bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nutrient Concentration Changes in Corn as Affected by Dry Matter Accumulation with Age and Response to Applied Nutrients1
Authors: Terman G. L. , Noggle J C 
Published: July 2010

AbstractHybrid corn (Zea mays L.) was sampled each week on field plots of soil testing adequate in P and K at Muscle Shoals, Alabama, in 1972, to relate plant analyses results to growth and maturity. Treatments of N compared were no N, 28 kg/ha at planting + 84 kg/ha topdressed at tasseling, 56 kg/ha at planting, and 112 kg/ha at planting. Plots of cumulative yields vs nutrient concentrations were used to evaluate the results.Corn yields increased markedly with amount of applied N, but single and split applications of N resulted in similar yields. Concentrations of N in the top leaves, ears, and entire topgrowth also increased at each harvest date with amount of applied N. Applied N also resulted in higher concentrations of P, Ca, and Mg, but lower K concentrations in the top leaves at most sampling dates. At each rate of applied N, concentrations of N in leaves, ears, and entire tops decreased with maturity. Concentrations of P remained about the same; Ca and Mg first decreased and then increased to maturity, whereas the opposite trends resulted for K concentrations. These opposite trends in results from this experiment and from other studies illustrate the strong reciprocal relationship between concentrations of K and Ca + Mg in plants. Nutrient concentration trends with increasing yields and age of plant are influenced in general by amounts of available nutrients and various growth‐limiting factors.
Tolerance of Five Cool‐Season Perennial Grasses to Selected Herbicides1
Authors: Canode C. L. 
Published: July 2010

AbstractThis research was designed to measure the tolerance of five species of perennial grasses to selective herbicides. Herbicides were applied in September or in April preceding production of the first or second seed crop of Kentucky bluegrass (Poa pratensis L.), smooth bromegrass (Bromus inermis Leyss.), orchardgrass (Dactylis glomerata L.), crested wheatgrass (Agropyron desertorum (Fisch. ex. Link) Schult., and red fescue (Festuca rubra L.).Seed yield of these species was not reduced by isopropyl carbanilate (propham) or isopropyl m‐chlorocarbanilate (Chlorpropham) at 3.4 and 4.5 kg/ha applied in September. Seed yield was significantly reduced by 5.6 kg/ha of propham applied in September to orchardgrass and chlorpropham, applied in September to red fescue. Seed yield was not reduced by 3, 6‐dichloro‐o‐anisic acid (dicamba) at rates as high as 4.5 kg/ha applied to Kentucky bluegrass in September, but was reduced by lower rates applied in April. Other species were less tolerant than Kentucky bluegrass to dicamba applied in both September and April. Seed yield of Kentucky bluegrass was reduced by 4‐amlno‐3,5,6‐trichloropicolinic acid (picloram) at 0.6 kg/ha applied in September before production of the first seed crop, but this species tolerated as much as 2.2 kg/ha applied to older stands. Other species were less tolerant than Kentucky bluegrass to picloram. Applicatlou of (2,4‐dichlorophenoxy)acetic acid (2,4‐D) to 2.2 kg/ha in September did not significantly reduce seed yield of any of the species, but applications of 1.7 or 2.2 kg/ha in April reduced seed yield of smooth bromegrass and red fescue.Application of propham, chlorpropham, or 2,4‐D did not reduce seed germination of any species. Application of picloram in September also did not reduce germination of grass seed, but application of 1.7 kg/ha or more in April reduced germination of smooth bromegrass seed in 1969 and red fescue seed in 1966 and 1969. Dicamba at the higher rates applied in September reduced seed germination of two grasses and when applied in April reduced seed germination of most of the grasses.
Diurnal and Seasonal Trends in Nitrate Reductase Activity in Field Grown Sorghum Plants1
Authors: Teare I. D. , Manam Radhamohanrao , Kanemasu E. T. 
Published: July 2010

