bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of Regression Residuals in the Calculation of Orthogonal Polynomial Coefficients1
Authors: Cady F. B. , Fuller W. A. 
Published: July 2010

AbstractA method is presented for calculating orthogonal polynomial coefficients when the levels of the independent variable are not equally spaced and(or) replicated. The coefficients may be found by using a standard regression computer program or by means of a hand calculator. The method is based on the orthogonality between the computed residuals and the independent variables in a regression analysis.
Interrelationships Among Dry Weight of Panicles, Threshing Percentage and Grain Yield in Sorghum1
Authors: Atkins R. E. , Reich V. H. , Beil G. M. , Kirby J. S. 
Published: July 2010

AbstractEvaluations of dry panicle weight and threshing percentage in relation to threshed grain weights were made from grain sorghum yield trials conducted at four Iowa locations over a 3‐year period. Correlation coefficients of 0.91 to 1.00 for the association of panicle weight with threshed grain weight indicated that weights from unthreshed panicles may serve as an expedient and effective selection criterion for relative grain yield among a group of hybrids.Variability exhibited among hybrids, locations and years for grain percentage of the panicle suggested that the use of a standard threshing percentage to estimate actual grain yields from dry weights of unthreshed panicles would not be advisable.Grain yields estimated for each entry in all tests, using a regression procedure derived from dry panicle weights and a sampling of threshed grain weights, were compared with actual threshed grain weights. Examination of the deviations of estimated from actual yields for nearly 500 comparisons cast considerable doubt on the reliability of the estimation procedure. Ranges obtained between the largest positive and negative deviations among hybrids within each experiment were consistently larger than would be acceptable in most grain sorghum experiments. When precise evaluations for grain yield per se are needed, the separation of grain from the panicles seems a necessary procedure.
Effect of Water Table Depth and Method of Watering on Yield of Stringbeans1
Authors: Williamson R. E. 
Published: July 2010

AbstractThe yield of stringbeans (Phaseolus vulgaris L.) grown in field lysimeters in which water tables were maintained at constant depths was determined for treatments with and without surface watering. The yield was highly dependent upon the method of watering. When both subsurface and surface water applications were made, the yield of pods and vines was almost 0 for the 15.2‐cm water table depth. As the depth to the water table increased, the yield continued to increase until the maximum yield was obtained with water tables at 61 to 76 cm. With only subsurface watering, the yield from the 15.2‐cm water table treatment was about half the maximum yield which was obtained at the 30.5‐cm water table depth.
A Versatile, Bibliographic Punched Card System for Agronomists1
Authors: Siemer E. G. , Wood D. R. 
Published: July 2010

AbstractA versatile, inexpensive, simply operated punched card system is described. Cards may be sorted according to 1) author, 2) biological organism, 3) two separate topics, 4) two external environmental factors affecting the organism, or 5) article type. The system is readily adaptable to scientists in many research disciplines.
A Model Demonstrating Use of Linear Programming in Determining Optimum Economic Crop Production from Soils Under Different Management Schemes1
Authors: Keefer R. F. , Bennett O. L. , Nesselroad P. E. 
Published: July 2010

AbstractA model involving use of linear programming to determine optimum returns from different types of management systems which affect crop yields has been proposed. This model has been successfully applied to an example of fertilizer‐yield data obtained on soils of three different fertility levels, and thereby illustrates the importance of agronomists in collecting data of this kind for the agriculturally important soil series. Value of the crop produced along with the capital available can easily be varied to meet the requirements of time and resources of the farmer. Various types of problems which may be solved by this model have been suggested.
Two Beta Sources Compared for Evaluating Water Status of Plants1
Authors: Rolston D. E. , Horton M. L. 
Published: July 2010

AbstractTwo sources of beta radiation, carbon‐14 (C14) and promethium‐147 (Pm147), were investigated for determination of leaf water content of three plant species over a range of water stress conditions. The plant species used were soybean (Glycine max L.), sorghum (Sorghum vulgare L.), and barley (Hordeum vulgare L.). Results obtained with both sources gave high correlations of relative turgidity with attenuated radiation. However, for relative turgidities above 60% in the plants studied, higher correlation coefficients were obtained using the C14 source. Results indicated that the C14 method appeared to be more sensitive to small changes in relative turgidity than was the Pm147 method. Leaf disc sections taken from sorghum and barley leaves gave more uniform response to water stress changes than did whole leaves.
Performance of Short Stature Grain Sorghum Hybrids at Different Row and Plant Spacings1
Authors: Atkins R. E. , Reich V. H. , Kern J. J. 
Published: July 2010

