bluuebunny/crossref_metadata_2025_split huggingface dataset:
Survival and Emergence of Volunteer Castor Seed in Soil1
Authors: Smith D. T. 
Published: July 2010

AbstractVolunteer castor (Ricinus communis L.) seedlings are a severe weed problem in crops grown after castor. Emergence and development of castor were investigated in the greenhouse and field to determine if certain cultural practices would reduce the abundance of volunteer castor seedlings. Castor seed remaining on soil after harvest of dwarf‐internode hybrids ranged from 52,000 to 2,260,000 seeds/ha. Seedling emergence was lower when exposed castor seed were subjected to high rainfall (20 cm) during the winter. Seedling emergence was higher the following spring when rainfall was low after harvest. There was no difference in emergence from seed planted in January to May. Plant height and foliar development were suppressed, however, when exposed seed were planted later, indicating that seedling vigor would be lower if soil preparation were delayed after castor harvest. Castor readily emerged from seed planted 20 cm deep in a greenhouse or in the field. Maximum emergence was 84% from seed planted 10 to 20 cm deep in warm sandy loam. Consequently, volunteer castor populations in subsequent crops would be lowest following moist winters and delayed, shallow coverage of seed.
Effects of Selected Herbicides on Annual Weed Control and Production of Processing Peas1
Authors: Harvey R. G. , Gritton E. T. , Doersch R. E. 
Published: July 2010

AbstractLittle information is available regarding the effects of herbicides on annual weeds in processing peas (Pisum sativum L.) and on the peas themselves. Therefore, field experiments were conducted over a 2‐year period to assess the relationship between annual weed control with herbicides and pea production. Herbicide treatments of α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine (trifluralin), 2‐chloro‐2,6‐diethyl‐N‐(methoxymethyl)acetanilide (alachlor), 2‐chloro‐N‐isopropylacetanilide (propachlor) 2‐(4‐chloro‐6‐ethylamino‐s‐triazine‐2‐ylamino) ‐2‐methylproprionitrile (cyanazine), [(4‐chloro‐o‐tolyl)‐oxy] acetic acid (MCPA), 4‐[(4‐chloro‐o‐toyly)‐oxy] butyric acid (MCPB), and MCPB plus 2,2‐dichloropropionic acid (dalapon) were applied to ‘Alaska‐’ and ‘Perfection’‐type pea cultivars. Satisfactory control of most grass and broadleaf weeds was obtained with trifluralin, alachlor, propachlor, and cyanazine. MCPA and MCPB gave partial control of broadleaf weeds but did not improve pea yield. The combination of MCPB and dalapon gave moderate weed control and subsequent moderate yield increases in the Perfections. Significant reduction in stands of both Alaska and Perfection peas resulted from trifluralin application; substantial reduction in shelled‐pea yield, however, occurred only in the Alaska. Severe injury to pea plants was caused by cyanazine in 1970, but not in 1971 when abnormally low rainfall was received. No injury to pea plants was observed from applications of either alachlor or propachlor. Under the conditions tested propachlor at 5.6 kg/ha and the combination of dalapon and MCPB at 1.1 and 0.8 kg/ha provided the most satisfactory annual weed control with the least risk of crop injury.
Influence of Harvest Method on In Vitro Dry Matter Disappearance of Alfalfa and Orchardgrass1
Authors: Shenk J. S. , Cook A. F. 
Published: July 2010

AbstractA study was undertaken to evaluate the influence of harvest method on forage quality. Alfalfa (Medicago sativa L.) and orchardgrass (Dactylis glomerata L.) forages harvested in the long form were, respectively, 8.0 and 5.0% higher in in vitro dry matter disappearance (IVDMD) than flail‐chopped forage. The flail‐chopped alfalfa forage had higher apparent cell wall concentration, less cell wall hemicellulose, and more cell wall lignin. Flail‐chopped orchardgrass samples had less cell wall hemicellulose and more cell wall lignin. Hand‐harvested samples of both species dried at a faster rate than the flail‐chopped samples. Differences in rate of drying were believed responsible for the changes in forage composition and IVDMD. Caution should be used when comparing the quality of forage samples harvested by different methods.
Soil Temperature Reduction During Pollination and Grain Formation of Corn and Grain Sorghum1
Authors: Adams John E. , Thompson D. O. 
Published: July 2010

