bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Day and Night Temperatures During Floral Induction on Morphology of Soybeans1
Authors: Thomas Judith F. , Raper C. David 
Published: July 2010

AbstractTemperature affects the vegetative and reproductive morphology of soybeans [Glycine max (L.) Merrill]. Descriptive information of the effects of temperature will assist in development of a dynamic simulation model. The purpose of this study was to determine the effects of day and night temperatures on growth and development of the determinate soybean cultivar ‘Ransom’. Seedlings were grown under a long‐day (non‐inductive) photoperiod at 26/22 C day/night temperatures in a temperature controlled greenhouse until the expansion of the first trifoliolate leaf. Plants then were moved into five controlled‐environment chambers programmed for 9‐hour photoperiods with temperature regimes of 14/10, 18/14, 22/18, 26/22, and 30/26 C. At the beginning of each night, groups of plants were moved from the five day temperatures to each of the five night temperatures to obtain a total of 25 day/night temperature combinations. Significant interactions between day and night temperatures for all measured characteristics except branch internode length made general evaluations of simple effects of day and night temperatures difficult. Instead, responses to the specific combinations of day/night temperature were considered. At the conclusion of 50 consecutive short days, area per leaf and vegetative dry weight were greatest at 26/10 C temperatures while pod dry weight was greatest at the higher night temperature combination of 26/22 C. The lowest net carbon dioxide exchange rate was obtained at temperatures of 14/26 C, and the highest rates at 26/14 and 26/18 C. The extent of apical dominance, given as the ratio between main stem height and total branch length, was greatest for plants from either warm day and warm night or cool day and cool night combinations. Warm night temperatures, in conjunction with any of the day temperatures, shortened the time from first exposure to inductive photoperiod to anthesis. At the four coolest day/night temperature combinations (14/10, 14/14, 18/10, and 18/14 C) pods were not formed even though floral initiation had occurred
Differential Response of Maize Inbreds to Zn1
Authors: Clark R. B. 
Published: July 2010

AbstractMaize (Zea mays L.) inbreds differ in their ability to take up and use Zn and these differences could be important for development and adaptation of plants to low Zn conditions. In pursuing the need for such information growth measurements and mineral element analysis were made on the inbreds A635 and H84 which showed differential Zn deficiency when grown with varied Zn in nutrient solutions. H84 was more “Zn‐efficient” than A645. H84 produced more total dry matter and more dry matter per unit Zn, developed fewer Zn deficiency symptoms, had more Zn in the tops compared to roots, and had fewer imbalances of other mineral elements when both were grown at low levels of Zn. At higher Zn levels, A635 produced as much as or more dry matter and had similar mineral element balances as H84. H84 also grew better than A635 when the two inbreds were grown together in the same low Zn solution. A635 showed greater changes in P, Ca, Mg, Mn, and Fe than H84 as Zn varied in solution. Differential responses between these two inbreds for Zn appeared to be caused by differences in the inbreds for translocation, requirements, and utilization of Zn, and for accumulation of imbalanced amounts of mineral elements which interact with Zn.
Effect of Plant Population on Yield and Height Characteristics in Determinate Soybeans1
Authors: Hoggard A. L. , Shannon J. Grover , Johnson D. R. 
Published: July 2010

