bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reflectance Discrimination of Cotton and Corn at Four Growth Stages1
Authors: Gausman H. W. , Allen W. A. , Cardenas R. , Richardson A. J. 
Published: July 2010

AbstractIncreasing leaf age of corn within four growth stages had little effect on near‐infrared light (750‐ to 1350‐nm wavelength interval) reflectance, whereas mature leaves of cotton had higher near‐infrared light reflectance than young leaves.Reflectance was linearly correlated with chlorophyll concentration for the four growth stages of corn (r −0.75**) at the 550‐nm wavelength; the linear correlation of reflectance with chlorophyll for the four growth stages of cotton was significant (r −0.71**) at the 650‐nm wavelength.The largest differences among reflectances of corn leaves of different ages within growth stages occurred when tassels were appearing in the leaf whorls; this may be the best time to discriminate corn from other vegetation with remote sensors. Reflectance differences among cotton leaves within the four growth stages were similar. Spectral wavelength intervals centered around the 680‐, 850‐, 1,650‐, and 2,200‐nm wavelengths provide for the optimum discrimination of vegetation.
Diffuse Reflectance Hypothesis for the Pathway of Solar Radiation Through Leaves1
Authors: Sinclair T. R. , Schreiber M. M. , Hoffer R. M. 
Published: July 2010

AbstractThe Willstätter and Stoll theory explains leaf reflectance as critical or total reflection of light at cell wall‐air interfaces of spongy mesophyll tissue, and is based on observations of the spectral properties of leaves in the visible wavelengths. Our data, obtained in the 0.72 to 1.3 μm (reflective infrared) wavelengths, showed that unexpectedly high levels of reflectance occurred from palisade tissue and from dehydrated leaves that had collapsed internal structures.A modification of the Willstätter‐Stoll theory, termed the diffuse reflectance hypothesis, allows a satisfactory explanation of the observed spectral properties of leaves in the reflective infrared, as well as the visible wavelengths.
Effect of Antitranspirants on Yield of Grain Sorghum Under Limited Irrigation1
Authors: Fuehring H. D. 
Published: July 2010

AbstractMost crops of grain sorghum are grown under conditions of limited irrigation or rainfall. Reduction of the degree and length of periods of moisture stress through the use of antitranspirants to control stomatal opening may increase the amount of time when photosynthesis takes place thus increasing crop yield with the water available. The purpose of this study was to determine the proper material, method, and timing of application for field use. Under limited irrigation conditions in the field, grain sorghum (Sorghum bicolor (L.) Moench) was sprayed at various rates and times with phenylmercuric acetate (PMA), atrazine, and Folicote. Mean grain yield increases of 5 to 17% were obtained, indicating considerable economic possibility. Rates of application required were aproximately 60 g/ha for PMA, 130 g/ha for atrazine, and 2 liters/ha for Folicote. However, more work is needed on rates and volume of spray. Application just prior to the boot stage was more effective than a later application.
Seed Dormancy and Germination in Indiangrass as Affected by Light, Chilling, and Certain Chemical Treatments1
Authors: Emal James G. , Conard E. C. 
Published: July 2010

AbstractThe lack of published reports on the effects of chemicals and light on germination of dormant indiangrass (Sorghastrum nutans (L.) Nash) seed prompted this study. Cleaned hand‐harvested spikelets were planted between layers of germination toweling in covered plastic boxes, or on top of or between several layers of filter paper in plastic petri dishes. Each germination test consisted of 4 replicates of 100 spikelets, with or without moist prechilling at 4‐6 C for 2 or 4 weeks, held for 7 to 15 days at alternating temperatures of 18–22 C (night) and 25–28 C (day), with or without light. Some tests received red light. In other tests, various concentrations of gibberellic acid were used as the moistening agent; in others, seeds were presoaked in sodium hypochlorite or sulfuric acid.Spikelets stored dry at room temperature (18–28 C) remained dormant for 7 months before dormancy began to decline. Pregermination moist chilling for 4 weeks usually resulted in near maximum germination. Light was required for maximum germination of seed chilled for 2 weeks. Red light was more effective than daylight when exposure time was 2 hours or less. Generally, spikelets failed to respond to light once they had failed to germinate in the dark. Soaking spikelets in sodium hypo‐chlorite solution increased germination only in the presence of light. Sulfuric acid and gibberelic acid treatments increased germination in the dark, but higher germinations were obtained in the presence of daylight.
Effect of Different Tillage Methods on Growth and Yield of Silage Corn1
Authors: Hakimi A. H. , Erami A. , Ghorashy S. R. 
Published: July 2010

