bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Cotton Response to Rates, Sources, and Timing of Nitrogen Application by Petiole Analysis1
Authors: Amer Fathi , Abuamin Hoda 
Published: July 2010

AbstractThree experiments were conducted on a calcareous clay loam soil to determine the relationship between nitratenitrogen content of cotton (Gossypium barbadense) petiole and yield; and to employ the petiole analysis technique for evaluation of calcium nitrate, ammonium nitrate, and urea as N sources and evaluation of timing of N application. Increase in cotton yield associated with unit increment of petiole nitrate was proportional to the decrement from the maximum and the data were fitted to the exponential equation of Spillman. Cotton yield was not affected by N source and time of application, but petiole nitrate was sensitive to both. Calcium nitrate was the best fertilizer and the availability coefficients of N in ammonium nitrate and urea as a fraction of that in calcium nitrate were 0.714 and 0.511, respectively. Splitting the applied N in thirds proved superior to a split into two applications or to a single total application, and the availability coefficients ratios were 20.889, and 0.566, respectively.
Photosynthetic Light Sensor for Measurements in Plant Canopies1
Authors: Norman J. M. , Tanner C. B. , Thurtell G. W. 
Published: July 2010

AbstractA photosynthetic light sensor is described, which is based on experimental evidence that absorbed quanta at various wavelengths in the visible region (400‐700 nm) are nearly equally effective in initiating photosynthesis. Silicon photovoltaic cells are used as light detectors and their spectral response tailorded with Wratten filters to provide quantum response. A sharp near‐infrared cutoff is obtained by subtracting the signal of a cell sensing only the infrared from the signal of the cell sensing both the visible and infrared wavelengths. This pair of cells is then placed under heat absorbing glass to further reduce their differences. The differenced current signals from the cells are fed directly into an operational amplifier designed for current amplification. A fair cosine rtsponse is obtained by using a flat piece of diffusing plastic as the uppermost part of the sensor. Calculations and measurements are made to estimate errors resulting from imperfections in spectral tailoring and cosine correction.
Recovery of Differentially Placed NO3‐N in a Silt Loam Soil by Five Crops1
Authors: Dancer W.S. , Peterson L.A. 
Published: July 2010

AbstractPlacement of NO3‐N at soils depths of 8, 23, 38, 53, and 69 cm was accomplished by an injection method with minimum disturbance to plant roots and to the soil profile. Utilization of the differentially placed NO3‐N by five crops for two cropping seasons indicated that these crops varied in their ability to recover the NO3‐N. Lima beans (Phaseolus lunatus L.) and green beans (Phaseolus vulgaris L.) obtained most of their N from the plow layer; while corn (Zea mays L.), tobacco (Nicotiana tabacum L.), and red beets (Beta vulgaris L.) recovered NO3‐N equally well from either the plow layer or the subsoil.
Molybdenum Response of Soybeans (Glycine max (L.) Merrill) in Iowa1
Authors: DeMooy cornelis J. 
Published: July 2010

AbstractHighly significant yield responses of soybeans were obtained for the first time from molybdenum treatment of seed at planting on several Iowa soils during 1968. Yields were raised 269 to 336 kg/ha (4 to 5 bu/acre)in response to 93 g molybdenum per ha at two sites in the soil pH range from 5.8 to 6.7. No responses occurred on some other soils in the same pH range. On calcareous Webster soil, molybdenum treatment resulted in a significant reduction in yield of 226 kg/ha. Yield effects were not accompanied by significant changes in molybdenum content of the leaves at bloom.
Effect of Adsorbed Cations on Phosphorus Absorption by Various Plant Species1
Authors: Franklin R. E. 
Published: July 2010

AbstractP uptake by excised roots of 10 different plant species was found to be stimulated by a short pretreatment with polyvalent cations, or by raising the ionic strength of the absorbing solution.The pretreatment consisted of a l‐min rinse with 10−3 N chloride salt solutions prior to exposure to 2 × 10−5 M KH2PO4. Also, the root CEC was estimated by isotopic exchange using a labeled CaCl2 solution. The stimulation of P uptake by the polyvalent cation pretreatments was significantly correlated with the amount of P taken up by the control and the root cation exchange capacities. The results supported the hypothesis that the cell wall can act act as a negatively charged membrane regulating P uptake.
Ethanol Concentration in Tomato Plants during Soil Flooding1
Authors: Bolton E. F. , Erickson A. E. 
Published: July 2010

