bluuebunny/crossref_metadata_2025_split huggingface dataset:
Infiltration and Soil Properties as Affected by Annual Cropping in the Northern Great Plains
Authors: Pikul Joseph L. , Aase J. Kristian 
Published: July 2010

AbstractFallow‐wheat (Triticum aestivum L.) cropping systems may be responsible for declines in soil organic matter and degradation of soil physical properties. A change to annual cropping may improve or at least maintain soil properties. Tillage and crop sequence effects on soil properties and water infiltration were tested after 9 yr of cropping on a Dooley sandy loam (fine‐loamy, mixed Typic Argiborolls) derived in glacial till. Annual cropping tillage of fall sweep and spring disk (AWFST), and no tillage (AWNT) were compared with conventional tillage in wheatfallow (FWCT) as the control. Statistical design was a randomized complete block with four replications. Soil samples were taken at 0.03−m increments to a depth of 0.3 m and were used to measure organic carbon (OC), pH, bulk density (BD), and particle size. Point resistance was measured in 0.02−m increments. Water infiltration into dry and wet soil was measured using a rainfall simulator. Maximum soil BD was 1.61 Mg m−3 on FWCT and 1.56 Mg m−3 on AWNT. Soil BD was not changed by one winter of freezing and thawing. Maximum point resistance was 2.2 MPa on FWCT and 1.7 MPa on AWNT. Cumulative 3‐h infiltration into dry soil was 52 mm for FWCT and 69 mm for AWNT. Final infiltration rate into wet soil was 5 mm h−1 for FWCT and 6 mm h−1 for AWNT. There was a significant difference in the depth distribution of OC between annual crop and FWCT treatments. Mass of OC in the top 0.09 m of soil was 1.65 kg m−2 on annual crop treatments and 1.45 kg m−2 on FWCT. Greater amounts of OC on the annual crop treatments compared with the FWCT attest to the beneficial aspect of annual cropping in maintaining a level of soil quality that is greater than FWCT. From a soil conservation perspective, no‐tillage has an additional advantage because surface cover is maintained throughout the year, thereby reducing the potential for soil erosion.
Deficit Irrigation of Cotton for Increasing Groundwater Use in Clay Soils
Authors: Cohen Y. , Plaut Z. , Meiri A. , Hadas A. 
Published: July 2010

AbstractThe interactive effects of a shallow, highly saline water table and irrigation management on crop production have not been clarified, due to difficulties in measuring crop water use. The detrimental effects of a rising water table and salinization due to irrigation can be eliminated, provided irrigation scheduling is based on a broad knowledge of crop water requirements. A deficit irrigation approach was used to (i) minimize deep percolation and (ii) study the capability of cotton (Gossypium hirsutum L.) to use water from the soil profile and from lower groundwater. Measurements of sap flow in the stem by the heat pulse method were used to determine transpiration. Transpiration of the mature cotton crop was nearly 20% lower than potential transpiration. Reduced irrigation application did not stimulate root expansion into wet, deep soil layers; therefore, it resulted in a reduction of the transpiration rate below its maximum rate. An appreciable water uptake from groundwater did not occur, presumably because of high sensitivity of the cotton root system to high soil density. Although the leaching fraction was nearly zero, salt accumulation in the root zone during the growing season was low.
Clipping Foliage Differentially Affects Phytosiderophore Release by Two Wheat Cultivars
Authors: Hansen Neil C. , Jolley Von D. , Brown John C. 
Published: July 2010