AbstractThe performance of two short‐stature grain sorghum (Sorghum bicolor (L) Moench) hybrids at two row spacings and four within‐row plant populations was evaluated at Ames, Iowa, in 1965 and 1966. Mean grain yield for both hybrids over all within‐row plant populations showed an 11% advantage for 76‐cm (30‐inch) over 102‐cm (40‐inch) row spacings. A within‐row population of five plants/30‐5 cm (1 foot) produced highest grain yields at each row spacing. With each row spacing, seeds/head and heads/plant decreased progressively as the within‐row plant population increased from four through eight plants/30.5 cm. Days to mid‐bloom, plant height, and 100‐seed weight were not altered appreciably as row spacings and within‐row plant populations were varied. Interactions among the treatments did not identify differential performance patterns of marked practical consequence, and the interactions most often did not meet the tests for significance.
Plant Constituents of an Early and a Late Corn Hybrid as Affected by Row Spacing and Plant Population1
Authors: Bryant H. T. , Blaser R. E. 
Published: July 2010

AbstractAn early and a late maturing hybrid corn (Zea mays L.) grown at different plant populations and row spacings were compared for proportion of ears, stalks, leaves, and husks to whole plant. Populations of 39,500, 49,400, 66,700, and 98,800 plants/ha were studied with each row spacing of 36, 53, 71, and 89 cm. The corn was harvested when the grain was well dented and silage and grain yields were also obtained.The stalks, leaves, and husks, as determined by hand separations, comprised a larger proportion, and the ears a smaller proportion of the total dry weight of the late than early hybrid. Each year the proportion of stalks to total dry weight of both hybrids was the smallest from rows 53 cm apart. The weight of the total corn plant, averaged for both hybrids at all population levels, decreased slightly with each increase in distance between rows. As plant population increased, the weight of the individual plant constituents, averaged for both hybrids at all rows spacings, decreased proportionally. The average yield of silage was larger but the average yield of grain was smaller from the late than early hybrid. Planting at 98,800 compared with 39,500 plants/ha gave larger silage yields with either hybrid.
Agronomic Factors Affecting Polonium‐210 and Lead‐210 Levels in Tobacco. II. Varieties and Curing Methods
Authors: Tso T. C. , Carr J. M. , Ferri E. S. , Baratta E. J. 
Published: July 2010

AbstractTobacco seedlings accumulated Pb210 and Po210 to a concentration much higher than that found in the soil. The levels of these radioelements decreased as the plants grew. Only minor differences were observed in harvested leaves of two flue‐cured varieties — ‘Coker 319’ and ‘Virginia Bright Leaf.’ The Pb210 and Po210 content in the seeds are in much lower levels than those in the respective leaves produced from the same plant. Neither of the two methods of flue‐curing — a closed system with wood or an open system with kerosene — resulted in significant differences in radioisotope levels of cured leaf. Pb210 and Po210, if present in the combustion products of wood, were trapped in or exhausted through the flue pipes and were not deposited on the tobacco. Kerosene, because it contains little radioactivity, would not contribute much to the Pb210 and Po210 level of cured leaf when fully exposed to products of combustion in an open system.
Crude Protein Content of Eleven Grasses as Affected by Yearly Variation, Legume Association, and Fertilization1
Authors: Johnson James R. , Nichols James T. 
Published: July 2010

AbstractA study in western South Dakota was used to examine the influence of legume association and nitrogen fertilization on the crude protein content of 11 grasses when grown on heavy clay soils. Treatments, arranged in a factorial field plot design, consisted of grasses grown in pure stands with and without nitrogen fertlization and of the same grasses grown with alfalfa (Medicago sativa L.). Grasses in anthesis were harvested from the 33 treatments for 2 years and analyzed for crude protein content. Seasonal effects, nitrogen sources, and differences in kinds of grasses were highly significant in affecting the crude protein content of the forage. Grasses generally maintained the same relative rank within nitrogen sources and seasons.
Role of Stubble in the Survival of Certain Ice‐Covered Forages1
Authors: Freyman S. 
Published: July 2010

