bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correcting pH‐Induced Manganese Deficiency in Bermudagrass Turf1
Authors: Snyder G. H. , Burt E. O. , Gascho G. J. 
Published: July 2010

AbstractManganese deficiency of ‘Tifgreen’ bermudagrass (Cynodon ✕ magenissii Hurcombe) turf has been observed in South Florida when soil pH exceeded 7 as a result of irrigation with alkaline water. A 2‐year field study on Pompano fine sand (a siliceous, hyperthermic, typic Psammaquent) was designed to evaluate three approaches to correcting this deficiency: 1) soil pH reduction with acid forming N sources, 2) Mn fertilization at rates up to 5 g/m2 using MnSO4, a Mn‐chelate, or a Mn‐frit, and 3) MnSO4 fertilization in combination with a series of fungicidal drenches for suppressing Mn‐oxidizing soil fungi. Sulfate and chelate Mn sources provided short‐term correction of the deficiency, but little response to the frit source was noted. Sustained correction was achieved with MnSO4 in combination with the fungicidal drenches. However, adequate Mn nutrition was obtained even in the absence of Mn fertilization when soil pH was maintained below 7 with acid‐forming N sources. This treatment appears most suitable for turfgrass, since considerable N commonly is used in turfgrass production.
Persistence and Productivity of Tall Fescue in Bermudagrass Sods Subjected to Different Clipping Managements1
Authors: Fribourg Henry A. , Overton Joseph R. 
Published: July 2010

AbstractBermudagrass (Cynodon dactylon (L.) Pers.) is a vigorous and productive forage crop in the U.S. mid‐South during the warm season, but is dormant from October through March. Tall fescue (Festuca arundinacea Schreb.) is semidormant in summer, grows well in spring and to some extent in autumn and winter. The objective of this study was to determine the effects of combinations of N fertilization level, harvesting management, and fescue row spacing, on the productivity and persistence of both bermudagrass and fescue in bermudagrass sods overseeded with fescue. ‘Kentucky 31’ tall fescue was overseeded in 25 or in 50‐cm rows in October, 1970 on an established ‘Midland’ bermudagrass sod growing on a coarse‐silty, mixed, acid thermic, aeric Fluvaquents soil at the West Tennessee Experiment Station, Jackson. Four rates of N fertilization included: none; or 200, 400, or 600 kg N/ha/year applied in four equal installments. Three clipping managements were superimposed: 5‐cm growth cut to a 2.5‐cm stubble, 10‐cm growth cut to a 5‐cm stubble, and 30‐cm growth cut to a 25‐cm stubble. Persistence of each species, composition of dry matter yield, and N content of harvested forage were measured from 1972–1975. When N was not applied, or when 200 kg N/ha/year were applied, fescue stands were excellent. Higher N rates resulted in half a stand. Fescue stands were less persistent in 50‐cm than in 2.5cm rows. Bermudagrass sods were maintained under all management conditions. Under the frequent 10 to‐5 cm and 5 to‐2.5 cm managements and with 200 kg N/ha/year, 1,500 kg dry matter/ha or more were harvested in each of four harvest periods (late winter to mid‐May, mid‐May to mid‐July, mid‐July to September, October through December) from the grass associations. The combination of the two species extended the season of production of the sod from 5 to 9 or 10 months/year during each of 3 years and increased dry matter production from 5,800 to 7,150 kg/ha/year. Most uniform production each year was obtained when fescue was seeded in 25‐cm rows and harvested from 10‐cm height to a 5‐cm stubble.
Soybean Desiccation by Paraquat, Glyphosate, and Ametryn to Accelerate Harvest1
Authors: Whigham D. K. , Stoller E. W. 
Published: July 2010

