bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen and Dry Matter in Five Spring Wheat Varieties at Successive Stages of Development1
Authors: McNeal F. H. , Berg M. A. , Watson C. A. 
Published: July 2010

AbstractDry weight and nitrogen content of leaves, stems, kernels, and roots were determined for five spring wheat varieties on seven dates.Maximum leaf development occurred by July 19 (flowering), and maximum stem development ocurred by July 29 (filling). By August 19 (maturity) the top weights were similar for all varieties except ‘Mindum’, which was significantly higher. The average ratio of root (to 5‐ft depth) to top growth on August 19 was 1:14.9.Uptake of nitrogen continued until harvest, although the rate was much slower after July 19. Nitrogen content in the roots was low at all sampling dates, indicating rapid translocation to aboveground parts. If all root nitrogen had been translocated to the kernels, the effect on kernel nitrogen would have been insignificant. The average ratio of root to top nitrogen on August 19 was 1:23.4.The r value of 0.95 between pounds of kernel nitrogen and pounds of top dry weight indicates that 90.2% of the variation in kernel nitrogen in this experiment is due to differences in plant dry weight. This leaves only 9.8% of the variation in kernel nitrogen which the plant breeder might be able to manipulate.We suggest that if wheat varieties which will translocate as much as 70% or more of leaf and stem nitrogen to the kernels can be found, they might be useful in breeding programs.
Conditioning Dry Bean Seed (Phaseolus vulgaris L.) for Better Processing Quality and Seed Germination1
Authors: Dexter S. T. 
Published: July 2010

AbstractBean windrows were sprayed with water to prolong or induce seedcoat toughening that protected the beans from cracking during combining without appreciably increasing their percentage moisture. After combining, the desired amount of moisture was added by mixing a suitable quantity of dampened sawdust with the beans and screening after various intervals. This would protect the beans during the processes of unloading, conveying, screening, and binning. With undesirably dry beans in the bin, moisture was added by circulating warm air at a relative humidity of about 75%. Seed beans, too dry to be drilled without damage to germination, were toughened with damp sawdust and seedling emergence was greatly improved. Damage incurred during combining was not nullified by later conditioning, but further damage could be prevented.
Some Interrelationships between Fertility Levels and Ophiobolus Patch Disease in Turfgrasses1
Authors: Goss Roy L. , Gould Charles J. 
Published: July 2010

AbstractOphiobolus patch disease developed rather quickly on young bentgrass turf after an initial methyl bromide fumigation. The disease occurred at random in 1961, but generally was much worse on plots receiving 9.8 kg of N per 100 m3 per season, regardless of P and K levels, than on plots receiving less or no N. However, by 1964, Ophiobolus patch was much more severe in the 5.9 kg of N plots than in those receiving 2.9 or 9.8 kg of N. Phosphorus had little effect on the disease in 1961, but by 1964 plots treated with 0.86 kg of P had only 15% as much infection as those receiving 0 P. Potassium exhibited a suppressing effect on the amount of disease throughout the experiment regardless of the P level. There was about five times as much disease in the 0 P and 0 K plots in 1964 as in the 0 P and 1.6 kg of K plots at all N levels. Interactions between P and K probably account for some of this difference, since this does not occur when P is added.
Influence of Limestone and Nitrogen on Soil pH and Coastal Bermudagrass Yield1
Authors: Adams W. E. , Pearson R. W. , Jackson W. A. , McCreery R. A. 
Published: July 2010

Abstract‘Coastal’ bermudagrass was grown on an extremely acid Cecil sandy loam soil in order to study the influence of limestone rate (0, 7,846, and 40,349 kg/ha), limestone placement (surface and mixed), and N levels (0, 224, 448, 896, and 1,793 kg/ha) on forage production, rooting, and changes in soil properties.Without limestone, annual forage production declined with time at the 448‐kg/ha N level and above, and Coastal bermudagrass plants exhibited a severe chlorosis. At the two highest N levels (896 and 1,793 kg/ha), up~o 90% of the plants died.Limestone increased annual forage yields at N rates of 896 kg/ha and above. Mixing the limestone with the surface soil resulted in significantly higher forage yields at the 1,793‐kg/ha level. The movement of Ca and Mg into all soil zones down to the 30‐ to 45‐cm zone confirmed the changes in soil pH.Soil pH was reduced by annual applications of 448 kg/ha of 1N and forage yields of Coastal bermudagrass were severely restricted.Coastal roots penetrated to 120 cm in soil with a range in pH from 4.0 to 4.5, emphasizing the extreme tolerance of this grass to very low soil pH.
Effect of Leaf Removal at Four Stages of Growth on Yield of Castorbeans1
Authors: Kittock D. L. , Williams J. H. 
Published: July 2010

