bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prostrate vs. Common Dallisgrass Under Different Clipping Frequencies and Fertility Levels1
Authors: Hart Richard H. , Burton Glenn W. 
Published: July 2010

AbstractProstrate and common dallisgrasses were fertilized with 0, 50, 100, 200, or 400 pounds of nitrogen per acre, and harvested every 2 or 4 weeks. Prostrate consistently produced higher forage yields than common, with the difference between varieties more marked at higher nitrogen levels and when cut every 4 weeks. Yields of both grasses were higher when cut every 4 weeks than when cut every 2 weeks, and increased with increasing rates of nitrogen, up to 400 pounds per acre. Higher yields of prostrate were due to faster growth in June, July, and August, with little difference between varieties before or after this period. Crude protein content of both grasses increased with increasing nitrogen and more frequent cutting, with no significant difference between grasses. Forty months after establishment, there were fewer weeds in prostrate dallis than in common. In view of these results, prostrate dallisgrass is recommended for light, poorly drained soils in the South when seed becomes commercially available.
Physical Soil Amendments, Soil Compaction, Irrigation, and Wetting Agents in Turfgrass Management III. Effects on Oxygen Diffusion Rate and Root Growth1
Authors: Letey L. , Morgan W. C. , Richards S. J. , Valoras N. 
Published: July 2010

AbstractThe O.D.R. values under tensiometer guided irrigation were found to be high at the time measurements were made. Under the set irrigation program, the O.D.R. were lowest for unamended soil, next lowest for peat amended soil, and highest for soil amended with lignified redwood and calcined clay. Root growth in containers receiving water on a set schedule was associated with the measured O.D.R. A value of about 0.15 µg cm−2min−1 appeared to be the lower limit for root growth. Each amendment promoted the development of a root system of unique characteristics.
Evaluation of Methods for Estimating Numbers of Rhizobia on Alfalfa Seed1
Authors: Ham G. E. , Frederick L. R. 
Published: July 2010

AbstractComparative studies were made to determine the relative efficiency of different laboratory tests in detecting Rhizobium meliloti when alfalfa seeds were inoculated with known numbers of bacteria. The bottomless bottle (modified Leonard) and crock techniques, which utilize more than one seed per container, overestimated the number of rhizobia present on alfalfa seeds due to the transfer of rhizobia among seedlings in the test container. The transfer effect probably was due to root growth accompanied by multiplication and movement of rhizobia. Positive results (nodulated plants) in a container indicated that at least one seed carried one rhizobium. When rhizobia were present on the seed, a container with one inoculated seed gave results that were not significantly different from the results obtained when all seeds were inoculated. The agar tube technique tended to underestimate the number of rhizobia present on alfalfa seeds because the anaerobic conditions in the support medium inhibited nodule formation. The sand tube technique gave the most accurate information.
Protein Content of Wheat Kernels from Different Parts of the Spike1
Authors: McNeal F. H. , Davis D. J. 
Published: July 2010

AbstractThree varieties of spring wheat were grown in replicated trials at six Montana locations. Grain protein percentages from different spikes and different parts of the same spikes were compared. Differences were not observed between main and tiller spike averages or between central and lateral kernels. However, a significant protein X location interaction for main and tiller heads indicates they are not always equal in protein content. Kernels from the top third of the spike were significantly lower in protein than those from the bottom and middle portions.
Influence of Moisture and Fertilizer on Growth and N and P Uptake by Sweet Peppers1
Authors: Thomas James R. , Heilman Marvin D. 
Published: July 2010

abstractTwo soil moisture treatments were combined factorially with four N and three P levels in a greenhouse study. Dry matter production and N assimilation by sweet peppers were significantly affected by the application of N and P and by soil moisture level. Growth ratios under dry and wet soil conditions suggest that high soil moisture reduced N absorption or N availability at low levels of N. The inhibiting effect of high soil moisture on N uptake was overcome by application of high rates of N. Application of P fertilizer increased N uptake. Moisture and N application rate affected the recovery of fertilizer N. Under high soil moisture conditions, fertilizer N recovery increased with rate of application. The opposite effect was noted under the dry moisture regime. Total P uptake increased with the application of N fertilizer on both P‐fertilized and nonfertilized soils. Total P uptake decreased as available moisture decreased. The critical NO3‐N content of leaf tissue was approximately 500 ppm.
Effect of Placement Depth and Root‐Inhibiting Chemicals on Uptake of Strontium‐85 by Field Crops1
Authors: Menzel R. G. , Eck H. V. , Champion D. F. 
Published: July 2010

