bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical Factors Controlling the Adaptation of Weeping Lovegrass and Tall Fescue to Acid Mine Spoils1
Authors: Fleming A. L. , Schwartz J. W. , Foy C. D. 
Published: July 2010

AbstractSuccessful revegetation of acid mine spoils can be facilitated by the use of plant species which can tolerate the existing growth‐limiting conditions. Although species differences can be determined by growth on the particular spoil, specific knowledge of the plant response to each of the potential stresses will increase the reliability of the selection process.The objectives of this study were to evaluate the response of weeping lovegrass [Eragrostis curvula (Schrad.) Nees] and tall fescue (Festuca arundicea Schref. var. ‘Ky 31’), to Al, Mn, and other major growth‐limiting factors which may be encountered in acid strip mine spoils and to specify which factors would account for the observed differences between these species.Weeping lovegrass and tall fescue were grown for 26 to 31 days in nutrient solution culture containing Al, Mn, and P as variables. Each experiment in the series was designed to compare the response of the two species to a specific growth‐limiting condition.Although both species withstood low pH (pH 4 to 5) and excess Mn (4 to 64 ppm), weeping lovegrass was more tolerant than tall fescue to A1 concentrations in the range 2 to 12 ppm. A concentration of 4 ppm Al severely inhibited the top and root devdopment of tall fescue, but 12 ppm AI was required to produce similar injury to weeping lovegrass.The application of 2 to 4 ppm P promoted the growth of both species without Al and decreased, but did not overcome the effect of 4 ppm Al on tall fescue. Higher P treatments (6 ppm), in the presence of 4 ppm A1, increased the top growth of tall fescue, with little effect on the root system. The response of weeping lovegrass to P was not altered by the presence of Al.Weeping lovegrass should be favored for revegetation of acid mine spoils of low pH which are high in exchangeable Al. Both weeping lovegrass and tall fescue could be grown on spoils dominated by Mn.
Growth of Kikuyugrass (Pennisetum clandestinum) Under Clipping. II. Regrowth Characteristics in Relation to Nitrogen Fertilization and Climate1
Authors: Whitney A. S. 
Published: July 2010

AbstractA better understanding of the response of kikuyugrass (Pennisetum clandestinum Hochst. ex Chiov.) to management and climate is needed in order to best exploit this important forage grass. The objective of this study was to describe kikuyugrass regrowth under a variety of conditions and to relate regrowth performance to N‐nutrition, environment, and sward characteristics. Kikuyugrass swards at two locations (Kula, 945 m elevation, and Makawao, 660 m elevation) were trimmed and fertilized with three levels of N (22, 56, and 168 kg/ha) at 10‐week intervals. During alternate 10‐week periods, plots were cut sequentially after 4, 6, 8, and 10 weeks of regrowth. Regrowth began slowly after a 10‐week period, especially at Kula during the cool season. Changes in the area: dry weight ratio of the forage indicated that this may have been due to retarded leaf development under low temperatures. At other times, regrowth at both locations was normally rapid after the 4th week and continued at a high rate through the 10th week. About 600 kg/ha of harvestable green vegetation (DM basis) were required support subsequent near‐maximum growth rates. This was equivalent to 8 cm harvestable height, 30% interception of blue light, and a leaf‐plus‐stem area index of 1.0.Crude protein (CP) yields tended to level off after weeks, especially during the warmer months. Percent CP in the low and moderate N treatments declined during the regrowth period from approximately 16 to 18% at 4 weeks to 8% at 10 weeks. Percent CP in the high‐N treatment was higher but more seasonally variable; 4‐week regrowth contained over 30% CP equiv. during the cooler months. Some of this N was present as NO3 which ranged from 20 ppm NO3‐N (low or moderate N‐level, 8 weeks regrowth) to over 2000 ppm (high N‐level, 2 to 6 weeks growth at Makawao). Nitrate levels thus approached potentially toxic concentrations for ruminants in some cases.Multiple regression analysis identified several factors as being significantly associated with growth rate: nitrogen nutrition of the sward, temperature (air or soil), and position on the growth curve. Unidentified site factors were also determinants.
Influence of Cutting Management and Environmental Variation on the Yield, Bud Activity, and Autumn Carbohydrate Reserve Levels of Crownvetch1
Authors: Brann D. E. , Jung G. A. 
Published: July 2010

