bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light Distribution in Field Soybean Canopies1
Authors: Sakamoto Clarence M. , Shaw Robert H. 
Published: July 2010

AbstractA study was conducted to determine the pattern of light interception and distribution in a field soybean community. Light interception occurred primarily at the periphery of the canopy. When the open space between rows closed or when it was nearly closed, interception was primarily at the top of the canopy.The distribution of light through a soybean community could be approximated by an exponential distribution. The slope of the regression of the logarithm of percent light interception of leaf area index (LAI) above the point of light measurement was affected by the morphology of the community.From the distribution of percent light and cumulative LAI, an estimate of the “effective” LAI was determined. The large amount of self‐shading and predominant interception at the periphery of the canopy indicates that many lower leaves are not receiving adequate radiation. An increase in yield could possibly be achieved by selecting varieties whose natural inclination leads to deeper penetration of useful energy to a greater number of leaves.
Occurrences of Trans‐Aconitate in Range Forage Species1
Authors: Stout P. R. , Brownell J. , Burau R. G. 
Published: July 2010

AbstractYoung plants of 94 separate species collected largely from hypomagnesemia (grass tetany) prone rangelands during late fall, winter, and early spring, have been analyzed for total aconitate. Species containing 1% or more of their dry weight as aconitate have been classed as accumulators. Forty‐seven percent of the grasses and 17% of the nongrass species fell in the high level category. The spread between individual species was very large (0.05 to 12.4%). Of the two aconitate stereoisomers, cis‐aconitate was low in all species whereas trans‐aconitate built up in the accumulators. Levels of trans‐aconitate fell rapidly with the onset of warming spring weather and higher growth rates. Mowings of mixed plant species reflected the aconitate characteristics of accumulator species. Substantial differences in trans‐aconitate levels may occur in roots, stems, and leaves of the same plant.
Tillage and Residue Management Practices for Soybean Production in a Soybean‐Small Grain Rotation1
Authors: Beale O. W. , Langdale G. W. 
Published: July 2010

abstractManagement of oat straw residues and tillage practices for soybean production in an oat‐soybean rotation were studied. The effects of tillage practices on soybean yields were not significant. Burning the oat straw before planting soybeans had no significant effect on yields. Fertilization of soybeans after growing the oats did not increase bean yields. Tillage and residue management had no marked influence on soil temperatures and available moisture. Soybean stands were somewhat larger if the oat straw was burned or moved from the seed zone. Properties of the lister‐plant‐tilled and disk‐harrow‐tilled soils were more favorable for soybean growth than those of the turnplow‐tilled soils, although this was not reflected in soybean yields.
Early Growth in Annual and Perennial Ryegrass1
Authors: Barbour Michael 
Published: July 2010

AbstractTwo stages of early growth are described for Lolium temulentum, an annual, and L. perenne, a perennial species of ryegrass. The first stage, from time of sowing to about the ninth day, is one of rapid growth. The second stage, which may be indicative of the rest of the growing season, is one of slower growth in which the annual has a higher photosynthesis and respiration rate, a larger root system, and a lower leaf starch content than does the perennial. Chlorophyll and water content of leaves of the two species are similar. The annual germinates earlier.
Temperature‐Emergence Relations of Cottonseed under Natural Diurnal Fluctuation
Authors: Wanjura D. F. , Hudspeth E. B. , Bilbro J. D. 
Published: July 2010

AbstractUnder field conditions, 103 hours of seed level temperature above 18 C were required for initial emergence of the cotton variety ‘Blightmaster.’ Unfavorable soil moisture, soil texture, and variations in planting depth could affect the emergence index. It should not be significantly affected by regimes with extreme temperatures or by varieties, except cold tolerant types. The minimum soil temperature for producing emergence of cotton seedlings averaged approximately 18 C for the temperature regimes of the study. High correlations exist between initial emergence time and minimum soil temperature or average mean air temperature during the same period. This suggests the possibility of predicting cotton emergence if air or seed level temperatures can be reliably forecast.
Effect of Chloride on Phosphorus Uptake by Corn Roots1
Authors: Carter O. G. , Lathwell D. J. 
Published: July 2010

