bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poor Growth of Alfalfa (Medicago sativa) on Some Alberta Soils1
Authors: Webster G. R. , Khan S. U. , Moore A. W. 
Published: July 2010

abstractAlfalfa grows poorly on certain soils in central Alberta where it had previously grown well. All affected (“poor”) soils studied to date have light textured surface horizons. Plants are generally short, spindly, yellowish‐green, and poorly nodulated with patches of vigorous growth often scattered throughout the fields. Macro‐ and micro‐nutrients applied in the field have produced unsatisfactory responses.A number of greenhouse experiments have been conducted using soils collected from areas of good and poor alfalfa growth and from an area that has never grown this crop. Steaming increased yields for two “poor” soils, and “Vaparn” increased yields and nodulation to a much greater extent than did fertilizer for one of these. Aqueous extracts from some “poor” soils, depressed growth and nodulation appreciably. Liming and nutrient solution increased yields for all soils, but failed to promote nodulation or produce healthy plants in soil sampled from areas of very poor growth. These treatments eliminate nutrient deficiency or toxicity as the primary causes for the poor growth. It would appear that these “poor” soils contain an agent toxic to alfalfa that is probably of biological origin. Barley was not affected by the toxic agent.
Apparent Photosynthesis in Field Soybean Communities1
Authors: Sakamoto Clarence M. , Shaw Robert H. 
Published: July 2010

abstractLimited data of net photosynthesis observations in a field chamber study indicated that a soybean community was light saturated at about 6,000 to 6,400 foot‐candles in the initial flowering stage and at 5,500 foot‐candles in the pod‐formation and the pod‐filling period. Thereafter, the saturation level dropped abruptly. Maximum net photosynthesis at light saturation showed a similar pattern.Data are presented which showed that although leaf area increased from flowering to pod‐formation, net photosynthesis did not increase correspondingly.Projection of the net photosynthesis‐light intensity curve indicates that the compensation point in the soybean community was about 1,000‐1,500 foot‐candles.
Chemical Fallow in Dryland Cropping Sequences1
Authors: Wiese A. F. , Burnett E. , Box J. E. 
Published: July 2010

AbstractIn continuous crops of dryland sorghum, propazine at 2.2 kg/ha eliminated one tillage and one cultivation operation during the crop year. At least one tillage operation was required to control volunteer sorghum before planting. In a wheat‐sorghum‐fallow cropping sequence, propazine at 2.2 kg/ha applied immediately after wheat harvest eliminated three tillage operations during the fallow period after wheat and one cultivation in the sorghum crop. The reduced tillage did not conserve extra wheat stubble for wind erosion control during the winter months. Diuron at 1.1 kg/ha applied in March to sorghum stubble eliminated cotton crop cultivation 2 of 4 years. Considerable sorghum residue was conserved for wind erosion control the winter after cotton harvest when no preplant tillage occurred.
Effect of Changes in Root Zone Temperature on the Subsequent Growth and Development of Young Corn Plants1
Authors: Beauchamp Eric G. , Lathwell D. J. 
Published: July 2010

AbstractCorn plants were grown to defined stages of shoot development in sand culture at root zone temperatures of 15, 20, and 25C from emergence. Some plants were grown at constant root zone temperatures and others were transferred to the other two root zone temperatures at the 2‐leaf and 4‐leaf stages and then grown to the 4‐leaf and 6‐leaf stages, respectively.The dry weights of the shoots and roots decreased with increasing root zone temperatures at similar leaf stages. Although relative growth rates and absolute growth rates were generally correlated, the latter were chosen on a rational basis to indicate the effects of root zone temperature changes on the rate of dry matter accumulation. The rate of morphological development of the plants increased substantially with increasing root zone temperatures. On the other hand, absolute growth rates of both the shoots and roots tended to be greatest at 20 and lowest at 25C. The optimum root zone temperature apparently decreased for shoot growth but increased for root growth during the 2‐leaf to 6‐leaf stage interval. The previous root zone temperature had a variable influence on subsequent growth for all three temperatures. This effect was difficult to explain but depended somewhat on the corn variety.
Comparison of Conventional and Automated Procedures for Nitrogen, Phosphorus, and Potassium Analysis of Plant Material Using a Single Digestion1
Authors: Thomas R. L. , Sheard R. W. , Moyer J. R. 
Published: July 2010

