohydrate percentages were generally lower during both years at the higher nitrogen rate. The lowest carbohydrate concentrations in 1965 occurred in April during a period of rapid vegetative growth and the lowest concentrations in 1966 occurred during late August. Carbohydrate levels did not seem to be greatly different among the various treatments at the end of the second growing season.
Heritability and Inheritance of Plant Height, Heading Date and Grain Yield in Four Spring Wheat Crosses1
Authors: Anwar Ataur Rehman , Chowdhry Abdur Rehman
Published: July 2010

F1, F2, and backcross populations from four spring wheat (Triticum aestivum L.) crosses involving tall and short varieties were analysed to determine inheritance patterns of plant height, heading date, and grain yield in wheat. In all popnlations the three characters were quantitatively inherited; and relative to the better parents, there occurred substantial heterosis for tall plant stature and higher grain yield, but for heading date the Fl's approached the midparent and did not exceed the early parent. Both narrow‐ and broad‐sense heritabilities were computed for these characters. The narrow‐sense estimates were smaller than the corresponding broadsense values in all the crosses.
Evidence of Cytoplasmic Male Sterility in Alfalfa1
Authors: Pedersen M. W. , Stucker R. E.
Published: July 2010

A new source of male sterility found in ‘DuPuits’ alfalfa (Medicago sativa L.) was classified as cytoplasmicgenic on the basis of male‐sterile F1's when the male‐sterile plants were crossed with either of two pollen‐fertile plants, a positive correlation (P<.O1) between sterility in the F1 and BC1 progenies, and a reciprocal difference in a cross where the reciprocal was identified with a recessive marker.

The mechanics of hybrid seed production appear workable, but major developmental problems include identification of lines with superior combining ability and insect and disease resistance; and pollination of the seed Crop.
Diallel Analyses of Yield and Other Agronomic Characters in Gossypium hirsutum L.1
Authors: Al‐Rawi K. M. , Kohel R. J.
Published: July 2010

Hayman's diallel cross analysis was employed to investigate the nature of the actions and interactions of genes involved in the inheritance of yield, its components, and other agronomic characters in Upland cotton (Gossypium hirsutum L.). Nine selected varieties, all possible F1 hybrid combinations among these varieties, and their corresponding F2's were grown in a split‐plot design with four replications.

Heterosis was measured as the departure of the F1 from the average midparent value, and inbreeding depression was measured as the reduction of F2 below F1 performance. Both heterosis and inbreeding depression effects were small but significantly different from zero for all 11 characters studied.

Weight of lint per seed and number of nodes met all the assumptions required for the diallel analysis. However, overall epistasis was found in plant height, earliness, boll size, and number of bolls per plant. multiple allelism and possibly correlated gene distribution appeared to be present in days to first flower, seed index, lint percent, number of seeds per boll, and yield.

The diallel analysis revealed that all the characters were polygenetically inherited and exhibited partial dominance. The results also showed that heterosis was due to dominance or epistatic gene action, or both.
Reaction of Sweet Sorghum Varieties to Downy Mildew (Sclerospora sorghi Weston and Uppal) in Texas1
Authors: Zummo Natale , Coleman O. H. , Jones Billy L. , Frederiksen R. A. , Bockholt A. J.
Published: July 2010

Resistance to downy mildew was found in sweet sorghum. Eleven of 51 entries grown at Beeville, College Station, and Weslaco, Texas, in 1968 did not show symptoms of the disease. Ten of these 11 varieties had one or more of the following varieties as one parent: Mn 1054, MN 1060, and MN 1500. Some plants of Mer. 64‐7 and Mer. 67‐12 infected with downy mildew were elongated (taller than healthy plants) whereas other diseased plants in the same plots were stunted.
Response of Smooth Bromegrass Genotypes to Cutting1
Authors: Nielsen E. L. , Drolsom P. N. , Voigt P. W.
Published: July 2010

The response of Bromus inermis Leyss. genotypes to different intensities of clipping was studied in two experiments. In Experiment 1, 29 selected plants were propagated in individual rows, one half clonally and one half from open‐pollinated seed. Alfalfa was interseeded between rows. The areas comprising the two propagation methods were each subdivided into 3‐cut early, 3‐cut late, and 2‐cut harvest schedules. Two cutting heights were employed on each. Growth recovery observations resulted in highly significant differences ascribed to genotypes, cutting schedules, and heights of cut. Propagation method was not significant. It was concluded that genotype response to defoliation could be evaluated in seeded rows.