Abstract‘Chaining’ crownvetch (Coronilla varia L.) was grown at four West Virginia locations: Morgantown, Wardensville, Reedsville, and Point Pleasant. These locations vary in amount and distribution of rainfall, temperature, snow cover, and length of growing season and show how combinations of environmental factors affect yield, morphology, and carbohydrate reserves. Yield and bud activity as affected by cutting at different growth stages and heights are presented. The effect of two and three harvests per season on yield and fall carbohydrate levels was also studied.Yields varied greatly among locations and years. Greater than 10,000 kg/ha were produced at Morgantown in 1969 and Reedsville in 1970 compared with total yields at Point Pleasant of 2,000 to 4,000 kg/ha from a thin stand. Greater yields generally were produced by two rather than three harvests per season. Clipping to stubble heights of 7.5 or 15.0 cm resulted in similar yields. First cutting yields generally increased as the first harvest was delayed to full bloom (mid‐June); however, delaying harvest past this period seldom increased yield. Cutting treatments did not detrimentally affect any of the stands, except possibly at Morgantown, where general vigor of the stand was lower the second season.The proportion of axillary buds producing growth increased with delay of spring harvest until full bloom and then declined. Delay of the first cutting and adequate moisture increased the proportion of axillary buds that produced regrowth. Cutting at different stubble heights generally had no effect on activation of axillary buds.Initiation of growth from crown buds was determined 2 weeks after cutting. Active buds at the crown and up to 2.5 cm from the base of 100 randomly selected stems were counted. Growth initiation from crown buds was greater when plots were cut at 7.5 cm than when cut at 15.0 cm for most cutting dates and locations. Crown bud activity was generally less during early spring and periods of moisture stress.Total non‐structural carbohydrates (TNC) in autumn were similar among locations. Slightly higher TNC values were associated with the 15.0 cm cutting heights, due mainly to changes in starch levels.
Ameliorative Role of Zinc on Maize Growth Under Alkali Soil Condition1
Authors: Shukla U. C. , Prasad K. G. 
Published: July 2010

AbstractWhile working with some of the Natrargids it was observed that zinc had beneficial effects on the germination and growth of plants. To verify this observation, a greenhouse experiment was conducted. Zinc application enhanced germination percentage, plant growth, Zn, and K concentration and K/Na ratio in maize (Zea mays L.) whereas Na concentration and P/Zn ratio decreased. Application of S alone increased Na and S concentrations, decreased K and Ca concentrations and K/Na ratio. Except for Zn and K, the concentrations of other nutrients studied were higher in plants receiving S than those receiving Zn or Zn + S treatments. The ameliorative role of Zn in plant growth under alkali soil conditions was found to be associated with the changes brought about in the chemical composition of plants.
Competition and Plot‐Dimension Effects in Yield Tests of Safflower Cultivars1
Authors: Abel G. H. 
Published: July 2010

AbstractInformation is needed on the competition effects of safflower, Carthamus tinctorius L., in yield trials of small plots. Six cultivars differing in growth rate and height were planted adjacent to one another in different plot sizes and shapes.In two‐row plots, differences in height in mid‐April (mid‐branching) were not related to yield of straw or seed. Adjacent plot differences of 18 cm in plant height at maturity did not affect straw yield, and differences of 25 cm did not affect seed yield. With adjacent plot differences of 41 to 59 cm, the taller cultivars produced more straw and the shorter cultivar produced less straw and seed than when grown in solid stand. Seed yield was more affected by competition than straw yield.Increasing the area of the plot from 1.4 to 5.8 m2 decreased variation. Plots of parallel basic units were more highly correlated for yield of straw and seed than end‐to‐end units.
Fertilizer Studies with Groundnuts on the Brown Sands of Guyana. II. Effect of Nitrogen, Phosphorus, Potassium, and Gypsum and Timing of Phosphorus Application1
Authors: Chesney H. A. D. 
Published: July 2010