AbstractTillage methods under irrigated soils in arid or semiarid regions have not been studied extensively. Four methods: chisel plow and one disking (T1), moldboard plow and two disking (T2), rotary tillage only (T3), and no tillage (T4) were used in the present study. A fullseason corn (Zea mays L.) hybrid (Israel variety ‘Neveh Vaar 70’) suitable for both silage and grain was planted on a calcareous clay soil at the College of Agriculture Experiment Station in Bajegah, Shiraz. Final plant stand was 50,000/ha. Plant height was used as an indicator of plant growth. Whole plants were harvested during the milk stage and fresh weights were determined. Greatest growth occurred with method T1. Silage corn yield were 49.7, 46.1, 44.1, and 40.7 mt/ha for methods T2, T2, T3, and T4, respectively.
Relative Susceptibility of Two Common Groundsel (Senecio vulgaris L.) Biotypes to Six s‐Triazines1
Authors: Radosevich S. R. , Appleby A. P. 
Published: July 2010

AbstractEffects of several s‐triazine herbicides were studied on common groundsel (Senecio vulgaris L.) previously reported to be resistant to two chloro‐triazine herbicides and on the same weed species from a location not previously treated with triazines. Herbicides tested were: 2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine (simazine), 2‐chloro‐4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine (atrazine), 2‐(sec‐butylamino)‐4‐(ethylamino)‐6‐methoxy‐s‐triazine (GS‐14254), 2,4‐bis(isopropylamino)‐6‐methoxy‐s‐triazine (prometone), 2‐(tert‐butylamino)‐4‐(ethylamino)‐6‐(methylthio)s‐triazine (terbutryn), and 2,4‐bis(isopropylamino)‐6‐(methylthio)‐s‐triazine (prometryne). The sensitive plants became chlorotic and died when treated with a triazine herbicide. Resistant plants never exhibited these symptoms. Plants of the sensitive biotype were effectively controlled by 0.5 ppm of atrazine or simazine, 1 ppm of GS‐14254 or prometone, or 4 ppm of prometryne. The resistant biotype failed to show any chlorosis or necrosis at the highest rates tested, 4 ppm of simazine and 30 ppm for atrazine, GS‐14254, prometone, and prometryne. Both biotypes were resistant to terbutryn at 30 ppm. These studies showed that resistance in one biotype was not restricted to chloro‐triazines but extended to methoxy‐ and methylthio‐triazines as well. The use of nutrient solutions rather than soil supported the conclusion that resistance is apparently due to physiological differences and not to differences in exposure to the herbicide caused by variation in germination tune, rooting depth, or morphology.
Peanut Accessions Resistant to Seed Infection by Aspergillus flavus1
Authors: Mixon Aubrey C. , Rogers Kenneth M. 
Published: July 2010

AbstractPeanuts (Arachis hypogaea L.) may become infected with strains of Aspergillus flavus Link ex Fr. that produce aflatoxin, a highly toxic substance when ingested by animals in food or feed products. Development of peanuts with resistance to penetration by the fungus would greatly alleviate the possibility of contamination by the health impairing substance. A new laboratory procedure with conditions conducive to optimum growth of Aspergillus flavus revealed that two peanut accessions were resistant to two toxin‐producing strains of the fungus. Seed with flesh seedcoat color from P.I. 337394 had an average of 5% seed infection for hand‐picked and hand‐shelled samples evaluated at optimum seed maturity in five separate evaluations during 4 years. Also, seed infection for samples of P.I. 337409 averaged 9% for similar evaluation. For two years, comparable checks of two susceptible accessions, P.I. 331326 and P.I. 343419, had an average of 92% and 91% seed infection, respectively, and ‘Argentine,’ ‘Florunner,’ and ‘Wilco 1’ had an average of 34%, 39% and 30%, respectively.
Adaxial and Abaxial Stomatal Resistance of Cotton in the Field1
Authors: Sharpe Peter J. H. 
Published: July 2010