abstractUptake of strontium‐85 was sharply reduced by burying it deeply enough in the soil or by burying it in contact with chemicals that inhibited root development in the contaminated zone. With soybeans grown at Beltsville, Md., uptake of strontium‐85 from 75 cm below the soil surface was only 1% of that from the surface 15 cm. But with sorghum grown at Bushland, Texas, uptake from 100 cm was 40% of that from the surface 15 cm. Application of sodium carbonate with strontium‐85 at 50 cm reduced uptake by both crops to only a few percent of that from the same depth when no chemical was used.
Oat Forage Production in the Cool Tropics as Represented by Colombia1
Authors: Crowder L. V. , Lotero Jaime , Fransen James , Krull C. F. 
Published: July 2010

abstractIn the cool tropics, forage yields of imported oat varieties and selections ranged from 5.5 to 9.5 T/A of dry material when harvests were made at the milk stage of growth. Production declined with two cuts, one made at the vegetative stage and one at the milk stage. Yields were considerably reduced when several harvests were made at the vegetative stage.Crude protein content of forage cut when the plants were 12 to 15 inches high varied between 15 and 20% on a dry weight basis. The more mature forage (milk stage) had from 6 to 10% protein.On land previously uncultivated, oats responded to application of P and, to a lesser extent, N. After several fertilized cash crops, a response to N was observed in the early stage of growth of the oats and at the harvests taken in the vegetative stage. As the plants became more mature and were harvested in the milk stage, less benefit was noted from applied N and little or no response occurred with P. Oats planted after potato harvest gave high yields without the use of additional fertilizer.Interseeded grasses and legumes became well established when oats were harvested several times in the vegetative stage of growth. When oats reached the milk stage, plant competition for soil water, light, soil nutrients and space often caused poor stands of the intersown crop, especially under water stress.Excellent oat silage was made from plants harvested in the milk stage and stored in a tower silo. Feeding trials showed that oat silage alone gave daily beef gains of 1.6 pounds per day.
An Inexpensive Raingauge1
Authors: Gamble E. E. , Daniels R. B. 
Published: July 2010

AbstractSmall, inexpensive raingauges were made from 2.5‐cm electrical conduit supported in short lengths of sunken pipe. They gave readings about 5% below those of standard gauges (20‐cm diam.) but were much less susceptible to damage and vandalism.
Effect of Leaf Removal on Amylose Content of Corn Endosperm1
Authors: Helm J. L. , Fergason V. L. , Thomas J. P. , Zuber M. S. 
Published: July 2010

AbstractInheritance studies involving amylose synthesis in corn require precise estimates of the genetic potential of the genotype. Information on the effect of nongenetic factors on the amylose‐amylopectin ratio are necessary. Corn plants are often subject to loss of photosynthetic area by such factors as hail, insect damage, leaf blights, and mechanical damage. Previous workers have shown that defoliation treatments at pollinating time did not influence grain quality, but affected grain yield by a reduction in the number of developed kernels. In this study, defoliation treatments at pollinating time were used to simulate loss of photosynthetic area. The treatments changed the amylose‐amylopectin ratios of the endosperm only slightly. The removal of the 6 upper leaves at pollinating time reduced the amylose percentage in high‐amylose inbred lines and hybrids by 1 to 3%. While statistically significant, these small reductions would be of little importance in interpreting the results from an inheritance study of amylose synthesis in corn.
Teaching Techniques Integrating New Developments in Agronomy1
Authors: Lynd J. Q. , Mitchell Roger , Miller D. A. , Allen B. L. 
Published: July 2010