AbstractRemoval of castorbean (Ricinus communis L.) leaves at four growth stages at the rates of 1/4, ½, 3/4, and total defoliation resulted in lower yields than the check. Differences between most partial defoliation treatments were not large enough to be significant. Stage of growth when partial defoliation treatments were applied had no significant effect on yield. Total plant defoliation at each of the four dates resulted in yields that were significantly lower than the check. Differences between dates were also significant. Regrowth following the first two total defoliations produced yields that were adequate to justify continuation of fields under farm conditions. Best yield recovery occurred following defoliation at the bloom stage of the primary raceme.Alternaria leaf spot [Alternarla ricini (Yoshii) Hansford] infection occurred after tertiary racemes started blooming but before quaternary racemes started blooming.
Physical State of Water in Plant Xylem Vessels1
Authors: Cary John W. , Jensen Marvin E. , Fisher Herbert D. 
Published: July 2010

AbstractThe vapor pressure psychrometer was used as a tool to study the physical state of water in plant xylem vessels. The experimental procedure involved measuring the change in diffusion pressure deficit (DPD) of corn and tomato plants when the stem was cut. When the DPD was greater than 4 bars in tomatoes and 28 bars in corn, the water in xylem vessels no longer appeared to flow in response to hydrostatic pressure gradients. The limiting value of DPD increased as the xylem radius decreased. A mechanism is suggested which describes the physical state and the movement of water through xylem tissue under high DPD. The proposal is based on the pressure difference across a curved air‐water interface and on the concept of an electrostatic double layer with its associated osmotic pressure.
Downy Brome Competition and Control in Dryland Wheat1
Authors: Rydrych D. J. , Muzik T. J. 
Published: July 2010

AbstractCompetition between downy brome (Bromus tectorum) and winter wheat causes serious economic losses to growers in the Pacific northwest. On a site which received 25 cm average annual rainfall and had a light soil (very fine sandy loam) winter wheat yields were reduced 28% by fewer than 54 downy brome plants per m2 (5 plants/ft2). On a site which received 55 cm average annual precipitation and had a silt loam soil, winter wheat yields were reduced 92% by more than 538 downy brome plants per m2 (50 plants/ft2). Downy brome seed‐to‐straw ratios were indicative of a tremendous yield potential. Seed‐straw ratios of 1:4 are probably an exception but ratios of 1:1 and 1:2 were common.Chemical fallow studies at three sites showed that nonselective downy brome control can be obtained by the use of herbicide combinations such as 3‐amino‐l‐2, 4‐triazole‐ammonium thiocyanate (amitrole‐T), plus chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine (atrazine) or amitrole‐T plus 2,4‐dichlorophenoxyacetic acid (2,4‐D). Amitrole‐T plus atrazine was more effective when used as a fall treatment. Amitrole‐T plus 2,4‐D was more effective in the spring. These chemicals reduced tillage requirements and decreased downy brome growth by 90%.
Cumulative Effects of Irrigation and Fertilizer on Soil Fertility1
Authors: Vittum M. T. , Lathwell D. J. , Gibbs G. H. 
Published: July 2010

AbstractIrrigating Lima and Kendaia silt loam soils with an average of 10.7 cm of water each year for 13 years caused no change in soil pH, organic matter, or available P, Ca, and Mg. Irrigation significantly reduced available K from an average of 109 kg/ha in nonirrigated plots to an average of 97 kg/ha in irrigated plots.Applying an extra 30 kg of P and 54 kg of K per hectare each year for 14 years significantly reduced soil pH, had no effect on organic matter, Ca, or Mg, and significantly increased available P and available K. At the end of the experiment, normal fertility level plots contained 25 and 96, and high fertility level plots contained 37 and 109 kg of available P and K per hectare, respectively.
Effect of Early‐Summer Seeding of Winter Wheat on Yield, Soil Moisture, and Soil Nitrate1
Authors: Dewey W. G. , Nielson R. F. 
Published: July 2010

