bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cold Tolerance Evaluation of Several Centipedegrass Selections1
Authors: Johnston W. J. , Dickens Ray 
Published: July 2010

AbstractCentipedegrass (Eremochloa ophiuroides (Munro) Hack.), an excellent lawn grass throughout much of the lower South, is often limited by its lack of cold tolerance. Studies were conducted to determine variability in cold tolerance among centipedegrass selections as affected by hardening conditions. Seven clonal selections were grown under controlled environmental conditions using sand culture and cold hardened during a 21‐day exposure with a 12‐hour photoperiod, 22 C day (16 C day in the second experiment), 4 C night. Unhardened plants recieved a 31 C day, 25 C night.In one experiment, following hardening treatments, plants were exposed to —9.7 C for 1.5, 3, 5, 7 or 9 hours. In a second experiment plants were exposed to —3.0, —5.6, —7.3, or —10.1 C for 4 hours. After low‐temperature exposure plants were transferred to favorable growing conditions and rated for top‐kill and survival after 7 and 21 days respectively.Top‐kill increased and survival decreased as duration of cold exposure increased or temperature decreased. Exposing centipedegrass to cold hardening temperature regimes prior to freezing resulted in less top‐kill and more survival. Cold hardening increased low‐temperature tolerance a maximum of 2.3 C; i.e., percent survival was the same for hardened plants at —9.6 C as for unhardened plants at —7.3 C. Selections differed in amounts of top‐kill. Mississippi I, Tennessee Hardy, Oklawn, and FC‐2 were generally less susceptible to top‐kill than PllA,, Mississippi II, and FC‐8. No survival differences were noted among Centipedegrass selections following low‐temperature exposures.
A Self‐Propelled High‐Clearance Soil Coring Machine1,2
Authors: Bausch Walter , Onken A. B. , Wendt C. W. , Wilke O. C. 
Published: July 2010

AbstractMechanical soil sampling equipment currently available is suitable for sampling prior to crop establishment or in low growing crops but cannot be used without plant damage in some tall crops. A self‐propelled high‐clearance soil coring machine was designed and constructed to obtain soil samples in a tall standing crop at a range of lateral as well as vertical distances. The sampler is hydraulically operated and has vertical pressure and rotary drilling capabilities. This equipment has a lateral travel span of 152 cm and the capability of coring to a depth of 9 m with the mast in any lateral position on the track. Two operators can use the sampler without difficulty; however, three operators are desirable if a large number of samples are to be taken. As many as eighty 30‐cm increment soil samples have been taken per hour when sampling a moist sandy soil to a depth of 2 m.
Preliminary N, P, and K Foliar Diagnostic Norms for Soybeans1
Authors: Sumner M. E. 
Published: July 2010

AbstractThe previous successful application of Beaufils' Diagnosis and Recommendation Integrated System (DRIS) to crops such as corn and sugarcane as a foliar diagnostic tool capable of revealing mineral imbalances led to the need for the development of DRIS norms for soybeans [Glycine max (L.) Merr.]. Preliminary DRIS norms for soybean leaves are developed from 1,245 sets of data on elemental (NPK) leaf composition and corresponding yields. This is done by dividing the population of observations into two subpopulations on the basis of yield. The norms are calculated from those forms of expressing the leaf parameters which significantly discriminate between the two subpopulations. The degree of nutrient imbalance in the plant is expressed in terms of a DRIS index which measures the extent to which a particular nutrient deviates from the established norm. The norms are developed in such a way that the influence of age of tissue sampled on the diagnostic index is minimized. The DRIS norms enable one to diagnose whether N, P, or K is the nutrient most limiting to soybean production in a particular case to be diagnosed. The results show that the diagnosis can be made irrespective of variety and age at which the leaf is sampled. The advantage of the DRIS system in predicting nutrient imbalances even when the nutrient concentration in the plant is in or above the critical or sufficiency level range, is illustrated.
Field‐Measured Water Uptake of Sudangrass Roots as Affected by Fertilization1
Authors: Flühler H. , Ardakani M. S. , Szuszkiewicz T. E. , Stolzy L. H. 
Published: July 2010

