bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Light Intensity, Temperature, and Root Gaseous Environment on Growth of Nicotiana tabacum L.1
Authors: Williamson R. E. , Splinter W. E. 
Published: July 2010

AbstractThe response of Nicotiana tabacum L. plants to various gaseous treatments (O2, CO2, N2) in the root environment was determined by microscopic examination of roots and measurements of stem diameter and leaf area. Superimposed on the gaseous treatments were three environmental energy input levels in which light intensity, air temperature, and nutrient solution temperature were varied. The plants were grown in an artificially lighted, controlled environment room with roots in an intermittent nutrient solution mist in airtight chambers. The roots were treated with gaseous mixtures for 24 hours and then returned to an atmosphere of air for a 5‐day recovery period. Mixtures of 1% O2 in N2, with or without CO2 present, reduced plant growth slightly at 1,000 ft‐c light intensity and 18.3C day temperature, but these mixtures progressively decreased growth as light and temperature increased. At 1,000 ft‐c light intensity and 18.3C day temperature a pure N2 treatment inhibited growth of plants; however, plants slowly resumed growth during recovery. At 4,000 ft‐c light intensity and 29.4C day temperature, N2 treatments killed the root system. Data obtained from measurements of stem diameters, leaf area, root weights, and water use suggest that the survival and growth of plants subjected to poor soil aeration is largely dependent on the ambient temperature and light intensity.
Weather and Technology in the Production of Corn in the U. S. Corn Belt1
Authors: Thompson Louis M. 
Published: July 2010

AbstractThe influence of weather was separated from the influence of technology on the yield of corn by the use of time trends for technology and multiple curvilinear regression for weather variables in five Corn Belt states. A time trend from 1930 to 1960 indicated an average annual increase of 51 kg of grain per ha. A time trend from 1960 to 1967 indicated an average annual increase of 201 kg of grain per ha. Weather variables accounted for most of the variation from the time trends. Average June temperature appeared optimum for corn while below‐average temperatures in July and August were associated with highest yields. Average precipitation from September through June appeared optimum for corn, but highest yields were associated with above‐average rainfall in July. The influence of August rainfall was not significant.
Carrot Population Density and Yield in an Arid Environment1
Authors: Robinson Frank E. 
Published: July 2010

AbstractFive plant densities of carrots, Daucus carota L. cultivar ‘Long Imperator #58,’ were studied under sprinkler irrigation in the arid Imperial Valley, California. Carrots on a 10‐cm square grid (870,000 per hectare) produced the least dry matter but the earliest roots of marketable size (35 T/ha). Twenty‐five days later plants in a 5.1‐cm square grid (3,370,000 plants per ha) produced both greater dry matter yields and yields of roots of marketable size (94 T/ha). The three greater densities of 13,590,000, 54,390,000, and 223,050,000 plants per ha produced greater dry matter yields but did not reach marketable size. Root‐to‐top ratios were approximately 1:1 in the two greatest densities and 2:1 in the three lowest densities.
Response of ‘Tifgreen’ Bermudagrass and ‘Windsor’ Kentucky Bluegrass to Various Light Spectra Modifications1
Authors: McVey G. R. , Mayer E. W. 
Published: July 2010

AbstractWindsor Kentucky bluegrass (Poa pratensis, L. ‘Windsor’) and Tifgreen bermudagrass (Cynodon dactylon, L. ‘Tifgreen’) were grown under transparent, acrylic plastic panels during the summermonths (June 1 to oct. 1, 1966) under outdoor conditions. Various acrylic plastic units were selected with the transmittance in the blue (410.510 mµ) ranging from 18 to 74% of full sunlight and in the grey (390‐760 mµ) ranging from 15 71% of full sunlight.Turfgrass color and quality (aesthetic value) were increased and clipping length and fresh weight removal reduced when bluegrass and bermudagrass were exposed to blue light as compared to grey light, at comparable light transmittance levels. These differences were more striking at the lower light intensities (less than 60% transmittance).Seedhead formation of bermudagrass was stimulated when the grass was grown under blue‐tinted acrylic plastic and suppressed when grown under grey‐tinted acrylic plastic.The degree of injury (as reflected by turf density) was not markedly altered by light quality except at very low light intensities. Bermudagrass was severely injured when grown under grey‐tinted acrylic plastic with less than 20% transmittance while turf grown under blue‐tinted acryfic plastic at low light intensities was only slightly injured.The minimum light quantity for acceptable turf quality of Tifgreen bermudagrass and Windsor Kentucky bluegrass should exceed 40 to 50% transmittance of the full sunlight if the turf is grown in blue transmitted sunlight or 60 to 70% transmittance if grown in grey transmitted sunlight.
Composted Municipal Refuse: Its Effects on Carbon Dioxide, Nitrate, Fungi, and Bacteria in Arredondo Fine Sand1
Authors: Rothwell D. F. , Hortenstine C. C. 
Published: July 2010