AbstractWinter wheat was planted at monthly intervals from June through October at four irrigated and three dryland sites in northern Utah over a 4‐year period. The effects of planting date on grain yield, soil moisture and soil nitrate were studied.At the dryland locations the June and July plantings exhausted most of the available moisture and nitrate to the greatest depths sampled (150 and 90 cm, respectively) by fall of the establishment year, thus largely negating the benefits of the fallow summer. Yields of the June‐seeded plots averaged approximately 1/10 those of plots planted in August, September, or October.In the irrigated trials soil moisture and nitrate levels were maintained near optimum through frequent irrigation and the addition of nitrogen fertilizer; yet, as in the dryland tests, yields in the early‐seeded plots were significantly below those of plots seeded at the later planting dates. Disease, winterkill, and possibly physiological old age appeared to be the major factors limiting yields of early‐seeded winter wheat grown under irrigation.
Mineral Composition of Six Tropical Grasses as Influenced by Plant Age and Nitrogen Fertilization
Authors: Gomide J. A. , Noller C. H. , Mott G. O. , Conrad J. H. , Hill D. L. 
Published: July 2010

AbstractThis study was conducted in central Brazil on a sandy loam soil which under normal conditions receives no fertilizer. The K, P, Ca, Mg, Cu, Mn, Fe, and Zn contents were determined on six grasses: Meilinis minutiflora Beauv., Digitaria decumbens Stent., Pennisetum purpureum Schum., Pennistetum clandestinum Hochst., Cynodon dactylon Pers., and Panicum maximum Jacq. var. ‘Gondlyodes Doell’Significant decreases in K, P, Mg, Cu and Fe in the forages (P < .01) occurred with advance in plant age from 4 to 36 weeks. The average K content for all grasses at 4 weeks of age was 1.42% and at 36 weeks of age 0.30%. Kikuyugrass had the highest K content at 36 weeks of age (0.54%). The average P content for all grasses was 0.26% at 4 weeks and 0.12% at 36 weeks. Pangolagrass appeared to be a poor source of P at all ages studied (average 0.12%).Nitrogen fertilizer had no effect on any of the minerals studied except for Mn which increased with N fertilization.Under the conditions of the experiment, the forages could be deficient in K and P for cattle and borderline in zinc.
Long‐Term Fertility Requirements of Coastal Bermuda. II. Nitrogen, Phosphorus and Lime1
Authors: Woodhouse W. W. 
Published: July 2010

AbstractData are presented on the effect of N, P and L variables applied over a 14‐year period on growth and chemical composition of coastal bermudagrass grown on a Eustis sand. N response was around 45 kg of hay per kg of N for rates up to 224 kg/ha with recovery of applied N in the range of 75 to 90%. Yield response flattened off rapidly beyond the 224 kg rate and N recovery declined rapidly beyond this point. The continued application of higher rates of N, 448 and 672 kg, produced a strongly acid reaction in the soil profile throughout the 30 to 240 cm zone, and this appears to have contributed to the relatively poor response at these levels of applied N. The application of only 1120 kg/ha of dolomitic limestone after 11 years of crop removal on an unlimed treatment produced an immediate and rather dramatic yield response. This appeared to be related to Mg supply. Around 25 ppm of soluble P in the plow layer appeared to be adequate, with critical level of P in the plant between 0.11 and 0.14% and optimum between 0.15 and 0.20%.
Factors Affecting the Alkaloid Content of Tall Fescue (Festuca arundinacea Schreb.)1
Authors: Gentry C. E. , Chapman R. A. , Henson L. , Buckner R. C. 
Published: July 2010

AbstractThe alkaloid content of tall fescue (Festuca arundinacea Schreb.) was investigated in seed and different stages of maturity during plant growth from seed to mature plants by paper and thin‐layer chromatography. Eleven alkaloids were found in a selection of Ky 31.No alkaloids were found in seed of Alta, Goar, or NK 36, whereas 3 alkaloids were present in seed of ‘Kenwell’ and ‘Ky 31’. The initial rate of alkaloid synthesis was much higher in Ky 31 than in ‘Alta’. In young seedlings of both varieties perloline, the predominate alkaloid, was detected in the seed and roots as early or earlier than in the shoot. Leaves from mature plants, contained 44% as much perloline and 61% as much total alkaloid as stems.Significant differences occurred in alkaloid content among and within varieties, and among various plant parts. Potassium and phosphorus greatly reduced perloline whereas nitrogen increased perloline synthesis. Perloline and total alkaloid content were reduced as the plant approached maturity. Pasture plants contained the largest concentration of alkaloids, whereas alkaloid content was drastically reduced when the plant material was field‐cured as hay.
Crop Seedling Uptake of DDT, Dieldrin, Endrin, and Heptachlor from Soils1
Authors: Beal M. L. , Nash R. G. 
Published: July 2010

