bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Partially Acidulated Rock Phosphate and Concentrated Superphosphate on Yield and Chemical Composition of Alfalfa and Orchardgrass1
Authors: Lutz J. A. 
Published: July 2010

AbstractData from field experiments on the relative efficiencies to alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) of partially acidulated rock phosphate (PARP) and fully acidulated rock phosphate (CSP) is limited and additional information on this subject is needed. Crop response to sulfur has been obtained in certain southeastern states and more information is needed to determine if continued cropping with the use of sulfur‐free fertilizers may result in sulfur‐deficient areas in Virginia.Florida rock phosphate was acidulated with H3PO4 at 20 and 100% of that required to convert rock phosphate to concentrated superphosphate. These two materials plus a check (O P) were applied as treatments for alfalfa and orchardgrass during 3 consecutive years in field experiments. Rates of total P for each crop were 0 and 100 kg/ha. The orchardgrass also received 25 kg/ha total P from CSP. The alfalfa received either 140 or 280 kg/ ha K from KCl or K2SO4. The orchardgrass, in addition to P fertilization, received N from NH4NO3 at rates of 168 and 280 kg/ha and K from KCl or K2SO4 at the rate of 140 kg/ha.Both crops responsed to P fertilization each year. In each of the 3 years with alfalfa and during the last 2 years with orchardgrass the PARP was as effective as CSP. Added S did not significantly increase alfalfa yields but did cause a highly significant increase in orchardgrass yields in the last year of the experiment. The N concentrations of both crops were significantly affected by P sources, while the higher rate of N significantly increased the N concentration of orchardgrass. Average P concentrations in both crops were higher with CSP. The K concentration in orchardgrass was significantly affected by P source in 1969 and 1970 but not in 1971. The K concentration of alfalfa was significantly affected by source and rate of K. The S concentration of alfalfa was significantly affected by source and rate of P and K. The S concentration of orchardgrass was significantly increased by the higher rate of N and by K2SO4.When both experiments were concluded significantly higher amounts of available P were present in the 0‐ to 15‐cm soil depth where PARP was applied.
Analysis of Interrelationships among Seedling Vigor, Field Emergence, and Yield in Wheat1
Authors: Das Gupta P. R. , Austenson H. M. 
Published: July 2010

AbstractTo evaluate various seed quality criteria, 86 samples of spring wheat (Triticum aestivum L. ‘Manitou’), obtained from farmers in 1969, were grown in the same year with and without Panogen 15 seed treatment in replicated field trials at three locations in Saskatchewan. Untreated seed samples were grown again in 1970 at one of the locations. Determinations were made in the laboratory of various seed and seedling characteristics supposedly related to seedling vigor. Grain yield was increased significantly due to Panogen 15 treatment by 2.5 and 4.9% at two of the three locations. Seed samples high in ‘unaided’ vigor as reflected particularly by a modified germination test of untreated seeds, showed little response to the fungicidal treatment. Yield variations between samples were most consistently dependent on standard germination, 02 uptake, and field emergence. It was concluded that the standard germination test could be supplemented with other tests to more reliably assess expected crop performance. The rate of 02 uptake by seed during the 8th and 9th hours of imbibition was found satisfactory. Further research to develop a rapid and efficient method of determining early seedling growth in darkness is recommended.
Measurement of Nitrogenase Activity of Intact Legume Symbionts In Situ Using the Acetylene Reduction Assay1
Authors: Fishbeck Kathleen , Evans Harold J. , Boersma Larry L. 
Published: July 2010

