bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developmental Basis of Maturity Differences in Spring Wheat1
Authors: Halloran G. M. 
Published: July 2010

AbstractCharacterization of the developmental basis of maturity of spring wheat (Triticum aestivum L. em Thell) was sought in studies of the range of vernalization and photoperiodic responses in a number of spring wheats.Vernalization responses of 12 spring wheat cultivars of Australian and overseas origin were evaluated as final leaf number of plants after cold treatment of germinated seedlings at 4 C for weekly intervals from 0 to 6 weeks. With the exception of the wheats ‘Bordan’ and the fixed crossbred ‘KB’ each genotype exhibited a marked response to cold treatment as decreased final leaf number; each appeared to attain its threshold response to cold within the 6‐week period of treatment. The behavior of two pairs of cultivars, ‘Insignia 49’ and ‘Early Summer Insignia 49’, and ‘Thatcher’ and ‘Winter Thatcher’, each pair believed to be near‐isogenic except for the presence and absence of vernalization response, indicated the likelihood that the possession of vernalization response, as such, was of no apparent significance in influencing final leaf number, spikelet number, and days to ear emergence under normal sowing times of spring wheat in southern Australia.Variation in photoperiodic response within and between genotypes was examined under two daylengths — that of a normal field sowing and that of an extended photoperiod (18‐hour). Photoperiodic response was shown to be likely of major significance in determining maturity of spring wheat grown in southern Australia. Reasonably high correlations were obtained between spikelet number and days to ear emergence under both the normal (r = +0.74**) and 18‐hour photoperiod (r = +0.67**). Wide differences in spikelet number between wheats of closely similar developmental patterns indicated the likely presence of a significant genetic component of spikelet number determination in wheat.It is postulated that in the absence of both photoperiod limitations and the need for vernalization, growth temperatures could differentially influence developmental rate among spring wheat genotypes.
Deicing Salt Movement and its Effects on Soil Parameters and Vegetation1
Authors: Buzio C. A. , Burt G. W. , Foss J. E. 
Published: July 2010

AbstractSalt damage to the environment occurs in restricted areas in humid regions as a result of factors such as industrial waste, sea water, and deicing salt. A study was conducted, therefore, to determine the distribution of salt leached from a deicing salt pile, and its effects on soil parameters (pH, Mg, P, and K) and plant successional changes in a hardwood forest area. Lateral movement and leaching of chloride was studied as it occurred in an adjacent slope by sampling the soil (Sunnyside Sandy Loam; Typic Hapludult) to a depth of 76 cm at 17 sites. The soil samples collected from the field were then analyzed for salt content by using the conductivity bridge. Lateral movement (of chloride) was extensive with subsequent leaching to a depth greater than 76 cm. Of the measured soil parameters, only K was found to be correlated with NaCI concentration. Within 3 years of the establishment of the salt stockpile, all the trees in the sampled area were dead. Out of 29 plant species found to have invaded the sites with less than 5,000 ppm of NaCI, only 10 were found in sites with concentrations greater than 15,000 ppm. Recommendations to be considered when establishing a deicing salt pile are presented.
Responses of Cowpeas to Applications of P and Fe in Calcareous Soils1
Authors: Kashirad A. , Bassiri A. , Kheradnam M. 
Published: July 2010

AbstractThe relationship between P and Fe in nutrition and development of plants have been studied in detail for some crop species. However, there is no such report available on cowpeas (Vigna sinensis L.). This study was initiated to investigate the effects of P and Fe on growth and mineral contents of cowpeas in two arid region soils.Cowpeas were grown for 8 weeks in two soil types (Typic Xerofluvent and Xerollic Xerochrept) from two locations (Airport and Kooshkak, respectively) containing various levels of P (0, 50, 100, and 200 ppm) and Fe (0, 5, 10, and 20 ppm). Airport soil (loam) had high soluble salts, high exchangeable Na and low organic matter, N, Fe, Zn, and Mn as compared to Kooshkak soil (silty clay).Symptoms of Fe deficiency developed only on plants growing in the Airport soil when no Fe was applied. With the application of Fe as little as 5 ppm, the symptoms were prevented. The dry matter yield of plants grown in the Airport soil was significantly lower than that grown in Kooshkak soil under all treatments. Best plant growth was obtained when 50 or 100 ppm P were added to each soil; however, no Fe was required in the Kooshkak soil while 20 ppm Fe were needed in Airport soil for optimum growth.The mineral contents in the tops of plants grown in either soil type were affected differently with increased levels of applied P or Fe. Significant interactions were observed between P and Fe treatments for most of the characteristics measured.
Hessian Fly Control in Wheat by Suppression of Fall Generations with Carbofuran1
Authors: Nelson L. R. , Morrill Wendell L. 
Published: July 2010

