bluuebunny/crossref_metadata_2025_split huggingface dataset:
In‐the‐furrow Application of Root‐knot Larvae in Field Plots1
Authors: Banks Donald J. 
Published: July 2010

AbstractA method of inoculating a small field plot with Northern root‐knot nematode, Meloidogyne hapla Chitwood, is described. An average of 11,353 nematode larvae that had been collected from tomato roots under a mist system in the greenhouse were distributed per 30.48 cm (foot) of row during planting. The larvae were dispensed in the furrow over peanut seeds by gravity flow through a glucose intravenous injection apparatus mounted on a garden planter.Differences in plant growth and pod yields in the inoculated and uninoculated plots were not apparent the 1st year. Visual differences in growth and statistically significant differences in pod yield and plant height, but not in stand, occurred the 2nd year after inoculation. Pod yields and plant heights were reduced 66 and 29%, respectively, in the nematode infested plots.
Toxicity of 2‐Chloro‐6‐(Trichloromethyl) Pyridine in Soybean (Glycine Max L. Merr.) Seedlings1
Authors: Riley D. , Barber S. A. 
Published: July 2010

AbstractSoybeans were grown for 18 days in a silt loam soil containing 0 to 20 ppm 2‐chloro‐6‐(trichloromethyl) pyridine (N‐Serve). Yield of shoots was reduced by concentrations of 8 and 20 ppm and their morphology was altered with concentrations as low as 1 ppm. Yield of roots was not greatly affected by up to 20 ppm, but their morphology was drastically altered with 8 and 20 ppm. Production of NO3 in the soil was reduced 90% by 8 and 20 ppm, 60% by 3 ppm and only slightly by 1 and 0.5 ppm of 2‐chloro‐6‐(trichloromethyl) pyridine.
Resistance to Greenbug in Three Millet Species1
Authors: Hackerott H. L. , Harvey T. L. 
Published: July 2010

AbstractPearl millet, Pennisetum typhoides (Burn.) Stapf and C. E. Hubb.; foxtail millet, Setaria italica L.; and proso millet, Panicum miliaceum L. were evaluated for resistance to the C‐biotype greenbug, Schizaphis graminum (Rondani), a recent serious pest of sorghum, Sorghum bicolor (L.) Moench. All trials were conducted in growth chambers at 27 C. Survival and reproduction of adult greenbugs confined to seedling and mature plants were greater on sorghum than on the millet species. The millets were also more resistant than sorghum on the basis of plant injury scores. Pearl millet seedlings were slightly more resistant than mature plants. Pearl millet supported the most greenbugs and proso the least in seedling trials with greenbugs confined to the three millet species individually and in all possible paired combinations. Since the millet species evaluated were highly resistant, they could serve as substitute crops for sorghum until greenbug‐resistant sorghum cultivars become commercially available.
Release of Nitrogen from Sulfur‐coated Urea in Flooded Soil1
Authors: Giordano P. M. , Mortvedt J. J. 
Published: July 2010

AbstractLaboratory and greenhouse experiments were conducted to investigate the release of N in Mountview sil from sulfur‐coated urea (SCU) and the subsequent uptake of N by rice (Oryza sativa L. var. ‘Nato’). The rate of N release was much greater in moist than in flooded soil. Granules of SCU became coated with FeS after 2 weeks in flooded soil. When the flooded soil was dried to about field capacity, oxidation of the FeS coatings appeared to seal the granules so that very little N was released. In general, the release of N was slightly greater from SCU applied to limed soils fertilized with PDry matter production and uptake of N by rice from SCU was similar to that from uncoated urea when both N sources were incubated in moist soil for at least 2 weeks prior to planting and flooding. Urea applied to the soil immediately before flooding was also effective, but SCU was not.
Response of Plants to Naphthenic and Cycloalkanecarboxylic Acids1
Authors: Wort D. J. , Patel K. M. 
Published: July 2010