AbstractIce sheets are sporadically responsible for widespread damage to forage plants in temperate latitudes. In search for an effective way of reducing such losses, an experiment was designed to determine whether stubble protruding through the ice sheet offered a certain amount of protection to the covered plants.Potted plants of 22 species and varieties were encased in ice, with and without stubble protruding, and were stored for 60 days at −4C ± IC. Check plants were stored at the same non‐injurious temperature but were not surrounded by ice. Injury to the plants was assessed from the amount of regrowth after 2 weeks in the greenhouse.Leaves of reed canarygrass, Kentucky bluegrass, and three varieties of orchardgrass, protruding through the ice, had marked protective effect on the encased plants. Similarly when stems of alfalfa varieties ‘Dupuits’ and ‘Ladak’ were exposed to the atmosphere, the plants suffered less damage than those which were entirely encased in ice. Meadow foxtail, smooth bromegrass, timothy, and red fescue were not injured by the ice encasement, while all the legumes were damagd in varying degrees.
Growth, Yield, and Yield Components of Safflower as Affected by Irrigation Regimes
Authors: Erie Leonard J. , French Orrin F. 
Published: July 2010

AbstractThree to nine irrigations were given in eight irrigation treatments of fall‐planted Frio safflower. Irrigations were given when 60 or 72% of the available water in the top 120 cm of soil was depleted. Five different irrigation cutoff dates were compounded on the soil moisture depletion treatments, ranging from 3 weeks before first blossoming until harvest.The yield of safflower seed increased with each increment of irrigation water to a maximum yield obtained with seven irrigations given until the last blossoms opened (3,961 kg/ha). Consumptive use for this treatment was 107 cm of water. When the last irrigation was given at the first flowering date, seed yield was reduced over 800 kg/ha. Giving the last irrigation about 10 days before blossoming reduced yields nearly one‐half. Weight per seed, oil content, and seeds per head also increased with irrigations up to seven, and the percentage of hollow seed decreased. The seven‐irrigation regime also resulted in the greatest yield per centimeter of water used by the plant. The level of moisture depletion before irrigation had no significant effect on any of the factors studied.
Influence of Temperature and Leachate on Germination of Atriplex polycarpa1
Authors: Cornelius Donald R. , Hylton Lynn O. 
Published: July 2010

AbstractDesert saltbush, Atriplex polycarpa, a valuable native browse plant, occurs on dry rangeland in central and southern California. Germination was determined at temperatures from 5 to 35C at 5° intervals. Highest germination occurred at 20C on the 5th day in germinators and at 15C after 14 and 30 days. Germination declined uniformly from the 15 or 20C level to lowest and highest temperatures.For treatment A one set of seed and blotters was moistened with tap water for duration of 30 days. In treatment B the seed was soaked (leached) for 48 hours; then tap water was used to keep blotters and seed moist. In treatment C seeds were kept moist by using the leachate from the seed that had been soaked. Highest germination occurred after treatment B; lowest after treatment C; and treatment A was between C and B in effectiveness. The presence of some undetermined substances in the leachate severely inhibited germination in treatment C. Partial removal of the leachate from the seed enhanced germination in treatment B.
Effects of N, P, and K and their Interactions on the Nitrogen Metabolism of Vegetative Barley Tissue and on the Chemical Composition of Grain in Hydroponic Culture1
Authors: MacLeod L. B. , Carson R. B. 
Published: July 2010