AbstractChemical desiccation is often desirable to hasten maturity so seed can be harvested earlier than normal. Soybeans {Glycine max (L.) Merr.} were sprayed with paraquat (1,1′‐dimethyl‐4,4′‐bipyridinium ion) at 0.6 and 1.1 kg/ha, glyphosphate {N‐(phosphonomethyl) glycine} at 1.7 and 3.4 kg/ha, and ametryn }2‐(ethylamino)‐4‐isopropyl amino‐6‐methythio‐s‐triazine} at 1.1 and 2.2 kg/ha 4, 3, and 2 weeks before the estimated harvest date to desiccate the soybeans and accelerate harvest. The objective was to determine the effect of pre‐harvest chemical desiccation on seed yield and quality. In field experiments, on a fine, montmorillonitic mesic Aquic Arguidoll, Flanagan series soil, harvest was accelerated, but all chemicals significantly reduced yields when they were applied 3 and 4 weeks before harvest. Yields were not significantly reduced by applications 2 weeks before harvest. Paraquat was the most effective desiccant for accelerating soybean harvest. Paraquat also reduced yield and seed weight the most while glyphosate had the least effect. Growth chamber studies indicate that ametryn and paraquat did not affect seed germination or seedling vigor, but all glyphosate applications significantly reduced germination and soybean seedling vigor.Chemical desiccation of soybeans prior to physiological maturity will significantly lower soybean yields. Glyphosate is not recommended as a desiccant.
Root Adjustments Associated with Salt Tolerance in Small Grains1
Authors: Bower C. A. , Tamimi Y. N. 
Published: July 2010

AbstractDiscovery of the physiological basis of salt tolerance in small grains and its use to obtain more tolerant cultivars especially of rice (Oryza sativa L.) by modern plant breeding procedures should permit substantial increases in world food production. The purpose of this study was to test the hypothesis that at a given level of root media salinity the salt tolerance of various small grain cultivare is directly related to the total salt concentration of the root water. Cultivars were grown in the greenhouse ;1 to 6 weeks after transplanting as seedlings on nonsalini: and saline culture solutions. Shoots of cultivars grown on saline solutions invariably had a lower water conteni: than shoots grown on nonsaline solutions, indicating thai: salt injury involves water stress. Salt tolerance of the various cultivars, expressed as relative yield on saline cultures, was highly related to the salt concentration of root water with two exceptions, and was highly related without exception when relative root growth on saline culture was taken into account.In agreement with previous observations, it was found that the order of salt tolerance of small grains, at least in the vegetative stage, is barley (Hordeum vulgare L.) > rye (Secale cereale L.) ≅ wheat (Triticum aestivum L.) > oat (Avena sativa L.) > rice.
Utilization of 15N Fertilizer by Nodulating and Non‐Nodulating Soybean Isolines1
Authors: Deibert E. J. , Bijeriego Manuel , Olson R. A. 
Published: July 2010

AbstractUncertainty remains concerning the magnitude of symbiotic N fixation by the soybean crop [Glycine max (L.) Merr.] when grown under varied N management systems. For deriving further enlightenment on the issue, 15N‐enriched fertilizer was applied on two soybean isolines with objectives of measuring the fraction of N derived from symbiotic fixation, residual soil N and applied fertilizer N. Plant samples were collected at full bloom, beginning‐seed, and full‐maturity stages in a field experiment conducted at the University of Nebraska Field Lab on Sharpsburg soil (Typic Argiudoll) of 3.3% organic matter content. Nitrogen fertilizer was applied at rates of 45, 89, and 134 kg/ha at planting or at full bloom.Nitrogen fertilization had no significant influence on yield or N and oil concentration of the nodulating isoline seed but increased these parameters of the non‐nodulating isoline, with delay in N fertilization being distinctly advantageous. Fertilizer utilization percentage by both isolines at later growth stages increased as fertilizer rate increased, contrary to N utilization patterns of cereal crops.“A ” value increases with increased N fertilizer rates suggested a soil N priming and/or root extension effect. Less plant N came from the soil with delayed N fertilizer application. Fertilizer applied at planting at rates above 45 kg N/ha reduced the symbiotically fixed N fraction, whereas delaying fertilizer application had no such influence at any rate of N employed.
Differential Use of Fe3+ and Fe2+ by Oats
Authors: Brown J. C. 
Published: July 2010

