bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crown, Tiller, and Rhizome Characteristics of Kentucky Bluegrass Cultivars1
Authors: Nittler L. W. , Kenny T. J. 
Published: July 2010

AbstractTo protect superior Kentucky bluegrass, Poa pratensis L., cultivars from becoming contaminated, it is important to develop techniques for testing seed lots for cultivar purity. This study was conducted to detect seedling characteristics that can be used in addition to characteristics described previously for making cultivar purity determinations.Seed of 26 cultivars and six experimentals lines were planted in inert sand and were grown in a growth chamber for 6 weeks with continuous light of 23,000 lux (22,000 lux from cool white fluorescent tubes and 1,000 lux from incandescent bulbs). A complete nutrient solution was used and temperature was kept at 24 C.Tillers of some cultivars grew horizontally 1 cm or more before turning upward. This formed a spreading crown. Tillers of others grew upward with little or no lateral spread to form a compact crown. Other cultivars tended to be intermediate in crown type. No plants of ‘Belturf’, ‘Fjord’, ‘Park’, or ‘Troy’ were classed as having spreading crowns. In contrast, 93% of ‘Bonnieblue’ plants had spreading crowns and the remaining 7% had semi‐spreading crowns.Troy had an average of 1.9 tillers/plant compared to 6.4 for ‘Sydsport.’ Cultivars also differed in number of rhizomes, with Fjord and ‘Kenblue’ each averaging 0.3/plant and ‘Sodco’ averaging 2.6/plant.Percentage of total stems that were rhizomes was only 6 for ‘Prato’ compared to 41 for Sodco.Cultivars with spreading crowns such as Bonnieblue and ‘Fylking’ could be distinguished from those with compact crowns such as Park or Troy. Likewise contrasting types in regard to tiller or rhizome number could be distinguished from each other.
Effect of Saponins on Palatability of Alfalfa to Meadow Voles1
Authors: Kendall W. A. , Leath K. T. 
Published: July 2010

AbstractForage constituents that effect the plant palatability are one of many factors that control animal intake. Saponins are biologically active compounds that occur in alfalfa (Medicago sativa L.) in various concentrations and may affect palatability. The purpose of this research was to evaluate the role of saponins in palatability. The meadow vole (Microtus pennsylvanicus) was used to test palatability because its small size and ready acceptance of forage permitted the assay of small amounts of forge and extracted saponins.Meals from alfalfas selected for high‐ or low‐saponin content with the Trichoderma viride Pers. ex Fr. or hemolysis bioassays were compared for palatability using meadow voles. The voles were fed a commercial mouse food ad libitum and offered a choice of the commercial food or test diet for 30 min at 0800 and 1600 daily. Saponin activity of the meals was evaluated with the T. viride bioassay. Purified saponin mixtures from ‘DuPuits’ and ‘Lahontan’ alfalfa and quinine sulphate were evaluated at various concentrations for palatability to voles.Meals of low‐saponin lines of alfalfa were generally more palatable than their corresponding high‐saponin lines except for selections of Lahontan which were both very palatable. The growth of T. viride was greatest on substrates with extracts of alfalfa meals that were most palatable to meadow voles. Purified saponins from Lahontan and DuPuits alfalfa reduced intake at a concentration of 4% of the diet. The palatability of 3% saponin from DuPuits in the diet was not increased by mixing with sucrose. Intake of quinine sulphate was inversely related to concentration, indicating that voles perceived the bitter substance.
Nitrogen‐Silicon Interaction in Plants Grown in Desert Soil with Nitrogen Deficiency1
Authors: Wallace A. , Romney E. M. , Mueller R. T. 
Published: July 2010

AbstractThe relationship of N to some other anions was investigated for plants grown in infertile soil low in soil organic matter from bare desert areas compared with plants grown in more fertile soil from around natural shrub clumps. The objective was to determine nutrient relationships in the infertility of desert soils even when supplied with N. Range grass [Hilaria rigida (Thurb.) Benth. ex Scribn.], barley (Hordeum vulgare L. ‘Atlas 57’), and bush beans (Phaseolus vulgaris L. ‘Improved Tendergreen’) were grown in such soils in a glasshouse. The latter two were with and without addition of N fertilizer. Plants grown in the infertile soil compared with the fertile soil had greatly decreased yields, were low in N, generally had increased concentrations of Si, and had slightly less total cation concentrations. Nitrogen fertilizer improved yields only slightly in the infertile soil but it increased N concentration and decreased that of Si in plants. The Si seemed to enter into the cation‐anion balance in the plants.
Nitrate‐N and Total N Concentration Relationships in Several Plant Species1
Authors: Terman G. L. , Noggle J. C. , Hunt C. M. 
Published: July 2010