Abstract‘Herta’ barley (Hordeum distichon L.) was grown in a greenhouse hydroponics experiment where nitrogen was supplied at concentrations of 10, 50, 100, and 200 ppm N, phosphorus at 25 and 100 ppm P, and potassium at 10, 50, and 200 ppm K in factorial combination. Barley tissue, harvested at the early vegetative, mid‐vegetative, and mature stages of development, was analyzed for total N, protein (alcohol‐insoluble) N, non‐protein (alcohol‐soluble) N, nitrate N, and reduced N. All N fractions, except nitrate N in the mature grain increased with increasing concentrations of N in the nutrient solution. As the concentration of P and K was increased, there was an increase in the dry matter yield and a decrease in the percentage of all N fractions, particularly in tissue at the early‐ and mid‐vegetative stages of development. The percent of protein N and non‐protein N fractions in the mature grain was lower with 100 P than with 25 P and also lower with 200 K than with 10 K or 50 K. Total production of protein N and non‐protein N per plant, however, was greater at the higher rates of P and K largely due to the increased yield of dry matter per plant. Interaction effects of N and K were more significant than NP interactions and than PK interactions except at the early vegetative stage. Potassium appeared to have more effect on the N metabolism of the plant in both vegetative and mature stages than did P.
Effect of Repeated Annual Use of Atrazine on Corn1
Authors: Burnside O. C. , Wicks G. A. , Fenster C. R. 
Published: July 2010

AbstractNormal use rates of atrazine (2‐chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine) for weed control in corn (Zea mays L.) applied for 3 consecutive years at three locations across Nebraska had no significant effect on corn yield or eight other corn yield components. Annual application rates of 9 kg/ha of atrazine during 1963–1965 caused a 21, 23, and 2% corn yield reduction in 1965 at Alliance, North Platte, and Lincoln, respectively. Generally there is a wide margin of safety when using atrazine to control annual weeds in corn.
Effect of Water Table Depth and Flooding on Yield of Millet1
Authors: Williamson R. E. , Willey C. R. , Gray T. N. 
Published: July 2010

AbstractYields of millet (Pennisetum glaucum (L.) R. Br.) grown in both sheltered and nonsheltered soil tanks increased with water table depth to a depth of 76 cm. In the sheltered tanks yields were similar for all water table depths greater than 61 cm. The N, P, and K contents of plants grown grown with water tables at 15 or 30 cm in the sheltered tanks were significantly lower than for deeper water table depths. Except for the tanks with 15‐ and 30‐cm water tables, the oxygen content by volume was generally above 18% at the 15‐cm depth, indicating that the region of greatest root mass (0 to 8 cm) was probably well aerated. Since yields were affected by water table depths down to 76 cm, it appears that the few roots extending below the 8‐cm depth were nevertheless necessary o supply nutrients to the plant. Yield data suggest that O2 was low in a portion of the root zone where water tables were less than 76 cm below the surface.Two days of flooding 4 weeks before the First harvest reduced the first harvest yield 40%, but did not affect the second harvest yield. Flooding at earlier or later dates caused less yield reduction.
Photosynthesis Under Field Conditions. XA. Assessing Sources and Sinks of Carbon Dioxide in a Corn (Zea mays L.) Crop Using a Momentum Balance Approach1
Authors: Lemon E. R. , Wright J. L. 
Published: July 2010

AbstractIn a previous communication we described a meteorological method of assessing the vertical distribution of photosynthesis and respiration activity in a corn crop. The method, however, is tedious. Here we describe a much simpler method. Results indicate that all the leaves of a corn crop appear to follow the same near‐linear light response curve, at least above the compensation point. Below the compensation point, all leaves evidently respire very little.
Effect of Harvest Frequency and Nitrogen Fertilization on Estimated Total Digestible Nutrients of Orchardgrass (Dactylis glomerata L.) Regrowth1
Authors: Reynolds J. H. , Barth K. M. , Fryer M. E. 
Published: July 2010

AbstractThe Estimated Total Digestible Nutrients in ‘Boone’ orchardgrass (Dactylis glomerata L.) regrowth were compared under three harvest frequencies, 3‐week, 4‐week, and 6‐week; and two levels of nitrogen fertilization, 112 kg/ha and 224 kg/ha, at Knoxville, Tennessee. In some cases, significantly higher ETDN percentages were found with the shorter intervals between harvests. With both nitrogen fertilization levels, total ETDN yields decreased with more frequent harvests. Total ETDN yields from the 3‐week harvest regime were significantly lower than those from the 4‐ and 6‐week harvest regimes. As the season progressed, a general downward trend in percent ETDN was observed within each harvest frequency. No significant differences in percent ETDN were found between different nitrogen levels of the same harvest frequency. Doubling the rate of nitrogen fertilization nearly doubled the ETDN yield within each harvest frequency. The effect of harvest frequency on ETDN yield was not as great as the effect of nitrogen fertilization rate.
Effect of Oil Coating a Fertilizer on Yield and the Uptake of Manganese and Zinc by Corn and Soybeans
Authors: Jones J. Benton 
Published: July 2010