AbstractSeed and soil treatments of the systemic insecticide, carbofuran, were investigated to determine their feasibility for control of the fall generation of the Hessian fly (Mayetiola destructor Say) on wheat (Triticum aestivum L.): By controlling the fall fly population levels, the second generation would not be of economic importance, and seed treatment would be an effective control method. The experiment was conducted in the field at Plains, Ga. on a sandy loam soil (Rhodic Paleudults; clayey, kaolinitic, thermic) and at Griffin, Ga. on a Cecil sandy loam soil (Typic Hapludults; clayey, kaolinitic, thermic). The cultivar ‘Holley’ was subjected to three carbofuran treatments; a seed treatment of 4.15 g AI/kg of seed, a broadcast soil treatment of 4.5 kg AI/ha, and an untreated control. The Hessian fly was effectively controlled in wheat by suppression of the first fall generation by using carbofuran either as a seed treatment or as a broadcast spray treatment. Seed treatments were biologically active for the period during which the first fly generation developed (ca. 30 days), while soil treatments remained biologically active for several months.
Mg, Ca, and K Status of Silage Corn and Wheat at Periodic Stages of Growth in the Field1
Authors: Schwartz S. , Kafkafi U. 
Published: July 2010

AbstractThe aim of this study was to compare the Mg and Ca content of a winter forage — wheat (Triticum aestivum) with a summer forage — corn (Zea mays L.) on several levels of N, P, and K fertilization. Specifically, the effect of soil fertility level and growth stage of the plants on the Mg content of the plant was studied with its connection to potential hazard of grass tetany (hypomagnesemia). Knowing the intrinsic differences between species of forage and the trend in Mg content changes during the growing season might help in preventing grass tetany. In two separate years corn and wheat were grown on a permanent plots fertilization experiment at the Bet Dagan experimental farm, Israel. In this field, five levels of N and P and three levels of K are checked in a factorial design. In the corn experiment the factorial combination of three levels of N; 0, 200, and 400 kg N/ha; three levels of P; 0, 80, and 150 kg P/ha; and two levels of K; 0 and 310 kg K/ha; were selected for detailed study. Plant samples were taken every week. In the wheat experiment five levels of N; 0, 30, 60, 120, and 240 kg N/ha on three levels of P; 0, 16, and 64 Kg/ha, and K at 270 kg/ha were sampled every 2 weeks. The plant material was dried, weighed, and analyzed. Magnesium and Ca uptake by wheat were found to be highly correlated (r = 0.986 for Mg and r = 0.982 for Ca) with N uptake and relatively unaffected by P fertilization. The absolute amounts of Mg and Ca taken up per ha of crop produced were considerably higher in corn i.e., 33.0 kg Mg/ha and 53.9 kg Ca/ha, than in wheat, i.e., 13.8 kg Mg/ha and 22.5 kg Ca/ha, when averaged over all treatments, exclusive of Ko. The antagonistic K‐Mg effect was readily observed in corn. Thus, 64.3 kg Mg/ha taken up in the N200P160K0 treatment was reduced to 39.1 kg Mg/ha in the N200P160K310 plots at equal dry matter production. With the exception of one stage of growth in wheat 4 weeks after emergence, Mg concentrations were below 0.2%, a level considered critical in the prevention of hypomagnesemic disorders in grazing cattle and sheep. Lowest Mg concentrations in Wheat, i.e., 0.06% to 0.07%, were observed in February just prior to and in the early stages of heading, 2 to 4 weeks prior to maximum dry matter production. Because of its lower uptake of Mg and Ca, wheat silage should be supplemented by Mg additives to prevent hypomagnesemic disorders. Based on this study, it is recommended that special attention should be paid to add Mg salts to milking cows in the mid‐winter months when grass pastures are used.
Quantification of Growth Drought Tolerance and Avoidance of Blue Grama Seedlings1
Authors: Wilson A. M. , Sarles J. A. 
Published: July 2010