AbstractThe acetylene reduction assay has been used extensively to detect and measure nitrogenase activity of free‐living microorganisms, excised legume and non‐legume nodules, and root systems, soil cores, and entire nodulated legume plants removed from their soil medium. This investigation was undertaken to determine whether or not the acetylene reduction assay can be used to measure nitrogenase activity of cultures of nodulated soybean (Glycine max.) plants in situ and to compare the nitrogenase activity of these cultures with the nitrogenase activity of detached nodules and excised root systems from comparable cultures. Entire cultures grown in Perlite or in soil were placed in polyethylene containers, covered with Plexiglas lids, exposed to acetylene, and assayed for ethylene production. Time course experiments showed that rates of acetylene reduction of plants growing in Perlite and in soil were linear for at least 90 min following an initial lag period of 15 min. Saturation of nitrogenase in intact cultures was obtained at a pC2H2 of 0.1 atm. The apparent Km for nitrogenase was 0.05 atm. For convenience, assays in the large containers were conducted at a pC2H2 of 0.025 atm. The Michaelis‐Menten equation was used to calculate rates of acetylene reduction at saturating levels of acetylene. The correlation coefficient between rates of acetylene reduction and nodule fresh weight was 0.99 for plants of the same age and 0.79 for plants of different ages. Acetylene reduction rates of either intact nodulated plants in Perlite or nodulated root systems removed from Perlite were significantly greater than acetylene reduction rates of detached nodules from comparable cultures. Relatively little diurnal variation was observed in nitrogenase activity of potted plants grown under controlled environmental conditions. The method is useful for the assessment of nitrogenase activity of legume cultures in a porous medium under standardized conditions, but its application to legumes in soil proved to be complicated by the water content of the soil which influences rates of gas diffusion within the culture medium.
Rice Responses to Nitrogen Under High Solar Radiation and Intermittent Flooding in Peru1
Authors: Sanchez P. A. , Ramirez G. E. , de Calderon M. V. 
Published: July 2010

AbstractThe purpose of this study was to characterize the varietal responses of rice (Oryza sativa L.) to N fertilization in a tropical desert climate where extremely high N application rates are needed to attain maximum yields. Eight rice cultivars of contrasting plant type and growth duration were tested at applied N levels of 0 to 480 kg N/ha in a field experiment with an intermittently flooded water regime. Among the semi‐dwarf cultivars, the earlier maturing ‘IR8x2019; produced a maximum yield of 11.7 ton/ha at 480 kg N/ha and the later maturing ‘IR5’ produced a maximum yield of 9.9 ton/ha at 400 kg N/ha. Among the tall‐statured cultivars of the traditional plant type, the earlier maturing ‘CEL 895’ produced a maximum yield of 10.6 ton/ha at 320 kg N/ha and the later maturing ‘Minabir 2’ attained its highest yield of 7.9 ton/ha at 40 kg N/ha. Yield responses to N were primarily a function of effective tillering capacity and not of panicle size. Increases in dry matter production from panicle initiation to harvest were highly correlated with grain yields. A 0.85% N content in the above‐ground parts at harvest was associated with maximum yields as well as a total N uptake of approximately 180 kg N/ha, suggesting the existence of an internal N requirement for rice in this environment. The apparent recovery of added N averaged 30%, which is considerable lower than in constantly flooded environments.The results indicate that: i) the shorter the growth duration of a cultivar within a specific plant type, the higher the yields and N response; ii) the extremely high N rates required are due to high levels of N uptake and low fertilizer recovery intermittent flooding.
Effect of Multiple Applications of 2,3,5‐Triiodobenzoic Acid (TIBA) on Yields of Stormproof and Nonstormproof Cotton
Authors: Freytag A. H. , Coleman E. A. 
Published: July 2010

AbstractField grown upland cotton (Gossypium hisutum L.) usually matures approximately 30 to 40% of the flowers that reach anthesis. Several investigators have shown 2,3,5‐triiodobenzoic acid (TIBA) to be successful in causing the retention of buds, blooms and pods of soybeans (Glycine max (L.) Merr.) Virtually no results have been reported on the use of TIBA to retain the 30 to 40% flower shed that occurs with cotton. Those who have applied TIBA to cotton have done so with single applications of higher rates than are reported here. This research is concerned with multiple applications of TIBA at lower concentrations.Field studies were conducted over a 2‐year period with 2,3,5‐triiodobenzoic acid (TIBA) applications to cotton in multiple foliar applications, from two to five times at concentrations ranging from 5 to 62.5 g/ha on ‘Dunn 56C’ (stormproof) and (Acala 1517BR2’ (nonstormproof). Applications commenced at first blossom and continued for a period of up to 5 weeks at weekly intervals. Seed cotton yields were increased 8 to 16% by 5.0 g/ha applied five times, 25.0 g/ha applied three times, 62.5 g/ha applied two times, 62.5 g/ha applied three times, and 58.7 g/ha applied two times. First fruiting nodes in both cultivars were generally lowered; also boll counts and boll weight were increased with most TIBA treatments that increased seed cotton yield. No morphological response of dwarfing, epinasty, or leaf crinkling were observed with any of the TIBA treatments as had been reported by other workers for other crops.
Dry Matter Yield—N and S Concentration Relationships and Ratios in Young Corn Plants1
Authors: Terman G. L. , Allen S. E. , Giordano P. M. 
Published: July 2010