AbstractNitrate reductase activity in plants has been suggested as a sensitive indicator of water stress. We studied nitrate reductase activities in sorghum (Sorghum bicolor L. Moench cv. ‘Pioneer #846’) using in vivo assay and compared activities by leaf position on culms and various positions on leaves — through diurnal and seasonal trends (from stalk elongation to maturity, 1971). We related leaf water potential (measured with pressure bomb) and atmospheric demand for water (solar radiation measured with a pyranometer) with nitrate reductase activity. Nitrate reductase activity was highest in the upper, fully‐expanded leaves — in the flag leaf at the 5.5 stage of physiological development. We also compared relative amounts of hydrocyanic acid in sorghum, which other workers have observed in relation to physiological age, with seasonal nitrate reductase activities. Diurnal water stress (shown as leaf water potential in relation to high solar radiation) lowered nitrate reductase activity. Nitrate reductase activity decreases as plant age and water stress increases and likely decreases as hydrocyanic acid increases.
Fertilizer Studies with Groundnuts on the Brown Sands of Guyana. I. Effect of Nitrogen, Inoculum, Magnesium, and Fritted Micronutrients1
Authors: Chesney H. A. D. 
Published: July 2010

AbstractThe Brown Sands are a dominant soil group in South Guyana. They are coarse textured ‐ sand to sandy loam; highly leached; acid, and, although not naturally fertile, they appear suitable for large scale cultivation of groundnuts [Arachis hypogoea (L.)].Two experiments were conducted on these soils to determine the effect of fertilization and inoculation on crop performance.In the nitrogen × inoculum (Rhizobium japonicum) series, N did not influence yield. It caused a decrease in nodulation with the effect becoming more marked with constant cropping. Inoculum up to 226 g/27 kg seed increased yields but decreased nodulation only at the last of three plantings. Both Mg and fritted micronutrients had no effect on yields; these results were difficult to explain considering the highly leached nature of this soil.
Soybean Response to Stand Reduction and Defoliation1
Authors: Teigen James R. , Vorst James J. 
Published: July 2010

Abstract‘Beeson’ soybeans (Giyeine max (L.) Merr.) were treated at a vegetative (V7) and a reproductive (R3) stage of development to determine how soybeans respond to two important components of hail damage‐stand reduction and defoliation. This information is used by the crop hail industry to construct crop loss charts. Treatments consisted of 0, 25, and 50% levels of stand reduction and defoliation in all combinations at both growth stages. Defoliation was accomplished by removing designated percentage of each leaflet with a hand shears. Stand reduction alone reduced seed yield a maximum of 17% while defoliation alone reduced seed yield a maximum of 6%. The largest yield reduction (23%) occurred when the 50% stand reduction and 50% defoliation treatment was imposed during the reproductive stage. Plant height at maturity and lodging were reduced slightly by both defoliation and stand reduction treatments with stand reduction causing the most change in these parameters. More pods and heavier seed were produced on plants remaining after stands were reduced. Defoliation during the reproductive stage reduced seed yield, number of pods per plant, and lodging more than similar treatments applied at the vegetative stage. Number of seeds per pod was not significantly influenced by the treatments. From the data we concluded that low levels of defoliation removed leaf tissue which contributed little to seed production, and the soybean community was able to compensate for plants removed from the population. Most of the compensation was due to an increase in number of pods per plant.
Centipedegrass Cold Tolerance as Affected by Environmental Factors1
Authors: Johnston W. J. , Dickens Ray 
Published: July 2010

AbstractCentipedegrass [Eremochloa ophiuroides (Munro) Hack.] is an excellent lawn grass throughout much of the lower South. However, lack of cold tolerance has limited its use. An environmental chamber study was conducted to determine: 1) the rate at which cold tolerance is developed and lost in centipedegrass and 2) the effect of photoperiod and temperature on cold tolerance development in an effort to identify factors or conditions contributing to cold damage in centipedegrass.Development of cold tolerance was determined by cold hardening (16 C day, 4 C night, 12‐hour photoperiod) centipedegrass for 0, 10, 20, 30, or 40 days. Loss of cold tolerance was determined by transferring cold hardened plants to favorable growing conditions for 0, 2, 4, or 6 days. In the photoperiod‐temperature study, plants received 8, 12, or 16 hours of light at 23 C followed by either a 23 C or 4 C night. In each study, following a 4‐hour exposure at −7 C, plants were returned to favorable growing conditions. Foliage kill and survival were determined after 7 and 21 days, respectively.Hardening periods greater than 10 days caused no increase in survival and only a slight reduction in top‐kill. Cold tolerance was lost rapidly; i.e., cold hardened plants exposed to 2 days of favorable growing conditions showed the same injury as unhardened controls. Photoperiod alone did not affect cold tolerance; however, a combination of a low night temperature (4 C) and short‐photoperiod (8 hours of light) gave maximum cold tolerance. In conclusion, centipedegrass acquires and loses cold tolerance within a few days, an important consideration in the lower South where winters are often interrupted by periods of warm weather.
Interaction of Water Potential and Temperature Effects on Germination of Three Semi‐arid Plant Species1
Authors: Sharma M. L. 
Published: July 2010