AbstractPlants have specific Fe requirements, dependent on their ability to make Fe available in a useful form. They are classed Fe‐efficient if they respond to Fe‐deficiency stress by inducing biochemical reactions that make Fe available in a useful form, and Fe‐inefficient if they do not. This study was conducted to characterize the use of Fe by Fe‐inefficient oats (Avena byzantina K. Koch) ‘TAM 0‐312,’ and Fe‐efficient oats ‘Coker 227.’ These cultivars were grown in nutrient solutions where they were subjected to different degrees of Fe stress induced by variable concentrations of either phosphate, CaCO3, or Fe. The oat plants were grown in an environmentally‐controlled chamber with 16 hours of light at approximately 320 µEm‐3 sec‐1 and 8 hours of darkness at a temperature of 24 ± 2 C. Coker 227 was more Fe‐efficient than TAM 0‐312 regardless of how Fe stress was induced and usually contained less Ca than TAM 0‐312. TAM 0.312 required 1.2 mg Fe/liter in the nutrient solution before it was green, whereas Coker 227 required only 0.6 mg Fe/liter. Susceptibility to Fe chlorosis in these cultivars was caused by the inherent nature of the plant to use either Fe8+ or F2+ and by the greater use of Ca by TAM 0‐312 than by Coker 227. The plant plays a key role in maintaining a proper nutrient elememt balance and the availability of a nutrient element for plant use.
Performance of Spring Barley in Narrow Rows1
Authors: Brinkman M. A. , Luk T. M. , Rutledge J. J. 
Published: July 2010

AbstractSeveral researchers in the U. S. and Canada have investigated the effect of row spacing on yield and other agronomic traits of small grains with variable results. The objective of this study was to compare the performance of spring barley (Hordeum vulgare L. emend Bowden) seeded in a very narrow row spacing (7.5 cm) with two row spacings (15 and 30 cm) commonly used in production agriculture and in experimental research. Three genotypes were planted at Madison, WI, in 1975 and 1976, in a St. Charles silt loam soil (Typic Hapludalf, fine‐silty, mixed, mesic) and at Arlington, WI, in 1977, in a Plano silt loam soil (Typic Arguidoll, fine‐silty, mixed, mesic). A seeding rate of 134 kg/ha was used in all row spacings. The three environments had yield levels ranging from high to low, due primarily to differences in rainfall.When results were combined over environments, 7.5 cm‐rows yielded 4% more grain than 15‐cm rows and 12% more grain than 30‐cm rows. These differences were significant, but differences were not always significant for a single environment. Straw yield response to row spacing was similar in magnitude to the grain yield response. The increased grain and straw yields in narrower rows were attributed to greater tillering. There was significantly less lodging in 7.5‐cm rows than in 15 and 30‐cm rows in the two environments in which lodging occurred.Although the grain and straw yield improvements in this study may not be large enough to encourage changing to grain drills with a row spacing narrower than 15 cm, the reduced lodging in 7.5‐cm rows may be an added advantage when lodging is substantial.
Bermudagrass Survival as Influenced by Deacclimation, Low Temperatures, and Dormancy1
Authors: Chalmers D. R. , Schmidt R. E. 
Published: July 2010

AbstractWinter survival is the most relevant problem in using bermudagrasses (Cynodon sp.) for turf in the northern limit for adaptation of semitropical grasses (upper south, U.S.). This research was conducted to investigate the effects of deacclimation, freezing temperatures, and duration of dormancy after exposure to freezing temperature on survival of bermudagrasses. ‘Tifgreen’ bermudagrass was taken from the field in February 1976, and deacclimated for 0, 2, 4, or 8 days at 27/13 C (day/night). Subsequently, rhizomes and stolons were subjected to temperatures of +2, 0, −2, −4, or −6 C for 24 hours. One‐third of the samples from each treatment were maintained in dark storage for 0, 45, and 90 days at 2.7 C ± before being grown in a greenhouse for 4 weeks.Rhizomes and stolons subjected to −1 or −6 C did not survive. Deacclimation with subsequent low temperature and extended dormancy duration appeared to have a compound influence on viability of stolons. Rhizomes were not so affected. At temperatures of −2 C or higher, viability of stolons did not decrease with deacclimation up to 4 days. However, with deacclimation up to 4 days, rhizome bud survival was enhanced. Survival of rhizome buds was significantly better at 0 C than −2 C; whereas, survival of stolon buds was not. Prolonged dormancy after exposure to low temperatures reduced the viability of both stolons and rhizome buds.Findings indicate that below freezing temperatures and prolonged dormancy durations after freezing hinder the survival of bermudagrass whereas, short deacclimation periods before freezing do not.
Use of Segmented Regression in the Determination of the Base Temperature in Heat Accumulation Models1
Authors: Gbur E. E. , Thomas G. L. , Miller F. R. 
Published: July 2010