AbstractTomato plants were studied to assess the potential value of ethanol accumulation in plant tissue as a measure of O2 stress resulting from short periods of soil flooding. Ethanol concentration in xylem exudate was markedly associated with air temperature, and to a lesser extent with light intensity and soil temperature under conditions of flooding. Field flooding results agreed closely with simulated environments.A small amount of ethanol was eliminated by transpiration from flooded tomato plants under environmental conditions that favored accumulation. A slightly higher amount of ethanol was excreted from the roots.Ethanol in tomato plant samples appeared to indicate the intensity of O2 deficiency during flooding by reflecting both soil O2 supply and environmental effects, and could serve as a useful indicator in relating tomato plant injury to flooded conditions.
Effects of Air Pollutants on Burley Tobacco Cultivars
Authors: Menser H. A. , Hodges G. H. 
Published: July 2010

AbstractNine burley tobacco (Nicotiana tabacum L.) varieties were tested for susceptibility to air pollutants in fumigation chamber and field experiments. Ozone administered for short intervals (1.0 and 1.5 hours) at relatively high concentrations (30.0 and 20.0 pphm, respectively) caused significantly more leaf injury than when used for a longer period (3.0 hours) at a lower concentration (10.0 pphm). These tendencies were apparent even though total ozone dosages were about equal. At the lowest rate, ozone caused the most injury to ‘Burley 2’ and ‘Ky 16,’ and the least injury to ‘Burley 49’ and ‘Ky 9.’ Cultivars exhibited much smaller differences in degree of leaf injury when ozone was given at high as compared to low concentrations. Burley 2 and Ky 9 continued to be susceptible and tolerant, respectively, at the high rates. Response of the nine varieties to low concentration mixtures of ozone and sulfur dioxide revealed: (1) the two gases acted synergistically to cause injury; and (2) Burley 21 and Burley 49 reversed positions of susceptibility to mixed gases as compared to injury by ozone.In the field weather fleck was more severe on Burley 2, Burley 21, Ky 9 and Ky 16 than on ‘Burley llB’ and ‘Burley 37.’ The varieties that showed the greatest fleck tolerance were Burley 49 and ‘Ky 12.’ Ozone, the primary cause of weather fleck, reached a phytotoxic level of 5.0 pphm (Mast 724‐1) on 20 dates during July. Highest concentration recorded was 12.0 pphm on July 24.All varieties exposed to pollutants in the chamber displayed identical symptoms. Ozone at low dosages caused tiny, bleached stipples or flecks to appear on the upper leaf surface. Ozone and sulfur dioxide mixtures induced upper surface fleck‐like markings very similar to (but a little larger than) ozone lesions. Field symptoms of weather fleck consisted of characteristic ozone flecking on Burley 2, Burley 11B, Ky 9, Ky 12, and Ky 16 and biracial necrotic lesions (2.0 to 3.0 mm) on Burley 37, Burley 49, and ‘Ky 35.’
Yield and Leaf Area of Type 41, Pennsylvania Broadleaf, Tobacco as Affected by Variety and Plant Population1
Authors: Yocum John O. , McKee Guy W. 
Published: July 2010

AbstractStudies in southeastern Pennsylvania utilizing two recommended varieties of Type 41, Pennsylvania broadleaf, tobacco indicated that conventional plant populations (13,000 to 15,000 per ha) may be too low for optimum yield of cured leaf. While leaf area per plant decreased as population increased, the decrease was more than compensated for by the increased number of plants. In 1965, nearly normal as regards precipitation, leaf area indices (leaf area/unit land area) just prior to harvest were, respectively, 5.54, 6.14, and 8.10 for 10,500, 14,600, and 20,900 plants/ha. Leaves were more erect at the high population than at the other two populations studied. In 1966, a relatively dry year with precipitation 56% of normal, leaf area indices were, respectively, 2.30, 3.68, and 5.32 for 9,000, 16,100, and 24,600 plants/ha. At all populations, leaves were less erect in 1966 than in 1965. Leaf quality was not significantly affected by plant population. Both total yield of cured leaf and gross cash return increased as population increased.
A Comparison of Three Methods for Estimating Root Length1
Authors: Reicosky D. C. , Millington R. J. , Peters D. B. 
Published: July 2010