AbstractThe application of a 5 × 10‐2 M solution of potassimu naphthenates (KNap) to the foliage of 14‐day‐old plants of maize, spring wheat, sugar beet, bush bean, and radish resulted in 8 to 21% greater growth of the foliage determined 21 to 50 days after spraying. Fresh weight of the radish taproot was greater by 13.5%. Treatment increased the weight of green pods per bush bean plant, harvested 35 days after KNap application, by 23%. Soaking spring wheat seeds in a 0.01 or 0.001% KNap solution for 12 hours immediately prior to planting, resulted in increases of 9 and 12% in weight of kernels per plant. The foliar application of 1 × 10‐2 M and 2 × l0‐2 M solutions of the potassium salt. of cyclopentane‐, cyclohexene‐, or cycloheptanecarboxylic acid was followed by an increase in weight of pods per bush bean plant, but the increases lacked statistical significance (0.05 level). The use of potassium cyclohexanecarboxylate invoked significant increases of 24 and 35% in pod yield. Results suggested that the presence of a 6‐carbon saturated ring in the molecule of the lower molecular weight eycloalkanecarboxylic acids is required for effective stimulation of plant growth. This may also be true of the naphthenic acid mixture extracted from petroleum.
Relationship Between Grain Yield and Leaf N, P, and K Concentrations for Corn (Zea mays L.) and the Factors that Influence this Relationship1
Authors: Voss R. E. , Hanway J. J. , Dumenil L. C. 
Published: July 2010

AbstractCorn grain (Zea mays, L.) yield and leaf N, P, and K concentrations were measured for 575 plots at 23 sites in western Iowa on Marshall and Monona soils. Variables included applied N, P, and K, indigenous fertility, plant population, soil yielding potential, past cropping, and soil moisture. The multiple‐regression equations for yield, as a function of linear and quadratic leaf concentrations, resulted in an R2 of only 0.24. A satisfactory equation contained linear, quadratic, and interaction terms for leaf N and P, several environmental factors, and the interactions among the leaf and environmental factor terms. The R2 of this equation was 0.71. Because of the general adequacy of leaf K, its addition to the above model did not improve the relationship. Leaf nutrient concentrations at predicted maximum yield and concentrations at 95% of predicted maximum yield varied with past cropping, plant population, soil yielding potential, and soil moisture. These experiments suggest that interpretation of leaf analyses should include consideration of soil, management, and climatic factors.
Growth of Sudan and Tall Fescue Grasses as Influenced by Irrigation Water Salinity and Leaching Fraction1
Authors: Bower C. A. , Ogata G. , Tucker J. M. 
Published: July 2010

AbstractSudan (Sorghum sudanense P. Stapf) and tall fescue (Festuca arundinacea Schreb.) grasses were grown in outdoor lysimeters with various irrigation water salinity levels and leaching fractions to determine the steady‐state salt profiles that developed and to relate the salt profiles to yield. Yields of both grasses were highly related to the average salinity of the root zone in spite of marked differences in vertical distribution of salt. The first increments of leaching were the most effective in preventing salt accumulation in the root zone. These results agree with those previously reported for a similar study with alfalfa (Medicago sativa L.). The observed leaching fractions required to achieve 90% of maximum yields of all three crops with 2‐ and 4‐mmho/cm irrigation waters agreed reasonably well with values calculated by the equation: LF = EC1w/ECe‐50 per cent, where LF is leaching fraction, and EC1w and ECe‐50 per cent are the electrical conductivities of the irrigation water and of the soil saturation extract at 50% yield decrease, respectively.
Nitrogen and Phosphorus in Jaraguagrass (Hyparrhenia rufa (Nees)Stapf) During the Dry Season in a Tropical Savanna as Affected by Nitrogen Fertilization1
Authors: Tergas L. E. , Blue W. G. 
Published: July 2010

AbstractThe effect of N fertilization during the latter part of the rainy season on yield and N and P composition of jaraguagrass (Hyparrhenia rufa (Nees) Stapf) during the dry season in the wet‐dry Guanacaste Province of Costa Rica was studied. The dry season persists from approximately December 1 through May. A split‐plot experiment with N rates as main plots and harvest dates during the dry season as subplots was established on October 13 on a newly mowed grass sward. Forage production increased with N fertilization through January 13 and decreased erratically as the plants dried. Forage N concentrations and contents were increased by N fertilization, but decreased after the initial harvest on November 30 as the dry season progressed. Forage P concentrations and contents also decreased. The decreases in forage N and P concentrations and contents were significantly correlated for each N treatment. Root N concentrations and contents generally increased as forage N decreased with time into the dry season. Forage regrowth during the subsequent rainy season was higher when the dry season harvest was delayed. Apparently these elements were lost from the forage by translocation to the roots. The beneficial effect of N fertilizer on forage quality persisted only for a relatively short time after initiation of the dry season.
Laboratory Methods for Estimating Plant Available Nitrogen in Soil1
Authors: Ryan J. A. , Sims J. L. , Peaslee D. E. 
Published: July 2010