AbstractImproved teaching techniques are essential for integrating the rapid expansion of new knowledge within agronomic sciences. The time lag in publication of texts results in distinct gaps between research information and classroom applications. There is great need for close cooperation among the several educational and research divisions of the societies in preparation of instructional materials.Methodology for attaining improved‐updated instruction are presented for the new comprehensive soil classification system, improved techniques for soil and plant nutrient: deficiency diagnosis and soil pesticide interactions.
Effect of Reflective Coatings on Soil Temperatures, Soil Moisture, and the Establishment of Fall Bell Peppers1
Authors: Gerard C. J. , Chambers G. 
Published: July 2010

AbstractReflective coatings when applied to modify the soil surface were effective in maintaining favorable soil temperatures and in suppressing evaporation for establishing plant stands. A high inverse relationship was obtained between soil temperatures at planting depth and stand establishment of fall bell peppers. Soil temperatures at 45 C to 47 C at planting depth prevented germination of peppers. Certain coatings were effective in suppressing soil temperatures below 43 C at planting depth and in providing a favorable environment for germination of fall peppers. The data suggest that the use of 41 to 61 liters/are (10 to 15 gal/1000 ft2) of better reflective coating materials adequately suppress evaporation and insure desired plant population of peppers. Pepper yields were a function of stand with the peppers growing under the better coatings producing about 5 metric tons per hectare or over five times the yield on the multi‐irrigated bare plots.
Surface Drainage Research: I. Bedding as Evaluated by Corn Response Under Two Fertility Levels on a Very Fine Textured Aeric Ochraqualf1
Authors: Rykbost K. A. , Zwerman P. J. , Lucey R. F. 
Published: July 2010

AbstractTwo‐year results show similar yields for nonbedded and bedded treatments. Bedding depressed silage yields 2.5 metric tons/ha and increased yield of grain in silage 190 kg/ha. Average precipitation in the fall of 1962 prevented the mechanical harvest of corn on 50% of the nonbedded and 5% of the bedded area due to wet soil conditions. After average spring precipitation in 1963, bedded areas dried faster and were planted 1 week earlier than nonbedded areas. This difference in planting date influenced yield and maturity. The application of 101 kg/ha of N, 29 kg/ha of P, and 28 kg/ha of K increased silage yield and grain in silage 13.4 tons/ha and 1750 kg/ha respectively. Mean silage yields at 1.8 meter increments from the center of the bed channel to the crown were 9.2, 18.4, 28.2, 35.2, 39.6, 41.5, 41.9, and 48.6 tons/ha. Response to the fertilizer treatment over the same spacing increments were 12.3, 14.6, 21.5, 18.8, 16.8, 11.6, 15.2, and 12.3 tons/ha of silage. Effect of fertilizer on grain in silage followed similar trends.
Effect of Radial Restriction on Lateral Growth of the Root‐Shoot Axis of Young Cotton Plants1
Authors: Mathers Aubra C. 
Published: July 2010

AbstractCotton was grown in the greenhouse with restrictions at the root‐shoot axis. These restrictions were produced by puddling the soil, which subsequently dried to form a high‐strength layer, or by using plexiglass clamps. They were created to simulate restrictions observed in the field so that observations could be made of cell injury caused by restriction of lateral growth.Observations of cross sections from these cotton plants indicated that both xylem and phloem cells formed after lateral growth was restricted were smaller than normal. Phloem cells already present were damaged by pressure exerted by cell division that occurred after plants were restricted.
Portable Equipment for Weighing Sweet Sorghum Stalks from Small Plots1
Authors: Coleman Otto H. , Broadhead Dempsey M. 
Published: July 2010

AbstractPortable equipment is described for use in weighing sweet sorghum stalks from small experimental plots. The three‐point base fits irregular soil surfaces. One man can easily transport this light (about 15.4 kg) equipment that weighs up to 34 kg.
Punch Planting to Establish Lettuce and Carrots Under Adverse Conditions1
Authors: Cary J. W. 
Published: July 2010

AbstractIt was observed in both the greenhouse and field that lettuce and carrots may be established by planting single seeds in holes punched through the soil crust. When the holes are not back‐filled, seeds planted as deep as 60 mm will produce healthy plants in a few days. Preliminary experiments indicate that in some climatic regions a practical field management system could be developed which will eliminate emergence problems arising from soil crusting and premature drying of shallow seedbeds. The open hole punch method may also prove useful in controlling the temperature and salinity adjacent to the seed and in reducing initial tillage and irrigation requirements.
Effect of Continuous Submergence Versus Alternate Flooding and Drying on Growth, Yield, and Nitrogen uptake of Rice1
Authors: Patrick W. H. , Quirk W. A. , Peterson F. J. , Faulkner M. D. 
Published: July 2010