AbstractLodging resistance may be an important factor in determining how soybean [Glycine max (L.) Merr.] cultivars respond to high populations. Therefore, the effects of plant population on yield, lodging, pod number, height, internode number, and average internode length for the lower, center and upper main stem internode regions, in determinate soybean cultivars differing in lodging resistance were studied in a field experiment on a typic Arguidoll soil. Group V cultivars, ‘Essex’ (most lodging resistant); ‘Forrest’ (intermediate lodging resistant); and ‘Mack’ (least lodging resistant); were evaluated in rows 97‐cm wide over a 2‐year period at populations of 23, 33, 43, and 53 plants/m of linear row (240,000; 340,000, 440,000; and 540,000 plants/ha). Lodging was moderate and increased as planting rate increased. Although yields were highest at the lowest plant density in all varieties, Essex did not respond to plant population as did the other two cultivars. Yield of Forrest at 23 plants/m was significantly greater than at 43 and 53 plants/m. Yield of Mack at 23 plants/m was higher than at the other populations. Pods per plant decreased as plant density increased. Forrest averaged significantly more pods per plant for all populations than Essex or Mack. Internode number in Essex was unaffected by population and was significantly less than in Forrest or Mack. Length of lower and central internodes increased and internode number declined as population increased in Forrest and Mack. Internode number and length offset each other resulting in similar heights across populations in Forrest and Mack while Essex was slightly taller with increasing populations. Essex which averaged 72 cm tall was significantly shorter than Forrest (93 cm tall) or Mack (90 cm tall) because of fewer and shorter internodes. However, yield of Essex was comparable to Forrest and better than Mack indicating that cultivars of short stature and improved lodging resistance can be grown without lowering yield. Yield stability across populations in lodging resistant Essex compared to significant yield reductions at the higher seeding rates in the more lodging susceptible cultivars, Forrest and Mack, indicates that lodging resistance is an important factor in determining how a soybean variety will respond to higher populations. Thus, lodging resistance is an important consideration in determining the optimum seeding rate of varieties best adapted to a particular area for maximizing yield, even in environments where lodging is only moderate.
Performance of Triticale in Comparison with Wheat, Oats, Barley, and Rye1
Authors: Morey Darrell D. 
Published: July 2010

AbstractTriticale (X Triticosecale Wittmack) is a relatively new cereal crop of interest for forage, food and feed grain production. The experiments reported here were conducted at Plains and Tifton, Georgia, to compare grain yields, test weight, height, lodging, disease reaction and protein production of triticale cultivars in comparison with the best adapted cultivars of wheat (Triticum aestivum L.), oata (Avena sativa L.), barley (Hordeum vulgare L.), and rye (Secale cereale L.). At Plains, ‘Volbar’ barley and ‘Coker 227’ oats tended to yield more grain than ‘Holley’ wheat, ‘Weser’ rye and 4 ‘Fasgro’ triticale cultivars during 5 years of testing. No differences in total protein production were noted for the 5 grain species at Plains.At Tifton, 5 years of testing showed no differences in grain yields of wheat, oats, barley, rye or the ‘Fasgro’ triticales. ‘Coker 227’ oats gave a higher percentage of protein than other grains but no differences in total protein production were obtained when all grains were considered. The newer triticale cultivar ‘6TA 227’ led the yield test in a 3 year comparison at Tifton, followed closely by ‘6TA 571’ and ‘6TA 579’.
Analytical Description of a Soybean Canopy1
Authors: Hommertzheim D. L. 
Published: July 2010

AbstractOne of the crucial components of a plant simulation model is the light distribution within the crop canopy. But in order to calculate the light distribution, the model must have knowledge of the leaf area distribution. This article describes an analytical procedure for calculating the leaf area distribution within a community of soybean plants arranged in a row configuration.The procedure has three main steps: 1) describe the plant analytically (i.e., size, shape, and spatial position of each leaf), 2) determine for a single plant the leaf area distributions as a function of height and distance from the center of the plant, and 3) combine the leaf area distributions of plants into a distribution for a community of plants in a row.The calculated leaf area distributions are sensitive to the distance between plants in a row, the leaf length to width ratios, leaf angles, plant growth stage, petiole lengths, and insect damage. The procedure can also be extended to other plant types, interspersing of weeds in the crop rows, and non‐wide row crop arrangements.
Split Root Observation System for Glass Root Dynamics Studies1
Authors: Lonkerd W. E. , Ritchie J. T. 
Published: July 2010

