bluuebunny/crossref_metadata_2025_split huggingface dataset:
Alkaloids of Reed Canarygrass as Influenced by Nutrient Supply
Authors: Marten G. C. , Simons A. B. , Frelich J. R. 
Published: July 2010

AbstractReed canarygrass (Phalaris arundinacea L.) genotypes contain varying amounts of indole alkaloids which are negatively associated with grass palatability to ruminants and which are potentially toxic to animals. Forage researchers need knowledge of the influence of environmental factors such as soil fertility on alkaloid concentration to aid control of these anti‐quality components of reed canarygrass.We conducted seven experiments to determine whether the alkaloids of reed canarygrass could be modified by inherent soil fertility or by application of nutrient elements to fertile and infertile soils.Mean alkaloid concentrations in four clones of reed canarygrass were doubled by growing the clones in an infertile peat, compared to a fertile mineral soil. Supplying the deficient nutrients (especially P and K) to an infertile peat significantly reduced alkaloids of grass growing in the soil, provided N levels did not exceed 240 kg/ha.Ammonium sources of N (NH4Cl and urea) caused greater alkaloid concentrations in reed canarygrass than did a nitrate source (NaNO3), while grass supplied with both sources (NH4NO3) had an intermediate alkaloid concentration.Relatively low levels of N (as low as 60 kg N/ha) applied to fertile mineral or peat soils caused increased alkaloids in grass clones inherently high in alkaloids. However, over 240 kg N/ha were required to significantly elevate alkaloid concentration in reed canarygrass growing in an infertile peat, and up to 225 kg N/ha in solution culture did not affect alkaloid concentration in a low‐alkaloid clone.We concluded that N fertilization is likely to increase alkaloid problems of reed canarygrass in situations where alkaloids are already high, but that practical levels of N (up to at least 200 kg/ha) will probably not increase alkaloid concentrations of those strains inherently low in alkaloids. Fertilization of infertile soils with deficient nutrients (other than N) may cause reduction in alkaloid concentration of reed canarygrass, even though P, Mn, or Cu individually did not affect alkaloids.None of the fertilizer elements changed the type of alkaloids (gramine, DMT, or 5‐MeO‐DMT) of the various clones and seed sources used in the seven experiments, indicating that this variable was genetically controlled.
Light Transmission in Field Communities of Sorghum1
Authors: Clegg Max D. , Biggs William W. , Eastin Jerry D. , Maranville Jerry W. , Sullivan Charles Y. 
Published: July 2010

AbstractMost plant canopy and solar radiation studies have comprised theoretical considerations, assuming a randomly oriented leaf arrangement. Lacking are field measurements concerning culturally arranged plant canopies in relation to interception of solar radiation. The purpose of this study was to describe the light environment under field conditions below and within grain sorghum (Sorghum bicolor (L.) Moench) canopies.Visible radiation was measured in sorghum using sensors mounted on a traversing system and having about the same sensitivity to direction and spectrum as does a leaf. As much as 89% more light was transmitted to a sensor when it moved between rows rather than across them. Therefore, measurement across rows is recommended.Light transmission profiles of sorghum canopies on clear and cloudy days were similar. Differences between transmission values over a diurnal period were less on cloudy than on clear days indicating more uniform light distribution. Visible radiation transmitted through sorghum canopies of .51‐m rows as compared to sorghum canopies of .76‐ and 1.02‐m rows or sorghum canopies of .76‐m rows as compared to sorghum canopies of 1.02‐m rows was less. This would indicate more visible radiation would be available for photosynthesis with narrower row spacings.Extinction coefficients (K) for canopy layers were calculated and for each layer proceeding downward K decreased. Extinction coefficients of sorghum canopies of different row spacings decreased as row spacing increased. Differences between hourly values of K were less on the cloudy day than on the clear day. For all conditions minimum values of K occurred at solar noon. These results agree with theoretical data.
Effect of Leaf Orientation, Leaf area, and Plant Densities on Corn Production1
Authors: Whigham D. K. , Woolley D. G. 
Published: July 2010