AbstractThe effects of N, P, K, and gypsum and timing of application of P on the performance of groundnuts (Arachis hypogoea L.), grown on the Brown Sands of Guyana, were studied. Generally, 15 kg N/ha gave optimum production. However, in a dry season on the coarser textured soils and during all seasons on a finer textured soil 32 and 48 kg/ha of N were needed, respectively. Application of up to 30 kg P/ha increased yields on all soils found under savannah vegetation except the finest textured one. P did not increase yields of groundnut on the soil occurring under forest vegetation. Potassium within the range tested (124‐164 kg/ha) had no effect on yield. Application of up to 495 kg gypsum/ha increased yield and reduced the number of “pops.” Application of all the P at planting produced higher yields than when the application was split, and this effect was greater during periods of stress and at low rates of gypsum. Timing of P applications had no effect on the number of “pops.”Both P and K increased in all four soils with repeated applications of the respective fertilizers. The amounts accumulated however, were small relative to the quantities applied. Potassium accumulation increased with the clay content of the soils. Total N increased in two soils only.
Manganese Supply, Growth, and Micronutrient Concentration in Grain Sorghum1
Authors: Ohki K. 
Published: July 2010

AbstractReference values for manganese related to plant growth are needed for the assessment of Mn status and micronutrient relationships associated with Mn in grain sorghum (Sorghum bicolor [L.] Moench.). Sorghum was grown to boot stage in nutrient solution with eight Mn levels from 0 to 4,000 µg Mn/liter under greenhouse conditions. Sorghum growth and Mn concentrations in vegetative tissues were dependent on Mn supply in nutrient solution. Mn concentrations of blades 1 (flag‐leaf) through 5 in basipetal order were related to plant growth but blade 1 was the most sensitive tissue in relating Mn concentration to plant growth. The critical Mn levels for blades 1, 2, and 3 were 10, 10, and 15 ppm, respectively, while critical levels for blades 4 and 5 were 32 and 60 ppm, respectively. Blade 1 is suggested as the leaf to sample at boot stage for evaluating the Mn status of the plant. Zinc concentration in blade tissue increased at Mn concentrations below the critical Mn level. Copper concentration remained relatively constant within a wide range of Mn concentration and Fe concentration decreased at low Mn supply levels.
Seed and Oil Quality of Flax After Swathing1
Authors: Dorrell D. G. , Hodgins M. W. 
Published: July 2010

AbstractSeed flax (Linum usitatissimum L.) is frequently cut before fully ripe and left to mature in the swath to hasten or overcome uneven maturity. To determine how swathing effects seed yield as well as seed and oil quality, oilseed flax cultivars were planted at different times in 2 years; then swathed at three stages of seed development ranging from the start of ripening to fully ripe. Swathed plots were sampled during the course of drying and compared with plants left standing. Measurements were taken on capsule moisture, seed weight, yield, color, germination, and oil content as well as fatty acid composition and iodine number of the oil. If swathing took place when the majority of the capsules contained approximately 35% moisture, subsequent drying in the swath produced seeds of excellent quality. Seed weight and total seed yield from swathed plots were slightly reduced; fatty acid composition of the oil was essentially unaffected; and seed color, seed germination, and oil content were slightly higher when compared to flax plants left standing to mature normally. Plants could be swathed when capsules contained as much as 50% moisture and still produce a high quality oil; however, seed germination, seed color, and yield were significantly reduced.
Water‐repellent Soil Clods and Pellets as Mulch1
Authors: Fairbourn Merle L. , Gardner H. R. 
Published: July 2010