AbstractA split root observation system was designed to provide accurate values of root lengths and water‐uptake rates for use in establishing principles of estimating water uptake from field soil.The system consists of four independent glass‐bottom root observation boxes, each suspended from a load cell mounted on a support structure. The boxes have a 5° lengthwise downward slope from the plant location and contain a shallow layer of soil about 2 cm deep A plant is supported and weighed by a fifth load cell. Using a voltmeter with a 1‐µv resolution, an overall system accuracy of ±2.0 g is possible for observation box weights and ±0.4 g for the plant weight. Root growth is recorded using time‐lapse photography. Photographic slides are projected on a screen and root lengths are estimated using a line‐intercept method.A sorghum (Sorghum bicolor (L.) Moench) plant was used to evaluate the system. A seedling was grown in nutrient solution until eight adventitious roots had lengths at least 25 cm long. Two roots were then planted into each observation box. System performance tests illustrated how hourly, daily, and long‐term data can be used to relate plant weight, leaf area, root length, and water uptake. Split root observation systems of this type provide quantitative information on how different root zone conditions of a single plant affect root growth, water uptake, and top growth.
Nitrogen and Aerification Influence on Putting Green Thatch and Soil1
Authors: Smith G. S. 
Published: July 2010

Abstract‘Tifdwarf’ bermudagrass, (Cynodon dactylon (L.) Pers. ✕ C. transvaalensis Davy.), forms excessive thatch under intensive golf course management. Retarding thatch buildup or increasing its decomposition need study. This experiment was conducted 1) to determine the effects of ammoniacal and nitrate‐N on turf growth and thatch production, and 2) to study the thatch‐soil environment as affected by fertilization aerification, and liming. An established Tifdwarf putting green was aerified at three frequencies (twice yearly, monthly, and biweekly) and fertilized with biweekly or weekly N at 0.48 kg/l00 m2 from ammonium sulfate or calcium nitrate. Lime was applied to neutralize acidity, and soil topdressing was evaluated. Thatch thickness and weight and N content of organic‐matter fractions were measured over time. Subthatch soil cores were analyzed for pH, K, Ca, Mg, and P. Bermudagrass root weights were also determined. Thatch thickness was extremely variable; maximum depth was observed under biweekly fertilization with ammonium sulfate combined with semiyearly aerification. Weight of thatch size fractions, though more difficult to obtain, proved a good indicator of thatch accumulation. Weight measurements supported thickness measurements. Ammonium sulfate produced maximum thatch weight, while increasing aerification frequency decreased weight of organic fractions collected. Ammoniacal‐N did, however, produce excellent quality turf and 50% greater root weight was measured under ammonium sulfate fertilization. Soil levels of Mg and P were unaffected by treatments. Ammonium sulfate significantly reduced soil pH, Ca, and K as compared to calcium nitrate. Surface liming was not effective in retarding acidulation. No changes in thatch weight or N content could be measured. Thatch accumulation was not adequately controlled by combinations of aerification, selective N sources, liming or soil topdressing. Measuring thatch proved difficult, as did correlating thatch with turfgrass quality and growth.
Yield Potential of Interplanted Annual Food Crops in Southeastern U. S.1
Authors: Cordero Alvaro , McCollum R. E. 
Published: July 2010