AbstractThe effect of corn (Zea mays L.) leaf orientation on grain yield and production practices has been the subject of conflicting reports over the past few years. Plant population is reported to be the cause of the discrepancies. The objectives of the present study were to determine the effect of plant population and leaf orientation on corn plant efficiencies and their interaction. Two contrasting leaf angles were compared by the use of near‐isogenic versions of the single‐cross hybrid (Hy2 ✕ C103) consisting of the liguleless (lg2) and its normal counterpart. Light penetration, light reflection, total dry matter production, and grain yields were measured to determine the effect of the leaf orientation, leaf area, and plant densities on corn production.Leaf angles of the two versions differed by 20°. Nine percent more light was intercepted by the horizontally oriented leaf type (HL). Plant populations (from 39,305 to 88,958 plants/ha) had no effect on leaf angle. High populations resulted in mutual shading which reduced the yield per plant. The mean leaf area per leaf of the HL was 17% larger than the vertically oriented leaf type (VL). Plants grown at 69,189 plants/ha had smaller leaves than those at the 49,421 population. Defoliation above the ear removed less leaf area than any of the other treatments and produced the smallest grain yield. All defoliation treatments reduced grain yield. Reflectors did not increase yield. Leaf orientation had little effect on corn production in rows spaced 76 cm apart.
Influence of Altitude on Seed Yield and Other Characters of Soybeans Differing in Maturity in Sikkim (Himalayan Kingdom)1
Authors: Basnet B. , Mader E. L. , Nickell C. D. 
Published: July 2010

AbstractA need exists for information on effects of altitude on yield and other characteristics of soybeans (Glycine max (L.) Merr.). Accordingly we evaluated the response of several imported varieties and a local variety for 2 years at altitudes of 1,394 and 1,636 m.Soybean growth and development was retarded at the higher altitude, and plants were shorter, lodged less, and had fewer nodes. Seeds with better quality were produced at the higher altitude. Seed weight varied with years at the two altitudes. Yield of most varieties was lower at the higher altitude. Seed yield differences among varieties were not consistent between years.The higher altitude prolonged the intervals from planting to first flowering 3 to 13 days, and planting to maturity 2 to 24 days. Dates of first flowering and maturity of groups V through VII soybeans were delayed more than those of earlier maturing groups.
Accumulation and Distribution of Mineral Nutrients, Carbohydrate, and Dry Matter in Soybean Plants as Influenced by Reproductive Sink Size1
Authors: Kollman G. E. , Streeter J. G. , Jeffers D. L. , Curry R. B. 
Published: July 2010

AbstractThe purpose of this experiment was to determine the extent to which the number of pods per node (“sink Size”) controls the accumulation of mineral nutrients, carbohydrate, and total dry matter in soybean plants (Glycine max (L.) Merrill). A quantitative description of the relationship between sink size and nutrient accumulation will help to identify nutrients which might limit yield at higher reproductive loads. Plants were grown in the field and various numbers of pods were removed as they formed to give an average of 0, 0.8, 1.1, 1.9, 2.4, or 2.7 pods per node. Leaf blades, stems plus petioles, pods, and seeds from mature plants were analyzed for N, P, K, Ca, Mg, and carbohydrate concentration. Increasing the sink size resulted in decreases in N and P concentration in leaves, stems, pods, and seeds and in Mg concentration in stems plus petioles. Conversely, K concentration in all plant parts and Ca concentration in leaf blades increased in response to increasing sink size. These increases in K and Ca concentration appeared to be due to a greater decline in the matter content than in K and Ca content as sink size increased, resulting in concentration of K and Ca. As sink size increased from zero to 2.7 pods per node: 1) carbohydrate content of leaf blades decreased 64%; 2) carbohydrate content of stems plus petioles decreased 40%; 3) mineral nutrient content of leaves plus stems decreased as follows, N — 72%, P — 64%, K — 28%, Ca — 18%, and Mg — 55%; and 4) total dry weight of leaves plus stems decreased 37%. When nutrient content of leaves and stems was plotted against sink size the result was a nearly perfect fit to a straight line for all nutrients except potassium. A comparison among nutrients of the slopes of these curves suggested that maximum reduction of N and P content in leaves and stems would occur at sink sizes smaller than required for maximum reduction of other mineral nutrients. Total Mg and Ca accumulated by above‐ground plant parts was not dependent on sink size, whereas total N, P, and K accumulated was strongly dependent on sink size.
Manganese Nutrition of Cotton Under Two Boron Levels. II. Critical Mn Level1
Authors: Ohki K. 
Published: July 2010