AbstractAn accurate determination of the base temperature in heat accumulation models is extremely important if the model is to be used for predictive purposes. A modification of the simple linear regression is proposed for estimating the base temperature from laboratory data. The results of a small simulation study indicate that the proposed method is more accurate than a commonly used method. A numerical example of the use of the proposed method is presented.
Test of the Stress‐Degree‐Day Concept Using Multiple Planting Dates of Red Kidney Beans
Authors: Walker G. K. , Hatfield J. L. 
Published: July 2010

AbstractCanopy temperature measurements indicate crop water stress and should be related to crop yield. In this study, several planting dates and soil moisture levels were used to evaluate the stress‐degree‐day (SDD) concept as an indicator of crop yield. Red kidney beans (Phaseolus vulgaris L.) were planted on four dates, equally spaced, during a 9 week period from mid‐May to mid‐July, 1978. Beans were hand‐planted in 20 ✕ 5 m field plots on a silt loam with 76 cm row spacing at 165,000 ha‐2 Five irrigation treatments within each planting date provided a wide range of soil moisture conditions. The driest treatment in each planting didn't receive additional water after germination, while the wettest was continually well supplied with water. Moisture extraction in all treatments was measured to 180 cm three times weekly with the neutron scattering technique. Canopy temperatures were measured with an infrared thermometer each day throughout the growing season about 1 hour after solar noon. Stress‐degree‐days were calculated for each treatment by using air temperature recorded next to the plot area. Linear regression demonstrated that seed yields were strongly dependent on the accumulation of stress degree days from flowering to maturity (r2 = 0.82), indicating the importance of the post‐vegetative stage to final yield. Inclusion of the SDD summation from emergence to flowering as a second independent variable did not significantly improve the regression (R2 = 0.83). Individual regression lines for each planting were not significantly different (P = 0.05), demonstrating that the yield‐stress degree day relationship was stable over a wide range of planting dates. Total water use was negatively correlated with stress‐degree‐days summed from flowering to maturity (r = −0.83), verifying the potential for using the SDD concept in water management. The data also confirm that the SDD concept is a valid representation of the effect of moisture stress on yield, and point to the potential for using remotely determined canopy temperatures in estimating yields over large areas.
Estimating the Contribution of a Perched Water Table to the Seasonal Evapotranspiration of Cotton1
Authors: Wallender W. W. , Grimes D. W. , Henderson D. W. , Stromberg L. K. 
Published: July 2010

AbstractWater supplied to a growing crop by capillary rise from a shallow water table can be an important resource. Several thousand hectares in the western San Joaquin Valley in California have a perched water table created by irrigation and a slowly permeable subsurface zone. When irrigations are made according to a schedule that is optimum for soils without a shallow water table, cotton (Gossypium hirsutum L.) frequently shows plantgrowth that is characteristic of excessive irrigation. Field studies were conducted to evaluate the contribution of a perched water table to the evapotranspiration (ET) demand of cotton and to develop an irrigation schedule that uses the resource effectively.Two independent procedures were used to estimate the water table contribution (WT) through capillary rise. A water budget method used a previously developed yield‐ET function to estimate ET from observed production levels. Soil moisture depletion (SMD), stored irrigation water (IW), and deep percolation (PW) were determined from neutron thermalization measurements on volumetric soil water content. WT was determined by rearranging the relation ET = SMD + IW − PW + WT. A second approach, associated the chloride in the water table (17.4 meq/l) with increased chloride concentrations in the soil above the water table. The equivalent water depth necessary to effect this change was calculated. Both procedures estimated WT to be near 36 cm for the growing season. A high standard deviation (18.7 cm) was caused, however, by considerable spatial variability for the chloride tracer method.A revised irrigation schedule for cotton was developed that uses water, of acceptable quality, derived from a water table as a beneficial raource.
Row‐Plant Spacing and Broiler Litter Effects on Intercropping Corn in Tall Fescue1
Authors: Harper L. A. , Wilkinson S. R. , Box J. E. 
Published: July 2010