AbstractAccumulation of NO3‐N in plants is important in regard to plant N nutritional status, in the formation of NO2‐N toxic to animals and people consuming the plants, and as a producer of lethal gas in silos. This paper describes relationships between NO3‐N and total N concentrations in plants grown in several greenhouse pot experiments, as affected largely by response to applied N and by continuing growth. Corn (Zea mays L.) was grown in soil with 200 to 800 mg of N/pot and in nutrient solutions with 2 to 16 ppm of N. Both crops were harvested at 4‐day intervals. Spinach (Spinacea oleracea L.) and mustard (Brassica pervirdis L.) were grown in soil with several rates of N, P, and K, and tall fescue (Festuca arundinacea Shreb.) with 1.0 and 2.0 g of N/pot.These experiments conducted on N‐deficient soils resulted in marked yield response and higher concentrations of total N and NO3‐N with increase in rates of applied N. Concentrations decreased with age, dry matter accumulation, and depletion of N. Total N was higher in leaves than in stems, but the reverse was true for NO3‐N. Concentrations of NO3‐N started to increase in various crops above minimum total N values of 1.5 to 4.5%, which were highest for leaves, intermediate for leaves + stems, and lowest for stems or petioles. Below these minimum total N values, NO3‐N remained near zero (< 0.1%). Discontinuous regression models appear most satisfactory to fit the entire range of the relationships between total and NO3‐N. It was concluded that NO3‐N concentrations in plants are negligible if the total N was < 1.5% to 4.5%, depending largely on plant part composition, plant species, and N source.
Soybean Root Development and Soil Water Depletion1
Authors: Stone L. R. , Teare I. D. , Nickell C. D. , Mayaki W. C. 
Published: July 2010

AbstractWe conducted a field study to investigate soybean (Glycine max L. Merr., ‘Williams’) root growth and water depletion patterns. Field water depletion and rooting data are needed to assist in developing and refining models that consider root‐soil‐water interactions.Irrigated and nonirrigated soybeans were grown on a deep, barrier‐free, Muir silt loam soil (fine‐silty, mixed, mesic, Pachic Haplustoll). Soil water content, determined using neutron moderation (15‐ to 150‐cm profile), was used to calculate water depletion rates. Soil water content and desorption curves (obtained for each 15‐cm profile depth increment) were used to estimate soil water potential. Available soil water was estimated using —15 bars soil water potential as the lower limit of availability. We collected soil volumes (centered on the crop row) 76 cm wide, 7.6 cm thick, and 180 cm deep (sectioned to 15‐cm increments) and washed roots free using 35‐mesh screen.During the first half of our study, maximum root and water depletion depths were nearly equal. Later, water depletion tended to be about 15 cm deeper than root growth (possibly as a result of upward water movement into the water‐depleted root zone). Our data indicate that, as soybean root weight increased, there was a drying effect so available soil water and soil water potential decreased. Depletion effectiveness (defined as cm3 of water/g of root/day) was greatest with lower root weights, higher soil water potentials, and greater available soil water. Depletion effectiveness increased with depth in the soil profile; probably as a result of the roots being younger, in wetter soil, and less crowded. Our data indicate that a small portion of the root system can be responsible for much water uptake.
Seedling Growth of Crownvetch, Ladino Clover, and Alfalfa under Shade1
Authors: Hart Richard H. 
Published: July 2010

