bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphorus Concentrations in Wheat Leaves in Relation to Phosphorus Toxicity1
Authors: Bhatti A. S. , Loneragan J. F. 
Published: July 2010

AbstractThe relationship between P concentration and the development of P toxicity symptcms in leaves was followed in young wheat plants growing on a siliceous sand at two levels of CaH4(32PO4)2 and of NH4NO332P accumulated in the terminal region of the first leaves prior to the appearance of necrotic symptoms. When symptoms developed they coincided closely with regions of 32P accumulation. NH4NO3 slowed down the rate of 33P accumulation in leaf tips and alleviated P toxicity symptoms.P concentrations in and near necrotic areas of leaf tips ranged from 4 to 5% dry weight and most of this could be expected to be present largely (80% or more) as inorganic orthophosphate salts. Phosphate concentration in the cell sap could reach values of 200 mM with an osmotic pressure of about 10 atmospheres. It is suggested that under certain conditions this high phosphate concentration might disturb the water relations of the leaf cells, thus causing the observed injury.
Phytotoxicity of Water Extracts of Fruit, Stems, and Roots of the Tomato Plant and a Technique for Its Determination1
Authors: Simmons R. Walter , Axley John H. 
Published: July 2010

AbstractA modified “rag doll” test was used to demonstrate that the entire tomato plant does not exhibit uniform toxicity to wheat seedlings. The major toxicity resides in the fruit as opposed to vines and roots.The “rag doll” test for seed germination was modified to become a biological toxin assay test. It had a coeffi. dent of variation of 37.9% and 35.9% for roots and shoots which is comparable to 79.8% and 64.4% for the petri dish test.
Differences in Annual Clover Responses to Phosphorus and Sulfur1
Authors: Jones M. B. , Lawler P. W. , Ruckman J. E. 
Published: July 2010

AbstractMany new varieties of winter annual legumes are now available for pastures in Mediterranean type climates. Since little work has been reported comparing the relative responses of these legumes to fertilization, 10 varieties of subclover, 6 of rose clover, 3 annual Medicagos, and 2 other annual clovers were grown in the greenhouse on a soil known to be deficient in P and S. There were four levels of P with S applied. The nil and highest P levels were repeated without S.Yield differences between varieties and species were small where no P or S was applied. Responses to S alone were generally not significant, but responses to P only and P plus S varied significantly. Differences in response to P and S fertilization were as great among varieties of a given species as between species.Highest yielding clover varieties tended to have lowest percentages of P and S. Differences in P and S uptake by the clover varieties were significant; however, uptake responses to fertilization tended to be relatively smaller than yield response differences, indicating that some varieties utilized absorbed nutrients more efficiently than others.Response to fertilization apparently must be considered on a varietal basis rather than generalizing about species.
Crownvetch Seedling Growth on an Acid Soil as Influenced by Soil Preparation and Lime Placement1
Authors: Faix J. J. , Elkins D. M. , Jones J. H. 
Published: July 2010

AbstractThe experiment reported here was conducted to compare. the effect of disturbed and undisturbed soil and of lime placement under both soil conditions on seedling growth of crownvetch. The results are applicable to crownvetch establishment for roadbank stabilization. Crownvetch seedlings were grown from seed on disturbed and undisturbed Wartrace silty clay loam soil core samples (pH 4.6) taken from a simulated roadcut. Lime at a rate of 13.45 metric tons/ha was added to the top 0.5 cm of undisturbed core samples of bulk density 1.494, or mixed throughout disturbed and screened soil of bulk density 1.267.Disturbed soil without lime, disturbed soil with lime mixed throughout, or disturbed soil with surface‐applied lime resulted in increased top and root growth over that in undisturbed soil. Top growth was significantly increased when lime was mixed throughout the disturbed core sample over that when lhne was added at the surface of the disturbed soil. There was no difference in root growth between these two treatments, but both were significantly higher than the other treatments. Disturbed soil without lime gave as much growth as when lime was surface‐applied on undisturbed cores, but there was an absence of nodules on all treatments where lime was not applied.
Effect of P, CaCO3 and CaSiO3 Fertilization upon Incidence of Corn Smut1
Authors: Tamimi Yusuf N. , Hunter James E. 
Published: July 2010