AbstractStudies evaluating simultaneous effects of more than one environmental factor on germination are rather scarce. Population dynamics of plant species would be understood better provided these effects are known. A study was undertaken to investigate the interactive effects of temperature with matric and osmotic potential on germination characteristics of three dryland species, Danthonia caespitosa Gaudich, Atriplex nummularia Lindl. and A. vesicaria Hew. ex Benth. Matric potentials were simulated by aqueous solutions of polyethylene glycol (mol. wt. 20,000) and their effects were compared with those of osmotic potential created by sodium chloride solutions.The rate and total germination of all the species declined with decreasing water potential. The germination rates increased with increasing temperature but final germinations were highest at intermediate temperatures (20 to 25 C). All species germinated better at low water potentials in the vicinity of the optimum temperatures. Interactive effects of temperature with both types of water potential were highly significant for all species. In general, osmotic effects were qualitatively similar to those of matric potential, although asmotic inhibition of germination was reduced at low temperatures.Both Atriplex had reasonable germination at extreme temperatures (5 C, 40 C) while D. caespitosa did not germinate at all. At low water potential (—15 bars) A. nummularia germinated in the range of 15 to 40 C, D. caespitosa germinated only at 25 C while A. vesicaria had poor germination at all temperatures. The order of species with respect to their capability to germinate against environmental stress was A. nummularia > A. vesicaria > D. caespitosa. It follows that because of capability of Atriplex spp. to withstand extreme temerature and water potential, germination is possible following rains during summer as well as winter, however Danthonia is likely to germinate only during spring and autumn.
Incorporation Depth and Rainfall on Weed Control in Soybeans with Metribuzin1
Authors: Wax L. M. 
Published: July 2010

AbstractMetribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthlo)‐as‐triazin‐5)4H) one] controls several species of annual broadleaf weeds in soybeans [Glycine max (L.) Merr.]; however, inconsistent weed control and excessive crop injury sometimes result from the use of metribuzin. To determine the extent to which rate of application, rainfall, and depth of incorporation influence weed control and crop injury with metribuzin, microplot and large plot field experiments were conducted in 1973 and 1974. In microplot studies, metribuzin provided 67 to 100% control of comon ragweed (Ambrosia artemisiifolia L.), prickly sida (Sida spinosa L.), velvetleaf (Abutilon theophrasti Medic.), and jimsonweed (Datura stramonium L.). Degree of weed control increased with a corresponding increase in herbicide rate from 0.56 to 0.84 kg/ha. Increased control of these species (and slightly greater soybean injury) resulted from increasing depth of soil‐incorporation from 0 to 7.6 cm. Control of common cocklebur (Xanthium pensylvanicum Wallr.) and ivyleaf morningglory [Ipomoea hederacea (L.) Jacq.] was only 35 to 75% but control did improve with increased herbicide rate and depth of incorporation. Abundant rainfall within 10 days after treatment resulted in 88 to 99% control of velvetleaf and 85 to 95% control of jimsonweed. However, control of these two weeds was poor under limited rainfall, unless metribuzin was incorporated to a depth of at least 5.1 cm. Ivyleaf morningglory was not controlled well with metribuzin in the microplots (12 to 62%) regardless of rate, rainfall, or depth of incorporation. In the large plot studies, metribuzin, under moderate‐to‐abundant rainfall conditions, controlled several annual broadleaf weed species, whether applied preemergence to the soil surface or used as a preplant soil‐incorporated treatment. Metribuzin injured soybeans and caused significant yield reduction when soil‐incorporated at 1.12 kg/ha.
Differential Aluminum Tolerance of Sugarbeet Cultivars, as Evidenced by Anatomical Structure1
Authors: Keser M. , Neubauer Benedict F. , Hutchinson F. E. , Verrill D. B. 
Published: July 2010