AbstractAn experiment was conducted near Sydney, Australia to determine the adaxial and abaxial stomatal responses of cotton (Gossypium hirsutum L.) to environmental factors under noncycling field conditions. Cotton plants were grown in small lysimeter pans and transpiration was measured by strain guage lysimeters. Leaf temperature, ambient temperature and other micrometeorological parameters were monitored continuously, Stomatal resistances were regularly measured for both surfaces with a diffusion resistance porometer developed by the author.It was found that under field conditions, the adaxial and abaxial stomata differ in their response to light, water stress, and ambient temperature. Under most conditions, including darkness and. drought, the adaxial surface was considerably higher in resistance than the abaxial surface. However, the differences in resistance between the two surfaces disappeared under a combination of high light and temperature conditions. High transpiration rates and low leaf resistance were associated with high ambient temperatures. With sufficient soil moisture there was no evidence of midday stomatal closure even under severe light and temperature regimes.It was found that sampling the resistance of one surface alone (particularly the adaxial) did not give an accurate estimate of the overall leaf resistance. In addition, it was also found that similar .resistances on both surfaces under any one set of environmental conditions does not necessarily imply that this will be so under all conditions.
Temperature Influence on the Physiology of Selected Cool Season Turfgrasses and Bermudagrass1
Authors: Watschke T. L. , Schmidt R. E. , Carson E. W. , Blaser R. E. 
Published: July 2010

AbstractCool season turfgrasses with rapid photosynthesis, low respiration, and some regulation of growth appear to be best adapted to high temperatures. Foliar and root growth, carbohydrates, photosynthesis in normal and reduced O2 atmosphere, CO2 compensation points (T), and dark respiration rates were determined in two temperature regimes (23 C light‐15 C dark and 35 C light‐25 C dark). Poa pratensis L., P. trivialis L., Lolium perenne L., Festuca rubra L., P. compressa L., and Cynodon spp. were used. Cool season species originating from warm areas grew better and tended to have lower dark respiration at high temperature than those from cooler areas Photosynthesis of cool season species approached that of bermudagrass at high temperature when photorespiration was inhibited by low O2 concentration. Plants with a combination of rapid photosynthesis and low respiration appeared to best supply metabolic demands for carbon. This was reflected by a slower decrease in carbohydrates and growth at high temperature than plants with low photosynthesis and high respiration. T increased in cool season species with increased temperature, and bermudagrass had a low T that was unaffected by temperature changes. T appeared to have some value as an indicator of photosynthetic efficiency between genera of cool season grasses.
Methods of Improving Adhesion of Bermudagrass Sod Late in the Season1
Authors: Burns Robert E. 
Published: July 2010

AbstractIn repairing athletic turfs it is necessary that new sod adhere rapidly and firmly to the substrate to prevent injury. This study was undertaken to investigate methods of increasing the adhesion of bermudagrass (Cynodon sp. var. ‘Tifway’) sod during the fall. Sod plugs (10‐cm diameter) were laid on lightly raked soil periodically from September 2 to November 16 at Griffin, Georgia. Treatments included overseeding with diploid or tetraploid annual ryegrass (Lolium multiflorum Lam.), N, P, and K fertilization, perforating the sod with 1‐cm holes, and covering with perforated clear polyethylene plastic with or without one of the above treatments. After 1 week the force necessary to shear the sod from the substrate was measured. The only treatment to give consistent results was overseeding with ryegrass, which increased adhesion 100 to 200%. The plastic further increased adhesion late in the season. Tetraploid ryegrass was no better than diploid. Due to low adhesion of sod planted on November 9, a subsequent sod (planted on November 16) was permitted to root for 2 weeks. The shear force required was twice that of the November 9 planting. This method would permit sodding of worn areas on athletic fields later than with bermudagrass alone.
Accumulative Effects of Manure and N on Continuous Corn and Clay Soil. II. Chemical Changes in Soil1
Authors: McIntosh J. L. , Varney K. E. 
Published: July 2010