AbstractDry matter‐N and S concentration relationships and N/S ratios were studied in corn (Zea mays L.) grown in several greenhouse pot experiments on soil deficient in both N and S for good growth. Such relationships and ratios are basic to the proper interpretation of plant analysis results. Minimum concentrations in the dry forage necessary for continued growth of corn at 6 to 8 weeks were about 0.70% N and 0.045% S. Total N/S ratios varied widely from this ratio of 16, depending on age of plant, excess of N or S necessary for growth, and as a result of dilution of one nutrient by growth response to the other. This value of 16 at the minimum N and S concentrations approximates the ratio in plant proteins. Variations from the ratio of 16 indicate varying amounts of labile, nonprotein N or S.
Component Plant Part Development in Maize as Affected by Hybrids and Population Density
Authors: Genter C. F. , Camper H. M. 
Published: July 2010

AbstractMaize (Zea mays L.) is used extensively as a silage crop. A relatively simple method is needed to evaluate hybrids for that purpose. Six maize hybrids, two each in early, midseason, and medium‐late maturity classes, were grown at four population densities over a 3‐year period. The hybrids were chosen on the basis of superior grain yield for their respective maturity class in previous tests. Populations were established at 34,600, 44,500, 54,300, and 64,200 plants per hectare. Data were obtained for each hybrid at each planting rate for grain and forage yield and on several other traits, including component plant: part ratios.The early hybrids tended to be lower in grain yield, total dry weight, weight per ear, moisture at harvest, ear height, plant height, and proportion of stalks but higher in proportion of ears than the later hybrids. Shelling percentage, proportion of leaves, and stalk diameter showed differences between hybrids but no trend among maturity groups.As population densities increased, total dry matter increased, whereas weight per ear, stalk diameter, and percent erect plants decreased. Plant and ear heights changed very little with changes in population density. Plants tended to become proportionately smaller as populations increased so that plant‐part ratios remained nearly the same. Barren plants were not included in the separation samples. Percent barren plants increased significantly with increased population density.High energy feeds are needed by high‐producing, lactating cows and cattle on finishing rations. Maize parts vary greatly in digestibility. In the absence of feeding trials, plant‐part separation data and total dry matter production may be the most useful indicators of the relative values of maize hybrids for silage.
A Walk‐in Drying Room for Removing Moisture from Seed Crops of Forage Introductions1
Authors: Dolan D. D. , Braverman S. W. , Pfleger F. L. 
Published: July 2010

AbstractA walk‐in drying room was constructed to remove field moisture from forage legume and grass harvested for seed. Steam at 48–50 p.s.i. was used as a heat source. The heat was transferred from thin coils to a moving air stream. Air flow was forced up or down through bags of drying plant materials. The temperature of the moving air may be adjusted, and there were 10 settings of circulation from completely recirculated air to completely exhausted air after a single cycle. Performance of the drying room was evaluated by drying 96 alfalfa (Medicago sativa L.) plants that had been separated into three components: tops, crowns, and roots. The initial moisture content was highest in the tops, intermediate in the crowns, and lowest in the roots. With the room operating at 43.5 C and with completely recirculating hot air, the tops dried most rapidly, crowns dried at an intermediate rate, and roots dried more slowly than either tops or crowns. At the end of 96 hours all three plant parts were equal in retained moisture content, and at 144 hours loss in weight had completely ceased and all three plant parts had attained stable dry weight.
Incorporation of 14C by Little Bluestem Tillers at Two Stages of Phenological Development1
Authors: Smith A. E. , Leinweber C. L. 
Published: July 2010