AbstractCultural practices could affect the flow of water and solutes toward groundwater. In this field experiment we analyzed the effect of fertilization on water uptake of sudangrass (Sorghum vulgare sudanense, Germain's piper cultivar) and its indirect influence on deep drainage and nitrate leaching. Root water uptake was calculated as sink term in the continuity equation using successive measurements of water content and matric potential profiles in connection with field measured hydraulic conductivity functions. The experiment was conducted in three field plots on Hanford fine sandy loam (coarse‐loamy, mixed, thermic, Typic, Xerorthent).Fertilization increased dry matter production and water uptake significantly and reduced deep drainage and nitrate leaching. Water uptake patterns and root length distribution was not correlated. Mainly due to fertilization with nitrate nitrogen, the evapotranspiration approximated the amount of irrigation water applied. These results indicate that optimum water and fertilizer use and minimum groundwater pollution per unit crop production are intimately linked together.
Soybean Growth and Elemental Content as Influenced by Soil Amendments of Sewage Sludge and Heavy Metals: Seedling Studies1
Authors: Dowdy R. H. , Ham G. E. 
Published: July 2010

AbstractMany research studies have substituted soluble metal salts for sludge borne metal in attempts to define heavy metal uptake by plants. To assess this experimental approach and the effect of sewage sludge on the availability of soluble metals, soybean uptake of sludge and salt borne heavy metals was measured.Soybeans (Glycine max L. var. ‘Corsoy’) were grown 30 days in a growth chamber on an Aquic Hapludoll loam soil receiving the following treatments: a) sewage sludge applications of 0, 34, 67, and 134 metric tons/ha; b) addition of a combination (L) of heavy metals, as inorganic salts, of 10 mg Cu, Cd, Cr, and 18 mg Zn/kg soil at three levels, L, 2L, and 4L; and c) sludge plus metal additions. Sludge applications increased dry matter production, tissue P and N content and reduced root nodulation. Heavy metals depressed plant growth and nodulation in the absence of sludge. A 34 metric tons/ha sludge application eliminated these adverse effects. The Zn concentration of seedling tissue increased with applied Zn, from both sludge borne and salt borne sources. However, per unit of added Zn, more Zn accumulated in tissue grown on sludge amended soil. The tissue concentration of Cu and Cd increased with added sludge. A 34 metric tons/ha sludge application depressed salt borne Cd uptake. Sludge borne Cr and Ni were not taken up by the plants. Plant uptake of salt borne Cd and Ni was enhanced by the presence of Zn, Cu, and Cr. Hence, the uptake of sludge borne metals cannot be predicted from data obtained in studies using inorganic salts as the metal source.
Influence of Seed Size and Density on Germination, Seedling Emergence, and Yield of Grain Sorghum1
Authors: Maranville Jerry W. , Clegg Max D. 
Published: July 2010

AbstractSeed size is highly influential in determining germinability and seedling vigor of grain sorghum (Sorghum bicolor L. Moench), but whether this factor is predominate over seed density (i.e. specific gravity) has not been established. A 2‐year study was conducted to determine to what extent seed size and density influence germination and subsequent field performance. Large and small seed lots from the same genotype were compared to “more dense” and “less dense” seed lots which were separated using either urea‐phosphate or sucrose solutions. The results indicated that seed lots with larger and denser seeds had a higher percent germination. The data also supported the conclusion that a higher percentage of viable seeds could be selected from seed lots with low average germinability by using specific gravity separations. However, the establishment of seedlings, final stands, and grain yields were not a function of size or density when the same number of viable seeds were planted in the field.
Effect of Management Practices on Thatch Accumulation, Turf Quality, and Leaf Spot Damage in Common Kentucky Bluegrass1
Authors: Murray J. J. , Juska F. V. 
Published: July 2010