AbstractBiological and chemical methods for obtaining an index of soil N availability to a test crop under different levels of N fertilization were evaluated on 15 Kentucky soils having a range of organic matter contents of 0.72 to 2.79%. Organic matter, N mineralized during aerobic incubation at 30C or 40C for 7 or 14 days, and extractable NH4+− ‐ 3 times after incubation under waterlogged conditions for 7 or 14 days at 30C and 14 days at 40C were all significantly related to N uptake and relative increase in N uptake by ‘X‐1605’ grain sorghum (Sorghum vulgares) during 18 weeks of growth in the greenhouse.When the soils were amended in the laboratory with P and K or P, K, and Ca and incubated under waterlogged conditions, the relationship between extractable NH4+‐N and N uptake by sorghum improved greatly over unamended soils. Nitrogen mineralized during aerobic incubation and NH4+‐N after incubation of amended soil under waterlogged conditions were among the better predictors of both N uptake and relative increase in N uptake.
Energy and CO2 Balance of an Irrigated Sugar Beet (Beta vulgaris) Field in the Great Plains1
Authors: Brown K. W. , Rosenberg Norman J. 
Published: July 2010

AbstractThe fluxes of latent heat and CO2 above an irrigated sugar beet (Beta vulgaris) field in the North Platte Valley of Nebraska were calculated by means of the energy balance. The advection of sensible heat to the field was large only when strong dry winds predominated or when the field acted as a leading edge of the irrigated river valley.Little evidence was found of midday depression in sugar beet photosynthetic rate. Contrary to reported aerodynamic evaluations of CO2 flux in the field, the energy balance calculations do not reveal a relationship between wind speed and CO2 flux, except for a negative correlation during a dry windy period. This decrease was attributed to increased stomatal resistance.The crop appeared to be light‐saturated at 0.8 cal cm‐2 min‐l short wave radiation. When CO2 flux is corrected for soil CO2 emission and plant respiration, agreement with plant sampling measurements of dry matter increase is good. Water use ranged from 171 g per g dry matter fixed on a cloudy day to an average of 365 g per g dry matter fixed on clear days. Since the sugar beet crop is saturated at less than full sunlight, water use is greater than is necessary for the production obtained.
Establishment of Crownvetch with Herbicides1
Authors: Peters E. J. , Lowance S. A. 
Published: July 2010

AbstractA number of herbicides were evaluated preplant, preemergence, and postemergence as aids to the establishment of crownvetch (Coronilla varia L.) in the field. In five experiments, during the four years of the study, the degree of weed control and the density of the crownvetch stands were evaluated during the seedling year. Yields of crownvetch and weeds were determined the year following establishment.Preplant applications of S‐ethyl dipropylthiocarbamate (EPTC), α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine (trifluralin), N‐butyl‐N‐ethyl‐α,α,α‐trifluoro‐2,6‐dinitro‐p‐toluidine (benefin), and a mixture of l,l‐dimethyl‐4,6‐diisopropyl‐5‐indanyl ethyl ketone and l,l‐dimethyl‐4,4‐diisopropyl‐7‐indanyl ketone (64‐296‐B) nearly eliminated all weed grasses and were somewhat better than preemergence and post emergence applications of 2,2‐dichloropropionic acid (dalapon) for controlling weed grasses. Mowing, in addition to the use of these herbicides, was necessary to control broadleaf weeds and to insure good stands of crownvetch. Stands of seedling crownvetch and yield the year following establishment were increased when herbicides and mowing were used during establishment.Postemergence treatments with an amine and ester of 4‐(2,4‐dichlorophenoxy)butyric acid (2,4‐DB), 3,5‐dibromo‐4‐hydroxybenzonitrile (bromoxynil), and 3,4‐dichloro‐4‐hydroxybenzonitrile (chloroxynil) controlled broadleaf weeds but the herbicides injured seedling crownvetch and reduced its vigor. Bromoxynil and chloroxynil were more injurious to crownvetch than 2,4‐DB. Injury from 2,4‐DB, bromoxynil, and chloroxynil was such that use of the herbicides could be justified only where stands would be lost without practices to control broadleaf weeds.
Influence of Nitrogen Source on Phosphorus Uptake by Corn from Soils Differing in pH1
Authors: Blair Graeme J. , Mamaril C. P. , Miller M. H. 
Published: July 2010