AbstractReference guideline values relating Mn concentration in plant tissue to growth is necessary for the assessment of the Mn nutritional status in cotton. Many of the presently available critical Mn levels were related to the presence or absence of deficiency symptoms. Refinement appeared necessary particularly in relation to the inter‐action of another nutrient. Therefore, a Mn ✕ B interaction study was conducted in nutrient solution under greenhouse conditions to determine the influence of low and adequate B levels on critical Mn levels of Upland cotton (Gossypium hirsutum L.) with 11 manganese rates from 0 to 4000 μg Mn/1 at two B levels of 35 and 500 μg B/1. The objectives were to determine 1) the most sensitive tissue relating Mn content to growth, 2) the critical Mn level in relation to growth and 3) the interaction of B on the critical Mn levels.Critical Mn levels of blade 1 through 5 ranged from 10 through 15 ppm Mn on a dry weight basis. Although Mn content in .blade 1 was the most sensitive in relating nutrient content to growth, the recently matured leaf (blade 3) was selected as the most practical tissue on the basis of sampling ease to use for evaluating the Mn status of cotton. The critical Mn level was 10 ppm Mn in blade 3. The critical Mn levels in blades 1 through 4 were independent of the B levels; however, low B increased the critical Mn level in the older blade (Blade 5). The stem and petiole tissue contained a small fraction of the Mn in blade tissue at high Mn levels. This reduced the desirability of selecting any of the vascular tissues for estimating the Mn nutrient status of cotton plants.
Water Uptake by Seeds as Affected by Water Stress, Capillary Conductivity, and Seed‐Soil Water Contact. II. Analysis of Experimental Data1
Authors: Hadas A. , Russo D. 
Published: July 2010

AbstractChickpea, pea and vetch seeds were germinated in pure, aerated water and in sand or aggregate fractions of various grain‐size classes. These were either 1) packed in columns at various water contents kept constant by passing water at different rates equaling the conductivity of the least conductive layer in every column or 2) sown in aggregated soil at equilibrium with different matric water potentials. Water uptake rates, seed diameter, and time of germination were determined, and seed‐soil water contact area was calculated. Water uptake data were analyzed to yield an approximation of the seed‐soil water contact impedance by using a simplified model.The results show that the seed‐soil water contact impedance increased as the wetted seed area and/or soil hydraulic conductivity decreased. The data also show that for optimal seed‐soil water contact in aggregated soils, the mean aggregate size should be one‐fifth to one‐tenth of the seed's diameter. Possible application to field practice, such as seed‐bed preparation, is discussed.
Responses of Grasses and Legumes to Soil pH1
Authors: Palazzo A. J. , Duell R. W. 
Published: July 2010

AbstractSpecies adaptation to soil pH has been generalized in the literature. This study was conducted to determine the responses of 19 varieties of grasses and legumes to soil pH ranging from pH 4.2 to 7.6 in field plots of a l~reehold sandy loam. Profiles of soil pH and relationships of pH to availability of nutrient elements, plant weights, and tissue analyses are presented. Different pH levels were developed over a period of 4 years as a result of surface application rates of NH,NO3 and Ca(OH)2= to a split‐split plot, randomized field design. Magnesium was included as a variable and applied to sub‐sub plots at rates of 0 and 44.8 kg of Mg/ha from MgSO4. Aluminum, manganese, iron, and zinc analyses of foliage of three grasses were made along with chemical analyses of the soil. The ph of the soil profile was taken at seven increments to a depth of 150 cm.Ca(OH)2 applications tended to raise soil pH to depth of 40 cm and NH4,NO3 applications depressed soil pH to a depth of 60 cm. Four fine fescue (Festuca rubra L.) varieties produced their greatest growth in the most acid plots (pH 4.2) studied. Negative linear correlations between plant weights and soil pH were found. Quadratic and curvilinear relationships were found for all other grasses which did best in a pH range from 6.0 to 6.5. The legumes required a higher soil pH for optimum growth than the grasses.‘Pennlawn’ red fescue (Festuca rubra L.), which did well in plots of the most acid soils, had lower contents of AI in above ground tissue than did ‘Kenblue’ Kentucky bluegrass (Poa pratensis L.) or ‘Manhattan’ perennialryegrass (Lolium perenne L.) which were limited in these soils. Tissue contents of Mn and other elements were neither too high nor too low to limit growth.
Stomatal Guard Cell Integrity and Resistance to Rumen Fluid Digestion1
Authors: Chatterton N. J. , Powell Jerrel B. 
Published: July 2010