AbstractExcessive thatch accumulation is a serious problem in maintenance of turfgrasses. Several turfgrass management practices have been shown to influence thatch accumulation. The present study was undertaken to determine the effectiveness of various management practices alone and in combinations in preventing thatch accumulation in common Kentucky bluegrass (Poa pratensis L.), and the relationship between thatch accumulation, turf quality, and leaf spot damage. Treatment effects on thatch accumulation were assessed by measuring total amount of organic matter in the thatch layer. Ratings for turf quality and leaf spot damage caused by Helminthosporium spp. were based on color and stand density.Three sets of treatments were arranged in a split‐split plot design: (A) Mower clippings removed vs. not removed; (B) lime applied as needed to maintain a soil pH 7, lime applied at 4.8 to 7.3 kg/are biannually, and no lime (soil pH 5.4); and (C) sub‐sub‐plots that were: (a) aerified (coring), (b) handraked, (c) verticut, (d) had applications of a wetting agent, (e) had additions of organic matter (Milorganite®3), and (f) untreated. Thatch accumulation was not significant during the first 5 years of the study. Clipping residue left on plots significantly contributed to thatch accumulation when all treatments were averaged, and after thatch had built up to approximately 1.25 cm in depth. Residue from clippings did not increase thatch on aerified turf or turf receiving the wetting agent. Maintenance of soil pH of 6.8 and biannual lime applications effectively reduced thatch accumulation over that of untreated soil. Biannual lime applications did not increase decomposition beyond that of liming as needed to maintain a favorable soil pH. Aerification resulted in the least amount of thatch followed by the verticut and handraked treatments. The wetting agent did not effectively reduce thatch, and the addition of Milorganite® significantly increased thatch production.The highest quality turf was produced by permitting clippings to remain on the turf, maintaining a favorable soil pH and aerification. Clippings increased turf quality during temperature and moisture stress periods. Leaf spot damage was reduced by aerification, applying the wetting agent, and removing clippings. There was no significant difference in thatch level among the check, aerified, handraked, verticut, and wetting agent 14 months after their discontinuance.
Peanut Seed Germination as Related to Soil Water Regime During Pod Development1
Authors: Pallas J. E. , Stansell J. R. , Bruce R. R. 
Published: July 2010

AbstractThe problem of poor peanut (Arachis hypogaea L.) seed germination has appeared to follow exceptionally dry years in Georgia; consequently, the interaction of soil water availability during the growing season and subsequent seed germination were studied. These results are a composite of 4 years of study under controlled rainfall shelters on Tifton loamy sand, a member of the fine‐loamy, siliceous, thermic Plinthic Paleudults, at six soil water levels. Soil water levels involved irrigation at specified soil water tensions in surface 30 or 60 cm. Soil water tension ranged from + 0.2 to > 15 bar. Good germination of all varieties was obtained when the average soil water tension in the surface 30 cm was maintained at less than 0.6 bars. On the other hand, allowing ‘Florigiant’ to reach a soil water tension greater than 15 bars during the growing season lowered its percentage of sound mature kernels 34%. Of those sound mature kernels, germination was lowered on an average 20%. By contrast, under the similar treatment, SMK's of ‘Florunner’ and ‘Tifspan’ were lowered 22 and 7%, respectively, and the germination of either cultivar was lowered only about 5%. Thus, the large‐seeded Virginia type peanut, Florigiant, was found to be the most susceptible to droughty soil conditions. Irrigation appears to be good insurance against poor peanut seed germination in the following year.
Influence of Plant Population on Field Performance of Three Soybean Cultivars1
Authors: Lueschen W. E. , Hicks D. R. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.] seeding rates in commercial fields have generally been greater than necessary to obtain maximum seed yield. Because of higher seed costs, we conducted a field study to evaluate the agronomic response of three recently developed soybean cultivars on a clay loam (Aquic Argiudoll) to three plant populations − 171,000, 342,000, and 513,000 plants/ha. Significant yield increases were obtained in only 1 year as a result of higher plant population. Yields in the other years remained constant across populations. Plant height and maturity were not affected by plant population while lodging was increased at higher plant densities. The height above the soil surface of the lowest pod‐bearing node increased as plant density was increased. Numbers of branches, pods, and seeds per plant decreased as population increased. Results presented herein indicate that soybeans have the capacity to compensate for a wide range in plant densities without affecting yield.
Fitting Plants Nutritionally to Soils. III. Sorghum1
Authors: Brown J. C. , Jones W. E. 
Published: July 2010

