bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nitrogen Fertilization of Maize on an Oxisol of the Cerrado of Brazil1
Authors: Grove Thurman L. , Ritchey K. Dale , Naderman George C. 
Published: July 2010

AbstractInformation about N management for crop production on the highly weathered, tropical Oxisols is limited. Six crops of ‘Cargill 111’ maize (Zea mays L.) were planted on an Oxisol (Typic Haplustox, fine, kaolinitic, isohyperthermic) of the Cerrado of Brazil to 1) define the N fertilizer response curve; 2) estimate increase in N content of aboveground dry matter per unit fertilizer; 3) estimate soil N supply; 4) determine the effects of timing of application on yield and N recovery; and 5) compare conventional and S‐coated urea. Treatments included sidedressed urea at 0, 60, 80, 100, and 140 kg/ha with 20 kg/ha applied at planting and the remainder 30 days later, sidedressed urea at 100, 140, and 220 kg/ha with 20 kg/ha applied at planting and the remainder equally split and applied 20 and 60 days later, 100 kg/ha lime‐coated NH4NO3 and 140 kg/ha sulfur‐coated urea. Grain and stover yields were measured for each crop and subsamples collected for N analysis. Soil samples were collected throughout the experiment and analyzed for organic N. Yield increased significantly with N fertilization. Average maximum grain yield of 6.1 metric tons/ ha resulted from application of 203 kg/ha N. Recovery of fertilizer N varied with application rate from 60% at 60 kg/ha to 35% at 220 kg/ha. A single application of fertilizer 30 days after planting produced the same yield and N recovery as split applications at 20 and 60 days. Neither Scoated urea nor lime‐coated NH4NO3 produced greater yield or N recovery than conventional urea. Average N content of above‐ground dry matter at maximum yield was 1.18%. Average uptake of soil N was 70 kg/ha/crop. There appears to be no fundamental difference in response of maize to N fertilizer between Oxisols and soils of the temperate regions.
Photosynthesis, Transpiration, and Ribulose Bisphosphate Carboxylase of Selected Crested Wheatgrass Plants1
Authors: Frank A. B. 
Published: July 2010

AbstractInformation on rates of physiological processes is needed to identify genotypes differing in physiological characteristics for use in varietal improvement programs. Apparent photosynthesis (AP), transpiration (E), stomatal conductance (rc), ribulose bisphosphate Carboxylase (RuBPc), specific leaf weight (SLW), and stoma frequency were measured in diploid, tetraploid, and hexaploid crested wheatgrass [Agropyron cristatum (L.) Gaertn.] plants from Iran to determine rates for these physiological processes in this species. Two named varieties of crested wheatgrass, A. desertorum (Fisch. ex Link) Schult. ‘Nordan’ and A. cristatum ‘Ruff’ were also evaluated.Mean AP rates were 22.0, 12.5, and 12.2 mg CO2 dm‐2 hour‐1 and mean E rates were 2.7, 1.4, and 1.6 g H2O dm‐2 hour‐1 for greenhouse‐grown tetraploid, hexaploid, and diploid plants, respectively. Field‐grown (natural water stress) hexaploid plants had higher AP rates (18.1 and 10.4 mg CO2 dm‐2 hour‐1 in 1976 and 1977, respectively) than did tetraploid plants (13.1 and 8.3). Activity of RuBPc averaged 12.1, 6.9, and 11.0 µmoles CO2/(mg protein)‐1 hour‐1 for greenhouse‐grown hexaploids, tetraploids, and diploid plants, respectively, and 8.7, 7.6, and 7.4 for field‐grown plants. The field soil was a Parshall fine sandy loam (Pachic haploborolls). The fact that tetraploid plants had the higher AP rates and dry matter production under non‐water stress growing conditions in the greenhouse may indicate a greater potential for increased growth and yield as compared with the other plants evaluated in this study. Hexaploids had the higher SLW with the tetraploids and diploids having similar and lower SLW. Stomate frequency was greater for the tetraploids as compared with hexaploid plants.In the greenhouse, the tetraploid plants fixed more CO2 per unit of RuBPc than either the diploid or hexaploid plants. Both greenhouse and field hexaploid plants had high RuBPc activity, but with less range in AP rates than greenhouse (nonstressed) and field (stressed) tetraploid plants which indicated that either stomatal response is sluggish in the hexaploids or that these plants are capable of fixing greater amounts of CO2 under waterstress conditions. The latter quality may indicate greater drought tolerance.
Soil Moisture Requirements for Germination of Sorghum, Millet, Tomato, and Celosia1
Authors: Fawusi M. O. A. , Agboola A. A. 
Published: July 2010