AbstractThe objective of this study was to test the hypothesis that reduction of pH at the soil‐root interface when NH4+ ions were absorbed is the cause of the increased absorption of P in the presence of NH4+.The influence of addition of (NH4)2SO4 or KNO3 to an MCP band on P absorption by corn was determined in a greenhouse study involving four soils ranging in pH from 4.2 to 8.2. The in‐situ activity of the corn plants was determined periodically during the growth, and the dry weight of tops and roots in the fertilizer zone as well as the nutrient content of the tops were determined after 17 days.Application of (NH4)2SO4 with MCP was found to increase fertilizer P uptake when compared to MCP alone on soils of pH 8.2, 7.4 and 5.5. No difference was measured on a soil of pH 4.2. Accumulations of Ca and P were found on the root surface of the plants grown in the alkaline soils. Ca, Fe and P was found on the root surface in a soil with a pH of 5.5. No root surface accumulation was found at a soil pH of 4.2. Fertilizer P uptake at 9 days was greatest where NH4+ and least where NO3‐ accompanied the P. Changes in the soil‐root interface pH and resulting changes in the H2PO4‐/HPO4= ratio at the root surface which are modified by the inherent soil pH are implicated in these findings.
Residual Mineral N Accumulation in Soil and its Utilization by Irrigated Corn (Zea mays L.)1
Authors: Herron G. M. , Dreier A. F. , Flowerday A. D. , Colville W. L. , Olson R. A. 
Published: July 2010

AbstractField experiments on fine textured soils measured fertilizer and mineralized soil NH4‐N and NO3‐N accumulation in the rooting profile and the effectiveness with which this residual N was used by irrigated corn. At rates of 168 and 252 kg N/ha there were substantial N gains in the 180 cm soil profile with only limited losses apparent below that depth. Delayed fertilizer application resulted in greater crop use efficiency and more residual N than with preplant application, suggesting greater losses through leaching and gaseous evolution with the latter in early spring months when there are no crop roots for rapid absorption of N. Smaller amounts of residual N remained in soil after corn grown in 51 cm rows for 3 years than with 72 and 102 cm row widths, corresponding with the larger yields obtained and heavier N utilization with 51 cm rows. Corn grain yield was related to residual soil N when no additional fertilizer was used, the quantity from 60 cm depth being proportionately less than that in the 180 cm profile but still quite effective as indicator of yield potential from the N standpoint. Use of a nitrification inhibitor with an NH, carrier clearly served a useful purpose in preserving mineral N in irrigated fine textured soils to the eventual benefit of yield.
Influence of Soybean Production Practices on Lodging and Seed Yield in Highly Productive Environments1
Authors: Cooper Richard L. 
Published: July 2010

AbstractThe effect of planting date, variety, row spacing, and seeding rate on lodging and seed yield of soybeans (Glycine max (L.) Merr.) in highly productive environments was studied at Ashland and Chenoa, Illinois, in 1969. Three planting dates, seven varieties, two row spacings, and three seeding rates were used.Highly significant date, variety, spacing, rate, and interaction effects were obtained on lodging and yield at both locations. Seed yield was generally unaffected by seeding rate where no lodging differential occurred, but tended to be significantly lower where the higher seeding rates caused severe early lodging. These results indicated that early lodging was a major factor contributing to the yield decrease that occurred at the higher seeding rates. Whether a lodging differential occurred between seeding rates was dependent on location, date, variety, and row spacing used. These data also suggested that lodging may be an important factor in preventing yield increases from earlier planting and from narrower rows. At Ashland, in absence of a lodging differential between dates, the highest yields were obtained from the earliest planting, but at Chenoa, where the first two planting dates were more severely lodged than the latest planting date, there was no yield advantage. The yield advantage of narrow rows was greatest for the third planting date, at both locations, where lodging was essentially the same in both row spacings. At the earlier planting dates, 17‐cm rows tended to be more severely lodged than 50‐cm rows, cancelling out potential benefits from more uniform plant distribution. This was attributed, in part, to the less effective natural thinning that occurred in the 17‐cm rows.
Grain Filling Period of Corn as Influenced by Phosphorus, Potassium, and the Time of Planting1
Authors: Peaslee D. E. , Ragland J. L. , Duncan W. G. 
Published: July 2010