AbstractA comparison was made of rice (Oryza saliva) grown under continuously submerged conditions and under alternately dry and flooded conditions in several greenhouse and field experiments. With nitrogen‐deficient soils, alternately dry and submerged conditions caused an appreciable decrease in growth, yield, and nitrogen uptake. With soils high in available nitrogen as a result of being in permanent pasture for several years, drying and reflooding resulted in a yield increase. Drying and reflooding apparently resulted in a loss of soil nitrogen which was detrimental in the nitrogen‐deficient soils and beneficial in the soils that had been in pasture.
Castorbean Yield and Quality as Influenced by Irrigation Schedules and Fertilization Rates1
Authors: Kittock D. L. , Williams J. H. , Hanway D. G. 
Published: July 2010

AbstractIrrigation of the growing crop in addition to preplant irrigation did not significantly increase yields of castorbeans (Ricinus communis L.) in 2 of 3 years. In 1963 one irrigation on July 25 produced yields that were significantly higher than either no postplant irrigation or six weekly irrigations. Delay of first irrigation 14 days reduced yields significantly. High nitrogen (180 kg/ha) significantly increased yields of ‘Baker 296’ variety, but not of ‘Lynn,’ grown only in 1963. Irrigation treatments had a significant effect on field loss of seed of Lynn. Highest field losses were from treatments receiving the earliest irrigation. Baker 296 seed losses were lower and differences between treatments were not significant. Nitrogen level had no significant effect on field loss. Weight per 100 seeds and oil content were inversely related to amount of irrigation water applied. Added nitrogen significantlty reduced Alternaria leaf spot infection. In the no‐irrigation treatment soil moisture approached the permanent wilting point in the 30‐ to 61‐cm depth of soil in late August, in the 91‐ to 122‐cm depth in late September, and significant utilization of soil moisture in the 152‐ to 183‐cm depth was evident in early September.
A Micro‐Digestion Procedure for the Determination of Aminoid Nitrogen in Plant Material1
Authors: Qashu Hasan K. 
Published: July 2010

AbstractPlant material from two brush species, Ceanothus crassifolius and Adenostoma fasciculatum, was analyzed for aminoid N content using three different digestion procedures. A micro‐digestion procedure in a sealed tube gave higher organic nitrogen recovery than two standard Kjeldahl digestion methods. Partial recovery of nitrate N was found when standard digestion procedures were used, but no nitrate N recovery was apparent from the sealed tube method.
An Experimental Plot Planter for Peanuts, Arachis hypogaea L.1
Authors: Culp Thomas W. 
Published: July 2010

AbstractA two‐row Cole planter was modified to seed experimental plots of peanuts. A spring‐clutch is inserted in the drive shaft to disengage the seed plate assembly and the drive wheel. A hand‐crank is attached to the drive shaft above the slip‐clutch. When the crank is turned, the seed plate spins and expels the seed from the hopper. Thus, the seed hopper can be rapidly cleaned of remnant seed after each plot is planted.
Effects of Temperature and Soil Moisture on Single vs. Split Nitrogen Applications to Rye (Secale cereale L.) Forage1
Authors: Cummins D. G. , Burns R. E. , Smart W. W. G. 
Published: July 2010

AbstractNitrogen was applied in single and split applications at rates of 0, 300, and 600 mg per pot (equivalent to 0, 50, and 100 pp2m) to rye grown in a growth chamber at 10 and 21 C. Low and high soil moisture levels were maintained by watering to field capacity when soil moisture reached 15 and 60% of field capacity. Responses to these variables were measured by forage yields, total N uptake, and percent N in the plants.With either low temperature or low soil moisture, higher forage yields were obtained with single N applications. Only under both high temperature and high soil moisture was it advantageous to split N. With high soil moisture, split N improved yields in the second harvest. This would, in effect, extend the grazing period. Soil moisture was more limiting to growth in the first harvest, while temperature was more limiting in the second harvest.When N was applied in a single application, plant uptake (mg N per pot) was usually greater than or equal to treatments with split applications.Plant N content at 21 C was higher with single N applications but at 10 C was higher with split applications. Generally, low soil moisture increased N content of the forage compared with high soil moisture.The variable responses to N obtained under different temperatures and soil moisture levels will aid in interpreting field results.
Yield of Corn Grain as Affected by Fertilizer Rates and Environmental Factors1
Authors: Voss Regis , Pesek John 
Published: July 2010