AbstractIn most tropical countries, tomatoes (Lycopersicon esculentum Mill.) are first started in nursery flats and transplanted to the field 4 to 6 weeks later to ensure good establishment. Seed of Celosia argentea (Amaranthaceae L.) usually fail to germinate under the slightest droughty condition. While sorghum (Sorghum vulgare L.) seeds germinate well in arid zones, field establishment and seedling growth are poor under very low soil moisture condition. It is suspected that if adequate soil moisture is maintained, good emergence and field establishment are possible by direct seeding of these crops into well‐prepared seed beds. A greenhouse study was carried out to investigate the optimum soil moisture required for the germination of these crop seeds. Two temperatures, 25 to 28 and 34 C and four moisture regimes, 25, 50, 75, and 100% of field capacity were used. The soil was a sandy loam belonding to Iwo series, derived from coarse‐grained granites, gnesses, and pegmatites.A 2 ✕ 4 ✕ 4 factorial arrangement in a randomized, complete‐block design was employed. Germination and early seedling growth of tomatoes were best at soil moisture between 50 and 75% of field capacity while Celosia seeds germinated best at 75% soil moisture regime. The optimum moisture requirement for the germination of sorghum and millet (Pennisetum americanum L.) ranged between 25 and 50% of field capacity. Celosia seeds seemed to have a narrower soil moisture tolerance than tomato, while tomato seeds seemed to be more temperature sensitive than Celosia. Both sorghum and millet seed germination were adversely affected by soil moisture in excess of 50% of field capacity, but were less temperatures sensitive than tomato. The observation that sorghum and millet performed well at low soil moisture regime partly explains their ability to survive in dry ecological zones. The moisture requirements of Celosia and tomato seeds suggest supplementation of natural precipitation with irrigation to maintain the required soil moisture for best seedling emergence and growth.
Prediction and Control of Porosity and Water Retention in Sand‐Soil Mixtures for Drained Turf Sites1
Authors: Spomer L. Art 
Published: July 2010

AbstractSand‐soil mixtures are commonly used in drained turf sites such as golf greens and athletic fields to ensure proper water retention. The objective of this study was to develop a physical model useful in developing mixture recommendations based on a few simple laboratory measurements on the components and which eliminates extensive field testing. A simple physical model which predicts the total porosity, water retention porosity, and aeration porosity of bidisperse sand‐soil mixtures from the bulk or mixing volumes of each fraction and their individual total porosities was developed and laboratory tested. The porosities of each of a series of compacted sand‐soil mixtures were measured and compared to those predicted by the model. Actual porosities were within 3% of predicted values. This model apparently accurately predicts the porosity and water retention of sand‐soil mixtures and should prove useful in developing recommendations for using such mixtures on golf greens.
Relationship Between Maize Single Crosses and Their Parent Inbred Lines for N Content in the Grain1
Authors: Russell W. A. , Pierre W. H. 
Published: July 2010

