bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Soil Temperature on Rhizobium japonicum Serogroup Distribution in Soybean Nodules1
Authors: Weber D. F. , Miller V. L. 
Published: July 2010

AbstractStudies were conducted to determine if temperature, as suggested in a previous study, influenced the distribution of serogroups in nodules of soybeans grown in these same soils. The soybean variety ‘Lee’ was grown at constant soil temperatures of 10, 20 and 30 C and 15, 20, 25 and 30 C, respectively, in two greenhouse experiments. Codorus silt loam containing an established population of Rhizobium japonicum was taken from sites of a previous date of planting study and incubated for one week at the desired temperature before uninoculated seed was planted.Plant growth characteristics, nodulation and distribution of R. japonicum serogroups in the nodules were recorded. Plant development and nodulation generally were favored by increasing temperatures with 30 C the most favorable temperature for all characteristics except nodule size.Serological distribution of R. japonicum in the nodules was influenced by soil temperature. Serogroups which were infrequently recovered at the lower temperatures became dominant at 30 C whereas serogroups forming the majority of nodules at 10 or 15 C formed fewer nodules at 30 C. Leaf chlorosis which is induced by R. japonicum serogroup 94 was evident only at 30 C where its incidence in the nodules was highest.
Herbicidal Effects on the Nodulation of Glycine Max (L.) Merrill1
Authors: Dunigan Edward P. , Frey J. Patrick , Allen L. D. , McMahon Aithel 
Published: July 2010

AbstractNodulation of legumes is one of the processes in the soil that is liable to be adversely affected by the application of herbicides. This investigation was conducted in a greenhouse and in the field to determine what effects selected pre‐ and post‐emergence herbicides had on total number, dry weight, fresh volume, and Fe content of nodules formed on soybeans [Glycine max (L.) Merrill]. Five soils were employed in greenhouse experiments. Several rates of seven herbicides were surface‐applied to the air‐dried, soils in pots at planting and each pot was watered immediately. After 5 to 7 weeks of growth the roots were carefully isolated from the soil, the nodules were removed, and the total number and dry weight of the nodules were determined. Analyses of the results indicated that different rates of several of the herbicides had detrimental effects on the nodulation process in four of the five soils used. Dry weight was more readily affected than was total number of nodules. With three of the soils, analyses were made to determine the effects of the herbicides on tap‐root and lateral‐root nodulation. Adverse effects were found at both sites with the greater sensitivity being noted on the tap‐root nodules. Field studies were conducted for 3 years on an Olivier silt loam soil using both pre‐ and post‐emergence herbicides. Plants were excavated from the soil after 8 to 12 weeks of growth and the nodules were removed from the roots. Analyses of the data obtained from determining both the dry weight and the Fe content of the nodules did not reveal any detrimental effects from any of the herbicides used.
Effect of Hormone‐Directed Presoaking on Emergence and Growth of Osmotically Stressed Wheat (Triticum aestivum L.) Seeds
Authors: Darra B. L. , Seth S. P. , Singh Harvinder , Mendiratta R. S. 
Published: July 2010

AbstractThe water potential gradient between a planted seed and the surrounding soil largely controls water absorption by the seed. Salinity of soil water affects this balance, which in turn lowers germination and seedling growth. Overcoming the inhibition of water intake by presoaking and the use of auxins and gibberellins has been shown to be advantageous for certain crops,but studies with wheat are limited. This approach constitutes the objectives of this investigation.The effects of presoaking wheat seeds in 10, 20, 50, and 100 ppm each of GA, IBA, IAA, and NAA at O, 3, 6, and 9 atm osmotic pressure on seedling development were observed. Auxins had little influence on emergence at 0 atm but promoted emergence at 3, 6, and 9 atm. Three‐indole acetic acid (IAA) and α — naphthalene acetic acid (NAA) at 50 ppm produced maximum shoot length, whereas gibberellic acid (GA) and three‐indole‐butyric acid (IBA) gave better results at 100 ppm. Increased concentrations of GA and NAA significantly reduced primary root length, whereas IAA increased root length. All hormones increased proliferation of lateral roots, but auxins produced more lateral roots at all salinity levels. Root/shoot ratio was decreased by NAA and GA. Water absorption was increased by all treatments. IAA and NAA at 50 ppm gave the better results. The data support the hypothesis that the beneficial effects of hormones may be the result of increased water absorption, which improves plant growth even under high salt concentrations in the growth medium.
Nitrogen and Boron Effects on Protein and Oil of Corn Grain
Authors: Jellum M. D. , Boswell F. C. , Young C. T. 
Published: July 2010