AbstractRecent observations of grazing‐induced Fe‐deficiency chlorosis in wheat (Triticum aestivum L.) grown on calcareous soil indicates that Fe deficiency should be considered one of the factors associated with decreased grain yield in grazed wheat. Quantity of phytosiderophore release by roots of Fe‐deficient grasses has been closely linked to resistance to Fe‐deficiency chlorosis in numerous species and could potentially explain these observations. Phytosiderophore release following clipping was determined for two wheat cultivars (‘Abilene’ and ‘2157’) widely divergent in field chlorosis resistance. Plants were grown hydroponically in a complete nutrient solution containing 0.2 mg L−1 Fe as Fe‐HEDTA (N‐hydroxyethylethylenediaminetriacetic acid). Phytosiderophore release was measured using an Fe‐binding assay under nonaxenic conditions. Abilene and 2157 wheat responded differently to clipping of foliage. Initial response in both was reduced release of phytosiderophore, but the Fe‐chlorosis resistant cultivar (Abilene) responded to clipping by quick and complete restoration of the initially suppressed phytosiderophore, whereas the susceptible cultivar (2157) did not. Clipped Abilene released more phytosiderophore per gram of root than control plants on some days, but 2157 did not. Root growth was equally suppressed by clipping in both cultivars, compared with uncut control plants. Differential effect of defoliation on phytosiderophore release by these two cultivars helps explain some of the differences in Fe‐deficiency chlorosis resistance observed in the field. These results indicate that Fe‐chlorosis resistant wheat cultivars should be selected when managing wheat for both forage and grain production on calcareous soils.
Harvest Frequency and Cultivar Influence on Yield and Protein of Alfalfa‐Ryegrass Mixtures
Authors: Jung Gerald A. , Shaffer John A. , Everhart John R. 
Published: July 2010

AbstractBinary mixtures of alfalfa (Medicago sativa L.) and perennial ryegrass (Lolium perenne L.) are commonly grown for forage in the U.S. Northeast. The competitiveness of ryegrass with alfalfa as modified by management practices has not been extensively studied. Two experiments were conducted to measure the influence of harvest frequency and ryegrass ploidy level on production, botanical composition, and crude protein concentration of alfalfa‐ryegrass mixtures. The first experiment used six replicates of a factorial treatment structure (three ryegrass cultivars × three harvest cycles) in a split‐plot design. The second experiment used three replicates of three cultivars × three harvest treatments. Increasing the length of the harvest cycle from 20 to 40 d increased alfalfa and total dry matter production (10.1 to 14.9 Mg ha−1) while decreasing ryegrass production and proportion (49 to 18%) of grass in the stand. Ryegrass was nearly eliminated from the stand at the 40‐d harvest cycle, but when the cutting cycle was changed to 20 d the next year, it became productive and contributed one‐fourth to one‐half of the total forage yield. Alfalfa, which had low productivity (7.3 to 8.4 Mg ha−1) in a 20‐d cycle, became very productive (16.4 to 17.4 Mg ha−1) when the cycle was changed to 40 d the next year. Crude protein concentration in alfalfa decreased from 248 to 200 g kg−1 as harvest cycle increased from 20 to 40 d. Ryegrass crude protein increased from 163 to 184 g kg−1 as harvest cycle increased. Frances and Diplomat perennial turfgrass ryegrasses were as productive and persistent as Citadel perennial forage ryegrass in binary mixtures with alfalfa.
Phenology and Tiller Characteristics of Big Bluestem and Switchgrass Cultivars in a Short Growing Season Area
Authors: Madakadze Ignacio , Coulman Bruce E. , Stewart K. , Peterson P. , Samson R. , Smith Donald L. 
Published: July 2010

AbstractWarm‐season grasses are increasingly being cultivated in North America for summer forage and biomass production. The cooler temperatures and shorter growing seasons typical of Canadian production areas, are major limiting factors to warm‐season grass production in these areas. This research assessed the morphological development and relationship of growing degree‐days (GDD) to plant morphology and tiller characteristics in nine cultivars of switchgrass (Panicum virgatum L.; Blackwell, Cave‐in‐Rock, Dakota, Forestburg, Pathfinder, Shelter, Sunburst, ND3743, and New Jersey 50) and in ‘Niagara’ big bluestem (Andropogon gerardii Vitman). The study was conducted for three years on a St. Bernard sandy clay loam (Typic Hapludalf) in southwestern Quebec. Stand cover, plant morphology, tiller number, height, and diameter, and leaf number per tiller were all assessed during the season. All entries persisted through the three years of the study and showed increases in tiller number (from an average of 565 to 683 m−2) from one year to the next. Dakota, Cave‐in‐Rock, and Shelter switchgrass had the highest ground cover ratings after three years (85, 85, and 84%, respectively). Dakota, ND3743, and Forestburg were early maturing; New Jersey 50 was the latest in maturity. Niagara big bluestem had the tallest tillers (183 cm) and largest rates of increase in height (2.8 cm d‐1), followed by Cave‐in‐Rock (2.0 cm d−1) and Blackwell (1.9 cm d−1). The shortest tillers were recorded for Dakota (111 cm) and ND3743 (118 cm). Changes in leaf number per tiller with GDD were best described by quadratic regression models (r2 = 0.80‐0.97). These models were stable over two years. Cultivars varied in the number of GDD required for maximum number of leaves per tiller, with later‐maturing cultivars generally requiring greater GDD accumulation. These data indicate that warmseason grasses can be grown successfully in eastern Canada.
Stability Parameters for Comparing Varieties1
Authors: Eberhart S. A. , Russell W. A. 
Published: July 2010