AbstractThe main objectives of this investigation were: a) to determine the N content of maize (Zea mays L.) parental inbred lines and their single‐cross progenies when grown at high levels of N sufficiency; and b) to determine the relationship between the N content of inbreds and of their single‐cross progenies. Such information is basic to the characterization of hybrids with respect to their N content at maximum yields relative to N and to the possible use of the N content of maize grain in N‐sufficiency diagnoses. Also, such information is useful to breeders who are interested in developing inbred lines and hybrids that have high protein content. There have been few investigations of the relationship between the N or crude protein content of grain of maize inbred lines and their hybrid progenies.The average N content in the grain of 29 inbred lines grown at Ames, Iowa, for 3 years (1974‐1976) ranged from 1.45% N for B73 to 2.27% N for W64A, and the average for all lines was 1.80%. For 52 single crosses grown near Martinsburg, Iowa, in 1976, involving 15 inbred lines, N content ranged from 1.35% to 1.80% and averaged 1.53%, whereas for 49 single crosses grown near Grundy Center, Iowa, in 1976, involving 52 hybrids and 17 inbred lines, N content ranged from 1.39% to 1.85% and averaged 1.63%. The simple correlation coefficients between the hybrids and the means of the two parents for N content were 0.84** for the Martinsburg experiment and 0.65** for the Grundy Center experiment. There was no evidence of dominance in the inheritance of crude protein content in either experiment, and the r‐values indicated that gene action was primarily additive for N content. This means the proximate values for N or crude protein content of single crosses can be predicted reasonably well from the mean percent N of the two parents.A classification of hybrids according to N content of the inbreds showed consistent average differences in N content between types. It can, therefore, be considered a useful way for the general characterization of hybrids until more information is obtained for more specific characterization.
Ionic Balance in Coastal Bermudagrass Influenced by Nitrogen Fertilization and Soil Salinity1
Authors: Thomas J. R. , Langdale G. W. 
Published: July 2010

AbstractA stimulus in yields of coastal bermudagrass [Cynodon dactylon (L.)] with N on moderately saline soils previously reported may be due to cation‐anion balance. Other investigators have shown that a normal organic anion (C‐A) concentration was one of the conditions necessary for maximum growth, and they have postulated that yield response to N fertilization of saline soils was due to the substitution of NO3 for Cl and an increase in (C‐A) concentration of the grass. The objective of this study was to compare the relation between yield and (C‐A) concentration of coastal bermudagrass under several N fertilizer‐soil salinity regimes.The grass was grown in pots in a greenhouse on Brennan fine sandy loam (Aridic Haplustalfs). The soil was salinized by treatment with saline water to develop four salinity treatments (S0, S1, S2, and S3) with electrical conductivities (EC) of 1.2, 4.8, 9.6, and 14.4 mmho/cm, respectively. Fertilizer treatments were applied in a factorial arrangement with N rates of 0, 67, 133, and 200 mg/kg of soil and P rates of 0, 20, 40, and 60 mg/kg. The concentration of organic anions in the grass was determined as the difference between the concentration of cations (Na, K, Ca, Mg) and of inorganic anions (Cl, NO3, H2PO4, SO4).Nitrogen fertilization increased the (C‐A) concentration of the grass at all salinity levels. The increase in Cl concentration with increasing salinity decreased (C‐A) concentrations. An increase in growth was associated with an increase in the (C‐A) concentration. However, SO4 deficiency apparently controlled growth on the adequately N fertilized nonsaline soil, and cation accumulation in the salinized soils depressed growth.
Drought Adaptation of Cowpea. III. Influence of Drought on Plant Growth and Relations with Seed Yield1
Authors: Turk Kenneth J. , Hall Anthony E. 
Published: July 2010

AbstractConcurrent studies described drought effects on seed yield, plant water status, and water use of cowpea (Vigna unguiculata L. Walp.). In the present studies, drought effects on the growth of cowpea were determined to analyze possible relationships between seed yield, plant growth, and drought, and to evaluate possible mechanisms for the extreme drought avoidance exhibited by cowpea.Two cowpea cultivars were subjected to different intensities of drought at the vegetative, flowering, and pod filling stages in the field during 2 years having contrasting weather patterns. Plant growth analyses were conducted at the end of the vegetative and flowering stages.Increase in percent ground cover with time during the vegetative and flowering stages was either slowed down or delayed by drought. Increasing levels of drought, as determined by cumulative xylem pressure chamber values, resulted in progressively less leaf area, shoot dry matter, number of leaflets, and average leaflet area with total leaf area having the greatest sensitivity, and leaflet size the least sensitivity to drought. These responses were partially responsible for the extreme drought avoidance by this crop, but they also may have caused yield reductions. Seed yields were correlated with the leaf area index at the end of flowering and with the percent cover duration from the beginning of flowering to pod filling, but they were not correlated with the amount of leaf area present during the vegetative stage. Earliness, determined by the dry weight in pods at the end of flowering, increased with moderate drought and decreased with more severe drought.Specific leaf weight increased with increasing levels of drought and may provide a measure of the long term water status experience of plants due to its correlation with cumulative pressure chamber values. A multiple correlation of seed yield with specific leaf weight and degree days above 35 C at flowering accounted for most of the variation in seed yield due to progressive drought and for three growing seasons with contrasting temperature regimes.
Comparison of Cottonseed Delinting Methods in Evaluating Seed‐treatment Fungicides1
Authors: Minton Earl B. , Quisenberry J. E. 
Published: July 2010