AbstractPlanting failures with blue grama [Bouteloua gracilis (HBK.) Lag.] prompted the investigation of relationships between physiological and morphological traits and seedling drought resistance. The objectives of this study were to quantify the tolerance and avoidance components of growth drought resistance, determine the conditions under which measurements should be made, and assess the variability among seedlings in characteristics that contribute to drought resistance. Blue grama seedlings were restricted to the seminal primary root, irrigated to maintain favorable soil moisture conditions, and retained in plant growth chambers at either a low or a high relative humidity. When leaf area had increased to the maximum that could be supported by water from the root, tiller water potential was determined for a quantification of growth drought tolerance; and total leaf diffusion resistance, water uptake, and green leaf‐blade area were determined for a quantification of growth drought avoidance. Growth drought tolerance, defined as the plant drought that is just sufficient to halt the increase of seedling leaf area, varied among seedlings from about −20 to −40 bars. Growth drought avoidance, defined as the difference between plant drought and the drought of the shoot environment, is related to total leaf diffusion resistance, maximum capacity for water uptake, and seedling leaf area. Estimates of total leaf diffusion resistance varied among seedlings from 6 to 23 sec cm−1 and maximum rates of water uptake varied from 1 to 8 g day−1. Differences among accessions in capacity for water uptake suggest that improvements might be made in a plant breeding program. Additional work is needed to determine whether drought tolerance and total leaf diffusion resistance are heritable traits. The concept of growth drought resistance is particularly useful because it can be quantified for individual seedlings.
Relationships Between B Deficiency Symptoms in Sunflowers and the B and Ca/B Status of Plant Tissues1
Authors: Blamey F. P. C. , Mould Diana , Nathanson K. 
Published: July 2010

AbstractSunflowers (Helianthus annuus L.) have an apparently high boron requirement but little information exists on the quantity of B necessary in plant tissues, particularly in a field‐grown crop. ‘Smena’ sunflowers grown in a field trial on an Avalon medium sandy loam (an Ultisol) showed symptoms of B deficiency in the absence of B fertilization, the most severe symptom being a malformation of the capitulum at anthesis which led to areas of no seed set. Since this symptom was apparently related to the reduced seed yield of the B deficient plants, the aim of this study was to establish relationships between the percentage deformed heads and the B concentrations and Ca/B ratios in three plant tissues, viz (i) month‐old seedlings, (ii) the topmost, mature leaf at flowering, and (iii) the seed. The mathematical relationship of best fit was established as that which minimized the residual sum of squares and maximized the correlation coefficient. In general, the B concentration proved superior to the Ca/B ratio as a measure of the status of B nutrition of the plant. Critical B concentrations, below which B deficiency symptoms increased markedly in severity and corresponding to 5% deformed heads, were calculated as 61 ppm in seedlings, 57 ppm in the leaf, and 17 ppm in the seed. It was estimated that on this soil type 1 kg borax/hit would, on average, increase the B concentration by 2 ppm, 3 ppm, and 0.2 ppm in these three tissues, respectively. The seedlings and the topmost, mature leaf at flowering provided reliable estimates of the B nutritional status of sunflowers in this study but the use of seed as an index tissue overestimated the B fertilizer requirements.
A Method for Taking Small Monoliths for Plant Root Studies1
Authors: Kauffman M. D. , Gardner E. H. 
Published: July 2010

AbstractObservations of plant root growth can be important in studies involving soil‐plant relationships. A simple method for removing and exposing plant root systems was developed to study the effect of lime treatments on the root growth of alfalfa (Medicago sativa L.) and wheat (Triticum aestivum L.). A chain saw was used to remove monoliths containing partial root systems and the soil was removed from the root systems using a washing technique which consisted of a detergent pre‐treatment and subsequent oscillation of the monolith in a water bath. The monolith was mounted on a grid of nails to reduce displacement of the root system during the washing process. Using this procedure the effects of lime treatments on root growth were observed.
Cottonseed Vigor Related to Harvest and Ginning Date1
Authors: Buxton D. R. , Patterson L. L. , Taylor B. B. 
Published: July 2010