AbstractCrownvetch (Coronilla varia L.) is more difficult to establish than many other legumes. This difficulty has been attributed to slow seedling growth of crownvetch when shaded by competing vegetation. We wanted to determine 1) do seedlings of crownvetch grow more slowly under shade than seedlings of other legumes, and (2) do seedlings of weedy crownvetch, derived from plants which survived 2 years in a weedy nursery, grow faster under shade than seedlings of cultivated crownvetch, derived from plants grown in a cultivated nursery? We seeded ‘Penngift,’ ‘Emerald,’ “weedy,” and “cultivated” crownvetch, ‘Vernal’ alfalfa (Medicago sativa L.), and common ‘Ladino’ clover (Trifolium repens L.) in pots in the greenhouse during winter and again during spring. Seedlings were grown for 4, 6, 8, and 10 weeks under shade screens which transmitted 76%, 35%, or 14% of total solar radiation. Emerald, Weedy, and Cultivated crownvetch grew at the same rate, which indicated there had been no natural selection for seedling vigor or shade tolerance in the wedy nursery. Penngift grew more slowly than the other crownvetches. Crownvetch grew faster than Ladino clover in both winter and spring, and faster than alfalfa in winter. However, under higher radiation in the spring, crownvetch tops grew at the same rate as alfalfa tops, and crownvetch roots grew slower than alfalfa roots. We concluded that crownvetch grew about as well as other legumes under shade, and that low seedling vigor under shade is not a major cause of establishment difficulties of crownvetch.
Alfalfa Weevil Effects on Regrowth of Alfalfa1
Authors: Fick Gary W. 
Published: July 2010

AbstractEarlier work indicated that large reductions in second cutting yields of alfalfa (Medicago sativa L.) could occur when larvae of the alfalfa weevil (Hypera postica Gyllenhal) fed on the stubble following the first harvest. To study the problem further, larval populations of known size were transferred to alfalfa plots after the first harvest was removed. The larvae fed on basal buds and, at the highest population (about 10,000/m2), completely destroyed active growing points in the stubble within 2 days. Measurements taken during the 40 days following the first harvest showed increasing regrowth delays for each increment of weevil population. Herbage yield, morphological stage, height, leaf percentage, in vitro digestibility, and crude protein content were all affected. Total nonstructural carbohydrate accumulation in taproots was also delayed by weevil damage to basal buds. The maximum delay in regrowth was 6 to 10 days and up to one‐third of the yield potential of the 40‐day regrowth period could be lost. The regression equation to predict the percentage of the maximum loss (Y) from the insect population in larvae/m2(X) was as follows: Y = 0.0531X. The regression equation, which was forced through the origin, had an r2 value of 0.868.
Methods of Computing Area1
Authors: Shih Sun‐Fu 
Published: July 2010

AbstractThe methods of computing area from maps are classified under two categories: 1) bounded area and 2) weighted sub‐areas. Pioneering methods of planimeter, coordinate squares, triangular rule, trapezoidal rule, Simpson's rule, double‐meridian‐distance, coordinates, and digitizer are compared with the newly introduced methods of weighing technique and finite segments, and also with a recently developed Monte Carlo process. The results indicate that the weighing technique and finite segments are relatively easy to use in laboratory and computerized procedure, respectively; and the Monte Carlo method is more applicable and powerful than other computerized methods.
Effects of Herbicides on Establishment of Centipedegrass1
Authors: Johnson B. J. 
Published: July 2010

AbstractThe control of weeds during the first growing season after centipedegrass [Eremochloa ophiuroides (Munro) Hack.] sprigging is a major problem for most homeowners. Field and greenhouse experiments were conducted on the effects of herbicides applied at different time intervals during the establishment of centipedegrass on weed control and rate of turfgrass cover. The soil type was either a Cecil sandy loam (member of the clayey, kaolinitic, thermic family of Typic Hapludult) or Cecil sandy clay loam.The survival of centipedegrass sprigs was as good with single applications of DCPA (dimethyl tetrachloroterephthalate) at 11.2 kg/ha, atrazine [2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino‐s‐triazine], at 1.1 kg/ha, simazine [2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine], at 1.1 and 2.2 kg/ha, and oxadiazon [2‐tert‐buty‐4‐(2,4‐dichloro‐5‐isopropoxyphenyl)‐Δ2‐1,3,4‐oxadiazolin‐5‐one], at 3.4 kg/ha, applied immediately after sprigging as in untreated plots. The turfgrass cover at the end of the growing season was as good or better in single treated plots as in multiple treated plots. Repeated applications of atrazine, simazine, and oxadiazon increased the control of large crabgrass [Digitaria sanguinalis (L.) Scop.] and goosegrass [Eleusine indica (L.) Gaertn.] when compared with the control in single treated plots. These results indicate that complete weed control is not necessary for optimum centipedegrass cover during the first season after sprigging.
Phosphorus Uptake Rate of Soybean Roots as Influenced by Plant Age, Root Trimming, and Solution P Concentration1
Authors: Edwards J. H. , Barber S. A. 
Published: July 2010