AbstractEffects of high levels of garbage compost, chicken manure, cow manure, and sewage sludge on microbial activity in Arredondo fine sand were evaluated by determination of relative numbers of bacteria and fungi, CO2 evolution, and nitrification. With each increase in garbage compost, relative fungal numbers increased at each measurement period; bacterial numbers increased, then decreased rapidly by the 4th or 6th day. The amount of cumulative CO2‐C evolved by these materials when mixed with soil was: cow manure < garbage compost < chicken manure < sewage sludge. Similar relationships were obtained when garbage compost was mixed with cow manure, chicken manure, or sewage sludge and added to soil. Nitrification decreased with increased levels of both sewage sludge and chicken manure and increased with increased levels of cow manure. However, little nitrification occurred when cow manure was mixed with equal quantities of garbage compost. Only slight nitrification occurred when the soil was amended with garbage compost.
Dry‐Matter Accumulation in Corn (Zea mays L.) Plants: Comparisons among Single‐Cross Hybrids1
Authors: Hanway J. J. , Russell W. A. 
Published: July 2010

AbstractEleven corn (Zea mays L.) hybrids were grown in the field for determination of dry matter accumulation in the different plant parts at successive stages of plant development. The length of time from stage O (emergence) to stage 2.5 (10th leaf fully visible) was the same for all hybrids, but the length of time from stage 2.5 to stage 5.0 (silking) and the length of time during which the grain increased in weight varied markedly among the hybrids. The daily rate of dry matter accumulation was similar for all hybrids. The relative proportion of grain and nongrain plant parts varied among the hybrids. Dry matter apparently accumulated in many nongrain parts of the plants after silking and was later translocated to the grain.
Relative Precision of Different Experimental Designs and Number of Replications in Pea Yield Trials1
Authors: Zuhlke Thomas A. , Gritton Earl T. 
Published: July 2010

AbstractThe relative efficiency of simple, triple, and balanced lattice designs relative to randomized complete blocks for fresh‐shelled pea yield trials was estimated from uniformity trial data. Lattices were always equal to or more efficient than randomized complete blocks, ranging from 100% with some short wide plots in the smaller block sizes to 236% for a long narrow plot with a block size of seven.The minimum detectable true difference as a percent of the experiment mean is given for several treatment, replicate, and plot size and shape combinations. The importance of minimizing experimental variability is demonstrated.
Corn Yields, Soil Temperature, and Water Use with Four Tillage Methods in the Western Corn Belt1
Authors: Olson Tamlin C. , Schoeberl LaVern S. 
Published: July 2010

AbstractCorn grown with four systems of tillage (conventional, wheeltrack planting, till planting, and listing) was compared for yield and several growth characteristics. Yields from the three reduced‐tillage systems in 1965, 1966, 1967, and 1968 were at least as good as those from the conventional system. The four tillage methods created a wide range of soil conditions, so that differences in growth and yield indicate the range of response that can be expected from tillage for the seasons experienced. Because of below normal rainfall, corn was under stress during flowering and ear formation in each of the four years. Soil temperature at seed depth was lowest in the listed plots where corn was planted in the bottom of the furrow. Although this resulted in slower plant growth, the delayed maturity was not correlated with final yield of dry grain or total dry matter. No significant difference among tillage systems in either total water use or in the pattern of water use was detected.
Effect of Cropping Systems and Nitrogen Levels on Corn (Zea mays) Yields in the Southern Piedmont Region1
Authors: Adams William E. , Morris H. D. , Dawson R. N. 
Published: July 2010