AbstractWe previously reported large variation in field emergence of commercially processed cottonseed (Gossypium barbadense L.) produced within a small geographical area of Arizona. The current investigation was conducted to determine if there were important management practices associated with the variation in seed vigor. An examination of the seed in question showed that much of the variation was associated with date of ginning and harvesting. Seed ginned after November were generally of low quality for planting purposes. To determine if low quality of late‐ginned seed cotton was associated with field weathering and/or the contribution of low quality seed in late matured bolls, open bolls of ‘Pima S‐5’ (G. barbadense) and ‘Deltapine 61’ (G. hirsutum L.) were harvested periodically during two autumns. The bolls were either exposed to various lengths of field weathering or had matured at different times during the harvest period. The seed was evaluated the following spring for germination, field emergence, and plant growth. Date of maturity had a greater effect on seed vigor than field weathering although both generally caused significant effects. Seed germination and emergence were influenced to a greater extent than plant height taken in the early summer or the date of initial flowering. Although the effect of date of maturity was greater than that of field weathering, the latter would be expected to affect a greater quantity of seed. This study stresses the importance of timely harvesting in order to obtain high quality planting seed.
Comparative Pre‐floral Growth of Flue‐cured Tobacco in Field and Controlled Environments1
Authors: Flynt Robin W. , Raper C. David , York Emory K. 
Published: July 2010

AbstractThe use of controlled‐environment facilities in agronomic research has raised questions about the comparability of plant growth in controlled and field environments. The objective of this study was to compare leaf area, leaf and stem dry weights, and stem height at several intervals during the exponential growth phase of tobacco plants (Nicotiana tabacum L. ‘NC 2326’) in field and phytotron environments. Since photosynthetically active radiation (PAR) in growth rooms usually is less than occurs in the field, the study included a range of accumulated daily PAR of 11.4, 17.9, and 25.0 E m−2day−1 in the growth rooms and 24.9 and 42.2 E m−2day−1 in the field. The lower PAR in the field was obtained by shading with open mesh fabric. For each PAR level in the growth rooms, plants were grown at day/night temperatures of 22/18 and 26/22 C.In the growth rooms, there was not an interaction between PAR and temperature on growth characteristics. During the exponential growth phase, there was little difference between PAR levels of 17.9 and 25.0 E m−2day−1 in growth characteristics measured at the five individual sample dates or relative growth rate (RGR) and relative leaf area growth rate (RLGR) calculated over all sampling dates. There was a consistent reduction in growth when PAR was reduced to 11.4 E m−2day−1, although the differences were seldom significant.In the comparisons of leaf weight and area growth between field and phytotron‐grown plants, growth of leaves was generally enhanced, though usually not to significant levels, for full sunlight. However, growth at the maximum growth room PAR of 25.0 E m−2day−1 tended to be greater than at 24.9 E m−2day−1 for the shaded field plots. Leaf growth at the lowest growth room PAR of 11.4 E m−2day−1 was nearly identical to that in the shaded plots. This apparent inefficiency of PAR utilization in field plots is postulated, on the basis of other experimentation, to be due to the seasonal pattern of temperature variations in the field rather than to a difference in the quality of light between field and phytotron. Stem height increased in the growth rooms at nearly twice the rate as in the field, regardless of PAR level. This difference in growth also is postulated to be the result of the temperature variations in the field.
A Methodology for Testing the Accuracy of Yield Predictions from Weather‐Yield Regression Models for Corn1
Authors: Nelson William L. , Dale Robert F. 
Published: July 2010