Experiment 2 involved seed‐propagated rows of 81 top‐cross bromegrass progenies overseeded with alfalfa. Significant genotypic differences in response to clipping occurred following 3 years of the same harvest schedules used in Experiment 1. Persistence under either of the 3‐cut schedules was poor, a portion of which was ascribed to ecological factors. The vigor of genotypes, measured by residual yields of 2‐cut plots, was significantly better at the higher stubble height.
Effect of Photoperiod and Light Intensity on Flowering in Sugarcane
Authors: James Norman I. , Smith Garry A.
Published: July 2010

Photoperiods of 9, 11, and 14 hr drastically reduced the number of panicles that emerged in several sugarcane clones (Saccharum spp.), as compared to a photoperiod of 12.5 hr. A light intensity of 1399 lux tended to reduce the number of panicles that emerged more than light intensity of 86 lux when the photoperiod was 12.5 or 14 hr. The higher light intensity (1399 lux) caused significantly greater delay of panicle emergence than the lower light intensity (86 lux).

Increasing the duration of the 12.5‐hr photoperiod from 0 to 12 weeks resulted in increased delay of panicle emergence; and 4 weeks of this treatment caused maximum delay when started as inflorescences were just beginning to form or were up to 1.25 cm long.
Effects of Various Dormancy‐Reducing Treatments on Seed Germination and Establishment of Indiangrass, Sorghastrum nutans (L.) Nash1
Authors: Geng Shu , Barnett F. L.
Published: July 2010

Spikelets of indiangrass, Sorghastrum nutans (L.) Nash, from cultivars ‘Cheyenne,’ ‘Holt,’ and ‘Osage’ were subjected to various dormancy‐reducing treatments and subsequently tested for laboratory germination and field establishment. Dormancy‐reducing treatments were: prechilling, hull removal, prechilling followed by hull removal, and hull removal followed by prechilling.

A cultivar‐by‐treatment interaction occurred in normal laboratory germination, suggesting cultivar differences in level of seed dormancy, type of seed dormancy, or susceptibility to caryopsis injury resulting from the treatments. Abnormal laboratory germination followed only treatments involving hull removal. Prechilling significantly increased establishment from Holt spikelets and resulted in a nearly significant (.05) establishment increase with those of Osage. Establishment from Cheyenne spikelets was unaffected by prechilling. Establishment from spikelets of all cultivars was significantly reduced following treatments involving hull removal, although in some instances those treatments significantly increased normal laboratory germination.

Economic feasibility of prechilling, as a practical means of improving indiangrass establishment, was considered questionable. However, in laboratory tests prechillng did not seem to remove all dormancy, indicating work with other dormancy‐reducing treatments is warranted.

Regression analyses indicated that field establishment was affected by seed set and caryopsis weight as well as by spikelet germination. When dormancy was reduced through prechilling, the effect of normal spikelet germination on fieId establishment was largely attributable to variation in seed set.

Statistical complications deriving from use of intact spikelets were discussed.
Response of Hard Red Spring Wheat (Triticum aestivum L.) to Environments in Relation to Six Quality Characteristics1
Authors: Busch R. H. , Shuey W. C. , Frohberg R. C.
Published: July 2010

Eight varieties of hard red spring wheat (Triticum aestivum L.) were evaluated by regression analysis for six bread quality characteristics to determine varietal response to environments. Means of all entries in each uniform nursery were used as environmental indexes for each characteristic. The linear regression coefficient allowed a comparison of predicted performance among varieties over a range of environments for each quality character

‘Thatcher’ had the highest response and ‘Polk’ the least response while the six other varieties did not differ in their responses to environments for protein. ‘Manitou,’ ‘Selkirk,’ and Thatcher had high means and an undesirably high response to increasing ash environments. All varieties except ‘Waldron’ and Minn. II‐54‐30, exhibited a lower response to environments for mixogram score than for the other quality characteristics studied. ‘Chris’ exhibited a high response to increasingly good environments for loaf volume, whereas Selkirk had a below average response and a low mean.

A minimum standard system of using check varieties with known environmental responses to aid in the evaluation of potential varieties for quality characteristics is proposed, based on the varieties' means and responses. Selkirk, Manitou, and Polk would provide the necessary number of checks for the evaluation of the six quality characteristics studied under most environments.