AbstractA study was made on the effect of KCl on P uptake by 20‐day‐old corn seedlings grown in water culture and 4‐day‐old excised corn roots grown on 0.2 mM CaSO4 solution. All P solutions were adjusted to pH 4. Those used for excised roots contained 0.2 mM CaSO4 and those used for 20‐day‐old corn seedlings contained 1.2 mM KNO3, 0.8 mM Ca(NO3)2, and 0.4 mM MgSO4. One‐hour absorption periods using concentrations up to 0.l M KCl showed no effect on 32P uptake from 2 to 260 µM KH2PO4 solutions with either type of plant material.
A Comparison of Coastal and Common Bermudagrasses (Cynodon dactylon (L.) Pers.) in the Piedmont Region. II. Effect of Fertilization and Crimson Clover (Trifolium incarnatum) on Nitrogen, Phosphorus, and Potassium Contents of the Forage1
Authors: Adams William E. , Stelly Matthias , Morris H. D. , Elkins Charles B. 
Published: July 2010

AbstractCommon bermudagrass forage grown with and without crimson clover contained significantly higher percentages of N, P, and K than Coastal bermudagrass forage similarly fertilized. The N content of the grass forage was increased by each increment of N applied, ranging from approximately 1.6% N with no N fertilization to 2.7% N at the 448‐kg/ha N rate. The P and K contents of both grasses were also increased by increasing levels of fertilization.Harvest date had a pronounced effect on the N. P, and K contents of the grass forage, which peaked at the July harvest.Coastal bermudagras recovered more nutrients from the soil than common bermudagrass—up to 86% of the applied N, up to 46% of the applied P, and as much as 191% of the applied K. This greater nutrient uptake by Coastal was a result of the higher yields obtained with this grass.The P and K contents of crimson clover grown in association with the grasses were significantly increased by fertilization. The K content of crimson clover grown with common bermudagrass was significantly higher than that of crimson clover grown with Coastal bermudagrass at most fertility levels.
Sugarcane Yields as Related to Acidity of a Humid Tropic Ultisol1
Authors: Abruña‐Rodríguez Fernando , Vicente‐Chandler José 
Published: July 2010

AbstractSugarcane was grown in 40 plots with widely varying pH, base saturation, and exchangeable aluminum contents which resulted from applications of 0 to 45 metric tons of limestone per hectare over a previous 7‐year period while in other crops, receiving a total of 4,180 kg of N, 545 kg of P, and 3,860 kg of K per hectare. Cane yields, sucrose content of the juice, and foliar composition of the leaves were determined. Soil in all plots of this typical ultisol (Cialitos clay) was sampled at end of the experiment.Cane yields increased with increasing exchangeable base content in the upper 15 cm of soil from less than 25 metric tons per hectare when exchangeable bases dropped below 3 meq to over 100 metric tons when exchangeable bases exceeded 8 meq/100 g of soil (58% base saturation).Cane yields increased with decreasing exchangeable Al from less than 25 metric tons per hectare when exchangeable A1 exceeded 8 meq to over 100 metric tons per hectare when exchangeable AI was less than 2 meq/100 g of soil. Yields increased sharply with increasing soil pH. Foliar composition and sucrose content of the sugarcane was not affected by the soil factors studied.
Factors in Paraquat‐Induced Chlorosis with Phaseolus Foliar Tissues1
Authors: Barnes Don L. , Lynd J. Q. 
Published: July 2010

AbstractBioassay procedures with leaf disks from Phaseolus vulgaris L., Indian bean, were used to determine factors influencing ( 1,1′‐dimethyl‐4,4'bipyridinium) paraquat activity. Relative phytotoxicity was determined by varying herbicide levels from 0 to 1.0 ppm ai with light intensity, temperature and reaction time. Reduction of extractable chlorophyll was closely related to increased paraquat concentrations. Increased time, temperature and light intensity accelerated rate and magnitude of leaf disk chlorosis induced with active paraquat levels.
Storage of Sugarcane Cuttings1
Authors: Broadhead Dempsey M. 
Published: July 2010