AbstractThe use of oil to adhere MnO and ZnO to a granular 8‐32‐16 fertilizer applied to corn and soybeans on a moderately fertile silt loam and a fertile silty clay loam had no significant effect on the uptake of Mn and Zn by the plants.
A Method for Marking the Point of Anhydrous Ammonia Release1
Authors: Hughes T. D. , Colliver G. W. , Welch L. F. 
Published: July 2010

AbstractA method for marking the point of anhydrous ammonia release is described. A steel tube welded to the back of the ammonia applicator knife serves to place a twine marker at the point of release as ammonia is injected into the soil. The twine can then be readily located several months later if sampling of the ammonia application zone is desired.
Water Stress Gradients in Plants and Soil‐Root Systems1
Authors: De Roo H. C. 
Published: July 2010

AbstractThe plant moisture stresses (PMS) in leaves, shoots, and roots of tobacco were determined as the negative hydrostatic xylem sap pressure in a pressure bomb.In the field, PMS in the midribs of leaves varied with the atmospheric stress and showed a reasonable diurnal course, while PMS of the adventitious roots did not change diurnally. Thus on a hot, sunny day during a dry period a steep PMS gradient between leaves and roots developed, which throughout the night gradually diminished. During the cool, humid early morning hours, leaf and root PMS were about the same. A comparison of root PMS with soil moisture stress, however, revealed an unexpected, steep, inverted gradient.In the greenhouse, small pot‐grown plants were observed to verify the field observations. The differences in equilibrated sap pressures or PMS of complete shoots and intact soil‐root systems clearly depended upon the relative rates of water absorption and water loss. In dry Merrimac sandy loam with soil moisture stresses (SMS) higher than about 12 bars, root PMS were lower than SMS, as had been observed in adventitious roots in the field. In moist soil with SMS lower than 12 bars, this situation reversed and a normal moisture stress gradient from soil to root existed.
Dimethylsulfoxide (DMSO) Effects on Four Economically Important Crops1
Authors: Erdman Howard E. , Hsieh J. J. S. 
Published: July 2010

AbstractRed kidney beans (Phaseolus vulgaris), Alaskan peas (Pisum sativa), Himalayan barley (Hordeum vulgare), and Tetratakus rye (Secale cereale) seeds were cultured on various concentrations of DMSO for different periods of time. Seed germination and growth of roots and plumules were measured to determine the effects of DMSO. Toxicity of DMSO was more clearly indicated by growth than by germination data. Recovery from subjection to DMSO for definite periods of time was shown. From the observed adverse effects of DMSO several mechanisms were suggested for DMSO action.Uptake of calcium, magnesium, potassium, and phosphorus increased with treatment time and concentration of DMSO. Uptake on a wet weight basis was doubled or tripled at 7.5% DMSO.If DMSO is to be used as a synergist for fertilizers, insecticides, etc., concentrations of less than 0.1% must be used because of adverse effects of higher concentrations on plants.
Relative Performance of Lespedeza Varieties under Different Managements1
Authors: Templeton W. C. , Franks K. N. , Taylor T. H. 
Published: July 2010

AbstractMorphological and reproductive responses of lespedeza, Lespedeza stipulacea. Maxim, and L. straita (Thunb.) Hook and Am., to two temperature regimes were studied in a greenhouse experiment prior to initiating field tests. Grown under a 9‐hour photoperiod, varieties varied in their response to temperature. Cool night temperatures ranging from 3.5 to 12C (38.3 to 53.6F) resulted in taller plants which required a longer period of tune to set seed. Four of the five varieties produced more seed per plant after exposure to cool‐night conditions than when exposed continuously to night temperatures ranging from 21 to 29C (69.8 to 84.2F).Six field experiments were conducted during a 3‐year period to evaluate yield responses of four varieties to different managements. Relative performance of varieties was little influenced by variations in seeding date, seeding rate, herbicide treatment of the established companion grass, or cutting management.It is concluded that management variables such as rates of seeding and growth in pure cluture or in grass association appear to be of less importance in variety comparisons than are such factors as date of planting and environmental effects at specific locations.