AbstractThis study was conducted to determine the effect of nitrogen and boron on protein and oil percentages and fatty acid composition of corn (Zea mays L.) grain. In one study, two rates (90 and 180 kg/ha) of nitrogen, two periods (December and preplant), with and without a nitrification inhibitor were applied to corn on a Norfolk loamy sand soil in the Coastal Plain region of Georgia. In a second study, three rates (0.28, 0.56, and 1.12 kg/ha) of boron were applied to the same soil as for study one. Check plots with no treatment were included in each experiment. Grain samples from each plot were analyzed for protein and oil percent by standard A.O.A.C. methods and the fatty acid composition of oil was determined by gas‐liquid chromatography. Protein percent increased with increasing rates of N without any effects from time of application or of the nitrification inhibitor. Nitrogen had no effect on oil percent or oil composition. Boron fertilization had no effect on any of the chemical characters measured in this study.
Water Loss from an Irrigated Sorghum Field: I. Water Flux within and below the Root Zone1
Authors: Stone L. R. , Horton M. L. , Olson T. C. 
Published: July 2010

AbstractKnowledge of actual water movement within field soil profiles under cropped conditions is important in aiding our understanding of water supply to plants and movement of water soluble fertilizers and pesticides. This work was done to evaluate water movement within and below the root zone of a sorghum (Sorghum bicolor (L.) Moench) crop during a 31‐day field study following water application. Hydraulic potential data from tensiometers placed at eight depths in the soil profile were used to determine the hydraulic gradients. Soil water flux in various depth layers was calculated using the hydraulic potential gradients and the determined hydraulic conductivity vs soil water content relationships. Upward water movement commenced in the 15 to 30 cm layer 3 days foflowing water application and 130 to 150 cm layer after 19 days. The upward water flux into the root zone reached a maximum of approximately 0.2 cm/day near the end of the study period. During the 31‐day study period, 6.0 cm of water were lost from the 150 cm soil profile by flux below the root zone. This illustrates the importance of considering water loss due to flux below the root zone in crop situations.
Drought‐Affected Mitochondrial Processes as Related to Tissue and Whole Plant Responses1
Authors: Koeppe D. E. , Miller Raymond J. , Bell David T. 
Published: July 2010

AbstractThe purpose of this study was to correlate the respiratory rates of whole seedlings, excised shoots, and isolated mitochondria of Zea mays L. (Wf9 ✕ M14) water stressed to various degrees. Drought stress was imposed by two different methods and monitored with a Peltier psychrometer. Respiration was determined in whole plants with an infrared gas analyzer and in excised shoots and mitochrondrial suspensions with an oxygen electrode. Substrate oxidation rates by mitochondria isolated from water‐stressed tissue decreased with increased stress. Similar decreased respiration rates were observed with excised shoots and whole seedlings when stressed on paper toweling. When the seedlings were stressed with carbowax 6000 in vermiculite, the respiration of excised shoots increased to a potential of about —16 bars and then decreased as stress was increased. The water content of these seedlings also appeared to increase and then decrease in a manner analogous to respiration. When water stress was alleviated by rewatering, the seedling water potentials soon returned to prestress levels in all but severely stressed samples. Respiration rates of excised shoots and mitochondrial suspensions and mitochondrial swelling‐contraction responses recovered more slowly. The results showed that in vitro mitochondrial processes were altered by water stress and that these alterations persist even when the mitochondria were isolated from the growing tissue. These results suggest that the decrease in the rate of whole plant respiration with increased stress may be due to membrane alterations that effect the ability of mitochondria to oxidize substrate.
Time Constants for Thermal Equilibration of Leaf, Canopy, and Soil Surfaces with Change in Insolation1
Authors: Wiegand C. L. , Swanson W. A. 
Published: July 2010