AbstractFifteen sorghum (Sorghum bicolor (L.) Moench) lines, representing diverse germplasm currently used in crop breeding programs in the United States, were grown on the seven soils, used in part I of this study, to produce Fe, Zn, and Cu stresses or Al and Mn toxicities in soybeans. All 15 sorghum lines developed Fe and Zn deficiencies with symptoms ranging from some interveinal chlorosis to necrotic and twisted leaf tips. The sorghum lines responded differentially to Cu stress. When Cu was added to the soil, yields increased and P, Fe, and Zn concentrations significantly decreased in the plant material.The sorghum lines responded differentially to Al in Bladen soil. Five lines grew poorly and developed a chlorosis with some purple pigmentation; five lines were green and made good growth; and five lines were intermediate in their response. The chlorotic lines contained significantly less Fe and P than the green sorghum. On Richland soil (high Mn), yields were relatively good and the sorghum plants did not develop any persistent toxicity symptoms.Care should be taken to select the sorghum line best adapted to Fe, Zn, or Cu stresses and to Al toxicity so that the plant and the soil may be compatible.
Effect of Forage Harvest Frequency on Subsequent Alfalfa Seed Production and Pollen Quality1
Authors: Abu‐Shakra S. , Bhatti M. L. , Ahmed H. 
Published: July 2010

AbstractThe most suitable time during the growing season for maximum seed production of alfalfa (Medicago sativa L.) depends on geographic area. This investigation was undertaken to study the influence of four forage harvest treatments on the subsequent seed production and pollen quality characteristics of irrigated alfalfa in Lebanon. In addition, wild alfalfa pollinators were collected and identified. Two seed crops were produced after both one and two forage harvests. After three and four forage harvests, only one seed harvest was produced. The two seed crops following the one and two forage harvest treatments produced mean yields of 1,116 and 1,140 kg/ha, respectively. The first seed crop contributed 83% of the total yield. The seed yield components of number of stems/plant, racemes/stem, pods/raceme, and seeds/pod of the first seed crop were higher than those of the second crop. Hard seed percentages were more than 50% in the second crop where seeds developed between late September and early November, compared to less than 20% in the first crop where seeds developed between late June and end of August. Pollen viability was not significantly influenced by forage cutting treatment. However, pollen tube growth immediately after germination was most vigorous from late May to the end of June. This coincided with the flowering of the first seed crop after one and two forage harvests. Four species of Megachile, nine of Andrena, one of Halictus, one of Anthidium and two of Anthophora were identified as alfalfa pollinators.
Sunflower Yield and Water Use as Influenced by Planting Date, Population, and Row Spacing1
Authors: Alessi J. , Power J. F. , Zimmerman D. C. 
Published: July 2010

AbstractSunflower (Helianthus annuus L.) has only recently been grown commercially as an oilseed crop in the drier regions of the Northern Great Plains. This study was conducted to acquire preliminary information on seed yield, oil concentration, and water use for oil‐type sunflower as affected by planting date, plant population, and row spacing; and to obtain an indication how these results were affected by yearly variation in precipitation and air temperature. Sunflower was grown at Mandan, N. Dak. at plant population of 25,000, 50,000, 75,000, and 100,000 plants/ha in 30‐ and 90‐cm rows on Temvik silt loam (Typic haploboroll). Soil water withdrawal by sunflower was generally confined to the upper 150‐cm soil depth. Water use by sunflower was consistently greatest for earlier plantings, and was not affected by population or row spacing. Significant positive correlations were obtained between seed yield and water use after 50% flowering. Water use before flowering was much greater in a year of high precipitation during this period than in a year when pre‐flowering precipitation was lower. Seed and oil yield were usually highest for lowest populations and for 30‐cm row spacing. Correlation coefficients showed that 80% of the total variation in oil concentration was accounted for by variation in water use and temperature. Oil concentration was more strongly influenced by water use than by temperature. Although late planting in 1973 increased seed yield for some of the higher plant populations, flowering was delayed until early September, increasing the frost hazard. Days from planting to flowering (50%) decreased as planting date was delayed.
Top and Root Relations of Field‐Grown Soybeans1
Authors: Sivakumar M. V. K. , Taylor H. M. , Shaw R. H. 
Published: July 2010