The model, Yij = μ1 + β1Ij + δij, defines stability parameters that may be used to describe the performance of a variety over a series of environments. Yij is the variety mean of the ith variety at the jth environment, µ1 is the ith variety mean over all environments, β1 is the regression coefficient that measures the response of the ith variety to varying environments, δij is the deviation from regression of the ith variety at the jth environment, and Ij is the environmental index.The data from two single‐cross diallels and a set of 3‐way crosses were examined to see whether genetic differences could be detected. Genetic differences among lines were indicated for the regression of the lines on the environmental index with no evidence of nonadditive gene action. The estimates of the squared deviations from regression for many hybrids were near zero, whereas extremely large estimates were obtained for other hybrids.
On the Choice of Tester Parent for the Breeding of Synthetic Varieties of Maize (Zea mays L.)1
Authors: Allison J. C. S. , Curnow R. N. 
Published: July 2010

The selection of genotypes (plants or first generation inbred lines) from an open‐pollinated variety to combine into a synthetic variety involves the choice of a suitable tester parent. A theoretical examination of a single locus shows that the recessive homozygote is the best tester for maximizing the expected mean yield of the synthetic variety.In practice the gene frequency and the amount and direction of dominance will be unknown. With no dominance the mean yield of the synthetic variety is independent of the tester. With partial dominance any tester will give some increase in mean yield. With overdominance the choice of the ‘wrong’ homozygote as tester could cause a reduction in mean yield but if the parental variety is used as tester the yield will at least not decline. The parental variety may therefore be a safer choice as tester than other varieties with contrasting gene frequencies.Criteria are derived for deciding which loci are most important in choosing a tester. It is argued that at these loci the parental variety is more likely than other available varieties to be near homozygous recessive. If positive dominance is important, a good tester may be produced by selecting for low yield within the parent variety.Much of the theory and many of the conclusions presented in this paper are not new. The aim of the paper is to give a unified mathematical account of the known theory and to generalize and interpret it.
Genetic Analyses of the Resistance to Mayetiola destructor (Say) in Hordeum vulgare L.1
Authors: Olembo J. R. , Patterson F. L. , Gallun R. L. 
Published: July 2010

Resistance to Hessian fly (Mayetiola destructor Say) was studied in the F1, F2, and F3, generations following intercrosses among 3 barley varieties and crosses of the 3 to ‘Mars’ and ‘Gull’ translocation stocks. A common dominant factor (symbol proposed Hf hf) was found in ‘Delta’, ‘Nile’, and ‘Abusir’ which governed resistance at cool greenhouse temperatures. The factor was independent of 4 translocation breakpoints which tested one or more arms of chromosomes 1, 2, 3, 4, 6, and 7.At higher greenhouse temperatures, two complementary dominant genes were necessary to explain resistance in Delta. The second factor pair which was ineffective alone was designated Hf2 hf2.
Correlated Inheritance of Maturity and Quality Factors in a Hard Red Winter Wheat Cross1
Authors: Schlehuber A. M. , Abbott D. C. , Jackson B. R. , Curtis B. C. 
Published: July 2010