AbstractExperiments were conducted to determine the time constant for thermal equilibration of a cotton (Gossypium hirsutum L.) plant leaf, the plant canopy, and a soil surface with a change in incident solar radiation (insolation). The time course of surface temperatures sensed by portable radiation thermometers during periods of full sun and artificial shading were the data obtained. The plant leaf and the canopy equilibrated in 40 seconds to 1 minute, but the soil required more than 10 minutes. These results have important implications in interpreting airborne thermal scanner data obtained under partly cloudy sky conditions.
Protein Content of Winter Wheat in Relation to Rate and Time of Nitrogen Fertilizer Application1
Authors: Hunter Albert S. , Stanford George 
Published: July 2010

AbstractThe effects of N fertilization in the northeastern states on percent protein in soft winter wheat (Triticum aestivum L.) need to be evaluated in relation to time and rate of application and variety as a basis for developing practices that achieve the desired range in wheat protein.Fall and spring applications of different N rates to ‘Blueboy’ and ‘Redcoat’ varieties of soft winter wheat were compared at five locations on limestone‐derived Pennsylvania soils. Average protein contents were increased from 10.9!)% with no N applied to 14.3% with N fertilizer. The optimum rate of N for maximum grain yield often resulted in higher protein content than is considered desirable in grain used for pastry making. Under comparable conditions, the average protein contents of Redcoat and Blueboy wheats, respectively, were 13.3 and 11.8%. Spring application consistently gave higher protein contents than fall application, although the average difference was small (0.6%).Yields of protein were higher for Blueboy than for Redcoat, despite higher percent protein in the latter, because grain yields of Blueboy were substantially greater than yields of Redcoat. The importance of soil N as a source of N in these experiments was illustrated by the significant correlation that existed between relative N mineralization rates of soils from zero‐N plots and corresponding protein yields.
Effect of Temperature and Plant Water Stress on Photosynthesis, Diffusion Resistance, and Leaf Water Potential in Spring Wheat1
Authors: Frank A. B. , Power J. F. , Willis W. O. 
Published: July 2010

AbstractPlants growing under field conditions are usually subjected to varying degrees of water stress, but the effect of temperature on the development of plant water stress and subsequent recovery is not well‐known. Therefore, a study was conducted in growth chambers to determine the combined effects of temperature and soil water supply on the development of plant water stress and subsequent recovery in spring wheat (Triticum aestivum L. ‘Waldron’). Measurements were made of leaf water potential, photosynthesis, and stomatal diffusion resistance on the fifth leaf at tillering and the flag leaf at heading, flowering, and grain‐filling growth stages for plants grown at 10, 18, and 27C. Stomatal closure of stressed plants was affected by both leaf position and age. Closure occurred at −13, −13, and −15 bars leaf water potential at tillering and at −18, −17, and −26 bars at heading for 10, 18, and 27C, respectively. As the flag leaf matured, stomata closed at progressively lower leaf water potential. In nonstressed check plants, temperature greatly influenced leaf water potentials. At heading, plants at 10C had a significantly lower leaf water potential than plants at 18 and 27C, probably resulting from chill‐induced water stress caused by increased internal resistance to water movement in the plant. At 18C, leaf water potential at tillering and at heading recovered to prestress levels 6 hours after stress ceased, but not until after 48 hours at the grain‐filling stage. Stomatal diffusion resistance recovered to prestress levels within 2 hours, except at grain‐filling, when recovery was incomplete after 48 hours. Recovery of photosynthesis was related to recovery of stomatal diffusion resistance at tillering and heading, except that photosynthesis never fully recovered to prestress levels, and photosynthesis of plants stressed at grainfilling showed no sign of recovery due to stress‐induced senescence.
Determination of Wheat Growth‐Environment Relationships1
Authors: Haun J. R. 
Published: July 2010