AbstractAn understanding of the phosphorus, P, uptake characteristics of plant roots is important for developing practices that improve P fertilizer efficiency. Since little is known about the nutrient uptake characteristics of soybean [Glycine max (L.) Merr.] roots, the objective of this research was to measure the P influx kinetics of intact soybean roots. Experiments were conducted with soybeans ranging in age from 18 to 74 days. Rate of P depletion from solution vs. P concentration in solution was used to determine maximum P influx, Imax; Michaelis constant, Km; efflux, E; and the lowest level to which the plants can reduce P concentration in solution, Cmin. The effect of increasing plant P requirement per meter of root length on P influx kinetics was studied by removing half of the roots 2 days before influx measurement.Average Imax for P decreased with increasing plant age, however the rate of decrease was less than previously observed with corn (Zea mays L.). Trimming roots increased Imax of 18 to 35‐day‐old plants so that P uptake per plant on trimmed plants was similar to that for untrimmed plants. Both Km and Cmin values increased with plant age. Root trimming had little influence on Km, and E was not influenced by plant age or root trimming. Phosphorus influx kinetics of soybean roots as affected by plant age and root trimming were different from those observed for corn so that P fertilization practices that give the highest efficiency for use of applied phosphate may differ for the two crops.
Cutting Height and Nitrogen Effects on Improved Perennial Ryegrasses in Monostand and Polystand Communities1
Authors: Carrow R. N. , Troll J. 
Published: July 2010

AbstractNew turf‐type perennial ryegrasses are being widely used by turf managers, however, little information is available on their competitiveness in polystands. The growth and persistence of three perennial ryegrasses (Lolium perenne L.) were evaluated in the greenhouse and growth chamber in monostands and in polystands with ‘Merlon’ Kentucky bluegrass (Poa pratensis L.) and ‘Penncross’ creeping bentgrass (Agrostis palustris Huds.). Cutting height treatments were 1.26, 2.54, 3.80, and 5.08 cm. Ryegrass tillering was greatest at the 1.26 cm cut, while no differences in tiller numbers were detected between 2.54 to 5.08 cm treatments. All ryegrasses competed well in bluegrass sod at .2.54 to 5.08 cm cuts but did not grow well in the bentgrass, regardless of cut.In two field studies several ryegrasses were seeded 25: 75 (seed number basis) with Merion Kentucky bluegrass and 50:50 with ‘Seaside’ creeping bentgrass. Mowing treatments and N treatments were imposed on the various mixtures in both studies. ‘Manhattan’ and ‘Pennfine’ ryegrasses were most competitive during establishment and the most persistent over 23 months in bluegrass mixtures. Shoot densities of the ryegrasses were not affected by cutting height or N treatments but bluegrass density was. When seeded with bentgrass, Manhattan and Pennfine were most competitive during establishment but no ryegrass cultivar composed more than 14% of the stand after 23 months. Low cutting height (1.26 cm) and high N (2.44 kg N/100m2) improved the competitiveness of the bentgrass but not that of the ryegrasses.The data from these studies indicate that the competitiveness of new turf‐type ryegrasses is dependent upon the companion grass. When seeded in mixtures with Kentucky bluegrass the new ryegrasses were persistent at cutting heights above 1.90 cm. In mixtures with creeping bentgrass the ryegrasses responded as temporary grasses.
Dry Seed Fatty Acid Composition and Seedling Emergence of Pima Cotton at Low Soil Temperatures1
Authors: Bartkowski Edmund J. , Buxton D. R. , Buxton D. R. , Katterman R. H. , Kircher Henry W. 
Published: July 2010

AbstractThe development of a rapid test to predict cotton lines (Gossypium spp.) which exhibit increased resistance to chilling injury would be a valuable breeding tool. The objective of this study was to evaluate the relationship of Pima cottonseed (G. barbadense L.) lipid composition to seed germination and seedling emergence under field conditions with low soil temperatures. Seed fatty acid methyl esters of selected genotypes were analyzed by gas‐liquid chromatography. Total seed lipid was fractionated into polar and neutral components and their associated fatty acid methyl esters were similarly analyzed. Low correlations were obtained between unsaturated/ saturated (U/S) fatty acid ratios of total seed lipid and laboratory germination percentages. However, seedling emergence under field conditions with low soil temperatures correlated strongly with U/S fatty acid ratios of total seed and polar lipids (r = 0.97** and 0.95% respectively)3. No advantage was realized by using polar lipids over total seed lipid for the analysis. Results of this study suggest the feasibility of using the rapid analysis of total seed lipid associated U/S fatty acid ratios for identifying cotton lines with chilling resistance during seed germination and emergence.
Massive Accumulation of Calcium Carbonate and its Relation to Nitrogen Fixation of Sainfoin1
Authors: Ross William D. , Delaney Ronald H. 
Published: July 2010