Simple correlations between maturity and 14 quality characteristics were evaluated for F4 progeny of a hard red winter wheat cross between an early, mellow gluten variety with a late, strong gluten variety. Correlation coefficients were low and statistically nonsignificant except for those relationships between maturity and sedimentation and maturity and specific sedimentation. In 12 other correlations between maturity and quality characteristics, the values were low and statistically nonsignificant. For all 14 quality characteristics, the range of the F4 exceeded the 2 parents. Midparent values equaled the progeny means in 7 characteristics, exceeded the progeny means in 5 characteristics, and were less than the progeny means in 2 characteristics (sedimentation and specific sedimentation).Genotypic and phenotypic correlations between heading date and eight quality characteristics tended to be small and indicated no strong genetic association which would impede selection for early maturity lines with good milling and baking quality characteristics. Heritabilities ranged from 25% for flour extraction to 78% for bake mixing time and to 87% for heading date. Results from lines selected for quality characteristics and early heading and grown continuously from F4 through F7 clearly indicated that selection was effective in improving mixograph mixing time, sedimentation, and protein content while maintaining maturity equal to the early parent.
Diallel Analysis of Seven Economic Characters in Snap Beans1
Authors: Dickson M. H. 
Published: July 2010

Seven varieties of snap beans (Phaseolui vulgaris L.) (‘Wade,’ ‘Earligreen,’ ‘Earliwax,’ ‘Streamliner,’ ‘Harvest King,’ ‘Slendergreen,’ and ‘Tendercrop’) and all possible F2's among them were evaluated. Number of seeds per plant, number of seeds in the best five pods, length of pod, number of pods per plant, days to flowering, plant height, and width were determined.Additive genetic variance was predominant in the first five traits, but not for plant height and width. Pod number also showed some dominance, with recessive genes contributing to high pod number. Inheritance of seed number per plant and per pod resulted in interactions where Tendercrop and Streamliner were included, but without these two varieties a simple additive system is apparent. Pod length was under additive genetic control without dominance. Days to flowering was additive, but over‐dominance was expressed for earliness. The data indicate which parents would be the best for the characters studied, with Earligreen and Slendergreen appearing to be superior.
Effect of Common Leafspot on Coumestans and Flavones in Alfalfa1
Authors: Bickoff E. M. , Loper G. M. , Hanson C. H. , Graham J. H. , Witt S. C. , Spencer R. R. 
Published: July 2010

The coumestan and flavone content of ‘Atlantic’ and ‘Cayuga’ alfalfa (Medicago sativa L.) was determined after infection with Pseudopeziza medicaginis (Lib.) Sacc., the common leafspot organism. A fluorometric assay on one‐ and two‐dimensional paper chromatograms was used to determine six phenolic compounds.Uninoculated checks contained less than 2 ppm ofcoumestrol and trace amounts of medicagol + 4'‐Omethylcoumestrol and 7,4'‐dihydroxyflavone. Samples collected 12 days after infection had significant amounts of all compounds studied except 3'‐methoxycoumestrol. Samples collected 18 days after infection showed increases of from about 2 to over 11 times the concentrations found in the 12‐day samples. The greatest increase from the 12‐day to the 18‐day samples was of sativol in both alfalfa varieties. However, accumulation of the phenolics was greatest in the more disease‐susceptible variety Atlantic.A similar set of samples infected with the alfalfa rust organism, Uromyces striatus Schroet, var. medicaginis (Pass.) Arth., was too low in coumestan and flavone content to obtain meaningful information. Rust urediospores contained large amounts of coumestrol and other coumestans, and the loss of urediospores by spore discharge before the late sampling date is assumed to have been the cause of the extremely low coumestan content in the rust samples.
Variation and Covariation in Agronomic and Malting Quality Characters in Barley. II. Interrelationships of Characters.1
Authors: Rutger J. N. , Schaller C. W. , Dickson A. D. 
Published: July 2010

Correlations between all possible pairs of 8 agronomic and 9 malting quality traits were calculated from a population of 102 random lines of the F4 generation from an intervarietal malting barley cross. A strong positive correlation between head erectness and lodging should prove useful for selection purposes, since head erectness can be determined in th absence of differential lodging. Plump barley was negatively correlated with barley color and positively with malt extract. Extract was positively correlated with bushel weight and the wort N/malt N ratio. Beta amylase was positively associated with diastatic power and the beta/alpha ratio. Diastatic power and beta/alpha ratio were positively correlated. Alpha amylase was positively correlated with the wort N/malt N ratio. Alpha and beta amylases were not correlated, indicating that these two traits are independently inherited.Grain yield exhibited no really large correlations with any of the other traits, indicating that it should be possible to select for most quality traits without seriously reducing yield.Correlations among three malting quality and two agronomic traits were compared with published reports by other workers.
Conversion of Alien Sorghums to Early Combine Genotypes1
Authors: Stephens J. C. , Miller F. R. , Rosenow D. T. 
Published: July 2010