AbstractIn greenhouse experiments, soybean, wheat, corn, alfalfa, bromegrass, and cucumber seedlings took up various amounts of DDT, dieldrin, endrin, and heptachlor residues from five soils treated with 0.5 or 5.0 ppm insecticide. Residue concentrations in plants were usually well below the soil treatment rates, though endrin and heptachlor residues in alfalfa and bromegrass exceeded the treatment rate of some soils. The order of residue uptake in increasing amounts was DDT < dieldrin < endrin < heptachlor.Correlations calculated between residues in seedlings and several soil characteristics revealed that organic matter negatively affected the uptake of DDT, dieldrin, and heptachlor. Silt negatively affected endrin uptake. Soil moisture content at 0.33 bar tension negatively affected DDT and dieldrin uptake by alfalfa. No significant correlations were found between uptake and soil pH, cation exchange capacity, or clay content.Soil analysis, 14 or 20 months after insecticide application, revealed residues of the insecticides, in increasing order of persistence, to be heptachlor < dieldrin ≈ endrin < DDT. Correlations calculated between residues in soils and the soil characteristics above, revealed that persistence was positively correlated with soil organic matter.
Effects of Tillage, No Tillage, and Mulch on Soil Water and Plant Growth1
Authors: Jones J. Nick , Moody J. E. , Lillard J. H. 
Published: July 2010

AbstractSeedbeds for corn (Zea mays L.) were prepared by both conventional tillage and the no‐tillage method, each with and without surface mulches. The mulches consisted of killed grass sod on the no‐tillage plots and straw applied on plots with conventional tillage. No‐tillage plots without a mulch were obtained by removing the killed sod. Mulched treatments, whether of undisturbed killed sod on the no‐tillage plots or of straw on conventional plots, gave the lowest values for runoff and the highest values for soil water content and yield of corn. Soil water conserved by the mulches was reflected in an average grain yield increase of 1,932 kg/ha. Differences in total soil water among treatments were significant to a depth of 30 cm. The effect of tillage was minor, but the data indicate the value of the killed sod mulch in the no‐tillage system.
Effect of Soil Gas Composition and Flooding on Growth of Nicotiana tabacum L1
Authors: Williamson R. E. 
Published: July 2010

AbstractThe responses of Nicotiana tabacum L. to flooding and to soil treatments consisting of combinations of O2, CO2) and N, gases were determined from leaf area and plant height changes and from final root weights. Leaf area and plant height were measured before treatment and after a 5‐day recovery period following treatment; root weights were obtained after the recovery period. The plants were grown in acrylic containers of soil located in an artificially lighted, controlled environment room.Flooding and pure N2 treatments for 24 hours almost prevented further growth. After 48‐hour treatments with pure N2 and flooding, roots and shoots were almost dead. Growth of plants treated with 1% O2 or 1% O2 + 20% CO2 was significantly less than that of the control. The 1% O2 + 20% CO2 treatment reduced leaf growth significantly more than did 1% O2. Although 1% O2 and 1% O2 + 20% CO2 caused injury, plants treated with these gaseous mixtures exhibited near normal growth at the end of a 5‐day recovery period. Permanent injury of tobacco by flooding is primarily due to lack of O2 in the root zone and not to excess CO2. Results obtained in the soil system were similar to those previously obtained in spray nutrient solution culture.
Effect of Phosphorus on Nitrate in Sugar Beet (Beta vulgaris L.)
Authors: Hills F. J. , Sailsbery R. L. , Ulrich Albert , Sipitanos K. M. 
Published: July 2010

AbstractCulture‐solution and field experiments indicate that P‐deficient sugar beets, particularly young plants, do not take up nitrate as well as plants adequately supplied with P. The increase in concentration of NO3‐N in whole tops of young seedlings, cotyledons, or petioles of first true leaves with increased P supply is greater than can be accounted for by a concomitant decrease in percent dry‐matter of these plant parts. The decreased absorption of NO3 by P‐deficient plants in aerated culture‐solution, with all roots exposed continuously to high concentrations of NO3 indicates that the phenomenon reflects not merely increased root extension but a physiological aberration brought about by P‐deficiency.
Nitrate and Ammonium as Sources of Nitrogen for Corn and Their Influence on the Uptake of Other Ions1
Authors: Blair Graeme J. , Miller M. H. , Mitchell W. A. 
Published: July 2010

AbstractNo yield differences in tops or roots were measured between ammonium and nitrate nitrogen sources in flow ‘United 108’ grown for 14 or 28 days in constant flow culture solution. There was a greater uptake of N from the nitrate source but approximately 25% of the total uptake remained as nitrate within the plant. Higher plant levels of phosphorus and sulphur were measured in the ammonium treatment and higher Ca++ and Mg++ in the nitrate treatment indicating a predominately cation‐anion balance effect.
Nitrogen Increases in a Non‐nodulating Soybean Genotype Grown with Nodulating Genotypes1
Authors: Vest Grant 
Published: July 2010