AbstractContinuous corn (Zea mays L.) was grown on a Panton clay soil (Typic Ochraqualf). Four rates of manure (0, 22, 44, and 66 tons/ha) and five rates of N (0, 56, 112, 168, and 224 kg/ha) were combined in a factorial arrangement and applied each year to the same plots. Also, 120 kg/ha of P and 90 kg/ha of K were applied for 4 years to all plots. Maintenance of structure and fertility had been difficult in this soil. It had not been intensively cultivated even though it lay in large, level fields.The objectives were to study the effects of the treatments on growth, yield, and nutrient uptake of corn and on the physical and chemical properties of the soil over a period of 5 years (six crops). Results of the first objective have been previously published (7) and effects chemical properties will be reported here.Cultivation and cropping for 5 years on the check plots reduced organic matter; (by N) 8.7% and OM (by 17.7%. An annual application of 44 tons/ha of fresh dairy cattle manure was needed to maintain soil OM. CEC was increased by manure treatments as would be expected from increase in soil OM.Soil test results (pH 4.8, NH4OAc extractions) showed that P from manure was more available than fertilizer P; 119 kg/ha of P from manure increased soil test P about the same as 480 kg/ha of P from fertilizer. However, K, either from manure or fertilizer, was readily fixed by the soil (60 to 75% of the applied). More than 414 kg/ha of K was needed to bring K potential in soil to the −3,500 calorie level suggested as adequate for standard free energy of exchange of K for Ca and Mg (13).Manure application up to 44 tons/ha did not contain enough Ca or Mg to maintain initial levels in the soil. Manure and N treatments had no measurable effects on Fe and Na levels in the soil. Averaged over all treatments, exchangeable Na decreased from 123 to 85 kg/ha and Mn from 45 to 20 kg/ha during the 5 years (1966 to 1971). Treatments of N did not affect rate of breakdown of OM nor decrease pH. The highest rate of N, compared to check plots, slightly increased Mn extracted (by 6 kg/ha). The highest rate of manure decreased extractable Mn (8 kg/ha) and AI (5 kg/ha).These data showed the value of fresh manure as a soil amendment in addition to its nutrient content. Land applications of manure should be encouraged as a method of disposal but its agronomic value emphasized to encourage use with a minimum of loss.
Effect of Fertility Treatments on the Growth, Chemical Composition and Yield of No‐Tillage Corn on Orchardgrass Sod1
Authors: Lutz J. A. , Lillard J. H. 
Published: July 2010

AbstractMany data are available on the relative efficiencies of various fertility treatments for corn (Zea mays L.) when grown by the conventional methods of clean tillage. Few data are available, however, on the relative efficiencies of sources and rates of N, P, and K on the growth, chemical composition, and yield of corn grown with the notillage system.An experiment was conducted at Blacksburg, Virginia, on Groseclose silt loam (Typic, Hapludults; clayey, mixed, mesic) to determine the effects of 168 and 280 kg N/ha, 0 and 100 kg P/ha from partially and fully acidulated rock phosphate, 25 kg P/ha from fully acidulated rock phosphate, and 140 kg K/ha from KCI and K2~SO4 on the growth, chemical composition of leaves and yield of notillage corn on a chemically killed orchardgrass sod.Growth was significantly slower with the higher rate of N, but significantly increased with increased rates of applied P. Plant growth rate was unaffected by sources of K. Leaf concentrations of N and K were unaffected by rates of N and sources of K, respectively, but the P and K concentrations were significantly increased with the higher P rates. Leaf Mn concentration was higher with the higher rate of N than with the lower rate. The Ca, Mg and Mo concentrations in the leaf increased with P fertilization, but the Zn concentration decreased with P fertilization.Corn yields were significantly higher with concentrated superphosphate than with partially acidulated rock phosphate applied at the same rate of P. The higher rate of N resulted in a significant reduction in grain yield of 552 kg/ha. There was no response to S in the K2SO4.
Winter Wheat Response to Herbicides Applied Postemergence1
Authors: Robison L. R. , Fenster C. R. 
Published: July 2010

AbstractPrevious research has indicated that herbicides will cause injury to wheat when applied at certain stages of growth. With the development of new herbicides and a complete change in wheat cultivars, work was initiated to determine the cultivar‐herbicide interaction. Twelve different herbicide treatments were applied to five different cultivars of winter wheat (Triticum aestivum L.) at four stages of growth for 3 years at two locations. All plots were kept weed‐free. The stages of wheat growth were fall seedling, spring tillering, boot, and heading. Wheat was most susceptible to injury when herbicides were applied in the boot stage. Wheat also showed considerable injury when herbicides were applied immediately following heading. Herbicide applications in the fall to the seedling stage did not cause as much injury as was expected on the basis of published research. Combinations of herbicides reduced injury below that of the commonly used higher rate of single herbicides. The higher rates of both the ester and amine forms of (2,4‐dichlorophenoxy) acetic acid (2,4‐D) and 3,6‐dichloro.o.anisic acid (dicamba) caused the most injury to all cultivars of wheat.
Sugarbeet Response to Irrigation as Measured with Growth Sensors1
Authors: Johnson Wendell C. , Davis Ronald G. 
Published: July 2010