AbstractEvaluating fungicides used to treat planting seed of cotton (Gossypium hirsutum L.) had traditionally been made with acid‐delinted seed and repeated on machine‐delinted seed under the assumption that the treatment response may depend upon the delinting method used. Machine and acid‐delinted cottonseed from the same seed lot were treated with different fungicides. The seed were planted in replicated field tests at eight locations for 3 years. Stand counts were recorded about 30 days after planting. Our primary concern was to determine the effects of methods of delinting cottonseed so seedling survival, but the effects of seed treatments, locations, and years and their interactions were determined. There were no differences in mean percentages of survived seedlings between acid and machine‐delinted cottonseed and there were no significant interactions of delinting method and any of the other variables except those noted below. Differences in seedling survival among years and locations were not significant, but the first‐order interaction between these components was significant, indicating a need to test fungicides each year at as many locations as is feasible. The results should be the same for acid‐delinted as for machine‐delinted cottonseed. There were stand differences among the seed treatments, but most of these differences were between fungicide‐treated seed and the untreated seed. Small differences occurred in percentage of seedling survival among the fungicide seed treatments. Either acid or machine‐delinted cottonseed can be usd to evaluate fungicide seed treatments for their effect on plant stands. Acid‐delinted seed should be used in these tests since most of the planting seed are acid‐delinted.
Herbicide Antidotes With Triallate1
Authors: Miller S. D. , Nalewaja John D. 
Published: July 2010

AbstractTriallate [S ‐ (2, 3, 3‐trichloroallyl) diisopropylthiocar‐bamate] must be applied and incorporated shallowly (2 to 3 cm) postplant to prevent wheat (Triticum aestivum L.) injury; however, deeper incorporation (6 to 10 cm) has given more consistent wild oat (Avena fatua L.) control. Antidotes which would increase the tolerance of wheat to triallate would allow preplant applications with deep soil incorporation for more consistent wild oat control. Research was conducted in the glasshouse with greenhouse potting soil (2:1:1 v/v/v Fargo silty clay, sand, and compost) or in the field on a Fargo silty clay (fine montmorillonitic, frigid, vertic Haplaquolls) to determine the effectiveness of several antidotes for increasing wheat tolerance to triallate. Treatment of the wheat seed with N, N‐diallyl‐2, 2‐dichloroacetanilide (R25788), 1, 8, napthalic anhydride (NA) or carboxin (5, 6‐dihydro‐2‐methyl‐1, 4‐oxathin‐3‐carboxanilide) increased tolerance of wheat to triallate in both the glasshouse and the field. R‐25788 and carboxin were more effective antidotes than NA with triallate. Applications of R‐25788 and 2, 2‐dimethyl 3‐dichloroacetyl‐oxazolidine (R‐28725) in combination with triallate and seed treatment with 4‐chloro‐2‐hydroxyminoacetanilide (S‐449) or R‐28725 were ineffective antidotes against triallate injury to wheat. This research indicates that R‐25788 or carboxin as seed treatments increased wheat tolerance sufficiently to allow preplant applications of 0.8 kg/ha triallate without injury.
Laboratory Analyses for Predicting Digestibility and Intake of Corn Silage1
Authors: Collins Michael , Ferreira Armando M. , Rohweder Dwayne A. , Jorgensen Neal A. 
Published: July 2010