AbstractSeeds of non‐nodulating soybean (Glycine max (L.) Merrill) genotype A62‐8 were mixed in a 1:1 ratio with seeds of nodulating genotypes ‘Delmar’ and ‘Scott’. Prior to planting, the mixtures were inoculated with 7 different strains or combinations of strains of Rhizobium japonicum. A62‐8 mixed with Delmar yielded significantly more with certain inoculum treatments than when the mixture was uninoculated. However, when mixed with Scott the yields of A62‐8 did not differ with inoculum treatments. The seed protein of A62‐8 was higher when the mixtures were inoculated than when uninoculated. The yield and protein percentage of inoculated Delmar and Scott were also significantly higher than the uninoculated checks. The amount of nitrogen fixed in each mixture‐inoculum combination was estimated by using yield and protein data from each genotype.
Nitrogen Accumulation in Fescuegrass Sod1
Authors: Giddens Joel , Adams W. E. , Dawson R. N. 
Published: July 2010

AbstractTall fescuegrass (Festuca arundinacea) was seeded in Cecil sandy loam for 5 years in separate plots. Established fescuegrass plots were plowed and planted to corn during the same period. In 1968 both areas were plowed and planted uniformly to corn (Zea mays). Total N, carbon, organic residues, bulk density, and aggregation were determined on the soils of both areas. Soils from both areas were planted to sudax in the greenhouse.Yields increased from 2,728 kg/ha for continuous corn to 5,940 kg/ha for corn following 5 years of fescuegrass. After destruction of sod, corn yield decreased in 5 years from 5,018 kg/ha to 3,205 kg/ha. Sudax yields showed similar trends. Topsoil N increased from .047% to .088% as result of grass, and decreased from .078% to .054% as result of turning the grass. Soil carbon showed similar relationships. Soil bulk density and aggregation were not significantly affected by treatments. It was concluded that nonsymbiotic N fixation accounted for part of the nitrogen increase in fescuegrass sod and nitrogen conservation the remainder.
Kinetics of P Absorption by Excised Roots and Leaves of Corn Hybrids1
Authors: Phillips James W. , Baker D. E. , Clagett C. O. 
Published: July 2010

AbstractThe kinetics of phosphate uptake was studied using H332PO4 to determine if the observed differences in accumulation of inorganic phosphate by corn hybrids could be explained on the basis of genetic differences in the mechanism of absorption. The absorption of phosphate by corn roots was found to be similar to that for barley roots in that two independent mechanisms of ion absorption were observed. Vmax for the absorption at high concentration was 40 × 10−8 mole P/Mg root × hour, while that of the low concentration reaction was 1× 10−8 mole P/Mg root × hour. The Km for the high and low concentration reactions were 2 × 10−1 and 10−4 mole P/liter, respectively.No difference was observed in the kinetics of uptake of phosphate by roots of the corn hybrids studied. Phosphate absorption by excised leaves was found to be different for the high and low phosphorus accumulators. The difference in absorption rates suggests a difference between hybrids in the strength of the phosphorus‐carrier bond. The variation observed between hybrids was sufficient to account for a 1.6‐fold difference in accumulation of phosphate.
In Vitro Dry‐Matter Digestibility of ‘Midland’ Bermudagrass Grown at Several Levels of N Fertilization1
Authors: Fribourg Henry A. , Edwards Ned C. , Barth Karl M. 
Published: July 2010

Abstract‘Midland’ bermudagrass [Cynodon dactylon (E.) Pers.] was grown at three locations without and with N fertilizer applied at several rates; four replications of a randomized complete block (RCB) design were used at each location. Dry‐matter yields of about 4 t/ha were produced by the no‐N treatment. This was doubled by adding 133 kg/ha of N and doubled again when 400 kg/ha of N were added. The 800 kg/ha of N treatment produced 2.5 t/ha more than the 400 kg/ha treatment. To ascertain the effects of N fertilization on in vitro dry‐matter digestibility (DDM), samples were composited from the four‐field replications of each harvest at each location. Four aliquots, one for each of four replications of a 9 ∗ 9 balanced lattice design (173% efficiency compared to RCB) were taken from each composite sample. Each replication was a run using one inoculum from a rumen‐fistulated steer fed Midland bermudagrass. The average DDM increased from about 37 to 46% over the range of applied N. The greatest increase occurred as the N rate was increased from 133 to 400 kg/ha. The yield of DDM was increased from about 1.5 to 9.0 t/ha with increasing N applications.