bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Rate and Date of Seeding of Small Grains on Yields
Authors: Woodward R. W. 
Published: July 2010

SynopsisOn irrigated soil in Western U. S., barley sown at rates of 30 to 40 pounds per acre yielded as well as at higher rates up to 140 pounds per acre. Rates of 50 to 60 pounds were adequate for other grains except when sown late. Lighter rates produced stiffer straw, larger heads and kernels, and higher test weight per bushel than the heavier rates. At late planting dates, higher rates helped control weeds and disease. Use of high grade, certified seed is urged for higher yields at lower rates.
The Relation Between Precipitation, Temperature, and the Yield of Soybeans on the Agronomy South Farm, Urbana, Illinois1
Authors: Runge E. C. A. , Odell R. T. 
Published: July 2010

SynopsisPrecipitation and maximum daily temperatures from June 25 through September 20 explained 68% of the variation in soybean yields from 1909 through 1957. Above‐normal precipitation during July (period of major vegetative growth) and from mid‐August to mid‐September (grain filling period) increased soybean yields, but abundant rainfall during other periods decreased yields. Maximum temperatures during July and August are too high for optimum soybean yields.
An Evaluation of the Thornthwaite and Mean Temperature Methods for Determining Potential Evapotranspiration1
Authors: Pelton W. L. , King K. M. , Tanner C. B. 
Published: July 2010

SynopsisMeasurements of potential evapotranspiration indicate that mean temperature cannot be relied upon for general use in estimating evapotranspiration during short‐periods. Mean temperature methods can be used with limited success for long‐period (growing season and annual) estimates of potential evapotranspiration, but energy balance methods are preferable if radiation data are available.
Yield and Chemical Composition of Oats for Forage with Advance in Maturity1
Authors: Smith Dale 
Published: July 2010

SynopsisPercentages of protein, fat, ash, P, Ca, K, and nitrate declined with maturity while N.F.E. increased. Percent fiber increased until the heads emerged from the boot and then decreased. Yield of dry matter per acre was highest at near ripeness but a high proportion of the total yield of important nutritional constituents was produced at early dough stage.
Effect of Defoliation and Root‐Pruning on Early Root Growth from Merion Kentucky Bluegrass Sods and Seedlings1
Authors: Dunn J. H. , Engel R. E. 
Published: July 2010

AbstractTwo root observation container tests and a solution‐culture test were established to determine the effect of defoliation and root‐pruning on root initiation and development from ‘Merion’ Kentucky bluegrass (Poa pratensis L.) sod and seedlings.The advantage of more rapid rerooting from sod and seedlings occurred with an increased amount of root removal as shown in three experiments. Sod pruned 1.3 cm thick gave an increased rate of root appearance and increased root density compared with thicker‐cut sod. Seedlings root‐pruned to 1 cm in solution culture regenerated roots more rapidly than those receiving less intense pruning.Clipping tops to 3.8 cm and cutting sod thin (1.3 cm) was the best combination for early rooting of sods. Defoliation of sods to 0 cm as shown in two experiments caused early root inhibition but later increased root growth after a sufficient interval for recovery of top growth.There was no association of carbohydrate content of tops and roots and root weights of sods at the conclusion of the root observation container experiments.
Movement of Three Herbicides in a Fine Sand Aquifer1
Authors: Schneider A. D. , Wiese A. F. , Jones O. R. 
Published: July 2010

AbstractIn order to determine movement of farm chemicals that might accidentally contaminate underground water supplies, low concentrations of three herbicides and NaNO3 as a tracer were injected into a sand aquifer through a dual‐purpose well. Herbicides used were picloram (4‐amino‐3,5,6‐trichloropicolinic acid), atrazine (2‐chloro‐4‐(ehylamino)‐6‐(isopropyl‐amino)‐s‐triazine), and trifluralin (α, α, α‐trifluoro‐2,6‐dinitro‐N, N‐dipropyl‐p‐toluidine). Recharge by injection continued for 10 days at an average rate of 81.8 m3/hour. After a 10‐day pause, the well was pumped for 12 days to determine if the herbicides and tracer could be recovered. Water samples were pumped from observation wells located 9, 20, and 45 m from the dual‐purpose well. Herbicides were detected in the 9‐ and 20‐m distant wells, but none of the herbicides or the tracer was detected in the 45‐m distant well. Picloram and atrazine moved freely through the aquifer, but some trifluralin adbsorbed to aquifer particles around the well. Although two herbicides moved freely from the point of injection, all of the chemicals were removed from the aquifer by pumping the contaminated water. Ninety‐three percent of the NO3 tracer and more than 91% of each herbicide were recovered with the pumped water. This study indicates that herbicides accidentally injected into a well in a relatively static aquifer can be recovered by pumping. Water could be utilized for irrigation of tolerant crops.
Seasonal Changes in Nonstructural Carbohydrate Levels and Innovation Number of Kentucky Bluegrass Turf Growing in Three Plant‐Climate Areas1
Authors: Younger V. B. , Nudge F. J. , Spaulding S. 
Published: July 2010