AbstractExperiments were conducted to develop a technique for storing sugarcane (Saccharum officinarium L.) cuttings. Three‐bud cuttings of C.P. 36–111 were stored in a household refrigerator at 3 and 5 C ± 1. The cuttings were enclosed in polyethylene bags (0.05 mm) or left exposed, and they were treated wth various fungicides or left untreated. The fungicides used were Captan (0.36%), mercuric chloride (0.1%), and phenyl mercuric acetate (0.025%). After 1 year of storage, 8% of the buds from cuttings, which had been enclosed in polyethylene bags after treating with phenyl mercuric acetate, grew into shoots. This treatment gave the highest percentage of bud survival. Unbagged cuttings dried out considerably in storage and bud germination was less and at a slower rate than bagged cuttings.
A Simple Rapid Test for Nitrogen Dioxide in Silage Gases1
Authors: Dexter S. T. 
Published: July 2010

AbstractThe presence of nitrogen dioxide, a dangerously poisonous gas sometimes given off in silage fermentation, can be detected by exposure of moistened potassium‐iodide‐starch test papers to the air in the silo, silo‐chute or area. The test paper turns from white to bluish black almost instantly in nitrogen dioxide of moderate concentration and more slowly in very low concentration.
Comparison of Methods for Estimating Cotton Leaf Area1
Authors: Johnson R. E. 
Published: July 2010

AbstractThe squared length of the main vein to the right of the central vein X factor was found to be the most precise of four methods employing linear measurements to estimate cotton leaf area. Due to the undulatory surface of cotton leaves, area was found to be underestimated by 5% when planimeter readings were taken of leaf margins. Leaf discs served well as reference area for determining area by the dry‐weight method provided both vein and interveinal tissue were sampled.
Sulfur Content and Yield of Alfalfa in Relation to Plant Nitrogen and Sulfur Fertilization1
Authors: Sorensen R. C. , Penas E. J. , Alexander U. U. 
Published: July 2010

AbstractNitrogen and S percentages or yields or all of these were determined for alfalfa grown in two areas of Nebraska where soil and environmental conditions are markedly different. The much higher critical concentrations of S found in forage grown on sandy soils of northeast Nebraska than the commonly accepted value of 0.22% were attributed to effects of drouth. N and S contents were closely related in alfalfa grown with and without applied S both on drouthy sandy soils and on a highly fertile soil with natural subirrigation. The curve relating N and S percentages in alfalfa grown on soils where S was applied was essentially parallel to that for soils where S deficiency was not a problem. N concentrations increased with yield increase to applied S.
A Refractometric Method for Testing Seed Coat Permeability1
Authors: Morris J. I. , Campbell W. F. , Wiebe H. H. 
Published: July 2010

AbstractUtilizing the refractometric method (3) to measure water flow by the resulting changes in concentration of a sucrose solution, we have designed an apparatus and procedure to measure the rate of water movement through seed coats of snap beans (Phaseolus vulgaris, L.). The degree of accuracy obtainable in reading the sucrose concentration on the refractometric scale was ± 0.05%. Using 0.2 ml of solution, it was thus possible to detect the movement of 0.4 mm3 of water across the seed coat membrane.Permeability of the seed coats ranged from 0.78 mg/mm2/hr for the least permeable to 1.82 mg/mm2/hr for the most permeable of the 11 varieties tested. With one exception, the white‐seeded beans were more permeable than the dark‐seeded ones.
Differences in Chemical Composition of Plant Sample Fractions Resulting from Grinding and Screening1
Authors: Smith J. H. , Carter D. L. , Brown M. J. , Douglas C. L. 
Published: July 2010

AbstractAlfalfa, barley straw, corn leaves, peas, red clover, and wheat straw samples were ground in a Wiley mill and screened to separate particle sizes. Particle size samples were analyzed for N, P, K, Ca, Mg, Zn, Se, and SiO2 The percentage composition of N, P, Ca, Mg, and Si02 generally increased with decreasing particle sizes of three wheat straw varieties, one baled and one hand‐cut sample each of barley straw and alfalfa, corn leaves, red clover, and peas. The K concentrations were unpredictable. Selenium tended to be more concentrated in the smaller than in larger particles. The variability in chemical composition because of particle sizes points out the necessity for adequate sample grinding and mixing for obtaining representative subsamples for chemical analyses and biological experiments.
Effect of Environmental Conditions on the Growth of Four Perennial Grasses. II. Response to Fertility, Water, and Temperature1
Authors: Baker Barton S. , Jung G. A. 
Published: July 2010