AbstractFactors other than total seasonal rainfall may be affecting corn (Zea mays L.) and possibly grain sorghum [Sorghum bicolor (L.) Moench] yield in central Texas. It has been suggested that high temperatures in central Texas during pollination and grain filling decrease the carbohydrate reserves of corn. Soil temperature was lowered in corn and grain sorghum plots during pollination and grain formation to observe the effect of soil temperature during this critical period on grain yield. Chilled water (12 to 14 C) was circulated through copper tubing 11 cm below the soil surface in plots 6.1 m long and 4.0 m wide located on Houston Black clay soil. Soil temperature in the upper part of the root zone (7.5‐ to 46‐cm depth) during soil cooling averaged 23 C in mulched, cooled grain sorghum plots; 22 C in mulched, cooled corn plots; and 26 C in bare, noncooled corn and grain sorghum check plots.Decreasing average soil temperature (7.5‐ to 46‐cm depth) during pollination and grain formation from 26 to 23 C reduced grain sorghum yield, but reducing average soil temperature to 22 C had no effect on corn yield. Soil cooling caused a significant (5% level) decrease stem temperature to a height of 61 cm in corn and some stem cooling at 61 cm in grain sorghum. Stem cooling of both corn and grain sorghum decreased with distance above the soil surface. Yield data obtained indicate that soil temperature during pollination and grain filling is not a factor limiting grain yield of corn and grain sorghum in central Texas.
Influence of Cropping System on Salt Distribution in an Irrigated Vertisol1
Authors: Hipp Billy W. , Gerard C. J. 
Published: July 2010

AbstractField studies were conducted to determine the influence of cotton (Gossypium hirsutum L.) and grain sorghum [Sorghum bicolor (L.) Moench.] on salt distribution in a vertisol profile. Electrical conductivity of soil saturated pastes taken from the root zone (0 to 90 cm) after 4 years of sorghum ranged from 2.6 to 4.8 mmhos/cm but ranged from 4 to 7.6 mmhos/cm at 0 to 90 cm after 4 years of cotton. Chloride concentrations showed similar trends in that CI‐ concentrations were 9 to 12 meq/liter at 0 to 90 cm after sorghum, but were from 18 to 30 meq/liter at the same depth after cotton. The differences in salt concentrations in the soil profile after the two crops were attributed mainly to higher water infiltration rate after sorghum (5.81 cm/hr) than after cotton (1.23 cm/hr). The indicate that cropping practice can be an important factor in salt accumulation in clay soils and that the crops should be alternated to avoid excessive salt accumulation in the root zone.
Competition Between Established Tree Roots and Newly Seeded Kentucky Bluegrass1
Authors: Whticomb Carl E. , Roberts Eliot C. 
Published: July 2010

AbstractLandscape situations frequently are such that trees may be well established when an attempt is made to establish turf. This occurs when renovating an old lawn, changing type of turf, or where new subdivisions are located in areas of established trees. This study was initiated to assess the effects of established silver maple (Acer saccharinum) and honey‐locust (Gleditsia triacanthos L.) roots on newly seeded Kentucky bluegrass (Poa pratensis). A connecting pot technique was used to maintain nearly uniform light intensity over tree‐shaded pots with or without tree roots.Silver maple and honeylocust roots established prior to seeding of common Kentucky bluegrass had a highly significant effect on growth of bluegrass, but the bluegrass had no significant effect on tree roots. Dry weight of foliage, sod and root yields, and root/sod ratios were reduced by presence of tree roots. Penetration of bluegrass roots into the main soil mass was restricted by silver maple roots. A mat of bluegrass roots about 0.95 cm (⅜ inch) thick was easily lifted from the soil containing tree roots.Established tree roots reduced the number of bluegrass plants established from seed, but had no effect on tiller production. It is hypothesized that biochemical inhibition (allelopathy) may be involved.
Laboratory Evaluation of Quality in Subtropical Grasses: I. In Vitro Digestion of Entire Plant vs Apical Meristem Portions of Digitaria1
Authors: Schank S. C. , Ventura M. , Moore J. E. 
Published: July 2010