AbstractNitrogen content in 10 plant samples of widely varying concentrations of N, P, and K was measured by a H2SO4—H2O2 ashing procedure and the AutoAnalyzer system and found comparable to nitrogen content obtained by conventional Kjeldahl analysis. Phosphorus content measured by the AutoAnalyzer system on the same H2SO4‐H2O2 ashing was similar to that obtained by dry‐ashing combined with the molybdo‐vanadate procedure. Potassium analyses on the solutions from the two ashing procedures by atomic absorption spectroscopy were comparable. Details are presented for simultaneous N and P analysis by the AutoAnalyzer and for K analysis by atomic absorption on plant material performed on a single H2SO4‐H2O2 digest at a rate of 160 samples per week by one technician.
Nature of Ice‐Sheet Injury to Alfalfa1
Authors: Freyman S. , Brink V. C. 
Published: July 2010

AbstractIce sheets frequently result in widespread damage to herbaceous plants in temperate latitudes; the cause of injury is a matter of controversy. In a series of experiments with alfalfa in which artificial ice sheets were formed over essentially unfrozen soil, marked changes in the soil atmosphere were recorded. Under one ice sheet, for example, which lasted for 50 days, soil CO2 rose to 8.7% and alfalfa plants died. From observations such as this and from experiments in which the CO2, O2, and N2 in ice‐covered soils were artificially altered, it was concluded that CO2 accumulation is the prime factor in the death of herbaceous plants under ice sheets.Intermittent thawing of artificial ice sheets reduced or eliminated injury. Stubble protruding through the ice sheet did not prevent injury.
Evapotranspiration by Snap Beans Grown in Sand Nutrient Culture1
Authors: Mielke L. N. , Peck N. H. 
Published: July 2010

AbstractEvapotranspiration by snap bean plants was measured by continuously recording changes in volume of solution in a sand‐nutrient culture system. Evapotranspiration rate increased with increased plant growth up to complete leaf canopy coverage over the sand surface. Plants with a complete leaf canopy had a maximum evapotranspiration rate of 1.3 mm per hour at 1300 hour. Daily evapotranspiration had high correlations with vapor pressure deficit and pan evaporation.
Yield and Stand Survival of ‘Coastal’ Bermudagrass as Influenced by Management Practices1
Authors: Holt Ethan C. , Lancaster J. A. 
Published: July 2010

AbstractA study was conducted over a 5‐year period to evaluate the effects of clipping practices and fertility levels on forage yields and stand survival of ‘Coastal’ bermudagrass, Cynodon dactylon (L) Pers. Yields were greater with a short stubble height (5 cm), infrequent harvest (35 to 40 cm of growth) and nitrogen fertilization. Yield and ground cover density increased with nitrogen fertilization and also in each succeeding year of the experiment. Root weight was not influenced by nitrogen fertilization and declined in each succeeding year of the study. Ground cover increase and root weight decline were slightly greater with close, frequent defoliation. Neither the density nor the root weight changes were related to yields. Differences in carbohydrate percent of both stems and rhizomes were detectable immediately following clipping, but no permanent or major sustained treatment effects were found. Height of cutting appears to be less important in Coastal bermudagrass production than either frequency of defoliation or level of fertilization, but Coastal bermudagrass will tolerate a wide range in both height and frequency of defoliation.
Relationship of Seedling Vigor to Respiration and Tetrazolium Chloride Reduction by Germinating Wheat Seeds1
Authors: Kittock D. L. , Law A. G. 
Published: July 2010

AbstractThe effects of age and size of seed on seedling vigor, rate of respiration, and 2,3,5‐triphenyl‐2H‐tetrazolium chloride (TTC) reduction by germinating seeds were studied in the laboratory. Wheat seed (Triticum aestivum ssp. compactum (Host) MacKey ‘Elmar’) was used. Stratification was necessary to eliminate the effect of dormancy in the youngest seed class. Significant positive correlations were found between rate of emergence and vigor (ability to emerge from deep seeding), emergence and rate of respiration, and between vigor and both tetrazolium reduction and rate of respiration for seed of different ages.With different seed size classes, significant positive correlations were found between seed weight and tetrazolium reduction, and between shoot weight per plot and tetrazolium reduction.In a preliminary test, varietal differences in seedling vigor, which were largely due to relative coleoptile elongation, were not correlated with TTC reduction. The possible place of TTC reduction as an empirical seedling vigor test and respiration of germinating seeds as a component of vigor are discussed.
Influence of Gas Mixtures on Cell Division and Root Elongation of Broad Bean, Vicia faba L.1
Authors: Williamson R. E. 
Published: July 2010