AbstractConservation tillage methods are needed to produce grain and forage for an important livestock industry on the highly erosive soils of the southeastern U. S. The objective of this research was to evaluate the effect of row widths, corn spacing within the row, and fertility level on the yield of corn (Zea mays L.) and Kentucky‐31 tall fescue (Festuca arundinacea, Schreb) when the corn was no‐till planted into 20‐cm killed strips of tall fescue grown under irrigated conditions in Cecil sandy loam (Typic Hapludult, clayey, kaolinitic, thermic). Corn row widths of 51 and 102 cm were the main plots, within‐row plant spacings of 16, 29, 38, and 47 cm were subplots and fertility levels of 9 and 18 metric ton/ha broiler litter and conventional fertilizer (358,134, and 268 kg/ha N‐P‐K, respectively) were sub‐sub lots in a randomized block design. The study was conducted for two corn seasons and two tall fescue seasons on the same plot area.Optimum corn plant density for obtaining the highest possible possible corn yields, while simultaneously maintaining the tall fescue sod, averaged 60,0000 plants/ha for the three fertility treatments. Average corn grain yields at this optimum plant density were 6.3 metric tons/ha for the 9 metric tons/ha broiler litter, 10.8 metric tons/ha for the 18 metric tons/ha broiler litter, and 8.7 metric tons/ha for the conventional fertilizer treatments. Based on total‐N analysis of broiler litter, the N from broiler litter was about 77% as efficient as N supplied from NH4NO3, in producing corn yield. Comparing similar plant densities with different row and plant spacings, we found that fescue yields were 2.6 times greater during the winter period under a 102‐cm wide row with plants spaced 16 cm apart in the row than under a 51‐cm wide row with plants spaced 29 cm apart within the row. Corn yields or corn plant populations were not significantly different at these two planting configurations. Despite the reduced sod area due to the herbicide killed strip, annual yields of tall fescue were also reduced at narrow row spacings because of decreased stand and sod vigor. This study illustrates the corn plant population and planting geometries which can result in good yields of tall fescue and interplanted corn under irrigation.
Planting Date and Water Deficit Effects on Development and Yield of Irrigated Winter Wheat1
Authors: Musick J. T. , Dusek D. A. 
Published: July 2010

AbstractMajor variability occurs in yield response of irrigated winter wheat (Triticum aestivum L. em Thell.) to water deficits and irrigation in the Southern High Plains. Evaluation of plant growth and development and yield components are needed to better understand water relations and to develop and test growth and yield models. The study was conducted to evaluate the effects of three planting dates, four to six water deficit treatments during stages of plant development, and two short wheats, ‘TAM W‐101’ and ‘Vona,’ differing in yield components. Planting dates were early (15 September), normal (12 October), and late (7 November). Water deficits were established by withholding irrigation and were terminated at selected plant stages by applying irrigation to level border plots. The study was conducted on a slowly permeable Torrertic Paleustoll (Pullman clay loam). We evaluated development stages, tillering, plant water potential, grain and dry matter yields, and yield components of heads per m2 spikelets per head, grain per spikelet, grain weight and number per m2.Early to normal planting, as compared with late planting (i) advanced the dates of phenological development, (ii) lengthened the time in the vegetative period, (iii) lengthened the time from floral initiation to inflorescence, (iv) increased tillering during vegetative growth and tiller senescence during jointing, and (v) increased dry matter and grain yields. Plant water deficits reduced yields by increasing tiller and stem senescence, which reduced harvested heads, and by reducing grain numbers (spikelets per head and grain per spikelet). Vona produced more secondary tillers and grains per head, but tiller‐stem senescence and smaller grain size resulted in harvested head numbers and grain yield similar to those of TAM W‐101.High yields (5,580 kg/ha) were associated with adequate fall‐tillering and irrigation during spring vegetative growth that minimized stress‐associated tiller‐stem senescence and reduction in spikelets per head. TAM W‐101 was more resistant than Vona to severe desiccation and tillerstem senescence under severe water deficits. A fall irrigation applied before winter dormancy delayed the need for a spring irrigation until jointing. Irrigation just before a period of above average rainfall did not affect yields. Yields comparisons of TAM W‐101 and Vona indicate that similar high yields can be produced by varieties having large differences in seed size and number per m2, suggesting that specific yield components may not be closely correlated with high yield potential.