AbstractControlled environment studies have shown temperature to be one of the most important factors controlling nonstructural carbohydrate levels and density of Kentucky bluegrass (Poa pratensis L.) turf. Little information is available showing similar responses to temperature on a seasonal basis in the field. The objective of this experiment was to determine how nonstructural carbohydrate levels and density of Kentucky bluegrass turf differ among climatic areas and from season to season within an area. Total nonstructural carbohydrates (TNC) and innovation development were studied in five Kentucky bluegrass cultivars grown in the field in three distinct climate areas of California. These are a maritime climate of coastal southern California, a southern California interior valley thermal belt, and a temperate mountain valley. The respective soils of these areas are San Emigdio sandy loam classified as coarse‐loamy, mixed (calcareous), thermic Typic Xerofluvents; Arlington fine sandy loam classified as coarse‐loamy, mixed, thermic Haplic Durixeralf; and Havala sandy loam classified as fine‐loamy, mixed, thermic Typic Argixerolls. Results showed that changes in TNC levels and numbers of innovations followed seasonal patterns which were closely associated with the prevailing temperatures of each specific location. Consistently high summer temperatures reduced TNC stores but moderate temperatures did not affect them. Brief periods of exceptionally high temperature also reduced TNC levels. Accumulation of TNC occurred at each location at the time when temperatures were well below optimum for growth at that location. In the cold winter location, TNC levels decreased during the winter months. Flushes of growth occurring in spring depleted TNC. Density, the number of innovations per unit area, decreased throughout the summer at the high temperature location but increased through the cool winter. In the location of moderate summer and winter temperatures the number of innovations remained high and showed less seasonal fluctuation. Temperature, rather than day length, appeared to be the primary factor affecting innovation development.
Distribution and Growth of Sorghum Roots in Response to Irrigation Frequency1
Authors: Merrill S. D. , Rawlins S. L. 
Published: July 2010

AbstractRoot growth responds to alterations in timing and distribution of irrigation. In order to better understand crop response to irrigation regime, basic information is needed on the response of root growth, and in particular, root distribution, to differences of irrigation frequency. The lysimeter experiments reported here were designed to observe the growth of sorghum roots under conditions where soil temperature and bulk density were nearly invariant in time and over soil depth.Grain sorghum (Sorghum bicolor (L.) Moench) was grown on Pachappa sandy loam soil (mixed thermic, coarse loamy, mollic Haploxeralf) in lysimeters with artificial lighting. Three irrigation frequencies were used. Soil strength was measured with a constant rate penetrometer on undisturbed cores from the lysimeters. Root length density was measured on soil samples taken five times during 76 to 79‐day growth periods. The relation between penetrometer soil strength (PSS) and matric potential (Ψ) was PSS = 3.717 − 21.52 Ψ (PSS in kg.cm−2, Ψ in bars), and for Ψ < −0.54 bar, PSS = 19.77 + 16.63 log10 (−Ψ). PSS, averaged over 12 to 14 day periods, differed by up to 20 kg.cm−2 from the upper to lower part of the profile in the least frequently irrigated treatment, in which part of the profile dried to −10 bars or less. In contrast, PSS variation with depth was no more than 2 kg.cm−2 under daily irrigation. While root penetration was as deep in the profile in all three treatments, root length density (cm . cm−3)was proportionally less in the upper profile of the less frequently irrigated treatments. The centroids of root length density profiles were located at a 10 to 15 cm higher depth under daily irrigation than under the least frequently irrigated treatment. Root length and dry weight yield were 20% to 30% higher under daily than under intermittent irrigation.The difference between growth in the least frequently irrigated treatment and that in the daily‐irrigated at given depths correlated significantly with average PSS and log‐averaged matric potential. Within a given treatment there were almost no significant correlations between percentages of root growth at various depths and average PSS or log‐averaged matric potential. The relation between root growth and soil depth itself apparently obscurred these relations. It is concluded that PSS measurements, along with measurements of water, salt, and O2, status, will prove useful for interpreting the response of root growth to alteration of irrigation regime.
Field Evaluation of a Water Relations Model for Soybean. I. Validity of Some Basic Assumptions1
Authors: Zur B. , Jones J. W. , Boote K. J. 
Published: July 2010