AbstractWater‐repellent clods and pellets of a Mollisol soil, Nunn clay loam, were tested in laboratory and field experiments to determine the potential for use in place of gravel as a mulch for reducing soil water evaporation. Solutions of two hydrophobic compounds, dialkyl quaternary ammonium chloride (Arquad), and sodium methyl silanolate (R‐20), were used either as a dip for soil clods and pellets or for mixing with the soil to form pellets. Seven treatments were tested for endurance in the laboratory by the wet sieve, alternate freezing and thawing, and alternate wetting and drying methods. The treatments were also exposed to the ambient climate. The most stable treatments, R‐20 dipped clods, R‐20 mixed pellets, and Arquad mixed pellets, were compared with treatments of gravel and bare soil in evaporation tests to determine the efficiency in reducing soil water loss. The three soil clod and pellet treatments were durable for over 1 year, and each reduced cumulative evaporation with time compared with a bare soil. First‐day evaporation rates after a 5.0‐cm water application showed bare soil was higher than gravel by 79%, R‐20 mixed pellets by 73%, R‐20 dipped clods by 63%, and Arquad mixed pellets by 36%. The R‐20 mixed‐pellet, mulch‐reduced soil water evaporation rate with nearly the same efficiency as gravel and could save about 30% more precipitation for plant use than a bare soil.
Germination of Italian Ryegrass Seeds1
Authors: Young James A. , Evans Raymond A. , Kay Burgess L. 
Published: July 2010

AbstractItalian ryegrass (Lolium multiflorum Lam.) is widely planted on western California and Oregon rangelands, but it does not persist or spread. Understanding seed germination characteristics may help to explain its rather poor competitive ability as compared to other naturalized annual grasses. We studied the germination of seeds (caryopses) of Italian ryegrass under constant and alternating temperatures, and we studied simulated litter as a germination substrate. Constant and alternating temperature regimes were used from −6, −4, −2, 0, 2, and 5 C and 5 degree increments to 30 and 40 C, with 16 hours at the lower temperatures and 8 hours at the higher temperatures. Seeds used were from a naturalized population and two commercial seed sources. Italian ryegrass germinated over a wider range of temperatures and at more extreme diurnal fluctuations than did other annual grasses from the same environment. Germination of the naturalized population was highest at both relatively cool (5 C) nights and warmer (10 to 25 C) days and at a second peak of 10 C nights and high (30 to 40 C) days. Commercial seed lots had maximum germination over a wider range of temperatures than the naturalized seed lot. Litter‐germinated seedlings were very susceptible to drying and had virtually no root regeneration in comparison to other annual grasses. The limited temperature range at which Italian ryegrass germinates and the inability of roots to resist drying or to regenerate after drying may limit it ecologically.
Differential Effect of Bermuda and Bahiagrasses on Soil Chemical Characteristics1
Authors: Tan K. H. , Beaty E. R. , McCreery R. A. , Jones J. B. 
Published: July 2010

AbstractThe use of bermudagrass (Cynodon dactylon (L.) Pers.) and bahiagrass (Paspalum notatum Flugge) has attracted considerable research attention with respect to forage production. Little information is available on the influence of these grasses on soil properties and a direct comparison to effectively estimate the differential effect of bermudagrass and bahiagrass on major soil chemical properties is still lacking. This research was conducted to observe the effect of these grasses on selected soil properties following 4 years of clipping and N fertilizers treatments. A randomized split plot experiment was carried out in three replicates using a Montevallo soil planted with several bermudagrass and bahiagrass varieties, receiving annual application of 0, 224, and 672 kg N per ha from 1967 to 1970. In 1971 herbage and soil samples were collected for yield and chemical analysis.The results indicated the absence of differences in the effects of the grasses on soil pH, N, P, K, and Ca, but there were differences in organic matter contents. The amount of organic matter accumulated in the soil under bermudagrass varied considerably with increased N fertilization, but showed a definite increase under bahiagrass. The lower root/herbage ratio of bahiagrass may explain the differences in soil organic matter under the two grasses. Base content and pH declined similarly in the soils under both bermudagrass and bahiagrass. The reduction in soil pH was related to decreasing amounts of K and Ca present in the soil. A negative correlation was also found between soil pH and N content of bermuda‐grass. In conclusion, over a period of time bahiagrass can be as effective as bermudagrass in its effect on soil properties.
Effects of Soil‐Moisture Regimes on the Growth of Barley1
Authors: Day A. D. , Thompson R. K. 
Published: July 2010