AbstractIncidence of corn smut was investigated in two fertilizer (5 ✕ 5 factorial) experiments on P ✕ CaCO3 and P ✕ CaSiO3. Phosphorus rates were 0, 84, 168, 336, and 672 kg/ha; CaCO3 and CaSiO3 rates were 0, 6.72, 13.44, 26.88, and 53.76 tons (metric)/ha. In both experiments, the effect of P on reduction of corn smut was statistically significant. Disease incidence was reduced from 12.1 and 13.1 to 7.4 and 5.8% with application of 84 kg P/ha in the P ✕ CaCO3 and the P ✕ CaSiO3 experiments, respectively. Further increases in rate of P did not significantly reduce incidence of smut below that of the 84 kg P/ha. Rates of CaCO3 or CaSiO3 did not significantly affect the incidence of corn smut, yet percent infection in the P ✕ CaSiO3 treatments was significantly lower than in the P ✕ CaCO3 treatments (P < .08). There was no significant effect of the P ✕ CaCO3 or P ✕ CaSiO3 interaction on incidence of smut. Soil pH, which ranged from 5.12 to 6.84, was also found to have no significant effect on infection.
Viability of Kentucky Bluegrass Pollen (Poa pratensis L. ‘Newport’) as Influenced by Collection Time and Temperature1
Authors: Teare I. D. , Maun M. Anwar , Canode C. L. 
Published: July 2010

AbstractAttempting to determine reasons for extreme variability in germination of Kentucky bluegrass pollen, we studied temperature and time effects, harvesting panicles from a seed field at 8:00 A.M., subjecting them to temperatures ranging from 21 C to 49 C, collecting pollen at hourly intervals for germination on agar medium and subsequent microscopic examination. Pollen viability decreased with increased exposure time and with higher temperature.The average germination of pollen collected at 8:00 A.M. was approximately 50%, so we collected pollen in the field at half hour intervals from 6:00 to 8:00 A.M. and at hourly intervals thereafter until 4:00 P.M. Germination of pollen exceeded 80% from 6:00 to 7:30 A.M., but declined to 50% by 8:00 A.M. and to less than 2% by 9:00 A.M. Pollen collected each hour from 11:00 A.M. to 4:00 P.M. would not germinate.
A Tractor Mounted Unit for Harvesting Potatoes in Experimental Plots1
Authors: Christenson D. R. , White R. P. 
Published: July 2010

AbstractA transportable unit for harvesting potatoes in experimental plots was developed by adapting a single row, power‐take‐off potato digger to a “three‐point” hydraulic tractor hitch. Digging depth was controlled by using a double acting hydraulic cylinder as the top link in combination with the lifting arms of the hitch. With the unit potatoes may be harvested from small plot areas without disturbing adjacent areas.
Exchangeable Aluminum Levels in Two Soils as Related to Lime Treatment and Growth of Six Crop Species1
Authors: Hutchinson F. E. , Hunter A. S. 
Published: July 2010

AbstractFifty soil samples were collected from the 12.7 to 15.8‐cm and the 43.2 to 48.3‐cmzones in five randomly selected selected sites for each of two acid glacial till soils to measure the relationship of pH and exchangeable AI. Alfalfa, alsike clover, orchardgrass, timothy, oats and barley were grown at three lime rates on one site of each soil which contained a high level of exchangeable A1 to determine the effects of varying pH and AI on crop yield. The Caribou and Thorndike soils contained an average of 255 and 346 kg/ha of exchangeable AI, respectively, at the 12.7 to 15.8‐cm depth, whereas the levels at 43.2 to 48.3‐cm were 152 and 347. There was significantly less A1 in the subsoil than in the topsoil of the Caribou. When limed rates of 0, 1,469 and 2,938 kg/ha for the Caribou and 0, 2,203 and 4,406 kg/ha for Thorndike soil, the average pH values were 5.03, 5.79 and 6.15, and 5.23, 6.08 and 6.46, respectively. Comparable exchangeable Al values were 196, 33 and 11, and 138, 21 and 19 kg/ha. Dry matter production of alfalfa, alsike clover and barley was significantly less when grown at AI levels greater than 100 kg/ha, whereas dry matter yields of oats, orchardgrass and timothy were uneffected at the above levels of A1. Grain yield of barley was reduced at the highest level of AI in one of the soils.
Germination of Cultivars of Trifolium subterraneum L. in Relation to Matric Potential1
Authors: Young James A. , Evans Raymond A. , Kay Burgess L. 
Published: July 2010

AbstractThe germination of 11 cultivars of subclover (Trifolium subterraneum L.) in relation to matric potential was dependent on the texture of the soil substrate. Germination terminated or was virtually zero at minus 6, 8, and 12 bars, respectively, on sand, loam, and clay substrates. Germination on soil beds in the greenhouse was dependent on substrate texture and the amount of seed coverage. On sand beds where the matric potential was high, hydraulic conductivity between the sand grains and the seeds on the soil surface was apparently so low as to impede germination. In all tests in which germination was more than minimal, variability among the cultivars was marked.
A Mechanical Node Harvester for Soybeans1
Authors: Clark R. C. , Fehr W. R. , Empig L. T. 
Published: July 2010