AbstractTimothy (Phleum pratense L.), bromegrass (Bromus inermis Leyss.), orchardgrass (Dactylis glomerata L.) and Kentucky bluegrass (Poa pratensis L.) were grown at four locations in West Virginia with and without supplemental water and at three levels of fertility during August of 1964 and 1965. The dry weight of top growth produced at each location depended upon species, moisture, fertility, temperature, and combinations of these factors. The addition of either water or fertilizer alone often did not significantly increase yields, but a combination of these two factors usually increased yields. When the moisture supply was low and temperatures high, the addition of fertilizer decreased yields.The location where the most top growth was produced, when no supplemental water was added, was usually the location receiving the most precipitation. When supplemental water was added, the most favorable location depended upon the temperature. All species except bromegrass produced high yields at the location having the coolest temperatures, whereas bromegrass often produced its lowest yields under these conditions. A temperature of −0.6 C was detrimental to timothy as well as bromegrass.The level of food reserves as indicated by etiolated growth was greatly affected by temperature and moisture. As the maximum temperature increased, the level of reserves decreased. The response due to supplemental water was highly dependent upon natural precipitation.The top growth and etiolated growth produced under natural climates were compared with that produced under controlled climates. A discussion of trends and limitations of such comparisons is given.
Effect of Fertilizer Nitrogen, Phosphorus, Potassium and Magnesium on Yield and Nutrent Content of Okra (Hibiscus esculentus L.)1
Authors: Ahmad N. , Tulloch‐Reid L. I. 
Published: July 2010

AbstractResponse of okra (Hibiscus esculentus L.) to N (0–336 kg/ha), P (0–280 kg/ha), K (0–280 kg/ha), and Mg (0–112 kg/ha) fertilization on River Estate Loam, Trinidad, was investigated. Best yields were obtained with 112 kg/ha N, 168 kg/ha P, 280 kg/ha K, and 112 kg/ha Mg. The effect on leaf composition of N, P, K, and Mg at three stages of growth of the crop and the amount of these nutrients removed in the fruit was studied. Levels of N in the leaf decreased rapidly with age and for rates above 224 kg/ha followed a similar pattern as the control. For 112‐ and 168‐kg/ha applications, high tissue N was maintained to the fruiting stage. N removed in the fruit increased with N and K applications but was adversely affected by P and Mg.P content in the leaf was not affected by fertilization at flowering and senescence but at fruiting the levels increased. P applications did not increase yield of dry matter or removal of N, K, Ca and Mg in the fruit. At flowering, tissue K was highest and showed response to fertilizers. With age of crop K decreased and effect of fertilizers disappeared. K removal in the fruit was favored by N.High tissue Mg as a response to fertilization was maintained to fruiting but decreased afterwards. Mg lowered the removal of N but increased P in the fruit.
Inclined Point Quadrat Estimation of Species Contributions to Pasture Dry Matter Production1
Authors: Olusuyi Samuel A. , Raguse Charles A. 
Published: July 2010

AbstractAn inclined point quadrat method was successfully used to determine proportional dry matter contributions of four perennial pasture forage species in a mixed sward. An increase in accuracy was achieved when more than one point was recorded for each needle probe.
Variations in Protein Levels in Grain Sorghum Grown in the Southwest Desert
Authors: Worker George F. , Ruckman Joseph 
Published: July 2010

AbstractCrude protein content of grain sorghum was determined in six varieties and 35 hybrids grown in the southwestern desert area of the United States. These samples represent production from April and July plantings during the period 1961 through 1966. Average protein content of grain produced from April plantings was 10.12% as compared with 14.82% from July plantings. The protein content of all cultivars was higher from July plantings than from April plantings and also vary more from year to year. Variations ranged from 8.54% to 21.53% crude protein, depending on cultivar, year, and planting date. Protein levels showed a high degree of positive correlation with seed size and air temperature and a negative relationship with yield.
Evapotranspiration‐Climate Relations for Several Crops in the Central Great Plains1
Authors: Hanks R. J. , Gardner H. R. , Florian R. L. 
Published: July 2010