AbstractThe translocation and deposition of photosynthates in forage species is of great importance to forage quality. Sustained production of perennial forage species is influenced by the quantity of photosynthate deposited in storage organs. Phenological development is generally accompanied by changes in physiological characteristics which would ultimately influence carbon assimilation, translocation, and deposition. The objective of this study was to quantify 14C assimilation, translocation, and deposition in little bluestem (Andropogon scoparius Michx.) tillers during two stages of morphological development. Little bluestem tillers at two differing stages of phenological development were subjected to an atmosphere containing 14CO2 for 4 hours. Treated tillers were harvested at arbitrary time intervals over a 24‐hour period and samples of each morphological structure were analyzed. Most of the 14C activity was confined to the ethanol extract and residue fraction. No activity was detected in the water extracts or starch fractions at either stage of development. Results indicated that the general pathway for 14C incorporation was similar at both stages of tiller development. However, approximately twice as much activity was found in the culm bases and roots of tillers before culm elongation as in those of tillers whose culms had elongated 24 hours after treatment. The noticeable difference was attributed to the inclusion of actively elongating upper culms that accumulated much of the 14C activity in the latter stage of development. Sucrose was the only carbohydrate containing activity in the culm bases, which indicates that it is the form in which 14C is translocated from leaves to roots.
Subsurface Sweep for Applying Herbicides1
Authors: Reid J. T. , Peacock H. A. 
Published: July 2010

AbstractSubsurface sweep applicators were designed and constructed using commercially available sweeps (25.4 cm wide) and spray nozzles. Performance was satisfactory, both in a replicated Upland cotton (Gossypium hirsutum L.) test and in a general field planting. Purple nutsedge (Cyperus rotundus L.) control was excellent, and there was a slight but nonsignificant increase in cotton yield. Precision placement of EPTC (S‐ethyl dipropylthiocarbamate) in both the horizontal and vertical planes was obtained with minimum disturbance to the profile of the finished seed‐bed. The device placed a 25.4‐cm‐wide band 5.1 cm under the soil surface. However, the same construction method could be used to make sweeps for other widths and depths of placement. Proper arrangement of the sweeps on a tool bar or cultivator can provide either band or broadcast coverage.
Effects of Seed Aggregation, Nutrient Availability, and Temperature on Germination of Subterranean Clover (Trifolium Subterraneum L.1
Authors: Caminos Juan , Raguse C. A. , Sumner D. C. 
Published: July 2010

AbstractGermination percentage was increased and emergence was accelerated when two or more subterranean clover (Trifolium subterraneum L.) seeds were planted in close physical proximity instead of singly. The effect was enhanced when a nutrient solution was supplied. However, raising the ambient temperature from 10 to 15C and from 15 to 20C either reduced the effects of seed aggregation and nutrient availability or caused the effects to be evidenced during a shorter time interval. As the influence of close seed spacing and improved nutrient availability were more pronounced at cool temperatures, they therefore could be of importance to stand establishment from new seedings in the California annual range when rainfall adequate to permit germination occurs later than normal.
Some Effects of 2‐Chloroethyl‐phosphonic Acid (CEPA) on Burley Tobacco (Nicotiana tabacum L.) Cured Detached from the Stalk1
Authors: Gupton C. L. , Nichols B. C. 
Published: July 2010

AbstractTo make mechanical leaf harvesting of burley tobacco (Nicotiana tabacum L.) practical, the problem of physiological immaturity of leaves cured detached from the stalk must h,e solved. An ethylene releasing agent, 2‐chloroethyl‐phosphonic acid (CEPA), has been found to “ripen” plant leaves. The objective of this experiment was to determine if CEPA treatment before harvesting burley tobacco and curing it detached from the stalk alleviates the physiological immaturity of such tobacco.Ten cultivars and breeding lines were grown in a split‐split‐plot design with genotypes as whole plots, methods of curing as subplots, and CEPA vs no CEPA treatments as sub‐subplots. Two weeks after topping and 4 days before harvesting, CEPA at the rate of 150 Mg/ plant was applied according to the experimental design. After curing, yield and grade index were determined for each treatment. Samples were then drawn from the leaf web, ground, and analyzed for percent total nitrogen, percent α‐amino nitrogen, water‐soluble acids, pH, percent ash, percent K20, percent nicotine, and percent nornicotine.The method of curing significantly affected grade index, percent total nitrogen, percent a‐amino nitrogen, percent nicotine, and pH. CEPA treatment effects were statistically significant for percent total nitrogen, percent α‐amino nitrogen, and percent ash. The level of each of these constituents was significantly closer to that of stalkcured tobacco after leaves cured detached from the stalk had been treated with CEPA. CEPA‐treated Burley 37, Va 509, and 69‐517 cured detached had more tobacco graded usable by cigarette manufacturers than did tobacco with any other treatments. These results indicate that some important chemical constituents and physical characteristics are modified in a desirable direction by CEPA treatments. However, there may be detrimental effects, such as off‐flavor of the smoke, associated with CEPA treatments which would preclude using the chemical.
Effect of Ammonium and Nitrate Forms of Fertilizer‐N and their Time of Application on Utilization of N by Wheat1
Authors: Spratt E. D. 
Published: July 2010