AbstractGrain production of field‐grown corn (Zea mays L.), as it related to the degree‐days3 occurring between initiation and maturity of the grain, was evaluated at O, 22, and 112 kg/ha of P and O, 56, and 224 kg/ha of K nutrition and with planting dates of April 7 and May 26. High levels of P accelerated development to silking but had little effect upon maturity of the grain. High levels of K accelerated development to silking and delayed grain maturity. Without added P and K, silking was delayed a maximum of 7 days in plots planted May 26, whereas maturity of the grain was accelerated 7 days. The number of degreedays between emergence and silking and between emergence and maturity were correlated (R2 = 0.58 to 0.87) with levels of applied P and K. The degree‐days between silking and maturity were also correlated with applied P and K (R2 = 0.61 and 0.81) and with grain yields (r2 = 0.62 and 0.71). These data indicate that nutrition influenced the rates at which corn plants developed through certain stages, and that the changes in these rates of development were associated with differences in grain yields.
Effects of Shading and Nitrogen on Growth of Grass‐Alfalfa Pastures1
Authors: Chan Wing‐To , MacKenzie A. F. 
Published: July 2010

AbstractThe relative competitiveness of alfalfa under varying nitrogen and shade conditions must be known to manage grass‐legume mixtures for maximum yield and quality of hay. Therefore, the growth of a grass‐legume mixture (predominantly Phleum‐pratense L. and Medicago sativa L.) under artificial shading and with added nitrogen was studied under field conditions in Quebec in 1967 and 1968. At low N levels, the alfalfa was a stronger competitor in the mixture under full sunlight, irrespective of the stage of growth. At high N levels, alfalfa yields were decreased due to increased grass growth. However, shading had very little effect on the competitive ability of the alfalfa at high N levels. Grass with upright leaves should permit more effective competition by alfalfa.
Harvesting Vernonia Anthelmintica (L.) Willd. to Reduce Seed Shattering Losses1
Authors: Massey John H. 
Published: July 2010

AbstractResults from four methods of harvesting Vernonia anthelmintica (L.) Willd. seed indicated that the highest yield (1,369 kg/ha) was obtained by cutting and windowing plants before seedheads opened. When harvest was delayed until all seed had ripened, yields were reduced to 264 kg/ha by shattering. Other methods gave intermediate yields.
Effect of Potassium and Nitrogen Fertilization on Lysine, Methionine, and Total Protein Contents of Wheat Grain, Triticum aestivum L. em. Thell.1
Authors: Hojjati S. M. , Maleki M. 
Published: July 2010

AbstractAn irrigated, split‐plot field experiment was conducted at Pahlavi University, Shiraz, Iran to study the effects of N and K fertilization on the lysine, methionine, and total protein contents of wheat (Triticum aestivum L. em. Theil., var. ‘Roushan’). The soil was calcareous silty clay loam. The area was flood irrigated once before seeding and four times during the growing season. Rainfall totaled 49 cm. The amino acids were assayed microbiologically.Yield of grain was not affected by application of 50 or 100 kg/ha of N, but decreased at the 200‐kg level. The ratio of grain to total dry matter decreased consistently with increasing application of N, showing that N stimulated the vegetative growth much more than seed production. Application of K did not show any significant effect on the yield of grain or on total dry‐matter production.Protein content of the grain was consistently increased by each additional increment of N, and so were the lysine and methionine contents. The increase in protein was about 1% for each addition of 50 kg N/ha. Percentage of lysine in the protein showed an inverse relationship with the N applied or the protein content of the grain. However, K significantly increased the lysine percentage in the protein. Percentage of the methionine in the protein did not change with varying rates of N or K.
Critical Levels of Sulfur in Bur Clover1
Authors: Jones M. B. , Ruckman J. E. , Lawler P. W. 
Published: July 2010

AbstractSulfur deficiencies are widespread in areas of California annual grassland where bur clover (Medicago hispida) is an important legume. The growth of this species is greatly increased by applications of S where S is deficient. The purpose of this study was to obtain information useful in assessing the sulfur status of annual grasslands in which bur clover occurred.The clover was grown in nutrient solution with varying levels of available S. Total S and SO4‐S concentrations in immature and mature leaves and in middle and lower stems were studied in relation to dry matter production. The concentration of total S where yields were 95% of maximum (“critical concentrations”) was 0.225% for both immature and mature leaf blades and was 0.080% for middle and lower stems. The “critical concentrations” for SO4−S were 160, 140, 100, and 160 ppm for immature and mature leaves and middle and lower stems, respectively. Organic S (total S minus SO4−S) reached a maximum at about 0.250% in leaves and about 0.100% in the stems. Where S was applied in luxury amounts unmetabolized sulfur accumulated as SO4−S. Highest concentrations were found in the lower stems, lesser amounts in the upper stems, and least SO4−S was found in the leaves.