AbstractWe developed a mechanical node harvester for sampling bulk populations of soybeans (Glycine max (L.) Merrill). The node harvester consists of a metal box mounted on the cutter bar of a Scythette. A population is sampled by discarding the top half of the plants, then cutting and collecting one node from each plant with the node harvester.The efficiency of the node harvester as a means of generation advance was compared with single‐seed descent, restricted cross‐bulk, maturity‐group bulk, and cross‐bulk. The methods were used to sample four varietal blends whose components could be distinguished by seed characteristics. The mechanical node harvester was not as accurate as single‐seed descent for equally sampling all plants of a population, but was five times faster than single‐seed descent. The principal advantages of the mechanical node harvester are that it (a) is as fast as the cross‐bulk method, (b) is more accurate for sampling than cross‐bulk, and (c) could be used as a mass‐selection device for improving the lodging resistance of a heterogeneous population.
Influence of Temperature on Seedling Growth and Carbohydrate Composition of Three Alfalfa Cultivars1
Authors: Ueno Masahiko , Smith Dale 
Published: July 2010

AbstractThree cultivars of alfalfa (Medicago sativa L.), ‘Vernal,’ ‘Cody,’ and ‘Florida 66,’ were grown 35 days from seed in three temperature regimes: hot (H) 32C day/27C night, warm (W) 27/21C, and cool (C) 21/15C. Plant maturity was delayed as temperatures decreased. Shoot weights of heights and plant parts for each cultivar generally were greatest in the W regime, followed in order by the H and C regimes. Most of the significant differences among cultivars occurred in the C regime where Florida 66 was shorter in shoot height and produced less growth than Cody and Vernal.Percentages of total nonstructural carbohydrates (TNC) in the plant parts were influenced more by temperature than percentages of structural tissue (ST). Weights of ST and TNC were closely related to dry matter yields, but temperature influenced the weights of ST more than those of TNC.
Effective Day Lengths for the Study of Photoperiod Sensitive Reactions in Plants1
Authors: Francis C. A. 
Published: July 2010

AbstractThe number of hours with a light intensity above the critical level for photoperiod sensitive reactions in plants is greater than the number of sunlight hours. In temperate latitudes, dark periods calculated from time of sunset to sunrise are nearly 1 hour longer than the effective dark period with an intensity less than 1 ft.‐c.; conversely, the effective photoperiod is longer by 1 hour. The length of the twilight period was used to calculate the number of “photoperiod effective” hours above critical intensities of 10, 5, 2, and 1 ft.‐c. (108, 54, 22, and 11 lux). These photoperiodic day lengths are presented for latitudes from 70° N to 60° S and all months of the year. Heavy cloud cover reduces the effective photoperiod, while scattered high clouds may reflect enough light from the sun below the horizon to lengthen the day slightly. These physical day lengths may be used to predict plant response for different planting dates in a given location when critical intensities of light and critical photoperiods which influence reactions in each crop species are known.
Soil Water and Soil Temperature Influences on Dryland Winter Wheat1
Authors: Black A. L. 
Published: July 2010

AbstractEffects of wheat straw mulch on soil water and soil temperature in the 0‐ to 7.6‐cm soil layer and their subsequent influence of plant development and grain yields of winter wheat (Triticum aestivum L., ‘Winalta’) were evaluated over a 3‐year period. Mulch rates of 0, 1,680, and 3,360 kg/ha were applied randomly or in bands centered over or between wheat rows planted in 35‐, 70‐, and 90‐cm row spacings. Band applications of straw were applied at the same rates per unit area as that covered by randomly applied straw but in band widths of 18, 35, and 45 cm for the respective row spacings.In a time sequence of correlations, number of tillers and number of adventitious roots were positively correlated with a moist soil‐degree day index (P=.01) based on May soil water and soil temperature measurements, number of adventitious roots was positively correlated with number of heads/ha (P=.01), and number of heads/ha was positively correlated with grain yield (P=.01). Numbers of adventitious roots, tillers, and heads and final grain yields were dependent upon the soil water and soil temperature of the 0‐ to 7.6‐cm soil layer during May. The intermediate straw mulch rate (1,680 kg/ha) applied randomly or in bands over the wheat row significantly increased the number of moist soil‐degree days and grain yields in 2 of 3 years compared to bare fallow or the high straw mulch rate (3,360 kg/ha).
Symap and Net Radiation in a Soybean Canopy1
Authors: Luxmoore R. J. , Millington R. J. , Peters D. B. 
Published: July 2010