AbstractA field experiment was conducted on Cecil sandy loam over a 7‐year period to determine the effect of cropping systems and nitrogen levels on corn (Zea mays L.) yields. Green manure crops and perennial grass or legume sods increased corn yields regardless of the level of N fertilization. Removal of corn stalks did not decrease corn yields when corn was grown continuously with or without annual green manure crops. Alfalfa (Medicago sativa L.) and tall fescue (Festuca arundinacea Schreb.) were equally effective in sod‐based rotations for corn. Coastal bermudagrass (Cynodon dactylon (L.) Pers.) was slightly less effective in sod‐based rotations because it competed with corn during the growing season. The beneficial effect of sod on corn yields lasted for at least 4 years after the sod was turned.
Influence of Tillage Management in a Stubble Mulch Fallow‐Winter Wheat Rotation With Herbicide Weed Control1
Authors: Oveson M. M. , Appleby Arnold P. 
Published: July 2010

AbstractStudies were conducted near Pendleton, Oregon, from 1962 through 1965 to compare the effect of no‐tillage and various times of stubble mulch tillage operations during the fallow season on moisture storage, nitrate accumulation, and winter wheat (Triticum aestivum L.) yields. Weeds were controlled during the spring and summer of the fallow year with nonpersistent herbicides. Plots which had received no tillage tended to store less moisture and to accumulate less nitrates than tilled plots. During the second crop year, yields from nontilled plots were significantly reduced compared to yields from tilled plots. Conventional stubble mulch tillage including two or three rod weedings tended to be the optimum tillage treatment. Delaying the first tillage until June decreased moisture storage in comparison to other tillage treatments.
Influence of Early Lodging on Yield of Soybean [Glycine max (L.) Merr.]1
Authors: Cooper Richard L. 
Published: July 2010

AbstractThe effect of early lodging on the yield of ‘Wayne’ soybeans (Glycine max (L.) Merr.) was studied in highly productive and lodging conducive environments at Ashland and Chenoa, Ill. A wire grid system was suspended horizontally over the treated plots to prevent lodging and permit development of undisturbed canopies. The check plots were permitted to lodge naturally. Two row spacings and three plant populations were used.Natural lodging occurred at early pod set (early August); and by mid‐pod fill (late August) lodging had reduced the canopy height by 46% at both locations (150 vs 81 cm at Ashland and 131 vs 71 cm at Chenoa). Seed yields in the lodged plots were reduced 21% at Ashland (47 vs 37 kg/are) and 23% at Chenoa (35 vs 27 kg/are). There were no significant interactions between treatment and spacing or population.
Effect of Photoperiod and Temperature on the Development of Sorghum1
Authors: Caddel J. L. , Weibel D. E. 
Published: July 2010

AbstractThree varieties of Sorghum bicolor (L.) Moench, (i.e., ‘Early Hegari,’ ‘80‐Day Milo,’ and ‘Wheatland’) were grown in controlled environment chambers and subjected to all combinations of 10‐, 12‐, and 14‐hour photoperiods, 27 and 32 C day temperatures, and 16 and 21 C night temperatures. Days to floral initiation were determined for each variety under each treatment combination. In addition, days to anthesis and days in the floral period (from initiation to anthesis) were determined for the treatment combinations involving 21 C night temperatures.Ten‐hour days hastened floral initiation and anthesis of each variety at all temperature combinations. Fourteen‐hour days delayed development, but with some temperature regimes the delay was not significant, compared to the shorter days. The rate of development for the varieties under 12‐hour days was highly dependent upon day and night temperatures, since floral initiation ranged from as early as that obtained with 10‐hour days to later than that obtained with 14‐hour days.The response to day temperature during the floral period was small, but statistically significant. The time to anthesis followed a pattern similar to that for the time to floral initiation.
Yield of Wheat and Soybeans and Oil and Protein Content of Soybean as Affected by Fertility Treatments and Deep Placement of Limestone1
Authors: Jones G. D. , Lutz J. A. 
Published: July 2010