AbstractBasic assumptions made in a model of stomatal feedback control, transpiration, and carbon dioxide exchange rate (CER) were tested on soybean (Glycine max L. Merr cv. Williams) grown in the field on an Arredondo fine sand soil. Intensive measurements were made of diurnal fluctuations in leaf water potential, stomatal resistance, transpiration rate (TR), and canopy CER during a drying cycle corresponding to the mid‐to‐late pod‐filling period of the crop. A threshold leaf water potential initiating stomatal closure at −1.6 MPa was measured in the field and verified the relationship assumed in the model. Linear relationships between transpiration rate and both radiation flux and vapor pressure deficit were found to exist only in well‐watered plants having low stomatal resistances (1 to 3 sec/cm). Following the time when stomatal closure was initiated, the dependence of transpiration rate on climatic variables quickly dissipated. Transpiration rate was independent of stomatal resistance for fully open stomata, quickly decreased following stomata closure and remained essentially constant at high stomatal resistances. This overall behavior was satisfactorily described by a modified Penman equation which includes a stomatal resistance term. A curvilinear relationship between CER and photosynthetically active radiation flux (PAR) existed as long as stomata were fully open. Following stomata closure, CER was independent of PAR above 500 µ/m2‐sec (full sunlight = 2,100 µE/m2‐sec). The dependence of CER on stomatal resistance was similar to that of transpiration rate but with greater sensitivity.
Microclimate Effects on Toxaphene and DDT Volatilization from Cotton Plants1
Authors: Harper L. A. , McDowell L. L. , Willis G. H. , Smith S. , Southwick L. M. 
Published: July 2010

AbstractAlthough the majority of chemicals used for insect control have low vapor pressures, the ability of these chemicals to vaporize is important in relation to possible efficacy reduction and their potential hazard as contaminants of nontarget areas. Micrometeorological methods were used to determine volatile losses of toxaphene (chlorinated Camphene) and DDT [1,1,1‐trichloro‐2,2‐bis(p‐chlorophenyl)ethane] from cotton (Gossypium hirsutum L.) plants under field conditions. Volatilization of the two insecticides from foliage was correlated best with air temperature and windspeed. Diurnal curves were developed for insecticide flux density, air temperature, windspeed, and net radiation. Peak air temperatures and windspeed coincided with peak flux densities in midafternoon whereas peak net radiation occurred 1 to 2 hours earlier. About 60 to 70 % of the mean daily flux occurred between 0600 and 1800 hours. Insecticide flux densities and the insecticide loads on the cotton plants decreased exponentially with time. The daily flux densities were about 3 to 5 % of the insecticide loads on the plants. The 50 %‐disappearance times (DT50) for toxaphene during mid‐growing season was 4.7 and 10.8 days later in the season. The DT50 for DDT was 10.3 days. The increase in surface soil pesticide loading during the study probably resulted from plant wash‐off, vapor‐phase movement downward from the plant foliage, and possibly mass movement in the evaporation stream from lower soil depths.
Denitrification Losses from Kentucky Bluegrass Sod
Authors: Mancino C. F. , Torello W. A. , Wehner D. J. 
Published: July 2010