AbstractThe root system from a 10‐week‐old soybean plant was washed free of soil and total root length estimated by three different techniques. Direct measurements were first made on fresh root samples and later, from projected black and white photograph transparencies of the fresh material, further estimates of root length were obtained by two additional methods. The first of these was the opisometer method which, in essence, requires tracing over the entire length of root in the sample. The second method, developed by Newman, requires counting of the number of intersections between the randomly diffused roots and a grid line of known length.The coefficient of variation for means of three estimates by each method showed that there was little difference in precision between methods. However, with Newman's method, an estimate was made in 1.0 hour compared with 5.0 hours for the direct method and 1.5 hours for the opisometer method.
Nitrate Accumulation in Smooth Bromegrass (Bromus inermis, Leyss.): I. Effects of Applied N, P, and K1
Authors: Vanderlip R. L. , Pesek John 
Published: July 2010

AbstractThe NO3−N content of smooth bromegrass (Bromus inermis, Leyss.) was determined for two N, P, and K fertilizer experiments in each of 2 years (1962 and 1963) on Shelby silt loam in south‐central Iowa to determine the extent to which nitrate would accumulate in this species and the effects of these nutrients on accumulation. Nitrate‐nitrogen content of the forage was determined by steam distillation on samples taken periodically throughout the growing season and related to rates of applied N, P, and K and time after fertilization and time after clipping by multiple regression techniques. All three elements affected the NO3−N content; however, the effects varied among site‐years. The effects were interrelated as shown by the large number of significant interactions. Time after application and time after clipping also were important in determining the NOa‐N content. A large number of applied element by time variable interactions were found significant indicating the dependence of the applied fertilizer effects upon either time after application or time after clipping.
Speeding the Drying of Alfalfa Hay with Fusicoccin1
Authors: Turner Neil C. 
Published: July 2010

AbstractFusicoccin, a wilt toxin produced by the fungus Fusicoccum amygdali Del., was sprayed onto alfalfa (Medicago sativa L.) 3 hours before cutting. Under constant environmental condition in the laboratory, the shoots treated with 10‐5 M fusicoccin solution dried to a moisture content of 40% (dry weight basis) in half the time of the controls. In the field the drying time to a moisture content of 22% (dry weight basis) was reduced from 54 to 46 hours; thus the hay could be safely stored after 3 days instead of 4 days. The fusicoccin also reduced losses by respiration. Rainfall probabilities for Connecticut suggest that use of fusicoccin would prevent damage by rain on 15% of the days suitable for haymaking. The results also suggest that fusicoccin will be more beneficial when drying conditions are poor.
Effect of Soil Temperature on Rate of Barley Development and Nutrition1
Authors: Power J. F. , Grunes D. L. , Reichman G. A. , Willis W. O. 
Published: July 2010

AbstractResults from this experiment indicate that for barley plants harvested at equal stages of morphological development, low soil temperatures per se are not deterimental to growth. Barley was grown to maturity in a growth room at soil temperatures of 9, 15.5, and 22C with either 9 or 44 ppm fertilizer phosphorus. At a given stage of plant development, dry matter production and N and P uptake were usually lowest at a soil temperature of 22C. Dry weights, grain yields, and nutrient uptake at 9C usually equalled or exceeded those at 15.5C — the soil temperature considered optimum for barely production. At 9C growth was very slow until the barley developed to the 4‐leaf stage, but thereafter approximated the growth rate at higher soil temperatures. Nutrient uptake and water use data suggest that the slow initial growth rate at 9C may be due to restricted nutrient translocation from roots to tops, rather than to reduced rate of uptake of water or nutrients. Soil temperatures affected both the growth rate and water use rate, resulting in only a small effect of soil temperature on total water used to reach a given growth stage.
Effects of Weather, Nitrogen and Population on Corn Yield Response1
Authors: Bondavalli Bruno , Colyer Dale , Kroth Earl M. 
Published: July 2010

AbstractThe effects of rainfall and temperature on the yield and response of corn (Zea Mays L.) to plant population and nitrogen application rates were estimated from experimental data collected at three Missouri sites over an 8‐year period. The growing season from May through August was divided into 15‐day periods to test for the effect of rainfall and temperature on corn response to several nitrogen and planting rates. Preseason rainfall and total rainfall during the growing season also were included as variables. Both temperature and rainfall variables affected yield significantly with the first half of August being most significant with respect to rainfall and the second half of May with respect to temperature. The economic optimum inputs at the mean rainfall for the growing season were 41,850 plants/ha and 163 kg N/ha. The optimal input of nitrogen was relatively sensitive to the rainfall level with the optimal population level less affected.
A Combination Belt, Cone and Vacuum Seeder for Experimental Cereal Plots1
Authors: Dewey W. G. , Agathangelides D. , Rich H. 
Published: July 2010