AbstractSainfoin (Onobrychis viciifolia Scop.) has many desireable qualities as a legume forage, but it is not widely grown because of its lack of persistence and poor N‐fixation on many sites. The effect of competition by non‐N‐fixing soil microorganisms on N‐fixation was studied at 0, 50, 80, 95, and 100% levels of autoclaved soil sterization. Plants were grown aseptically for 30 days, dipped in Rhizobium inoculum, and transplanted to the sterilized soil. After 47 and 87 days in the growth chamber at 24/18 C, the plants were harvested. Nitrogen fixation was determined by the acetylene reduction capacity of the complete root system. Unexpectedly, root distortion accompanied by massive accumulation of CaCO3 was stimulated in sainfoin roots that were grown in autoclaved soil to reduce the soil microorganisms. The purpose of the data presented is to describe the accumulation of Ca and its affect on N‐fixation in sainfoin. Distorted roots of plants grown in 100% sterilized soil contained up to 33% Ca. High levels of Ca in the roots were accompanied by low levels of Ca in the plant forage. Number of nodules produced and the capacity of roots for reducing acetylene decreased as root distortion and CaCO3 accumulation increased. The properties of sterilized soil that stimulate CaCO3 accumulation were not determined, but several possibilities are discussed. Root distortion also occurs in field‐grown plants and may be related to the decline of sainfoin stands in the field.
Yield, Leaf Growth, and Tillering in Bahiagrass by N Rate and Season1
Authors: Beaty E. R. , Engel J. L. , Powell J. D. 
Published: July 2010

AbstractIf tiller numbers/area of Pensacola bahiagrass (Paspalum notatum, Flugge) could be correlated with yield and tillers/area is related to N fertility status, fertility and yield research would be simplified. To test the concept that a yield predictive model could be developed, an established Pensacola bahiagrass sod was fertilized with 0, 84, 168, and 336 kg/ha N in 1973 and 1974. Starting in early June and continuing until October plots were clipped monthly at heights of 2.5 and 7.5 cm. Before clipping, 1.0 tillers with mature leaves/plot were collected and numbers of clipped elongated and unclipped leaves were determined. Tillers on duplicate (15 cm)2 areas were counted after clipping.Dry forage was increased over the 0 N check by adding 84 and 168 kg/ha N. The 336 kg/ha N did not increase forage yields over 168 kg/ha N. Clipping at 2.5 cm produced almost three times as much forage as clipping at 7.5 cm. Number of leaves/stolon/season averaged between 20.2 and 22.0 and was influenced by N rate. At each of the five harvest dates, an average of 1.3 leaves/tiller (growing point) was elongating. Nitrogen application increased tiller numbers by up to 300% and the largest number of new tillers occurred in June. Some data as collected were predictive of N and leaf generation rate, but variations in tiller numbers/area and probably leaf weight/N relationships prevented the development of an effective yield prediction model. Further refinement of the data is needed.Statistical models based on tillers/area were not effective in predicting yields. The lack of an effective relationship between tillers/area and yield was believed due to many young tillers dying before contributing to yield and variations in leaf size reflecting N fertilization and tiller age.
Method of Soil Temperature Control for Turfgrass Research1
Authors: Aldous D. E. , Spaulding R. A. , Kaufmann J. E. 
Published: July 2010

AbstractSince growth of cool season grasses is more related to soil temperatures than air temperatures, a method was developed for independent control of soil and air temperatures utilizing a modified chest‐type freezer placed inside a controlled environment growth chamber. The freezer door was replaced with a plywood top insulated with styrofoam. Pots containing two cultivars of Poa pratensis L. were suspended through holes in the top into the freezer chamber and root zone temperature was controlled utilizing a sensitive thermostat. Carboys containing nutrient solution were placed in the chamber and subirrigation was accomplished by pressurizing the carboys with an air pump. The temperature of the material in the pots reached equilibrium with the freezer environment in 4 hours. The system was effective in controlling root‐zone temperatures at optimum for shoot growth (22 C) during a 10‐week period where ambient temperatures were increased in 4 C increments every 2 weeks from 22 C to 38 C. The system could be used wherever growth or physiological responses to soil temperature must be separated from responses to air temperature.