AbstractDenitrification may represent an important mechanism in the fate of N applied to turf. Denitrification losses were directly measured from fertilized ‘Baron’ Kentucky bluegrass (Poa pratensis L.) sod samples sealed in acrylic chambers using the acetylene inhibition technique. Losses were correlated with soil texture, percent soil saturation (SAT), and temperature. Losses from turf on a Hadley silt loam soil and Hadley silt soil (both coarse‐silty, mixed, nonacid, mesic Typic Udifluvents) incubated at 22°C did not exceed 0.4 and 0.1%, respectively, of the applied potassium nitrate fertilizer (4.5 g N m−2) when soil water levels were less than 75% saturated. Soil saturation increased denitriflcation losses from the silt loam and silt soils to 1.1 and 5.4% of the applied N, respectively. The relationship between percent soil saturation and denitriflcation loss was quadratic and highly significant for both soils. The equations are: milligrams of N2O–N m−2 10 d−1 = 1432.50 − 38.96 (percent SAT silt soil) + 0.26 (percent silt soil)2 or 130.80 − 5.40 (percent SAT silt loam soil) + 0.05 (SAT silt loam soil)2. A linear relationship [milligrams of N2O m−2 10 d−1 = 0.49(°C) − 9.70] existed between denitrification losses and soil temperatures between 11 and 30°C in the silt soil at 75% of soil saturation. Soil temperatures of 30°C or greater coupled with saturated soil conditions resulted in the greatest losses, equivalent to 44.6 and 92.6% of the applied N to the silt loam and silt soils, respectively. Denitrification losses did not increase at soil temperatures above 30°C. These results indicate that denitrification loss from fertilizers applied to turfgrasses may not be a serious problem unless the soils are saturated and at higher soil temperatures.
Comparison of the Trench‐Profile and Core Methods for Evaluating Root Distributions in Tillage Studies
Authors: Vepraskas M. J. , Hoyt G. D. 
Published: July 2010

AbstractThe trench‐profile method has not been widely used to evaluate root distributions in tillage studies because it is generally considered to be more of a qualitative than quantitative technique. The objective of this study was to determine if the trench‐profile method could be used to quantify and compare root development between tillage treatments as effectively as the widely used core method. Tobacco (Nicotiana tabacum L.) roots were evaluated for no‐till and strip‐till treatments on a Typic Hapludult, and corn (Zea mays L.) roots were evaluated for nonsubsoiled and subsoiled treatments on a Typic Paleudult. Distribution of roots with depth were generally similar between methods for a given site and treatment. Coefficients of variation at a given depth were similar between root count methods and increased from approximately 20% near the surface to over 120% at a depth of 1.0 m. For comparisons within a given site, significant (0.05 level) differences in root development between treatments were found at one site using the trench‐profile method, but no significant (0.10 level) differences were found at either site using the core method. Root data were significantly correlated (site r's were 0.89** and 0.87**) between root observation methods, but different relationships were found between study sites. Expressing root data on a proportional basis rather than as an absolute measure (root number or length) appeared suitable to equate data from the two methods. The number of man‐hours required to obtain root data by the trench‐profile method was about one‐fifth of that required to use the core method to obtain comparable amounts of data.
Cyst Nematode vs. Tolerant and Intolerant Soybean Cultivars
Authors: Radcliffe D. E. , Hussey R. S. , McClendon R. W. 
Published: July 2010

AbstractThe soybean cyst nematode (SCN), Heterodera glycines Ichinohe, is a major pathogen in soybean [Glycine max (L.) Merr.], and although resistant cultivars have been developed, new races of H. glycines build up that are capable of damaging the resistant cultivars. The use of tolerant and susceptible genotypes of soybean, which support SCN development and reproduction without serious plant growth reduction, is a promising method for limiting SCN yield suppression without creating selection pressure for new races of this nematodeA field study was conducted for 2 yr to determine the effect of SCN initial population (Pi) densities on soybean root and shoot development in the intolerant and susceptible cultivar, Bragg, and the moderately tolerant cultivar, Wright. Shoot and root growth was stimulated at the low Pi but reduced at high Pi in both years. Harvest seed weight showed a similar response in 1986, but declined steadily with increasing Pi in 1987 when there was less rainfall. The moderately tolerant cultivar, Wright appeared to be a smaller, more efficient plant than the intolerant cultivar, Bragg. Wright had a smaller root system than Bragg, but the roots in the top 0.15 m exhibited compensatory growth in response to early infection by SCN whereas Bragg root growth was suppressed. Wright also had a proportionately deeper root system, compared to Bragg, and this may be part of the mechanism of tolerance.
Ammonium Thiosulfate Effect on Herbicide Longevity in Soil
Authors: Goos R. J. , Ahrens W. H. 
Published: July 2010