AbstractPlow sole placement (30.5 cm deep) of dolomitic limestone at rates of 0, 22.4, and 44.8 mt/ha was compared with wheat (Triticum aestivum) grown on Tatum silt loam in 1969 and followed by soybeans [Glycine max (L.) Merrill] in 1970. Treatments consisted of 0, 12.2, 24.4, and 48.8 kg P/ha without K; 24.4 and 48.8 kg P/ha with 23 kg K/ha; and 48.8 and 97.6 kg P/ha with 46 kg K/ha with each rate of lime. The P and K treatments were surface‐applied and disced in.Wheat and soybean yields were increased by P and K treatments but not by deep lime placement. Placement of lime on the plow sole increased the oil content from 23.02 to 23.49% but did not affect the protein content of the soybeans. Differences among P and K treatments in oil and protein contents of the soybeans were highly significant. The P contents of soybean leaves were unaffected by deep lime placement, but the K contents of soybean leaves were decreased with increased lime rate.
Relationships of Vigor Tests and Seed Source and Size to Sorghum Seedling Establishment1
Authors: Abdullahi Ango , Vanderlip R. L. 
Published: July 2010

AbstractConditions provided in standard seed germination tests are regarded as too “ideal,” and better methods of evaluating the seeds' capacity to germinate under less “ideal” field conditions are needed. In this study, vigor tests involving artificial aging of seeds, soil cold test, soaking of seeds in NH4Cl, as well as standard germination, were compared to determine their correlation with field seedling establishment of grain sorghum [Sorghum bicolor (L.) Moencb]. All the tests showed significant correlations with seedling establishment in the field, but the NH4Cl treatment gave better correlations. Effects of seed source and size on vigor and field establishment of seedlings were also determined. Both factors were important in determining germination and field seedling establishment. Large seeds tended to perform better in the laboratory tests than in the field. Results between laboratory and field conditions were more consistent with medium or small seeds. Significant source ✕ size interactions in both laboratory germinations and seedling establishment in the field indicated that the effects were not due to seed size per se.
Evapotranspiration from Soybean and Sorghum Fileds1
Authors: Brun Lynn J. , Kanemasu Edward T. , Powers William L. 
Published: July 2010

AbstractThe evapotranspiration model, presented by Monteith (1965) and later tested by Black et al. (1970) on a loosely structured snap bean (Phaseolus vulgaris) canopy, was used to separate soil evaporation and transpiration on soybean [Glycine max (L.) Calland] and sorghum [Sorghum bicolor (L.) Pioneer #846] canopies during the growing season.Soil evaporation was estimated as the net radiation below the crop canopy minus the soil heat flux. Stomatal resistance was determined with the diffusion porometer (Kanemasu et al. 1969). Potential evapotranspiration, soil evaporation, and transpiration rates were determined on an hourly basis. The sum of transpiration and soil evaporation was compared to the lysimetric estimates of evapotranspiration.The model and the lysimeters were in agreement, except under conditions of high atmospheric demand when the model underestimated actual evapotranspiration.The model showed the proportion of water lost as transpiration was closely correlated to leaf area index (LAI) with transpiration at approximately 50% of the total evapotranspiration at a LAI of 2 and as much as 95% at a LAI of 4.
Germination and Establishment of Salsola in Relation to Seedbed Environment. II. Seed Distribution, Germination, and Seedling Growth of Salsola and Microenvironmental Monitoring of the Seedbed1
Authors: Evans Raymond A. , Young James A. 
Published: July 2010

AbstractThe purpose of this study was to ascertain when and under what conditions seed germination and seedling growth of Russian thistle (Salsola kali var. tenuifolia Tausch.) occurs in the field. Continuous monitoring of temperature and moisture parameters of the seedbed microenvironment was conducted during critical periods of germination and seedling growth. Seedling emergence was sampled weekly concurrent with seedbed monitoring. Seed dispersal investigations and seedling emergence studies in relation to burial depth were also carried on. Seed germination and seedling emergence of Russian thistle commenced in midwinter and early spring with below 0 C night temperatures alternating with 10‐ to 19‐C day temperatures. Optimum emergence occurred in March, with temperatures of 0 to 5 C alternating with those of 12 to 25 C. Afterripening requirements curtailed germination of 1970 seeds, compared with those of 1968, at early dates, but by March no depression occurred. Soil moisture potentials less than —15 bars reduced seedling emergence and increased mortality. Low relative humidity at the soil surface during the day curtailed establishment of plants from surface seeds. Seed burial, litter cover, and variable microtopography were all conducive to establishment of Russian thistle.
Nitrogen Nutrition of Field‐grown Soybean Plants: II. Seasonal Variations in Nitrate Reductase, Glutamate Dehydrogenase and Nitrogen Constituents of Plant Parts1
Authors: Streeter John G. 
Published: July 2010