AbstractTwo sibling genotypes of a Digitaria hybrid were harvested over five regrowth periods in order to compare in vitro organic matter digestion (IVOMD) and to determine methods of sampling sub‐tropical grasses. Entire top growth and apical meristem portions were collected at 3, 5, 7, 9, and 11 weeks of fall regrowth using four field replications of each genotype. The IVOMD of the apical portion remained relatively constant over a 6‐week period, being 67.6% at 5 weeks and 67.5% at 11 weeks, indicating that the apical portion is in a comparable “physiological age” regardless of date of cut. The entire top growth decreased in IVOMD from 69.7% at 3 weeks to 61.6% at 11 weeks. Significant differences (5% level) between the two hybrids were detected at the 5‐week harvest date.
Relationships between Drouth and Corn Yields on Selected South Atlantic Coastal Plain Soils1
Authors: Sopher Charles D. , McCracken Ralph J. , Mason David D. 
Published: July 2010

AbstractThe objectives of this study were to determine the effects of drouth‐days by physiological growth periods on corn (Zea mays L.) grain yields and to develop a onefigure drouth index suitable for expressing these effects. A drouth‐day was defined as a 24‐hour period when potential evapotranspiration exceeds rainfall plus the effective moisture storage capacity. The physiological growth periods were: two equal‐length periods prior to tasseling; tasseling; and a maturity period. The study was conducted on two major North Carolina Soil Groups.On the better drained (Udultic) soils of the Upper and Middle Coastal Plains, drouth‐days accounted for 62.6% of the corn yield variation. The effects of drouth were detrimental in the second and fourth growth periods, and grain yields were reduced to zero after five drouth‐days during the tasseling period. For the very poorly drained (Aquultic) soils of the Tidewater Region, drouth‐days accounted for 41.2% of the yield variation. Detrimental drouth‐day effects were only present during the second and tasseling periods. The reduction of the effects of drouth‐days on these soils was attributed to moisture extration from an underlying water table.Using the derived regression coefficients for weights, the drouth‐days by physiological growth periods were weighted and summed to develop a one‐figure drouth‐index. This index may be used as a single climatic variable in regression‐correlation studies of the crop‐soil ecological system.
Aerodynamic and Energy Balance Comparisons Between Awned and Nonawned Barley1
Authors: Benci J. F. , Aase J. K. , Ferguson A. H. 
Published: July 2010

AbstractThe objective of the study was to evaluate the influence of awning characteristics of barley (Hordeum vulgare L.) on the partitioning of the heat load and the turbulent characteristics of the lower atmospheric boundary associated with the plant canopy. Aerodynamic studies of full‐awned, half‐awned, and nonawned isogenic barley indicated that awns increased the roughness length for the barley canopy. Increased turbulence over the full‐awned canopy increased the air‐sensible and latent heat fluxes. After awn emergence, net radiation was approximately 100 ly/day higher over the full‐awned than over the other two isogenic lines. Between 80 and 100% of the increased net radiation was dissipated by air‐sensible heat flux.
Temperature Variation Within and Between Rooting Media in Plant Growth Chambers1
Authors: Knievel Daniel P. 
Published: July 2010

AbstractControlled environment chambers are commonly used to study influence of microclimatic variables on plant processes. An often neglected variable in these studies is temperature of the root zone. Diurnal temperature patterns of soil at 2 and 5 cm and sand at 5 cm in a cool regime (16.8C day/12.8C night) and of soil at 2 and 5 cm and nutrient solution in a warm regime (37.8C day/31.2C night) were measured. Root zone temperatures in the cool regime were higher than air temperatures during the day and cooler at night. Temperatures of the root zone in the warm regime were lower than air temperature during both day and night periods. These data call attention to diferences in root zone and air temperature which can occur during temperature controlled environmental studies.
Flax Growth in Cecil Soil Containing Mordant Violet 391
Authors: LaFleur K. S. , Craddock G. R. 
Published: July 2010

AbstractThe purpose of this study was to determine if addition of a metalizable anionic dye to a phosphate‐fixing soil would release phosphate for plant consumption. Some evidence of phosphate release was obtained.Addition of Mordant Violet 39 to Cecil surface soil increased flax growth in this soil. In a growth chamber experiment incorporating the dye, plant height increased about 40%, planet weight increased about 60%, and plant phosphorus increased about 100%.The dye‐grown flax was necrotic. It contained more manganese and less calcium and magnesium than control flax.
Influence of N Fertilization and N Carryover on Yield and N Concentration of Dactylis glomerata L.1
Authors: Donohue S. J. , Rhykerd C. L. , Holt D. A. , Noller C. H. 
Published: July 2010