AbstractSoil‐applied herbicides often are mixed with liquid fertilizers to reduce application cost and increase time efficiency. Ammonium thiosulfate (ATS, 12‐0‐0‐268), a common liquid S fertilizer, can reduce microbial reaction rates in soil. The purpose of this study was to determine the influence of ATS on duration of effectiveness of soilapplied, microbially‐degraded herbicides. Greenhouse and growthchamber experiments were conducted using a coarse‐loamy Pachic Udic Haploboroll and a coarse‐silty Aeric Calciaquoll. The ATS at 0.3 to 0.38 mL kg‐1 soil extended the longevity of weed control by 2,4‐D [(2,4‐dichlorophenoxy)acetic acid], alachlor [2‐chloro‐,N‐(2,6,‐ diethylphenyl)‐N‐(methoxymethyl)acetamide], EPTC (S‐ethyl dipropylcarbamuthioate), cinmethylin [exo‐l‐methyl‐4‐(1‐methyIethyl)‐2‐[(2‐methylphenyl)methoxy]‐7‐oxabicyclo[2.2.l]heptane], and triallate [S‐(2,3,3‐trichloro‐2‐propenyl)bis(l‐methylethyl)carbamothioate]. The ATS had little effect on longevity of weed control by butylate [S‐ethyl bis(2‐methylpropyl)carbamothioate] or metolachlor [2‐chloro‐N‐(2‐methoxy‐1‐methylethyl)acetamide]. The lowest rate of ATS needed to extend 2,4‐D and EPTC efficacy was 0.15 mL kg−1 soil (about 8 gal A−1 or 26 kg S ha−1 assuming a tilled soil bulk density of 1.0 and a 5‐cm incorporation depth). This rate of ATS may be too costly for current use, but the concept deserves further evaluation because of the wide use of ATS and the need to extend the longevity of certain soil‐applied herbicides.
Performance of Randomized Block Designs in Field Experiments
Authors: Lin C. S. , Binns M. R. , Voldeng H. D. , Guillemette R. 
Published: July 2010

AbstractSuccessful application of randomized block design in field experimentation depends on whether the blocking is done properly with respect to the direction of soil variation, and on whether plot variability within blocks is homogeneous. To investigate to what extent the first problem (orientation) causes inefficiency in the design, 60 sets uniformity trial data of soybean [Glycine max (L.) Merr] yield were used to investigate soil variation in one and two directions. The results show that the total sum of squares of soil variation attributable to one direction (taking the direction of the larger variation of row or column) was 39.3%, and to two directions was 52.7%. The difference of 13.4% reflects the fact that the blocking was not perpendicular to the direction of the soil variation. To study the second problem (heterogeneity within blocks) two sets of soybean data were used to compare various statistical techniques, namely:. (i) lattice design and analysis, (ii) fitting constants by position effects of rows and columns, (iii) covariate analysis by plot number, and (iv) neighbor analysis. The general conclusion is that when variability within blocks is homogeneous, a randomized block is satisfactory. However, if the plots are heterogenous then reanalyzing the data (ii) does reduce the error, but the average variance of difference is not as good as the standard (lattice) design, (i). In contrast, the analyses by (iii) and (iv) can result good precision as by lattice design.
Soybean Growth and Yield after Simulated Bean Leaf Beetle Injury to Seedlings
Authors: Hunt Thomas E. , Higley Leon G. , Witkowski John F. 
Published: July 2010

AbstractAlthough the bean leaf beetle [Cerotoma trifurcata (Forster)] is a major pest of seedling soybean [Glycine max (L.) Merr.], the effects of beetle injury on soybean growth and yield are poorly understood. This study was conducted to characterize growth and yield responses of soybean to simulated bean leaf beetle injury occurring during seedling stages. Also, single‐day and sequential defoliation techniques were compared. The study was conducted on a Sharpsburg silty clay loam (fine, montmorillonitic, mesic Typic Argiudoll) in a soybean (‘Elgin 87’) field near Mead, NE. Treatments consisted of an undefoliated check and various levels (0‐80%) of simulated bean leaf beetle defoliation (sequential and single‐day) and/or cotyledon removal. Cotyledons were removed at stage VC, sequential defoliation was begun during stage V1, and single‐day defoliation was imposed on the last day of the defoliation period (late V3). Soybean yield significantly decreased 12% as seedling defoliation increased to 68%. Seedlings experiencing sequential defoliation did not reach a critical LAI of 3.5 until well into their reproductive stages, limiting light interception and dry matter accumulation. Cotyledon removal coupled with defoliation also reduced height up to 28% at R2.1 and delayed canopy development up to 11 d. Cotyledon removal reduced leaf area development of the seedling soybean 32%. Plants without cotyledons required up to 34% less defoliation than plants with cotyledons to delay canopy development and reduce yield. Single‐day defoliation techniques were less accurate than sequential defoliation techniques and overestimated the amount of leaf tissue a continuously defoliating insect would remove.