AbstractWheat (Triticum aestivum L. em. Thell.) growth data were obtained from field plantings in North Dakota by observing morphological development at intervals of 1 to several days. The system of observation was based on rate of production of leaves and other plant parts. The emergence of each leaf or other unit was subdivided into appropriate decimal divisions. The rate of development was determined by subtraction of the previous day's observation from the current observation of morphological development.Environmental data collected in the vicinity of the plants included solar radiation, maximum and minimum air temperature, maximum and minimum soil temperature, rainfall, soil moisture, and evaporation. The status of soil moisture was also estimated by the Thornthwaite‐Mather method. In subsequent statistical analyses, environmental data were evaluated with respect to their current effects as well as to the delayed or lagged effects for each of the 4 days prior to growth observations. These variables were used in their original form and also transformed into the square, cube, and selected cross products of important variables to account for curvilinear effects and interactions of various environmental factors. Daily growth rate was used as the dependent variable; age, cumulative development, and environmental data, with appropriate lags and transformations, were used as independent variables. Multiple regression analyses were conducted to determine the overall relationship of the various environmental factors to growth rate. A prediction equation was obtained.The objective of this research was to determine whether data from daily visual quantification of wheat development could be related to variations in the major environmental variables. Daily growth rates for 1966, predicted by the equation obtained from analysis of 1967 data, were in close agreement with observed growth rates. Due to the complex interrrlationships of environmental factors, the 13 independent variables of this equation are not necessarily an exclusive or unique expression of the environment. However, tests of significance and tests of the prediction equation on unrelated data indicated that quantitative morphological observations may provide a potent dependent variable for relating plant growth to environmental factors.
Response of Nodulating and Nonnodulating Soybeans to a Species of Endogone Mycorrhiza1
Authors: Schenck N. C. , Hinson K. 
Published: July 2010

AbstractOur purpose was to determine the effect of an Endogone endomycorrhizal fungus on nodulating and nonnodulating isolines of ‘Hardee’ soybeans (Glycine max (L.) Merr.) growing in methyl bromide‐fumigated soil in the field. Inoculation with Endogone significantly increased seed yield and other traits of the nodulating but not the nonnodulating isoline. Indirect evidence suggested Endogone did not significantly increase nitrogen absorption of the nonnodulating isoline.
Influence of Soil Water Status and Meteorological Conditions on Evaporation from a Corn Canopy1
Authors: Ritchie J. T. 
Published: July 2010

AbstractIn predicting evaporation rates for field crops, it is important to consider the influence of soil water status on the actual evaporation rate relative to the potential rate. This study was conducted to determine actual evaporation rates of corn (Zea mays L.) as influenced by soil water status and potential evaporation rate. Actual evaporation rates were measured during the 1972 growing season with a weighing lysimeter. Evaporation rates were found to be practically independent of the soil water status for all existing conditions of potential evaporation. During the season more than 20 cm of soil water was removed from the 120‐cm deep profile.Leaf diffusion resistance and leaf water potential measurements indicated that at least 80% of the extractable soil water was freely available to plant roots. These findings differ from those of Denmead and Shaw (Agron J. 54:385–390, 1962) who found that evaporation reduction in container grown corn plants started when about 20% of the extractable water was removed from the soil for potential evaporation rates above 6 mm/day. The difference between the results from the experiment reported by Denmead and Shaw and this experiment point out that serious errors are possible when using their results for predicting evaporation from corn plants growing under field conditions.
Influence of Potassium Nutrition on Net CO2 Uptake and Growth in Maize (Zea mays L.)1
Authors: Estes G. O. , Koch D. W. , Bruetsch T. F. 
Published: July 2010