AbstractIntercropping may be one way to increase the productivity of land. If so, it is of scientific as well as practical interest to know how the increase is achieved and devise methodologies which will exploit such systems to the fullest. This report compares the productivity of two component intercrops with that of their respective monocultures under differing nitrogen regimes.Two soil conditions were tested in each of 2 years—a poorly drained Portsmouth fsl (Typic Umbraquult, fine‐loamy, mixed, thermic) and a well drained Orangeburg sl (Typic Paleudult, fine‐loamy, silicious, thermic). Treatment variables were cropping system (intercrops vs. monocultures), row arrangement, and N rates from zero to 270 kg/ha. Corn (Zea mays L.) was used as the overstory crop and soybeans (Glycine max L. Merr.), snapbeans (Phaseolus vulgaris L.), or sweet potatoes (Ipomea batatas Lam) as the interplanted understory species. All interplanted species were at the same population as their monoculture checks.With adequate N, monoculture corn in conventional rows (97 un) averaged 9,400 kg/ha. Planting monoculture corn in paired 46‐cm rows, with 147 cm between row pairs, caused a 12% reduction in yield. An additional reduction of 5 to 10% resulted when soybeans or snapbeans were interplanted into corn in the 147‐cm space between row pairs. Monoculture soybeans yielded 2,750 kg/ha with only minor variations among sites. Interplanted soybean yields were site and year dependent, however, and varied from 33 to 55% of their respective monocultures. Intercrop soybean yields were inversely related to the amount of N applied to corn. Yields of spring‐planted monoculture snapbeans ranged from 7,000 to 15,500 kg of fresh pods/ha. Regardless of yield level, however, interplanted snapbeans yielded 48% of the monoculture check. Fall snapbeans, relay interplanted into maturing corn in mid‐August, also produced about 50% of a crop. Land equivalent ratios (LER) of 1.20 to 1.40 thus suggest a 20 to 40% increase in total productivity during one 200‐day season by intercropping. Higher production by intercrops was most easily interpreted in terms of total leaf exposure. Monoculture corn had a leaf‐area duration (LAD) of 150 days; but when soybeans were interplanted into corn, LAD of the intercrop exceeded 300 days.
Relationship Between Laboratory Cold‐Test Methods and Field Emergence in Maize Inbreds1
Authors: Burris J. S. , Navratil R. J. 
Published: July 2010

AbstractReliable estimates of field emergence under adverse planting conditions are required for maximum crop management. The “cold‐test” is widely used as such a parameter. Various versions of the laboratory cold‐test for corn (Zea mays L.) were studied on 15 inbred lines. Substrates ranged from sterile Kimpak to sand‐soil mixtures to a test utilizing pure soil. All procedures incorporated a 10 C 7 day stress period followed by a grow‐out period at approximately 25 C. Variability between test results on the same sample was as much as 60%. The lowest coefficient of variability was achieved with a method incorporating a cellulose substrate covered with a small amount of soil. The test utilizing the sterile substrate was found to have laboratory performance characteristics similar to the soil tests. It appears that for the inbreds studied, much of the cold‐test response is due to the temperature stress and little to the soil.The ability of any of the tests to predict field emergence was quite variable. The lowest correlation and predictability was recorded with the method suggested by the AOSA Vigor Committee, while the sterile substrate test exhibited intermediate correlation performance compared to the other methods involving soil or soil mixes.The cold‐test is not a consistently reliable predictor of early field emergence. The variability inherent in the test makes comparison between laboratories difficult.
Evaluation of Temperature Effects on K Uptake by Corn1
Authors: Ching P. C. , Barber S. A. 
Published: July 2010

AbstractChanges in both plant uptake and soil supply parameters with temperature may restrict K uptake from cold soils. The objective of this research was to determine the effect of temperature on each of the soil and plant parameters used in a model simulating K uptake by corn (Zea mays L.). Then, using these measurements, to compare predicted by the simulation model with observed uptake. The parameters used in the simulation model were for the plant: root length at the start of the experiment; root growth rate; mean root radius; K influx as affected by K concentration outside the root; water influx; and for the soil: initial K concentration in soil solution; buffer power of K on the solid phase for K in solution; and the effective diffusion coefficient for K in the soil. The soil parameters were measured after equilibration of soils at 15 and 29 C in the laboratory. Where no additional K was added to the soil, soil solution K at 15 C was one‐half, buffer power was 1.7 and the effective diffusion coefficient was 0.4 of that at 29 C.The plant growth experiments were conducted in a controlled climate with an air temperature of 29 C and root temperatures of 15 C and 29 C. The K influx characteristics of corn roots as affected by root temperature were determined in solution culture experiments. Potassium influx at 15 C was one‐half that at 29 C. Root length increase while plants were subjected to root temperature differentials for 6 days (age 10 to 16 days) was 8 tunes greater at 29 C than at 15 C. These two factors resulted in a shoot K of 8.1% at 29 C and 3.7% at 15 C. Root growth rate, root radius, and mean water influx were measured for plants growing in soil at 15 and 29 C. Potassium uptake predicted by the simulation model was correlated (R2 = 0.98) with observed K uptake. A sensitivity analysis predicted the effects on K uptake of changes in the parameters used in the model that were due to temperature changes.
Evaluation of Cluster Analysis for Comparing Treatment Means1
Authors: Willavize Susan A. , Carmer S. G. , Walker W. M. 
Published: July 2010