Alien sorghums from the world collection of sorghums are being converted to early, combine‐height strains adapted, to the United States and other temperate areas. Conversion is being accomplished by a crossing and backcrossing program in Puerto Rico under favorable shortday photoperiods during the winter, with selection for early, short genotypes within segregating populations in Texas under long‐day conditions during the regular growing season.After 2½ years of work on the conversion program, the procedure has proved workable, with only minor changes in time of seeding. Data indicate that the majority of alien strains used segregate for three to four height or maturity genes when crossed to a 4‐dwarf early line.
Effects of Light Intensity and Carbon Dioxide Concentration on Photosynthetic Rate of Soybean1
Authors: Brun W. A. , Cooper R. L. 
Published: July 2010

Photosynthetic response curves to CO2 concentration and light intensity were determined for the soybean varieties ‘Hark’ and ‘Chippewa‐64’.At light intensities above 5,380 lux, the photosynthetic rates of both varieties were limited by the CO2 concentration of the surrounding atmosphere within the range investigated (270 to 1670 ppm).At normal atmospheric CO2 concentration (300 ppm), photosynthesis of both varieties was light saturated at about 21,530 lux. At a CO2 concentration of 1670 ppm, photosynthesis was not light saturated in either variety at the highest light intensity tested (75,350 lux).The photosynthetic rate of the variety Hark was higher than that of the variety Chippewa‐64 at 45 of the 48 combinations of light intensity and CO2 concentration tested.
Relative Productivity of Homogeneous and Heterogeneous Oat Cultivars in Optimum and Suboptimum Environments1
Authors: Frey K. J. , Maldonado Uriel 
Published: July 2010

We tested six oat cultivars and the 57 mixtures among them for yield at two sowing dates (early and late) for 3 years. The mean relative yield (actual yield of mixture divided by mean yield of component cultivars) of all mixtures was 100% at the first sowing date and 104% at the second. The advantage of heterogeneous oat populations increased as the environment became more stressed.At the first date, the relative yield of only one mixture was significantly better than expected, whereas at the second date eight were significantly better. The interaction variances for “dates Χ cultivars” and “dates Χ mixtures of two cultivars” were highly significant, but none of the interactions of “date Χ mixtures of three, four, or five cultivars” was significant. This indicates that the mixtures of cultivars gave more stable production when tested across sowing dates than did cultivars. There was no association between the number of cultivars in mixtures and the grain yields of the mixtures. Several mixtures yielded more than the best cultivar when averaged across both environments.
Effect of Natural Selection on Performance of a Barley Population1
Authors: Rasmusson D. C. , Beard B. H. , Johnson F. K. 
Published: July 2010

A barley composite population obtained by mixing seed of 6,000 entries from the barley world collection was grown under severe stress, imposed by late planting, in Minnesota for 6 years. During this time the composite was advanced using a random lot of seed from the previous year's harvest. Remmant seed from each year ultimately was planted in yield trials to ascertain the change, if any, in the yield potential of the composite.Yield of the population increased significantly indicating a substantial response to natural selection. The improvement amounted to 57% during the six years or an average of 9.5% for each year of natural selection.
Preliminary Wind Tunnel Studies of the Photosynthesis and Evapotranspiration of Forage Stands1
Authors: Hunt L. A. , Impens Ivan I. , Lemon E. R. 
Published: July 2010

Surface characteristics, photosynthesis, and evapotranspiration of vegetative stands of alfalfa and orchardgrass, grown in flats in a glasshouse, were investigated in a small wind tunnel. The windspeed parameters of the crop surfaces were determined at low radiation intensity at each of two windspeeds, and the rates of net photosynthesis and evapotranspiration were measured at the two windspeeds at each of three radiation intensities.The roughness length (zo) increased with windspeed and was greater in orchardgrass. Rate of net photosynthesis, but not evapotranspiration, also increased with windspeed. In consequence, water use was most efficient under the highest wind regime. The rate of net photosynthesis increased to the intermediate radiation intensity, whereas evapotranspiration increased and water use efficiency decreased to the highest radiation regime.The work indicated that a small wind tunnel of the type described would be useful for further studies of the photosynthesis and evapotranspiration of forage stands.