AbstractRoots were grown in airtight chambers in an intermittent nutrient solution mist. Various gaseous mixtures were used to determine the effects of short‐term aeration deficiencies on cell division and root growth. Following treatments of 4 to 24 hours, the roots were aerated with air for 5 days. Root tip samples were prepared for microscopic examination at several times during and after treatment.Oxygen levels of I to 10% without CO2 reduced the rate of cell division as much as 80% at the end of a 94‐ hour treatment; however, cell division resumed rapidly after treatment. Nitrogen reduced cell division in secondary roots within 15 minutes, stopped all division within 94 hours, and frequently killed primary root tips. After being returned to air, the rate of cell division in the old secondary root system was approximately 70% of normal within 48 hours, but few new roots developed. Mixtures of gases containing 1 to 10% O2 plus enough CO2 to equal 91% killed part of the secondary root system but rarely killed the primary root tip. These data show that either zero 02 or high CO2 for only 94 hours injures the root system of Vicia faba L. and that high CO2 is more injurious than zero 02.
Long‐Term Fertility Requirements of Coastal Bermudagrass, I. Potassium1
Authors: Woodhouse W. W. 
Published: July 2010

AbstractA trial involving four levels of K on coastal bermudagrass was conducted over an ll‐year period on a Eustis sand. Applied K increased yields by about one‐third the first year with K deficiency becoming so acute on the K0 treatment in succeeding years as to virtually eliminate the stand on that treatment after the 7th year. Under low to moderate rates of applied K, the grass removed far more K than was applied. Roots penetrated to a depth of at least 244 cm and exchangeable K was affected to a depth of 122 cm. K content of the forage declined linearly from the beginning to the end of the growing season under low to intermediate levels of applied K. Optimum K content fluctuated widely both between and within growing seasons as did the degree of luxury consumption. Exchangeable K appears to be preferable to the strong‐acid method in identifying zones in this soil affected by the application of K. Neither method was effective in identifying supplies of native K. Findings indicate that long‐term trials with plants of this kind can be of value.
Effect of Planting Date on High‐Amylose Corn (Zea mays L.)1
Authors: Helm J. L. , Fergason V. L. , Zuber M. S. 
Published: July 2010

AbstractFour high‐amylose single cross hybrids were planted near Columbia, Missouri, for the 4‐year period 1962 through 1965 on the following dates: April 20th, May 10th, June 1st, and June 20th. Amylose content of the endosperm and number of degree days during the growing season were inversely correlated with later plantings having higher amylose contents. However, later planted corn had a lower yield, test weight, whole kernel nitrogen content, kernel hardness, and number of days to tassel. Whole kernel ash content and ear height increased with later planting. It is doubtful if the increased amylose content of the endosperm will offset the reduced agronomic performance of later plantings.
Water Diffusivity of Germinating Soybean, Corn, and Cotton Seed1
Authors: Phillips Ronald E. 
Published: July 2010

AbstractTheory and procedure are presented whereby the diffusivity of germinating seed can be calculated if certain conditions are fulfilled. These conditions are (1) the ratio of amount of water absorbed at a given time to amount of water absorbed at the time of germination must exceed a certain, critical value for the ratio of the time required for germination to the time under consideration, and (2) the shape of the seed is assumed to be a sphere but the seed can deviate considerably from the shape of a sphere, for example, football shaped, without introducing appreciable error.The diffusivity of soybean seed germinating in aerated, distilled water was approximately four times larger than for corn seed and approximately 18 times larger than for cotton seed. The diffusivity of soybean and corn seed germinating in Zanesville silt loan soil at four moisture contents ranging from wilting percentage to field capacity was approximately equal at each soil moisture content. The diffusivity of each seed increased as soil moisture content increased. The diffusivity of cotton seed germinating in Zanesville silt loam soil could not be calculated because condition (1) above was not fulfilled.
Amazon Cacao (Theobroma cacao L.) Shade and Manurial Experiment (K2‐01) at the Cocoa Research Institute of Ghana. I. First Five Years1
Authors: Ahenkorah Yaw , Akrofi G. S. 
Published: July 2010