AbstractEffects of soil‐moisture stress at three different stages of growth (jointing, flowering, and dough) on grain yield, grain quality, and plant growth of Spring barley (Hordeum vulgare L. emend Lam.) planted in November were studied under the field conditions at Mesa, Ariz. The experiment was conducted to determine the limitations to irragation water conservation in a semi arid environment. Four by four Latin square designs were used to compare four irrigation treatments. Effects of soil‐moisture stress for 7 days at the jointing, flowering, and dough stages of growth and/or until 100% of available water in the first 3 feet of soil was depleted were compared with plants not stressed. Withholding irrigation water during the jointing stage of growth did not reduce and in some cases increased grain yields. Moisture stress at the flowering and dough stages of growth decreased grain yield. Moisture stress at the dough lowered grain bushel‐weight. Stressing barley for water at jointing resulted in shorter plants, less lodging, more tillering, and more heads per unit area. Moisture stress at flowering and the dough stage decreased seeds per head and seed weight, respectively. Cultivars differed in response to soil‐moisture stress. Adequate soil‐moisture must be provided throughout the growing season for maximum yields of high quality grain from Spring barley grown as a Winter‐annual under irrigation.
Oat Agronomic and Grain Quality Responses to Growth Regulators1
Authors: Oplinger E. S. , Veith W. A. , Youngs V. L. 
Published: July 2010

AbstractLodging often limits oat (Avena sativa L.) yields and retards or prevents establishment of forage legumes seeded with it. We tried to determine whether growth regulators might be used to prevent oat lodging and to learn their effects on grain yield and quality. Ten chemical growth regulators were applied to foliage of two cultivars at two stages of development. Studies were conducted over a 3‐year period (1971–1973) at Arlington, Wis. on ‘Froker,’ a stiff‐strawed cultivar, and ‘Ajax,’ a weak‐strawed cultivar. Agronomic characteristics evaluated included grain yield, test weight, plant height, and lodging. Quality aspects evaluated included groat protein yield, weight, percent, oil concentration, fatty acid composition, and protein and mineral concentrations of both groats and hulls.Several chemical treatments reduced plant height and lodging; however, these were often accompanied by lower test weights and lower yields. Low rates of application which were ineffective in reducing lodging also resulted in few beneficial effects on yield. With a few exceptions the treatments had little effect on grain quality.
Population Density and Sampling Location Effects on Net Radiation Measurements over Corn1
Authors: Linvill D. E. , Dale R. F. 
Published: July 2010

AbstractLittle information is available on the amounts of net radiation utilized by different populations of corn (Zea mays L.). To increase the range in corn microenvironments for a weather and corn growth study, we used two planting dates and two populations in 1970 at West Lafayette, Ind.The soil was Chalmers silt loam. Soil moisture in the top meter remained above 60% available throughout the season. Net radiation was measured 1 m above two corn populations of 42,000 (42K) and 62,000 (62K) plants/ha within an early and a late planting. Pairs of Fritschen‐type net radiometers were exposed from a permanent mast within each of the four microenvironments. Replication was with two portable masts moved every week to alternate temporary locations in each population. Differences between net radiation measured within the same population at the permanent and temporary mast locations generally were larger than those between the permanent mast locations in the 42K and 62K populations. For the incompletely replicated experiment, we used a difference of differences t‐test to determine that there were no significant differences (α level 0.20) between net radiation measured over the 62K and 42K populations. Sources of experimental error discussed are instrumental calibration, field measurements of net radiation, possible canopy wear associated with the temporary mast movement, and nonhomogeneous crop canopies, especially with the net radiometers exposed ≤ 1 m above the crop. Without adequate replication interpreting environmental measurements risky, especially in row crops.
Techniques for Vegetatively Establishing Kentucky Bluegrass Turf1
Authors: Solon E. G. , Turgeon A. J. 
Published: July 2010

AbstractField studies were undertaken to investigate establishment of ‘A‐20’ Kentucky bluegrass (Poa pratensis L.) from plugs and shredded sod planted in prepared soil in early summer. Plug spacing was more critical than plug size in determining the rate of turfgrass establishment. Where companion grasses were seeded in conjunction with plugging, faster ground cover resulted, but the lateral growth of the A‐20 plugs was retarded. Planting of shredded sod resulted in poor turfgrass cover due to desiccation of the plants and annual weed development initially; however, good turfs were developed within 2 years with heavier planting rates resulting in faster establishment.