AbstractReliable crop‐weather‐technology models are needed for yield prediction and for the determination of climatic risks in crop production. Accurate and timely assessment of crop yields would help both government and industry allocate the food supply more efficiently. Analysis of variance (ANOVA) techniques were used to evaluate the accuracy of yield predictions for corn (Zea mays L.) in Indiana counties with four statistical models: 1) Thompson approach 2) modified Thompson approach, with a nitrogen technology term, 3) a 1974 model by Leeper, Runge, and Walker and 4) a 1975 model by Dale and Hodges. For models 1), 2), and 4), separate versions were developed with the particular series of weather and corn yield data for each county. All models were used to predict yearly average corn yields for a county with data not used to fit the regression coefficients. A significant difference among models was detected by the ANOVA. Multiple comparison tests indicated that regression models 2), 3), and 4) were more accurate than model 1). This result was attributed mainly to the handling of technology or the weather‐technology interaction effects on corn yields. The trend variables used in model 1) acted to confound weather and technology effects and create unstable regression models. Although the direct application of the results of this study is limited to Indiana, the general regression problems and methodology for testing regression models for their accuracyin predicting crop yields are believed to have universal application.
Seed Yields of Meadowfoam as Influenced by N, Seeding Rates, and Soil‐Water Table Levels1
Authors: Calhoun Wheeler , Crane J. M. 
Published: July 2010

AbstractThe vegetable oil from meadowfoam, Limnanthes alba var. alba, promises to be an agronomic source of several unique long‐chain fatty acids needed by industry. Studies were made on N fertility, seeding rates, and soilwater levels to determine those cultural practices necessary to maximize the production of oil bearing seeds of meadowfoam. The treatments for N fertilizer experiments consisted of two sources of N, ammonium sulfate and ammonium nitrate, and two rates for each source of N at 56 and 112 kg/ha. Seeding rates of 11.2, 22.4, 33.6, and 44.8 kg/ha were used in the seeding rate experiment. The soil‐water levels used were no drainage, soil‐water level maintained at 30.5 cm, and soil‐water level maintained at 61 cm below the soil surface, by creating hydraulically isolated soil plots. The soils used were Typic Ochraqualfs (Dayton) and Typic Olbaqualf (Concord). Seed from meadowfoam plots for all experiments was harvested with a Hege 125 self‐propelled plot combine.The addition of N increased total seed yields. The use of ammonium sulfate as an N source as compared to ammonium nitrate depressed seed yields. A seeding rate of 33.6 kg/ha in drill rows 15‐cm apart produced highest seed yields. Lowering of soil‐water levels in soils with low permeability rates did not improve seed yields. This study indicates that meadowfoam has the potential for commercial production on poorly drained wet soils in high winter rainfall areas of Oregon.
N Losses in Irrigation Return Flows from Flooded Rice Plots Fertilized with Ammonium Sulfate1,2
Authors: Bilal I. M. , Henderson D. W. , Tanji K. K. 
Published: July 2010

AbstractLosses of N from fertilized croplands are of concern from standpoints of fertilizer use efficiency as well as potential water pollution. Field experiments were conducted to evaluate the discharge of inorganic N in surface irrigation runoff and seepage in 7.6 ✕ 67 m test plots cropped with paddy rice (Oryza sativa L., cultivar Earlirose). Cultural practices commonly used in rice production in California were imposed on three plots and extensively monitored from planting to harvest. Plots 1 and 2 were continuously flooded throughout the growing season while Plot 3 was oncedrained in the 5th week after planting for a 1‐week period. Granular (NH4)2SO4 was applied at a rate of 168 kg N/ha to all plots but the mode of application and timing differed. In Plot 1 the fertilizer was partly soil‐incorporated and partly soilbroadcast before seeding and flooding. In Plots 2 and 3, 112 kg N/ha was soil‐incorporated before planting and 56 kg N/ha was top‐dressed in the floodwater in the 6th week after planting.The seasonal water application varied from 454 to 530 cm of which 104 cm was lost as evapotranspiration, 204 to 219 cm as surface runoff, and, by difference, 128 to 222 un as seepage losses. The total seasonal losses of N from both the irrigation runoff and seepage were 18.6, 36.4. and 30.2 kg N/ha for Plots 1, 2, and 3 or 11, 22 and 18% of the applied fertilizer, respectively. The seep age losses were 45, 61, and 70% of the total seasonal N losses in Plots 1, 2, and 3, respectively