AbstractA drill is described which combines the desirable features of belt, cone, and vacuum seeders. The drill and tractor unit is easily portable in the back of a pickup truck. We are using the drill primarily to seed wheat and barley nurseries, but it could be used equally well for a variety of other crops.
The Effects of Potassium on Ammonium Nutrition of Tomato (Lycopersicon esculentum Mill.)1
Authors: Ajayi O. , Maynard D. N. , Barker A. V. 
Published: July 2010

AbstractTomato plants (Lycopersicon esculentum Mill.) grown in pot culture in the greenhouse were easily injured by continuous, prolonged application of (NH4)2SO4. When an equivalent amount of K was supplied with the NH4, plant injury due to excessive NH4 was prevented. The presence of K in the NH4 culture system enhanced growth and restricted total N and NH4‐N accumulation. The magnitude of the restriction of N constituents suggests that the ameliorating K effect was due in part to a K:NH4 competition for uptake but principally to the enhancement of NH4 assimilation.
Preparation of and Plant Response to a Yellow Phosphorous‐Ammonia Solution1
Authors: Cressman H. K. , Richards G. E. , Edwards T. A. 
Published: July 2010

AbstractYellow phosphorus was dissolved in liquid anhydrous NH3 and evaluated as a P source for corn (Zea mays L.) and ryegrass (Lolium multiflorum L.). The composition was phytotoxic and the P was of low plant availability. When the solution was incubated in soil prior to seeding corn, toxicity was less pronounced. The residue following evaporation of NH3 was also phytotoxic. In a short term study on a fine‐textured soil, corn failed to respond to either toxic compounds or orthophosphate present in the zone of NH3 injection.
Influence of Date of Planting on the Yield of Kenaf (Hibiscus cannabinus, L.)1
Authors: Whiteley Eli L. 
Published: July 2010

abstractKenaf (Hibiscus cannabinus L.) is a promising new annual source of pulp for industry. Dry matter yields which are sufficiently high to compete with existing crops in Texas are needed. Adaptation and cultural studies were undertaken to determine levels of productivity that can be expected in the eastern part of the state. Some varieties of kenaf are classified as daylength insensitive and should produce high yields from early planting dates. However, in this test the variety × planting interaction within years was not significant. The earliest planting date produced the highest yield in only one (1967) of the 3 years of the study. Moisture and light influenced yields as much as date of planting.Average dry mater yields of 5.17 to 14.29 tons/ha were obtained over the 3 years of tests. Yields in excess of 12 tons/ha were obtained each year of the tests. Differences in production potential of available varieties were obtained. Yields of some of the varieties were quite different from year to year. 'Guatemala 45' produced 6.52 tons/ha in 1968 and 14.67 tons/ha in 1969.
Black Layer Development in Corn1
Authors: Rench W. Eugene , Shaw Robert H. 
Published: July 2010

AbstractA study was made to determine the relationships between visual kernel black layer development, dry matter accumulation, and moisture level.Kernels taken from the same plants every 3 days were rated as to their visual black layer phase of development from plants approaching maturity. Remaining kernels from the same sample were dried and evaluated for dry matter and moisture content.Peak dry matter accumulation coincided with initial occurrence of visual black layer formation. Weight lost by kernels from initial visual black layer development to completed black layer development was significant.Kernel moisture declined significantly during black layer development. Black layer mature kernels had moisture levels that differed statistically between varieties and within a variety planted at different dates.
Response of Alfalfa Varieties to Different Water Table Depths at Various Stages of Growth1
Authors: Rai S. D. , Miller D. A. , Hittle C. N. 
Published: July 2010

AbstractTwo varieties of alfalfa, Medicago sativa L., ‘Kentucky Syn. Z1’ and ‘Narragansett,’ were grown in glazed tiles 90 cm deep with water tables of 15, 30, and 45 cm from the surface. When the water‐tables were raised immediately after the harvest, the dry matter yield was drastically reduced in both varieties. No significant yield difference was found when the treatments were applied 14 or 28 days after harvest. The highest yield was obtained when water table was held 45 cm from the surface and when applied 14 or 28 days after harvest.
Overseeding Winter Annual Grasses in Sericea Lespedeza1
Authors: Hoveland C. S. , Carden E. L. 
Published: July 2010