AbstractScanning‐electron micrographs were made of Dactylis glomerata L. leaf tissue following digestion in rumen fluid to observe differential digestion of various cell types. Fresh leaf blade sections were subjected to the activity of rumen fluid at 39C obtained from a rumen‐fistulated Black Angus steer. Digestion by rumen microorganisms allowed the cuticle to float free as the mesophyll was digested. Close examination revealed that the stomatal guard cells were slow to digest and that they remained attached to the interior surface of the cuticle. The lack of significant microorganismal entrance into fresh leaf tissue, except through cut edges, may be explained by the combined resistance of the cuticle and stomatal guard cells to digestion. We propose that the cellulose of guard cell walls of Dactylis glomerata L. is infused with either a cutin‐like compound or with silica. Possibly a combination of cutin and silica provides guard cells with resistance to digestion by rumen fluid organisms. Additionally, electron micrographs are presented that vividly display the shape and orientation of the guard cells from a new perspective.
Estimation of Leaflet, Trifoliolate, and Total Leaf Areas of Soybeans1
Authors: Wiersma J. V. , Bailey T. B. 
Published: July 2010

AbstractThe importance of rapid, nondestructive, and accurate measurements of leaf area for agronomic and physiological studies is well known. Several mathematical formulas have been derived for estimating leaf areas for numerous crops, but there is little information available for soybeans [Glycine max (L.) Merr.]. The purpose of this study, therefore, was to develop prediction equations for estimating leaflet, trifoliolate, and total leaf areas of soybeans.Statistical analyses of soybean leaf areas were divided into three levels: leaflet, trifoliolate, and total leaf area. At each level, we compared the predictive abilities of three regression equations, each involving a different independent variable. On the basis of these results, we chose one independent variable at each level for subsequent regression analyses of various hypotheses. Prediction equations derived from independent variables involving measurements of length and width were superior at each level to those involving measurements of only length or width. Our data indicate, however, that considerable savings of time, with little loss of predictive ability, could be possible by measuring only length or width in each instance.With the use of independent variables involving measurements of length and width, regression analyses were performed to assess the effects of cultivars at each level and also the effects of leaflet orientation on the trifoliolate and the trifoliolate position on the plant at their respective levels. In general, these analyses indicated that a single regression equation could be used at each level. Leaflet, trifoliolate, and total leaf areas of the 12 cultivars we studied could be estimated by the following equations, respectively: A = 0.624 + 0.723LW (R2 = 0.985); A = 0.411 + 2.008LW (terminal leaflet) (R2 = 0.983); A = 6.532 + 2.045 (∑L1W1 terminal leaflets) (R2 = 0.965).
Evaluation of Kentucky Bluegrass and Red Fescue Cultivars for Sod Production1
Authors: Hurley R. H. , Skogley C. R. 
Published: July 2010

AbstractUntil recently, much of the commercial sod produced in the Northeast has been ‘Merion’ Kentucky bluegrass (Poa pratensis L.) Many turf authorities now feel that blends of improved Kentucky bluegrass and red fescue (Festuca rubra L.) cultivars should be used to broaden the genetic base of the mixture. This type of mixture would be adaptable to a wider range of environmental conditions.‘Merion’, ‘Baron’, ‘Fylking’, and ‘Pennstar’ Kentucky bluegrasses and ‘Jamestown’, ‘Highlight’ (Festuca rubra var. commutata Gaud.) and ‘Pennlawn’ red fescues were studied singly and in mixtures for commercial sod production. Cultivar compatibility in mixtures were evaluated by turf quality ratings and tiller counts, rate of establishment, durability as measured by tensile strength of harvested sod, and rate of sod knitting after transplant.All cultivars and mixtures provided acceptable visual turf quality with Baron, Pennstar, and Baron‐Pennstar, Merion‐Baron mixtures providing the highest turf quality ratings.Tensile strength was not altered by use of improved Kentucky bluegrass cultivars alone or in mixtures. Red fescue significantly reduced sod strength when included in mixtures with Kentucky bluegrass. This reduction did not affect handling of the harvested sod when up to 67% red fescue by weight was included in the seed mixture.Jamestown and Highlight red fescue produced significantly more tillers than Pennlawn, and those cultivars were better able to compete with Merion Kentucky bluegrass.
Influence of Aluminum Ions on Developmental Morphology of Sugarbeet Roots1
Authors: Keser M. , Neubauer Benedict F. , Hutchinson F. E. 
Published: July 2010