AbstractEarly attempts to cultivate the sugarbeets (Beta vulgaris L.) in Maine were not successful due to large amounts of soluble Al in acid soils. The objectives of this study were to determine if a differential tolerance to Al exists among sugarbeet cultivars grown world‐wide, and whether such tolerance could be detected in early stages of seedling growth by examination of morphological and anatomical structures.All cultivars were grown in culture solutions of 0 and 4 ppm of Al at pH 4.8. Four parts per million was used because this concentration in culture solution was toxic to cultivar IS 922, a cultivar previously grown on a commercial basis in Maine. After 10 days growth, some cultivars exhibited more tolerance than others. This study concentrated on eight cultivars of the 116 originally tested. Cultivar IS 922 was used as the control; two cultivars were chosen for low tolerance, and five for their high tolerance to Al toxicity.At 0 ppm of Al, all cultivars showed normal anatomical and morphological development. At 4 ppm of Al, the two most susceptible cultivars accumulated large amounts of aluminum phosphate. The meristematic zones of primary and lateral roots of these plants lost their normal pattern of organization and further growth appeared inhibited. Variability existed within each of the five cultivars chosen for their apparent tolerance, some plants accumulated aluminum phosphate and others did not.This study indicated that differential tolerance to Al exists among sugarbeet cultivars, and among individual plants within the same cultivar. Tolerance can be determined at early developmental stages.
Influence of Water and Fertilizer Management on Yield and Water‐input Efficiency of Corn1
Authors: Rhoads F. M. , Mansell R. S. , Hammond L. C. 
Published: July 2010

AbstractDamaging plant water stress develops in corn grown on coarse‐textured, low water retaining soils of the south‐eastern U.S. during 1 to 2‐week periods without rainfall. However, in most years rainstorms cause leaching of soluble fertilizers from the root zone. This study was conducted to evaluate efficiency of water input in terms of corn grain yield per unit of water, with two fertilizer application methods under three soil‐water management systems on a Troup loamy sand (Grossarenic Paleudult). Water management consisted of (a) control — natural rainfall only, (b) trickle irrigation scheduled daily (0.64 cm/day), and (c) trickle irrigation scheduled by tensiometer (1.30 cm/application). Tensiometers were placed in each treatment at six depths between 15 and 150 cm below the soil surface and readings were recorded daily. Methods of applying fertilizers were designated (a) conventional — 1/3 of N and all P and K applied broadcast preplant, and remainder of N applied in two sidedressings; (b) program fertilization — N‐P‐K applied broadcast small increments (5, 5, 10, 20, 20, 20, and 20%) at 2‐week intervals after corn emerged. Average grain yields for the above water management treatments were 2,790, 4,160, and 5,700 kg/ha respectively. Conventional fertilization had an average grain yield of 3,680 kg/ha and program fertilization 4,760 kg/ha. Water‐input efficiencies based on grain yields and total water input were 57, 42, and 76 kg/ha/cm for no irrigation, daily irrigation, and tensiometer scheduled irrigation respectively. Highest irrigation water.input efficiency (150 kg/ha/cm) occurred with program fertilization and tensiometer scheduled irrigation. Irrigation water‐input efficiency was lowest (10 kg/ha/cm) with corn receiving daily irrigation and conventional fertilization.
Root Growth Along Plexiglas Surfaces by Sugarcane Under Different Soil Salinity Conditions1
Authors: Gerard C. J. 
Published: July 2010