AbstractForage yields of rye (Secale cereale L.), rescue (Bromus catharticus Vahl.) and ryegrass (Lolium multiflorum Lam.) seeded annually for three years on Serala sericea (Lespedeza cuneata (Dumont) G. Don) were compared.Rye furnished 1,400 kg/ha of dry forage by March 20 while rescue and ryegrass produced less than 250 kg/ha by the same date. Rye extended the productive season by about 2 months and increased total annual yields 2,000 kg/ha over the 6,600 kg/ha produced by sericea alone. Sericea growth in spring was not reduced by rye, but it was reduced by rescue and ryegrass. None of the species reduced stands of sericea.
Rapid Transectioning of Plant Leaves1
Authors: Gausman Harold W. , Schupp Marcia 
Published: July 2010

AbstractPhotomicrographs of oleander leaf transections (Nerium oleander L.) were taken within 15 min after leaves were excised from the plant and sectioned with a Hooker plant microtome. This rapid procedure, compared with the approximately 20‐day conventional method involving tissue fixation, paraffin embedding, staining, and sectioning with a rotary microtome, apparently gave a truer representation of the leaf mesophyll arrangement (particularly size of intercellular spaces), and usually gave better definition to leaf cuticles, druses, multiple epidermal layers, trichomes, and stomates within stomatal crypts. Variability among leaf sections, however, was greater for the Hooker than for the conventional method. Discounting some disadvantages, the rapid procedure should be useful in a portable field laboratory for “on‐the‐spot” sectioning and photomicrographic recording of plant tissue development.
Soil Heating Studies with Cool Season Turfgrasses. III. Methods for the Establishment of Turf with Seed and Sod during the Winter1
Authors: Ledeboer F. B. , Skogley C. R. , McKiel C. G. 
Published: July 2010

AbstractTurf establishment methods using seed and sod transplants were investigated on electrically heated soil during two winters. Five turfgrass species were seeded on March 3, 1968, in plots maintained at 4.4, 10.0 and 15.5 C soil temperatures. Plots were half covered with a black polypropylene screen giving 55% shade. Treatments produced similar responses in all grasses. Germination time was reduced by increasing soil temperature and adding cover. Response differences between 10 and 15 C were smaller than between 4 and l0 C. ‘Manhattan’ perennial ryegrass germinated first under all treatments and established most rapidly. Following germination, cover influenced grass development more than did soil temperature. Regardless of soil temperature, grasses in open plots developed slowly until mid April. During early grass establishment, cover effect was magnified by increased soil temperatures.‘Merion’ Ky. bluegrass sod rooted better at 8 C than at 6 C. Rooting was inhibited by shade, but foliar growth increased. Medium shade (55%) did not cause serious rooting inhibition. Shade effects were increased by increasing temperatures. N treatments produced better rooting in open plots, but under shade, N decreased rooting. Practically no rooting occurred under 73% shade.
Internal Water Status and Water Transport in Seed Onion Plants1
Authors: Millar A. A. , Gardner W. R. , Goltz S. M. 
Published: July 2010

AbstractWater potential, transpiration rate, and stomatal resistance of the various parts of the onion (Allium cepa L.) plant were measured under field and controlled conditions.Water potentials of florets and pedicels were always lower than leaf water potentials. Water potential difference between the florets and the soil of as much as —9 bars were found. The greatest drop in water potential was found between the flowers and the upper part of the seed stalk. These differences in water potential were found even when plants were growing in soil well supplied with water.Transpiration rates of the leaves were the greatest of all plant parts, the seed stalk next (about 15 to 20% of the flux density from the leaves), and the umbel lowest, representing a very small fraction of the total. Stomatal resistance of the leaves was at all times lower than seed stalk stomatal resistances. An almost on‐off stomatal behavior by which the onion plant regulates its transpiration was found to operate in a narrow range of leaf water potential, —3 to —7 bars.The relation between flux density and water potential drop was found to be highly nonlinear in plants growing in different soils and under a wide range of soil water potential and environmental conditions. Impedance to water flow in the seed stalk was 5 to 8 times greater than in the leaves. For the same conditions potential drop between soil and root surface was less than 5 cm of water.