AbstractSpatially disposed net radiation data from a soybean canopy were mapped using an interpolation and mapping computer program called “Symap.” A large proportion of radiation was intercepted by the upper peripheral layer of leaves. The Symap program has application to other crop environment studies.
Effects of Nitrogen Rates and Plant Spacing on Sunflower Seed Yields and Other Characteristics1
Authors: Massey John H. 
Published: July 2010

abstractField experiments were conducted to determine effects of nitrogen and plant spacing on sunflower (Helianthus annuus L.). Nitrogen rates were 0, 56, 112, and 168 kg/ ha, and plants were spaced 15, 30, and 46 cm apart within rows 1.1 m wide.Nitrogen at 56 kg/ha increased seed yield, grams of seed per head, seed size, and head diameter 653 kg/ha, 17.7 g, 1.9 g/200, and 2.2 cm, respectively, as compared to nontreated plots. Plant height was increased 11 cm and stem diameter 4 mm by 56 kgN/ha. No further increases resulted from additional N. Nitrogen did not affect number of leaves per plant.Seed yield decreased, but yield per head and head diameter increased with each 15‐cm increase in plant spacing. Seed were larger at 30‐ and 46‐ than at 15‐cm spacing. Spacing did not affect plant height or number of leaves, but stem diameter increased with wider spacing.There was no significant interaction between nitrogen and plant spacing for any characteristic studied.
Evaluation of Cool Season Grass Species and Varieties Using In Vivo and In Vitro Techniques1
Authors: Wurster M. J. , Kamstra L. D. , Ross J. G. 
Published: July 2010

AbstractDigestibility of the cool season grass species, smooth bromegrass (Bromus inermis Leyss), intermediate wheatgrass [Agropyron intermedium (Host) Beauv.] and the crested wheatgrass complex [Agropyron sibericum (Willd.) Beauv. and Agropyron desertorum (Fisch.) Shult.] was measured at heading and 2 weeks after by in vivo and in vitro techniques. In addition, plant fraction percentages and digestibilities were determined throughout the season for two varieties within each of the above species, ‘Manchar’ and ‘Sac’ bromegrass, ‘Greenar’ and ‘Oahe’ intermediate wheatgrass, and ‘P‐27’ Siberian wheatgrass and ‘Nordan’ crested wheatgrass. Both in vivo and in vitro criteria, as well as chemical analyses, indicated that intermediate wheatgrass was lower in digestibility than the other two species. Bromegrass and crested wheatgrass differed very little; bromegrass was slightly superior under in vivo test, while crested wheatgrass was slightly but significantly superior when in vitro techniques were used. A high correlation (r=0.89) was found between in vitro and in vivo dry matter digestibility.At heading and 2 weeks after, in vitro dry matter digestibility indicated that Greenar was significantly superior to Oahe. No significant difference was found between the varieties of the other species. When entire plant and plant fractions were sampled over the growing season, Sac bromegrass was significantly superior to Manchar, Greenar intermediate wheatgrass to Oahe and Nordan crested wheatgrass to Siberian. These results indicate the possibility of selecting for more highly digestible stems and sheaths to produce a variety for utilization at the time of maximumd dry matter yield. For grazing purposes, however, selection at an early stage for whole plant digestibility would seem desirable.
Cutting Management Effects on Growth Rate and Dry Matter Digestibility of the Sorghum‐Sudangrass Cultivar Sudax SX‐111
Authors: Edwards Ned C. , Fribourg Henry A. , Montgomery M. J. 
Published: July 2010

AbstractRelationships between growth rate and dry matter digestibility, as influenced by frequency of cutting and stage of growth, were examined for a sorghum‐sudangrass hybrid cultivar (Sorghum bicolor (L.) Moench ✕ Sorghum sudanense (Piper) Stapf. ‘Sudax SX‐11’). Growth rates were obtained by harvesting intact plants and measuring yield components at weekly intervals. Digestible dry matter (DDM) was estimated by measuring the dry matter disappearance using the nylon‐bag technique.The seasonal distribution and amounts of dry matter and of DDM were altered by variations in cutting management (early‐boot vs. 75‐cm growth) and environmental conditions. DDM of entire plants was proportional to percent leaves and inversely related to percent stems. DDM of stems decreased about three times more and faster than the DDM of leaves during a 14‐week period. DDM of entire plants decreased from 90% when plants were 30 cm high to less than 60% when plants were 250 cm tall, and remained relatively constant for 6 weeks after panicle emergence.
Chemical Element Accumulation by Populations of Corn (Zea mays L.) Selected for High and Low Accumulation of P1
Authors: Baker D. E. , Wooding F. J. , Johnson M. W. 
Published: July 2010