AbstractThe goals of this portion of the study were to determine (a) the distribution of N compounds in the aboveground portion of soybean plants and (b) fluctuations in the capacity for N assimilation in the leaves. Soybean plants (Glycine max (L.) Merr., ‘Harosoy 63’) grown der field conditions were sampled at 14 growth stages for the determination of dry weight, total N, amino N and nitrate N of leaves, stems, and fruits. Nitrate reductase activity and glutamate dehydrogenase activity in leaves were determined at 13 harvest dates. Free amino acid content of leaves, stems, and fruits was determined for one replicate and 13 harvest dates.Amino N was only 2 to 6% of total N in stems and leaves at most harvests indicating that amino acids transported to the tops are rapidly converted to protein. However, up to 40% of the N in stems was in the form of nitrate at the earliest harvests but this proportion fell rapidly to 5% in the flowering stage and to zero in later stages of development. Nitrate reductase content of the leaves was also highest preceding flowering while glutamate dehydrogenase showed the opposite trend, increasing four‐fold from the flowering stage to latter stages of seed development. Seasonal averages indicated that asparagine was the predominant free amino acid in stems and fruits. Asparagine content of leaves decreased approximately 20‐fold and stems 100‐fold from the first to the thirteenth harvest. The N nutrition of the soybean plants in this experiment appeared to be dependent on nitrate assimilation prior to flowering, but strongly dependent on the assimilation of ammonia from N fixation from the flowering stage to maturity.
Use of Rubidium as a Chemical Tracer for Potassium in Long‐term Experiments in Cotton and Barley1
Authors: Hafez A. , Rains D. W. 
Published: July 2010

AbstractConsiderable controversy surrounds the technique of using Rb to chemically or isotopically label K. A series of experiments were conducted to determine the usefulness of this technique when other, potentially interactive, ions are present in the media and the plants are exposed to these solutions for extended periods.Cotton (Gossypium hirsutum var. ‘Acala, SJ‐1’) and barley (Hordeum vulgare var ‘Arivat’) were grown in the greenhouse for 45 days in culture solutions containing various ratios of Rb/K. Na and NH4 were added to determine the extent of the interaction of these cations with Rb and K.The distribution of Rb and K in different plant parts was determined chemically at the end of the growth period. Quantitative tagging of Rb for K depends upon factors of ionic concentration of both ions, the ratio of Rb/K in the substrate, plant species, and the presence of other monovalent cations, such as NH4 or Na ions.Roots of both cotton and barley plants retain Rb preferentially over K. Ammonium ions compete more with K than with Rb uptake. Cotton blades reflect the Rb/K ratios of the culture solution, with a maximum deviation of 20% over the fiftyfold range of K concentration examined.
Digestibility of Bloom and Bloomless Sorghum Leaves as Determined by a Modified In Vitro Technique1
Authors: Cummins D. G. , Dobson J. W. 
Published: July 2010

AbstractForage quality of three near‐isogenic lines of sorghum [Sorghum bicolor (L.) Moench], differing primarily in the bloom and bloomless characteristic, was studied. The bloom type has a white, powdery‐appearing wax on the surface of the leaves and stems not present on the bloomless type. In vitro dry matter digestibilities (IVDMD) were determined by a modified in vitro technique on 10.2‐cm green‐leaf segments and conventionally on similar material dried and ground. IVDMD of green leaves was 22% higher on the bloomless type compared to the bloom type, with little difference between types from the samples dried and ground. These results suggest that the bloom reduced IVDMD, and that quality of sorghum forage may be improved by selecting for the bloomless characteristic. The potential of an IVDMD technique utilizing green‐leaf segments is demonstrated by these results.