AbstractThe feasibility of increasing N rates on forage grasses, brought about by low cost commercial N fertilizer, has focused attention toward the effects of high N levels on grass development and production and the hazard of ground water pollution where the applied N is not completely utilized by the forage. A 3‐year study was initiated to investigate the effects of N fertilization and N carryover on dry matter yield and percent N in orchardgrass (Dactylis glomerata L.) and to determine the N rate that would give minimal pollution problems. The N treatments, 0, 84, 168, 336, 672, and 1344 kg/ha/year of N were applied for 2 years previous to the experiment. With the initiation of the study, plots were split, half receiving N treatment and half receiving no N fertilization.Dry matter yield was found to increase up to 336 kg/ha of applied N. At the higher N rates, yields leveled off or declined, apparently due to stand reduction. Nitrogen fertilization also increased total N content of orchardgrass.Response of orchardgrass to N carryover the first year of the residual study, as measured by dry matter yield, was found at residual N rates greater than 84 kg/ha. Nitrogen carryover during the second year was observed only at the 672 and 1344 kg/ha residual N rates, and only at the 1344 kg/ha residual N rate the third year of the study. Nitrogen carryover affected total N content only in the first year of the study and only at the two highest residual N rates.Over a 5‐year period, N application equaled N removal at 246 kg/ha/year of applied N. Above this rate, N carryover was observed. This study indicates that on Crosby silt loam soil, approximately 250 kg/ha of N should be applied per year on orchardgrass in central Indiana.
Effect of Site of Exposure to Nitrapyrin and 6‐Choropicolinic Acid on Growth of Cotton and Wheat Seedlings
Authors: Geronimo J. , Smith L. L. , Stockdale G. D. 
Published: July 2010

AbstractNitrapyrin (2‐Chloro‐6‐(trichloromethyl) pyridine) is a selective nitrification inhibitor and 6‐chloropicolinic acid is its principal metabolite in plants and soil. Nitrapyrin has been found to produce more phytotoxicity on some graminaceous species than 6‐chloropicolinic acid, and the opposite has been found for some dicotyledenous species. This study was conducted to determine if the differences in activity observed with nitrapyrin and 6‐chloropicolinic acid on some monocotyledenous and dicotyledenous species could be due, at least in part, to differences in the site of exposure of the seedlings to the two chemicals. Chemically treated bands of soil were placed either above or below the seeds of cotton (Gossypium hirsutum L.) and wheat (Triticum aestivum L.), and the effect of the chemicals was assessed by weighing top growth of the plants. Nitrapyrin reduced the top growth of both cotton and wheat when exposure occurred through both the roots and shoots of the germinating seedlings. 6‐Chloropicolinic acid reduced the top growth of both species when exposure occurred through the roots only. The site of exposure of the germinating seedlings to the chemicals influences the degree of phytotoxicity obtained. The inherent activity of each compound against each species, however, appears to be a more important factor with regard to phytotoxicity.
Effects of Cutting Management on a Desmodium intortum (Mill.) Urb / Setaria sphacelata (Schumach.) Mixture1
Authors: Olsen F. J. 
Published: July 2010

AbstractA study was conducted to determine the influence of two heights (8 and 20 cm) and three frequencies of cutting (3, 6 and 9 weeks) on the yield, botanical composition, and nutritive value of Desmodium intortum (Mill.) Urb grown in association with Setaria sphacelata (Schumach.). The mixture was established on a latosol soil at Kabanyolo, Uganda. Herbage samples were hand separated to ascertain botanical composition. Crude protein (CP) and in vitro dry matter (IVDM) analyses were determined for each species for all cutting treatments.Annual dry matter yields of the mixture ranged from 5.67 to 14.97 mt/ha. The productivity of the mixture was enhanced as the tune of the cutting interval increased. No notable yield differences were found between cutting heights.Close frequent clipping had a deleterious effect on D. intortum. The slow recovery of this legume after close cutting led to a rapid increase in the grass and weed components.The CP content of D. intortum was more than double that of S. sphacelata. There were significant differences in CP content among cutting irequencies in S. sphacelata. As the time of the cutting interval increased, the CP content decreased.In vitro dry matter digestibilities of S. sphacelata varied from 61.9 to 68.2%. As the time of the cutting interval increased, the IVDM percent digestibilities of S. sphacelata decreased. There were no notable differences among IVDM digestibility percentages of D. intortum.This study demonstrated that the productivity and persistence of D. intortum were greatly influenced by the clipping treatments applied. Results clearly indicated that proper cutting management is needed in order to maintain the legume in the mixture. Long cutting intervals (6 to 9 weeks) at 20‐cm height were essential to keep D. intortum in adequate amounts when grown in association with S. sphacelata. The CP percent and degree of in vitro digestibility indicated that a balanced D. intortum/S. sphacelata mixture would adequately meet the nutritional requirements of grazing animals.
Siduron Toxicity to Turfgrasses as Affected by Several Climatic Factors1
Authors: De Mur Antonio R. , Youngner V. B. , Goodin J. R. 
Published: July 2010