AbstractField data describing both the top and root growth of soybeans [Glycine max L. (Merr.)] at different morphological stages are very limited. Such quantitative data are essential for analyzing or simulating growth patterns of whole soybean plants.Soybean top and root growth studies were conducted at the Western Iowa Experimental Farm on Ida silt loam soil [fine, silty, mixed (calcareous) mesic family of typic Udorthents]. Plant height, dry matter distribution of above‐ground plant parts, leaf area index, root length, and root dry weight distribution were measured at different physiological stages.Top‐root ratio of soybeans was 3.8 when the plants were in stage V6, and the ratio increased to 9.0 by the time that the plants reached stage V15R2. From the root length and leaf data, the total length of roots required to supply water and nutrients to each m2 leaf area was calculated. These root lengths increased from 630 m/m2 leaf area when the plants were in V6 stage to 1,190 m/m2 at V13R2 stage then decreased to 345 m/m2 at stage V15R2 as the soil dried. Root length in a specific layer decreased whenever soil was drier than —2 bars or volumetric water content was below 16%.Plant height and leaf area were positively correlated (r = 0.95). Most of the leaf area was concentrated in the upper portions of the soybean canopy when leaf area was maximum.
Trickle Irrigation and Fertilization of Tomatoes in Sand Dunes: Water, N, and P Distributions in the Soil and Uptake by Plants1
Authors: Bar‐Yosef B. 
Published: July 2010

AbstractTrickle irrigation has a special advantage in sandy soils where the accurate control of water and ions in the plant's root volume is critical. The purpose of the present work was to investigate the simultaneous migration of water and nutrients from a drip source in the field, to study the plant's response to various moisture and concentration distributions in the soil and to define optimal conditions for maximum yields.Tomato plants (Lycopersicum esculentum Mill.) grown in a field of fine sand received various daily rates of water, N, and P applied through a trickle irrigation system. Highest fruit yield (about 110 tons/ha) was obtained, when the daily average water content in the soil root volume was about 5% (w/w), the N concentration in the soil solution 140 ± 40 ppm N, and the N uptake rate about 100 mg N plant−1day−1. The estimated daily water consumption by the plants varied between 0.4 and 1.0 liter plant−1day−1, depending on the plants leaf area and climatic conditions. The estimated water quantity used to produce 1 g dry matter was similar in all the treatments — about 250 ± 40 g H2O/g d.m.
Forage Yield and Percent Cell Wall Constituents of Pensacola Bahiagrass as Related to N Fertilization and Clipping Height
Authors: Stanley R. L. , Beaty E. R. , Powell John D. 
Published: July 2010

Abstract‘Pensacola’ bahiagrass, Paspalum notatum, Flugge, is widely grown in the Southeast but little is known about the influence that cutting height has on forage yield and forage quality. The effect of height of clipping and N fertilization rate on yield and cell wall constituents was measured over a 2‐year period on an established stand of Pensacola bahiagrass growing on a loamy sand (Psammentic paleudults) which was fertilized annually with 0, 84, 168 and 336 kg/ha of N and clipped monthly at heights of 0, 2.5, 5.0, 7.5, 10.0, and 12.5 cm above the stolons. Highest forage yields were obtained when forage was harvested at ground level and yield was least when harvested at 10.0 or 12.5 cm. Cell wall constituents of the forage ranged between 70 and 72% and were not influenced by N fertilization or clipping height. Forage from the first harvest was lower in cell wall constituents than all later harvests. The data suggest that harvesting close to the soil will increase yields but quality as measured by cell wall constituents will be largely unchanged by N application or clipping height.
Effect of Ammonium to Nitrate Ratio on Growth and Pigment Development of Kentucky Bluegrass Cultivars1
Authors: Nittler L. W. , Kenny T. J. 
Published: July 2010

AbstractRed pigment development or lack of development in leaf sheaths is a useful characteristic for testing cultivar purity of Kentucky bluegrass, Poa pratensis L. However, additional knowledge is needed on the effect of nutritional and environmental conditions on expression of this characteristic so that conditions can be used that will produce the most precise and consistent results. Therefore we grew Kentucky bluegrass seedlings in sand and supplied them with solutions in which 10, 25, 50, or 75% of the N was NH4 and the remainder was NO3.Growth and pigment development were affected by the ratio of NH4 to NO3 in nutrient solutions and cultivars differed in both characteristics. Red pigment development, as determined by percentage of tiller height showing red color, was greatest when plants .were grown with a nutrient solution in which 75% of the N was NH4. Growth, as determined by tiller height, was less for plants grown with the 75% NH4 solution than for those grown with the other three solutions.Tiller height does not appear to be a very useful characteristic for cultivar purity testing, but red pigment development is very useful. The nutrient solution to use will depend on what cultivars are to be tested. In some cases it will be desirable to grow two or more groups of seedlings and use a different nutrient solution on each.