AbstractThe objective of the investigation of which this report is a part was to identify chemical elements, organic compounds, or metabolic processes which are associated with genetically controlled P accumulation in corn (Zea mays L.).Two populations of corn, each with subpopulations selected for high and low P in ear leaves, were produced by randomly sib mating the F2 and five and six subsequent generations of an early maturing single‐crossed hybrid and a late maturing single‐cross hybrid. Each single‐cross hybrid contained homozygous inbred lines previously characterized as contributors of low and high concentrations of P to other single‐cross hybrids. In ear leaves, high P was associated with significantly higher, but not substantially different, concentrations of N and B. In seedling plants, grown for three weeks in a growth chamber, high accumulation of P was associated with higher concentrations of N and significantly higher concentrations of S, Ca, Cu, and B.
Effect of Seed Size upon Rate of Germination in Soybeans1
Authors: Edwards Calton J. , Hartwig Edgar E. 
Published: July 2010

AbstractThe rate of emergence of near‐isogenic soybean [Glycine max (L.) Merr.] lines that differed in seed size was measured when germinated in Sharkey clay at moisture levels of 20, 22.5, 25, 27.5, and 30%. Weight per 100 seed of lines used was 9.5 g, 13.6 g, and 22.6 g. No emergence was observed at 20% moisture. The small and medium seed size gave more rapid emergence and greater root development than the large seed at each soil moisture level where germination occurred.
Leaf Area Index, Tillering Capacity, and Grain Yield of Tropical Rice as Affected by Plant Density and Nitrogen Level1
Authors: Fagade S. O. , De Datta S. K. 
Published: July 2010

AbstractTo study the effects of plant density and N level on tillering capacity, leaf area index, and other growth characteristics and grain yield of flooded rice (Oryza sativa L.), we planted an improved tropical rice cultivar, ‘IR8,’ two experimental lines, ‘IR305‐4‐12‐1‐3’ and IR127‐ 80‐1‐10’, and a traditional tall tropical cultivar, ‘Peta,’ at three nitrogen levels in puddled soil. All cultivars were transplanted at five spacings and also broadcast. Of the three improved semidwarf rices, ‘IR305‐4‐12‐1‐3’ had the highest tillering capacity. Increasing plant density and nitrogen level increased the leaf area index (LAI) of all varieties at flowering. Broadcast‐planted plots had higher LAI values than transplanted plots. In the sunny dry season, broadcast‐planted ‘Peta’ had the highest LAI value, 14.6. In comparison, ‘IR127‐80‐I‐I0’, a low‐tillering line, had a LAI value of only 7.0. Grain yield increased with increased LAI values in the dry season, except for ‘Peta’ which lodged severely just after flowering. In the cloudy wet season, broadcast‐planted ‘IR8’ had the highest LAI value, 10.2, but it lodged. ‘IR8’ that was transplanted at close spacings did not lodge and it had higher yields. Thus even with an improved cultivar like ‘IR8’, grain yield declines at a high value if the crop lodges.
Influence of No‐tillage on Soil Moisture1
Authors: Blevins R. L. , Cook Doyle , Phillips S. H. , Phillips R. E. 
Published: July 2010

AbstractField studies were conducted to compare the effect of no‐tillage versus conventional tillage corn (Zea mays L.) production on soil moisture. The studies were made on a Donerail silt loam in 1968 and 1969 and on a Maury silt loam in 1970. Soil moisture was measured periodically at various depths in the soil profile during the growing seasons.No tillage treatments had higher volumetric moisture contents to a depth of 60 cm during most of the growing season. The greatest differences occurred in the upper 0 to 8‐cm depth. Beyond a depth of 60 cm, systems of tillage had little influence on soil moisture during the growing seasons. Soil moisture curves indicate different water withdrawal patterns under the two contrasting methods of tillage. The decrease in evaporation and the greater ability to store moisture under no‐tillage produces a greater water reserve. This can often carry the crop through periods of short‐term drought and avoid the development of detrimental moisture stresses in the plant. The more efficient use of soil moisture by no‐tillage is reflected in higher corn yields. This study further substantiates the effectiveness of no‐tillage systems of corn production on well to moderately well‐drained silt loam soils in Kentucky and other regions with similar climatic regimes.