AbstractEighteen experiments were conducted on the Clarion, Nicollet, and Webster soil series in Iowa to determine which selected measureable soil, management and weather factors affect the yield and response of corn grain to applied N, P, and K in multirate experiments and to quantify these combined effects through multiple regression analyses. The unfertilized plot grain yields were related to soil test values for N. P. K. and pH; time of planting; yielding ability of the corn hybrids planted; plant population and weather as characterized by a stress day criterion based on moisture depletion of the rooting zone. Soil pH and soil sources of N, P, and K; time of planting; plant population; yielding ability of the hybrids; and the stress days in the 5 weeks following planting affected the yield response to applied nutrients as indicated by multiple regression analyses.Methods for determining which factors affected yield and response to applied nutrients are described. The effect of a measurable uncontrolled factor on the response to an applied nutrient was determined by examining the slopes of the n‐dimensional yield surface.
Influence of Plant Spacing and Population on Aspects of the Microclimate within Corn Ecosystems1
Authors: Colville W. L. 
Published: July 2010

AbstractThree experiments were designed to evaluate the influence of planting pattern (drilled, hill‐dropped, and checked) and plant population on the microclimate of corn. Data were collected on an hourly basis between 0600 and 2400 hours for a period of days following pollination. The quantity of light reaching the soil through the leaf canopy was statistically greater under hilled than drilled corn, diminished with increasing plant population but remaining stable at populations of 49,400 or more plants per hectare. Light was the only factor influenced significantly by planting patterns. Soil temperatures at a depth of five centimeters under a stand of 69,160 plants/ha were reduced 10 C and under a stand of 19,760 by 5.5 C (at 1400 hours) compared to an outside bare soil location. Air temperatures within ecosystems were not greatly modified by population or method of planting. Relative humidity increased with increasing plant population. Microclimate readings were affected by the time at which the reading was taken.
Relationships between Five Laboratory Stress Tests, Seed Vigor, Field Emergence, and Seedling Establishment in Reed Canarygrass1
Authors: Mark Jerry Lee , McKee Guy W. 
Published: July 2010

AbstractField emergence and seedling growth from spring and summer plantings of 21 seed lots of reed canarygrass were compared with germination results from four stress tests (cold flood, hot flood, accelerated aging, and acid) and with the standard laboratory germination test. For the 21 seed lots, results of all tests were significantly correlated with each other and with field emergence and fall dry‐top weight. Germination following either the hot flood test or the cold flood test was a better indicator of actual field performance than the standard germination test alone. Considering speed and convenience of testing as well as relation to field performance, a combination of standard laboratory germination test and hot flood test was superior to either alone or to other test combinations. The standard laboratory germination test percentage multiplied by 0.33 provided a fairly adequate evaluation of field emergence, somewhat underestimating emergence under relatively favorable environmental conditions and slightly overestimating emergence under less favorable environmental conditions. Seed lots which were comparable in germination on the standard germination test and which were no more than a year old were variable in vigor and in field performance. In contrast, seed lots 3 or more years old were consistent in performance on the several tests although their vigor was reduced compared to seeds 1 year old.
Effect of Corn Population and Simazine on Weed Growth1
Authors: Eplee Robert E. , Klingman G. C. 
Published: July 2010

AbstractFive rates of 2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine (simazine) were applied both preemergence and at lay‐by to five levels of corn (Zea mays L.) populations. Increased weed control resulted from the combination of corn competition and the herbicide simazine. This increased weed control may be associated with a competitive advantage given to the corn and/or the effect of shading upon the retention of the herbicide on the soil surface. Corn 46 cm tall significantly reduced weed growth with additional suppression obtained from simazine. It is proposed that shading may reduce soil temperatures, which in turn may reduce the loss of simazine through photodecomposition and/or volatilization.