AbstractUnder dryland conditions after periods of substantial rains, evapotranspiration from oats, winter wheat, and native grass was as high as 2.0, 1.5. and 1.0 times the evaporation from a BPI pan. During periods of similar water availability, the ratio of ET to E pan for sudangrass was similar to that for native grass, whereas the ratio for sorghum and millet was about the same as that for wheat.
Ionic Balance and Corn Growth in a Port Byron Soil1
Authors: Blanchar R. W. , Hossner L. R. 
Published: July 2010

AbstractCorn (Zea mays) was grown on a Port Byron soil treated with either NH+4—N or NO−a—N and various rates of CaCl2·2H2O. The corn tissue was analyzed for Ca2+, Mg2+, K+, N, P, S, Cl, and NO−a—N. Equilibrium extracts of the soil were analyzed for Ca2+, Mg2+, K+, and electrical conductivity.The organic anion content of corn was determined as the difference between inorganic cations and anions. The organic anion content varied from 252 to 751 µeq/g plant due to changes in N fertilizer and CaCl2·2H2O addition. The growth of corn was not related to organic anion content.Plant weight was inversely proportional to the negative logarithm of the ionic strength of the soil solution.Fertilization with NH+4—N resulted in an increased SO=4 content of the plant in the absence of CaCl2·2H2O.Calcium content of the plant was a linear function of pCa in the soil solution. Magnesium and potassium contents of the plant tissue were related to the functions pMg—0.5pU and pK‐pU of the soil solution, respectively.
Detection of Iron Ethylenediamine Di(O‐Hydroxyphenylacetate) in Plant Tissue1
Authors: Jeffreys R. A. , Wallace A. 
Published: July 2010

AbstractA method was developed for the extraction of iron ethylenediamine di(ο‐hydroxyphenylacetate) (FeEDDHA) from plant tissue and the technique was used to study the absorption of FeEDDHA by plants. A published method for the extraction of FeEDDHA was modified in an attempt to eliminate plant components which interfered with the spectrophotometric determination of the iron chelate. The method which was developed involves the use of lead acetate and ammonium sulfate to precipitate interfering substances. The FeEDDHA is then extracted into η‐amyl alcohol.Tobacco plants were exposed to FeEDDHA at various concentrations and for various periods of time. The leaves of the plants were subsequently analyzed to determine whether they contained detectable amounts of the intact iron chelate. The results suggested that FeEDDHA accumulated in the leaves of plants which had been grown on the high levels of the iron chelate or which had been grown on FeEDDHA for long periods of time.
Soil Water Flux below a Ryegrass Root Zone1
Authors: LaRue M. E. , Nielsen D. R. , Hagan R. M. 
Published: July 2010

AbstractThe net water flux below the root zone of a rye grass crop was measured in the field for plots receiving equal total quantities of irrigation water but applied in unequal amounts at different frequencies. Hydraulic conductivity values calculated from field‐measured soilwater potential gradients and laboratory‐measured soilwater characteristics were used to compute the soilwater flux. The amount of water moving into or out of the root zone was influenced by the irrigation frequency. The nature of the hydraulics of a natural field soil, its variability in space, and its implications for the interpretation of soil‐water depletion data are also provided.
A New Laboratory Seed Blower with Continuous Operation
Authors: Hardin E. E. , Mikkelson B. G. , Grisez J. P. 
Published: July 2010

AbstractA newly designed laboratory model seed blower has value as a research tool to crop specialists where material can be separated by air separation. The unique feature of this blower is the continuous seed flow into the air stream allowing large quantities of seed to be cleaned uninterrupted.
Differential Response of Timothy Varieties to Captain1
Authors: Nittler L. W. , Kenney T. J. 
Published: July 2010

AbstractSeedlings of seven cultivars of timothy, Phleum pratense L., were grown in soil to which captan, N−[(trichloromethyl) thio]−4−cyclohexene−l,2−dicarboximide, was applied as a drench immediately after the seeds were planted. Stunted plants occurred in all varieties, but the number differed significantly among varieties. ‘Climax’ had the fewest and ‘Heidemij’ had the most. Effect of captan was much greater when applied as a surface drench than when mixed with the soil before planting. Excessive watering resulted in more stunted plants than light watering.