AbstractHigh concentrations of aluminum in low pH soils are toxic to sugarbeet (Beta vulgaris L.). In a test to determine the effect of increased concentrations on seedling development, 4, 8, and 12 ppm Al nutrient culture caused significant reduction of root and hypocotyl growth. The primary root curved and the root cap broke away. Lateral roots emerged as small outgrowths on the primary root axis and developed abnormally. Anatomical examination of primary and lateral roots revealed extraneous material in the apical meristem, root cap, and cortical region. Apical regions of the primary and lateral roots did not exhibit their typical organization and cells divided in an irregular pattern. Aluminum can be an important factor in the suppression of sugarbeet growth in acid soils.
Turfgrass Wear Tolerance Mechanisms: III. Physiological, Morphological, and Anatomical Characteristics Associated with Turfgrass Wear Tolerance1
Authors: Shearman R. C. , Beard J. B. 
Published: July 2010

AbstractThis investigation was conducted to assess the relationship of various turfgrass physiological, morphological, and anatomical characteristics to wear tolerance. No data of this nature is available in turfgrass literature. Species differences were noted for verdure, shoot density, leaf width, load bearing capacity, leaf tensile strength, percent moisture, and percent relative turgidity. However, no significant correlations were found between species wear tolerance and the afore mentioned characteristics. Analysis of the combined relationship of these factors to wear tolerance indicated that only leaf tensile strength and leaf width contributed significantly to the variation in turfgrass wear tolerance among seven turfgrass species.Sclerenchyma tissue and lignified cell comparisons were made between Kentucky 31 tall fescue (Festuca arundinacea Schreb.) and rough bluegrass (Poa trivialis L.). Results were presented as percent of the total cross‐sectional area of leaf blades and stems. Sclerenchyma tissues of Kentucky 31 composed 18.6% of leaves and 23.4% of stems, while the contents of rough bluegrass were 8.9 and 10.3%, respectively. The percent lignified cells of Kentucky 31 tall fescue and rough bluegrass were 49.8 and 21.4%, respectively, based on total leaf cross‐sectional area. The percent Sclerenchyma fibers and lignified cells were closely associated with the wear tolerance observed for the two species.
Performance of Three Warm‐season Perennial Grasses and a Native Range Mixture as Influenced by N and P Fertilization1
Authors: Taliaferro C. M. , Horn F. P. , Tucker B. B. , Totusek R. , Morrison R. D. 
Published: July 2010

AbstractSeveral perennial, warm‐season grass species are being used to revegetate depleted rangeland in parts of the southern Great Plains, particularly Oklahoma and Texas. This experiment was conducted to provide comparative data on the yield and quality of forage of three introduced grasses and a native range grass mixture as influenced by nitrogen and phosphorus fertilization.‘Midland’ bermudagrass [Cynodon dactylon (L.) Pers.], ‘Morpa’ weeping lovegrass [Eragrostis curvula (Schrad.) Nees], ‘Plains’ bluestem [Bothriochloa ischaemum (L.) Keng var. ischaemum] and an existing native range grass mixture consisting largely of Bouteloua and Andropogon sp., with some Panicum and Sorghastrum sp., were evaluated for dry matter (DM) yield for 3 years and crude protein (CP) and in vitro dry matter digestibility (IVDMD) for 2 years under four levels of N and two of P. Levels of N were 0, 67, 135, and 269 kg/ha applied annually in split applications. Levels of P were 0 and 90 kg/ha; the 90 kg level applied annually in a single March application.All grasses and the range mixture responded to increasing N levels with increased DM yield and CP percentage. The three introduced grasses also responded to increasing N levels with increased IVDMD, but the native range mixture did not. The three introduced grasses and the native range mixture responded in yield to application of 90 kg/ha of P. Yield response to P was significant and increased in response with increasing amounts of N. This response was greatest at the 135 and 269 kg/ha N levels. The addition of P had no discernible effect on the IVDMD of the introduced grasses or native range mixture but decreased their CP percentage. Significant interactions included grass (G) × N, G × P, G × year, and N × P. Morpa weeping lovegrass and Plains bluestem were more productive than Midland bermudagrass, particularly in the absence of and at the 67 kg/ha N level. At the higher N levels, Midland bermudagrass was most responsive to P. The native range mixture was least responsive to N and P fertilization and its DM yield was significantly less than that of the other three grasses.