AbstractThe experimental layout, initial crop husbandry, preliminary girth measurements and yield results before and after the imposition of 2 years' shade and fertilizer treatments on the Amazon cacao Shade and Manurial Experiment (K2‐01) at Tafo are reported.In assessing the uniformity of the 4‐year‐old cacao stand analyses of data on girth measurements gave C.V. of 10.26% and 12.86% for subplot and main plots, respectively. These are remarkably lower and highly satisfactory compared with the C.V. of 57.75% for the corresponding yield.Statistical evaluation of variations between NPK fertilizer, block, cropping seasons, and shade effect is reported. The significant slope effect during the minor crop season was interpreted to be only a seasonal reflection of the probable variation in the available soil moisture. The shade effect of this experiment is compared with a similar and older experiment (Kl) at Tafo. The significant shade effect during the 1964/65 season in both cases varies with time of the year irrespective of the different shade trees.Shade, K, and PK fertilizer effects are highly significant with the dtshaded cacao yielding almost twice as the plots under heavy shade whilst the fertilizer is about 10% greater. “No shade” with PK treatment has the uniformly highest yield followed by the “medium shade” with PK and the least being “heavy shade” with PK fertilizer. Shade effect is well marked during the main cropping season while that of K is pronounced without overhead shade.There is a suggestion of rapid depletion of exchangeable K after 7 years of continuous cropping. The Amazon cacao on the WACRI series does not respond to the NPK fertilizer until it is over 5 years old.
Measuring the Color of Growing Turf with a Reflectance Spectrophotometer1
Authors: Birth Gerald S. , McVey George R. 
Published: July 2010

AbstractA single−beam spectrophotometer was used to measure the spectral reflectance properties of growing turf. From the data a two−wavelength reflectance ratio R745/R675 was developed for an objective index of turf color. This ratio changed from 3.0 for light green turf color to 6.5 for dark green turf color. (visual rating of 4 to 10, respectively). A two−filter instrument (Ratiospect) was used to measure this index on eight samples of turf of three species. A correlation of 0.984 was obtained between the Ratiospect readings and a visual score of turf color.
Effect of Several Fertilizer Treatments on the Production of American Beachgrass Culms1
Authors: Augustine Marshall T. , Sharp W. Curtis 
Published: July 2010

AbstractCoastal dune stabilization is greatly influenced by the type of vegetative cover. The most effective plant species for initial dune stabilization along the Atlantic coast is American beachgrass (Ammophila breviligulata Fern.) being very responsive to fertilization as measured by culm numbers produced.Each of 17 different fertilizer treatments significantly increased culm production. Potassium increased production in the 1st year only. Annual fertilization with soluble nitrogen fertilizer alone was effective. Magnesium ammonium phosphate as Mag Amp, applied at planting only, rapidly increased culm numbers for 3 years but decreased thereafter, approaching the effectiveness of annual applications of mixed 10‐10‐10 mineral fertilizer.
Emergence Time, Seed Quality, and Planting Depth Effects on Yield and Survival of Cotton (Gossypium hirsutum L.)
Authors: Wanjura D. F. , Hudspeth E. B. , Bilbro J. D. 
Published: July 2010

AbstractTime of emergence is a good indication of a cotton plant's vigor and potential yielding ability. Emergence time of the cotton plant integrates the effects of seed quality and planting depth. In this study, plant survival and yield were most highly correlated with emergence time and to a lesser degree with germination percentage and planting depth.
Coding of the Independent Variable in Yield Function Calculations1
Authors: Escobar Giron Jorge A. , Cady F. B. 
Published: July 2010