AbstractBecause siduron is absorbed by roots and transported by the transpiration stream, its phytotoxicity might be affected by environmental factors that influence transpiration. To test this, bermudagrass (Cynodon dactylon L. ‘Santa Ana’) and Kentucky blue‐grass (Poa pratensis L. ‘Merion’) were grown in controlled‐environment chambers at various temperatures and light intensities and treated with 1 and 5 ppm siduron. Untreated plants were also included. Bermudagrass was susceptible to 1 and 5 ppm siduron concentrations at all temperatures and light intensities. Shoot growth was reduced more than root growth. When air temperature was 30/20 C (day/night) the toxicity of the herbicides was greater than at a lower air temperature (22/15 C). Low light intensity decreased the toxicity of siduron to bermudagrass. Bluegrass was tolerant at all concentrations and all temperature and light treatments. Root temperature did not affect toxicity of the herbicide but maximum growth of bermudagrass was at 20 C and Kentucky blue‐grass at 15 C root temeprature. At 10 C, growth of both species was distinctly reduced. Differential rates of absorption are not the basis for selectivity.
Cultivar Differences Among Triticale Seedlings Treated with Various Growth Regulators1
Authors: Cole D. F. 
Published: July 2010

AbstractSeedlings of four triticale (proposed scientific name Triticale hexaploide Lart.) cultivars were grown in vermiculite with continuous light at 20 ± 1 C from seed that had been treated with various growth regulators during imbibition prior to planting. The objectives were to determine useful characteristics in cultivar identification and the effect of various growth regulators on growth and development of triticale. Growth regulators tested were: gibberellic acid (GA3); (2‐chloroethyl) trimethyl ammonium chloride (CCC); Tris‐(2‐diethylaminoethyl)‐phosphate trihydrocloride (SK & F 7997‐A3); and a water control.All parameters, percent emergence, internode length, dry weight, and length of leaves 1, 2, and 3, were significantly affected by cultivars and growth regulators. A chemical & cultivar interaction was evident in length of the first internode and length of leaf 1. Internode length in the winter cultivars was significantly increased, whereas only one of the spring types responded to GA. The data indicate that certain cultivars could be distinguished from other cultivars in controlled environments when the seedlings are grown with and without growth regulators.
Chemical Properties of Tobacco Leaves as Affected by Carbon Dioxide Depletion and Light Intensity1
Authors: Raper C. David , Weeks W. W. , Downs R. J. , Johnson W. H. 
Published: July 2010

AbstractPlants growing in controlled‐environment rooms are frequently subjected to self‐depleted CO2 levels that manufacturers' “make‐up air systems” do little to alleviate. Flue‐cured tobacco (Nicotiana tabacum L. ‘Coker 319’) rapidly depletes CO2 from a 400 ppm (μl/liter) ambient level of 200 ppm. When compared with plants grown to maturity in an atmosphere continually adjusted to the 400 ppm level by supplementary CO2, chemical assays of leaf constituents indicated lesser effects of the CO2 depletion than anticipated. The contents of starch, soluble carbohydrates, and polyphenolics were meagerly depressed in a CO2‐depleted atmosphere. A reduction in light intensity below 322 hectolux had a greater effect accumulation of these compounds than did CO2 depletion, The CO2 depletion did affect the composition of the soluble carbohydrate fraction in leaf tissue.The CO2 and light treatments in this experiment were continued until au advanced stage of leaf senescence. Both CO2 depletion and reduced light intensities prolonged the growth period of leaves before the onset of senescence. We conclude that the extended period of growth, as well as the chronological timing of other morphological eve:ats, explains many of our reported results.