AbstractHigh starch samples are difficult to filter using the neutral detergent fiber (NDF) method. Additional research is also required to identify the best in vitro dry matter disappearance (IVDMD) technique for prediction of in vivo digestibility of whole‐plant corn (Zea mays L.) forage. We designed experiments to compare methods of NDF and IVDMD determination for predicting in vivo intake and digestibility, respectively. In Experiment I, normal corn (105‐day maturity) harvested at five maturity stages (75% silk and 12, 24, 36, and 48 days later) was analyzed for NDF with and without amylase addition during refluxing. The standard deviation among triplicate samples was ±1.08 and ±0.56 for the unmodified and modified procedures, respectively. In Experiment II, normal and brown midrib corn of three maturity stages (75% silk and 24 and 60 days later) and mature (60 days) waxy and male sterile corn were analyzed using the treatments outlined above. In vivo digestibility was regressed on IVDMD dtermined by four methods (IVDMD, IVDMD + amylase, IVDMD + nitrogen, and IVDMD + NDF) and in vivo intake on NDF and NDF + amylase values. A greater percentage of variation in in vivo dry matter intake was explained when amylase was added (R2 = 96.0%) than when not (R2 = 52.0%). The addition of amylase to the in vitro fermentation vessel improved the prediction of in vivo dry matter digestibility (R3 = 67.2%) compared with the unmodified procedure (R2 = 53.3%).
Drought Sensitivity at Various Growth Stages of Barley in Relation to Relative Evapotranspiration and Water Stress1
Authors: Mogensen V. Overgaard 
Published: July 2010

AbstractPrevious investigations into the influence of drought on yield of barley (Hordeum distichurn L.) have been related to either the intensity of water stress or the duration of drought periods. Little attention has been given to the combination of intensity and duration of water stress. In this investigation drought sensitivity (F), calculated as relative grain yield reduction (1 — u/U) of barley at various growth stages, was related to the number of stress days (SD). The number of stress days was calculated as the product of relative evapotranspiration deficit (1 — Ea/Er) and the duration of drought periods (days). Barley (‘Zita’), grown in loamy sand (mixed mesic Typic Udipsamment) in lysimeters, was exposed to drought at different development stages. The lysimeters were automatically protected from rain by a mobile glass roof. Each drought treatment consisted of a single period without irrigation. Watering resumed when all available soil water was used. The first drought occurred during jointing and the final one during ripening. Relative evapotranspiration (Ea/Er) was found to be a more sensitive expression for crop water stress than leaf water potential. Relative evapotranspiration began to decrease when two‐thirds of available soil water had been used. The length of drought periods is defined from that time until irrigation was resumed. Drought sensitivity per stress day (F/SD) was decreased from 0.14 during jointing to 0.08 during booting. For drought after heading F/SD was 0.038 corresponding to a 3.8% grain yield reduction per stress day. This means that one stress day corresponds to one day without grain growth.
A Retractable, Neutron‐Probe Access Tube1
Authors: Glenn D. M. , Henderson R. L. , Bolton F. E. 
Published: July 2010

AbstractSoil moisture measurements with a neutron‐probe moisture meter provide a rapid and non‐destructive means for measuring soil water in long‐term studies. The inability of farm machinery to pass over the extended access tube limits its use in some situations. A retractable, neutronprobe access tube was designed to allow implement passage at the normal speed and tillage depth without contacting the access tube.This design has been used for soil‐moisture studies in a fallow‐crop rotation in which 6 to 10 tillage operations, including planting, have been performed over the access tubes. It has worked well with disks, sweeps, harrows, chisels, and deep‐furrow planters.
Soil Contamination of Forage Samples by Forage Plot Harvesters1
Authors: Stringer W. C. , Peiffer R. A. 
Published: July 2010

AbstractSoil contamination of herbage samples during harvesting may inflate forage yields and render samples unfit for chemical analysis. Observations of soil in herbage samples led to these experiments to quantify soil contamination of herbage samples by various plot harvesting methods. Three harvester designs were compared: the Carter flail harvester; a Penn State‐designed flail harvester with a blower to provide lift to the forage stream; and the conventional sicklebar and rake method. Soil contamination by harvesting was determined by comparing ash content of harvested samples with that of handharvested samples. The flail harvesters resulted in considerable soil contamination of samples. The Carter harvester consistently introduced more soil (5.1 to 9.1% by weight) into the herbage than the sicklebar and rake (0.1 to 1.0% by weight). However, the flail‐with‐fan did not always exceed the sicklebar‐and‐rake in soil introduction. It appears that significant soil contamination and yield inflation is possible with flail‐type forage harvesters.