AbstractCoding or transforming the independent variable(s) in regression situations affects estimation and hypothesis testing. Methods are developed for understanding these coding effects and a table presented with the factors required to calculate easily the estimated coefficients and subsequent t‐statistics in one system of coding from another. The systems of coding include four commonly used codings of the original values. A worked example of a quadratic polynomial model in two variables is then given and the results interpreted with the objective of decreasing the potential confusion that may arise from a coding situation, e.g., when the independent variables have been coded for convenience in calculation but the final yield function is desired in units of the original variables.
Relationships Between N Response, Plant Population, and Row Width on Growth and Yield of Corn1
Authors: Nunez Roberto , Kamprath Eugene 
Published: July 2010

AbstractThe leaf area index increased linearly as the plant population of corn (Zea mays L.) was increased from 34,500 to 69,000 plants per hectare. The leaf area per plant, however, decreased as the plant population increased. Nitrogen rates of 112 to 280 kg per hectare and row width had no effect on leaf area per plant nor the leaf area index.The yield of grain per plant was dependent upon the leaf area per plant. The efficiency of a given leaf area to produce grain was higher as nitrogen rates increased.The yield of grain per hectare of the long season hybrid was not influenced by row width except under drought conditions where 53‐cm wide rows gave higher yields than 106‐cm wide rows. Highest grain yields were obtained at 280 kg of N per hectare and 51,750 plants per hectare. Maximum yields were obtained with a leaf area index of 3.5 and remained constant up to an index of 4.5 with adequate nitrogen.
Effects of Nitrogen‐Potassium Levels on the Growth and Chemical Composition of Kentucky Bluegrass1
Authors: Monroe C. A. , Coorts G. D. , Skogley C. R. 
Published: July 2010

AbstractThe performance of an apomictic strain of Kentucky bluegrass under eight fertility levels was studied during 1966 and 1967 under greenhouse conditions. Fertilizers were applied as nutrient solutions. Treatments included two nitrogen (65 and 130 ppm) and four potassium (0, 100, 200, and 400 ppm) levels in all factorial combinations. Clipping weights, weights of underground plant parts (roots and rhizomes) and tops, vigor scores, tiller counts, blade widths, and rhizome lengths were taken as measures of growth. Amounts of N, P, K, and C in leaf tissue were determined by chemical analysis.All growth measurements, except rhizome lengths under 130 ppm N, were increased by potassium when compared to the 0‐ppm K level. However, levels of K above 100 ppm were often detrimental under 65 ppm N and sometimes had little effect with 130 ppm N.N content of leaf tissue was increased by 130 ppm N while levels of K exceeding 100 ppm appeared to cause a slight, although significant decrease under both N rates. N and K had no significant effect on P content of leaf tissue. Added K increased the amount of K in leaf tissue up to the 200 ppm level. High nitrogen increased the K content significantly, but the increase was less than 0.2%.The balance between N and K appeared to effect growth responses. With 65 ppm N, 100 ppm K had the greatest effect on increasing growth measurements. With 130 ppm N, the balance requirement was less critical but the 200 ppm level gave the greatest growth measurement increases. The 400 ppm K level generally resulted in reduced growth regardless of N levels.
Water Use by Cotton From Low and Moderately Saline Static Water Tables1
Authors: Namken L. N. , Wiegand C. L. , Brown R. G. 
Published: July 2010

AbstractA 4‐year lysimeter study was conducted to determine the contribution of low to moderately saline, shallow static water tables to the total water use and yield of cotton grown on deep, permeable soils. Water tables controlled at 91‐, 183‐, and 274‐cm depths contributed 54.4, 26.4, and 17.3% of the total water use under the high moisture treatment and 60.6, 48.9, and 39.2% under the low moisture treatment. Total water use consisted of soil profile depletion, rainfall, irrigations, and additions of water to maintain the water tables. Water uptake from the 274‐cm water table was strongly related to the salinity level (electrical conductivity of saturated soil extract, ECe) of the capillary (183‐ to 274‐cm) zone. Lint cotton yields were related to the total amount of water obtained from the table as well as to the salinity level of the capillary zone. Moderate salinity (ECe of 10 to 14 mmhos/cm) of the capillary zone reduced monthly and seasonal water use from the water tables as compared with low salinity (ECe of 2 to 3 mmhos/cm) conditions. The high moisture treatment delayed significant use of water from 183‐ and 274‐cm water tables until late in the season, when irrigations were discontinued and the upper soil profile dried.