AbstractUnivariate cluster analysis of treatment means is considered as an alternative to the least significant difference for those experiments where pairwise multiple comparisons are applicable. Although cluster analysis procedures produce distinct, non‐overlapping groupings of the treatments, little previous study has been made of their statistical behavior. The objective of the present research was to examine statistical properties of four clustering algorithms in terms of their power and Type I and III error rates for several patterns of homogeneity among treatment means. The Scott‐Knott (SK) divisive procedure and three agglomerative procedures based on single linkage (SL), complete linkage (CL), and unweighted pair group averages (UPG), respectively, were compared to the least significant difference (FLSD) when a preliminary F test of overall treatment effects is performed.Results of simulation studies indicate that the overlapping nature of the groupings of treatments obtained with the FLSD provides considerable protection against Type I and Type III errors. Both types of errors occurred with higher frequencies for all four clustering algorithms than for the FLSD. Furthermore, comparisonwise Type I error rates for the FLSD are determined by the researcher's choice of significance level, while the rates for cluster analysis are dependent on both the significance level and the degree of precision of the experiment. Consequently, researchers should contemplate with caution any possible adoption of cluster analysis as a replacement for a pairwise multiple comparison procedure such as the FLSD.
Topsoil and Subsoil Potassium Calibration with Leaf Potassium for Fertility Rating1
Authors: Woodruff J. R. , Parks C. L. 
Published: July 2010

AbstractPlants obtain K from both topsoil and subsoil, but soil testing is usually performed on surface soil. Interpretation of subsoil tests for available K has also been limited by insufficient calibration of subsoil K level with plant growth response. Leaf K response was used to calibrate topsoil and subsoil K levels for fertility rating.A 4‐year corn (Zea mays L.) — soybean (Glycine max L.) rotation on Marlboro loamy sand (Typic Paleudult) using various rates of K showed a buildup of K in the top 4 cm of B2 horizon with moderate annual K fertilization, but little change in Ap horizon K. Leaf K contents were sufficient where soil tests showed low topsoil and medium subsoil K. No yield response to K was obtained even after 4 years without K fertilization.A 1‐year corn experiment on Orangeburg sand and Faceville loamy sand (Typic Paleudults) using various rates of K showed increased K in both Ap and subsurface horizons 50 and 70 days after K application. No yield response to K additions was obtained on either soil, even though the Orangeburg Ap horizon tested low in available K. The lack of yield response at low K ratings suggested a need for adjustment in the rating.A 3‐year survey of the relationships among corn and soybean leaf K, and available K in Ap and top 10 cm of B2 horizons was made in the Middle Coastal Plain. Most of the soils were Typic Paleudults except for eight Psammentic Paleudults. A range of K application rates was not used at each site, preventing examination of relative yield response to soil K. Correlations were found between leaf K in both corn and soybeans and K in Ap and B2 horizons. To examine the contribution of K from each horizon, soil test calibration was achieved by multiple linear regression of leaf K on Ap and B2 available K values. Soil K fertility ratings were established from the regression equation using values for critical and sufficient leaf K to mark low and high soil test values.This work indicated that soybeans may obtain K from B2 horizons at greater depths than corn and that available K in the B2 horizon should be considered along with Ap soil test K to characterize the soil fertility status, particularly in cases where coarse‐textured topsoils occur over finer‐textured subsoil material.