AbstractMost research with sugarbeets (Beta vulgaris L) under natural field conditions has been concerned with longterm effects of moisture or fertility levels on overall yield and sugarbeet quality. Variations in ambient conditions under which experiments have been conducted, together with the interrelationships of these variables with each other and with plant factors, have resulted in variable and sometimes contradictory results. There is, therefore, a need for more information on the effects of microclimatic and soil conditions on plant growth. In the study herein, root growth sensors that provide a continuous record of sugarbeet root growth were used to study the short‐term growth response of sugarbeets to irrigation and to variations in ambient meteorological and soil conditions.The continuous growth records of two typical irrigated sugarbeet roots were compared at Bushland, Texas, during a 48‐day period, June 25 to August 11, 1970, in a record dry season when there was little interference from rainfall on the effect of irrigation on root growth. The roots received 10 cm of irrigation water on staggered dates so that the growth record of a root not being irrigated at a particular time might be used to interpret the growth response to irrigation of the second root. The soil was slowly permeable, requiring an average of about 3 days for free water to disappear after an irrigation. A slowgrowth period of about 3 days in length occurred after each. irrigation during which time the irrigated root grew more slowly than the unirrigated root. When moisture stress was not extreme at the time of irrigation, a temporary decrease in growth rate actually occurred after irrigation.In general, root growth occurred at night. In the daytime, growth ceased or a shrinkage in circumference occurred which was proportional to the degree of moisture stress. As the need for moisture by the plant increased between irrigations, the increment of nighttime increase in circumference became progressively smaller and that of the daytime shrinkage, progressively greater. By the time the plant showed visual signs of a severe need for irrigation, the net daily growth had approached zero. Some daytime root shrinkage, however, was also noted during the slow‐growth period when the soil moisture content was very high. Although the reasons for the slowgrowth period after each irrigation were not directly determined in this study, logical explanations based on the literature of plant and soil‐water relationships are poor aeration and/or cooling of the soil.
Influence of Straw Application Rates, Plowing Dates, and Nitrogen Applications on Yield and Chemical Composition of Sugarbeets1
Authors: Smith J. H. , Douglas C. L. , LeBaron M. J. 
Published: July 2010

AbstractFertilizer N applied at ever‐increasing rates sometimes accumulates in the soil. The practice of fertilizing grain straw with N to stimulate decomposition is questionable, but decomposition of straw immobilizes N that must be compensated for in fertilizing the succeeding crop. Too much N decreases the sucrose content of sugarbeets and decreases sucrose recovery. Experiments were conducted to determine the relative value of early and late straw applications, plowing with N applied in the fall or spring, and the amount of N needed to compensate for straw applications in obtaining optimum beet and sucrose yields with maximum quality.Sugarbeets (Beta vulgaris L.) were grown following winter wheat (Triticum aestivum L., var. ‘Nugaines’) in 1970 and 1971 on a Pormeuf silt loam soil near Kimberly, Idaho. Straw was applied to the beet plots at rates of 6.7, and 13.4 metric tons/ha, and the plots were plowed either in early September or mid‐November. Nitrogen was applied at 67 kg N/ha in the fall and at 67 and 134 kg N/ha in the spring. The treatments were arranged in a split‐split plot design with 4 replications. Control plots were used with all experiments. N fertilization increased beet, top, and sucrose yields, as well as amino N, Na, K concentrations, and impurity index. It decreased the sucrose percentages of the beets. Straw applications decreased beet, top, and sucrose yields, Na and amino N concentrations, and impurity index, but they did not influence K content of the beets. Early plowing increased sucrose percentage and yield and decreased Na, K, and impurity index. Interactions between straw applications and plowing dates were significant for sugarbeet and beet top yields. Approximately 7.5 kg N fertilizer per metric ton of straw were required to compensate for the deleterious effects of the straw.