AbstractA hypothesis was tested: that NH4+‐N applied early and NO3−‐N applied later would be a beneficial cultural practice for wheat production. It is generally agreed that cereals prefer NH4+‐N during early growth.One growth chamber and three field experiments were conducted with wheat (Triticum aestivum var. Manitou) using ammonium (NH4+‐N) and nitrate (NO3−‐N) sources of fertilizer‐N applied either at sowing or as the heads emerged or at both times. A nitrification inhibitor was used with ammonium sulphate to supply NH4+‐N and untreated calcium nitrate and ammonium nitrate were used as sources of NO3−‐N. Levels of nonassimilated mineral‐N (NH4+‐N and NO3−‐N) in the green leaves and stems of wheat varied widely according to the source of N applied and its time of application. High levels of NO3−‐N in the plant at flowering led to high percentages of N in the grain. Consequently, fertilizer‐N applied as NO3−‐N as the heads emerged (‘boot’ stage) increased the percent N (protein) in the grain more than NH4+‐N. Split applications of fertilizer‐N, with NH4+‐N applied at sowing (with a nitrification inhibitor) to give maximum leaf and stem growth and NO3−‐N applied at the ‘boot’ stage to increase grain protein levels, may be worth considering as an agronomic practice for wheat production, particularly if new cultivars could be developed to use effectively the increased leaf area to produce more grain. Also, manipulating the nitrogen metabolism of the wheat plants affected the uptake of other nutrients, for example, applying NH4+‐N increased P and Zn uptake.
Effects of Light, Temperature, KNO3, and Storage on Germination of Cogongrass1
Authors: Dickens Ray , Moore G. M. 
Published: July 2010

AbstractCogongrass (Imperata cylindrica (L.) Beauv.) was introduced into the southeastern United States and has become a pest in the Gulf Coast area. An efficient seed germination procedure would aid the study of control of this species. Seed were germinated in the laboratory to determine the effects of light, KNO3 temperature, and storage time on germination. Cogongrass germinated at temperatures ranging from 25 to 35C with optimum germination near 30C. Light increased both rapidity of germination and total germination. Neither rapidity of germination nor total seed germinated was affected by KNO3 in the presence of light. Germination in the dark was enhanced by KNO3. Cogongrass seed exhibited a gradual decrease in germination percentage over 13 months when stored in the laboratory.
Distribution of Corn Roots in Sandy Soil with a Declining Water Table1
Authors: Follett R. F. , Allmaras R. R. , Reichman G. A. 
Published: July 2010

AbstractThe purpose of this study was to relate the distribution of corn (Zea mays L.) roots to depth of a declining water table in a sandy soil association. Knowledge of root response to declining water tables is important for proper crop production management. Roots from 10 monoliths (91 cm deep), centered over and perpendicular to the corn row, were obtained at about full silk (August 26) from corn growing in 91‐cm rows. Water table depths ranged from 1.33 to 2.64 m at silking after declining at the rate of about 1.3 cm/day since July 1. About 20% of the evapotranspiration was supplied by natural precipitation with the remaining 80% from soil water depletion and the water table for the period from July 1 to September 16 (final harvest). Shoot growth was maximum at intermediate water table depths. An equation describing root distribution was obtained from a regression fit of root depth (Y) as a function of water table depth (X1) and cumulative root weight (X2). A similar fit was made using root length as X2. In no case was more than 10% of the total measured root weight or more than 20% of the total measured root length below 75 cm. The distribution of roots with depth indicates water requirements for corn in these sandy soils must be supplied to a root zone with maximum depth of about 100 cm.Retarded root growth was observed where soil oxygen diffusion rate (O.D.R.) was less than 26 g/cm2/108 min. Such O.D.R. values were obtained at depths greater than 30 cm at the shallow water table site. Apparent normal root development occurred when O.D.R. values were greater than 30 g/cm2/108 min and matric suctions were about 100 mb.