AbstractRoot growth responses by sugarcane (Saccharum officinarum L.) to stress induced by salinity as a function of time or growth stage have not previously been investigated. This type of investigation is essential to a better understanding of the tolerance of plants such as sugarcane to salinity or stress. Root environment chambers seem to provide the best opportunity to study the growth interactions of roots and tops of plants and their environment. Root growth in soils irrigated with waters with electrical conductivities of 1.1, 5.0, and 8.0 mmhos/cm varied with stage of plant growth, time and salinity treatments. Root growth of sugarcane was greatest at soil depths of 20 to 60 cm in May, June, and July, a period of high growth rate and high evaporative conditions. During these months, average root intensities of sugarcane, irrigated with waters with salinities of 1.1, 5.0, and 8.0 mmhos/cm, were about 0.5, 1.0, and 1.5 mm/cm2, respectively. Moisture stress induced by osmotic potentials of about −1.8 and −2.9 bar and high evaporative conditions stimulated root intensities but reduced top growth by 22 and 50%, respectively. These studies using root chambers have contributed to a better understanding of the interactive influences of stages of plant growth, salinity, and environment on root growth by sugarcane.
Sensitivity of Sesame to Various Salts1
Authors: Nassery H. , Ogata G. , Maas E. V. 
Published: July 2010

AbstractPlants tolerate widely varying proportions of salts in the root media but nutritional imbalances and specific ion toxicities may occur if one salt predominates under saline conditions.The relative sensitivity of sesame (Sesamum indicum L.) to various ions and the nature of the specific ion toxicities were studied in water culture experiments. At 0.10 MPa osmotic pressure, NaNO3, NaCl, Na2SO4, and CaCl2 reduced the yield (shoot + pods) of Sesame by about 15, 26, 33, and 65%, respectively. At 0.20 MPa, Ca(NO3)2 was more injurious than NaCl or any combination of the two salts.Chemical analyses indicated that sesame roots did not accumulate C1, Na, and Ca readily, since the accumulation factors for these ions were near or less than 1. However, leaves accumulated these ions to a considerable extent. Leaf Na concentrations of 162 µmol/g fresh wt were associated with necrosis but no evidence of C1 toxicity was noted. Calcium‐induced necrosis seemed indirect, possibly a consequence of decreased Mg concentration. Ion concentration gradients indicated a specific accnmulation of Na in the stem. This retention was greater, and less Na reached the leaves, when the anion was C1 than when it was SO4, a difference that may explain the greater sensitivity of sesame to Na2SO4 than to NaCl.The high sensitivity of sesame to single‐salt salination emphasizes the importance of using salt mixtures in salt tolerance studies. At extreme Na‐Ca ratios, ionic imbalance predominates and growth suppression exceeds that due to osmotic stress.
Nitrogen Fertilization Increases N and Alters Amino Acid Concentration of Cottonseed1
Authors: Elmore C. D. , Spurgeon W. I. , Thom W. O. 
Published: July 2010

AbstractUtilization of seed proteins from cotton (Gossypium hirsutum L.) as an ingredient of food products for nonruminant animals may provide producers with a salable seed commodity in addition to oil and meal. It was important to confirm and more fully establish the effects of N fertilization on cottonseed protein concentration and protein quality (amino acid composition). In order to achieve this, seed was collected in 1976 from a N fertility experiment which had been established with the same N rates the previous 2 years. Cotton (‘DES 56’ was grown on a Dundee silt loam soil, a fine‐silt, mixed, thermic, Aeric Ochraqualfs, with four replications. The experimental design was a split‐plot with N rates (67, 90, 112, 134, and 157 kg ha‐1) as the main plots and time of application (preplant, 1/2 preplant‐1/2 sidedressed, and sidedressed) as subplots (the same plots received the same treatment each year). We measured yield of seed cotton, seed N concentration and amino acid composition.In 1976 the higher N rates increased seed N concentrations from 6.05% N up to 6.60% N, whereas time of application had no effect. Application of N decreased lysine and increased arginine concentration, whereas histidine, serine, tyrosine and phenylalanine were affected by time of application. Glycine was affected by both rate and time of application. Correlation of seed N concentration with amino acid concentration showed that arginine, cysteine and proline were positively related and that lysine, histidine, and threonine were negatively related to seed N. The effects produced by application of fertilizer N to cotton in a field situation result in seed N and amino acid concentration similar to results reported previously in an unusual field situation and allow for better prediction of N effects on cottonseed composition.