AbstractA heavy dependence on K fertilization in the northeastern U. S. coupled with the luxury accumulation of this element in plants suggest a need for further research. The objective of this greenhouse experiment was to relate CO2 uptake, determined by a radioactive carbon method, and yield of maize (Zea mays L., var. Wisconsin 335A') with K concentration and content of tissue. Plants were grown at substrate levels of K from O to 9 mM/liter of K in hydroponic culture.A significant correlation existed between both concentration and content of K and dry weight of plants. There was a curvilinear relationship between both leaf (youngest fully expanded) and plant K percentage and net CO2 uptake. Leaf content of K between 0.75 and 1.0% was considered critical (42‐day‐old maize) because CO2 fixation was seriously reduced at lower concentrations. There was a close agreement between CO2 assimilation and dry weight over the range in substrate K concentrations, .50 to 9.0 mM/liter. An increase in dry weight at the K level of 0.25 mM/liter was not accompanied by an increase in CO2 fixation. Uptake of CO2 increased nearly 60% between K concentrations of 0.25 and 0.50 mM/liter but at a much slower rate between 0.50 and 9.0 mM/liter.
Relationship of Sericea Lespedeza Leaf and Stem Tannin to Forage Quality1
Authors: Donnelly E. D. , Anthony W. B. 
Published: July 2010

AbstractThe leaves of sericea lespedeza (Lespedeza cuneata [Dumont] G. Don) have been found to contain more tannin than stems. Tannin has been found to reduce digestible dry matter (DDM) of sericea and digestibility of crude protein. An experiment was conducted to study quality of high and low‐tannin sericea leaves and stems separately. Low‐tannin sericea leaves averaged 20 percentage points higher in DDM than high‐tannin leaves, and 19 percentage points higher than low‐tannin stems as indicated by the in vivo nylon bag method. The DDM of low‐tannin stems was as high as that of high‐tannin leaves. High‐tannin leaves averaged only slightly higher in DDM than stems of high‐tannin plants. Tannin in both leaves and stems of the high and low‐tannin groups was negatively associated with crude protein. Data indicate that lowering the tannin content of sericea by breeding increases both the percentage and digestibility of crude protein. Much improvement in sericea forage quality can be made by breeding for low‐tannin and high leaf percentage.
Model of Light Penetration into a Wide‐Row Crop1
Authors: Allen L. H. 
Published: July 2010

AbstractThis model predicts direct‐beam radiation penetration into wide‐row crops. The crop is modeled as “hedgerows” with an open middle between the rows. Leaf area density is given height and cross‐row functional distributions, but is considered uniform along the length of the row. Input parameters which can be varied are: time of day, time of year, latitude, longitude, atmospheric trans‐missivity, slope of the soil surface, row direction, row spacing, crop height, width of the hedge‐row, leaf area density distribution functions, and mean leaf angle. The model can predict the average direct‐beam penetration to any depth as a function of distance from the row, and the average penetration for the whole hedge‐row system. Light penetration was predicted for E‐W, N‐S, NE‐SW, and NW‐SE row orientations for August 17, 1967, using row geometry of E‐W wide‐row grain sorghum (Sorghum bicolor L. Moench) grown at Akron, Colorado. Low predictions of light interception in the morning and afternoon by E‐W rows resulted in the lowest predictions of daily total intercepted light. Under the input conditions, the model predicted 37, 44, 42, and 42% daily interception for E‐W, N‐S, NE‐SW, and NW‐SE row orientations, respectively. The NE‐SW row orientation may be best since the model predicted that the most light would be absorbed at 1000 hours, when moisture stress would be low, and the least at 1400 hours, when moisture stress would be high.
Comparison of Ethanol‐Extracted and Unextracted Crownvetch Forage Fed to Weanling Meadow Voles1
Authors: Barnes R. F. , Fissel G. W. , Shenk J. S. 
Published: July 2010

AbstractThe potential effects of adverse constituents in crownvetch (Coronilla varia L.) forage on animal response were assessed using the weanling meadow vole (Microtus pennsylvanicus) as the test animal. ‘Chemung, ’ ‘Emerald,’ and ‘Penngift’ crownvetch were harvested at the early‐bud and late seed‐set stages during two growing seasons. Crownvetch forage extracted with ethanol and unextracted forage were incorporated into diets supplemented with adequate levels of protein, carbohydrate, vitamins, and minerals and fed to weanling meadow voles. Of 72 voles fed unextracted crownvetch diets, 46 died within 6 days, and most of the remaining voles lost weight. Deaths and weight losses were greatest on the mature crownvetch diets, with more deaths occurring from the 1969‐harvested forage than from that of 1971. The deleterious substance was apparently removed by ethanol extraction of the forage as shown by the death of voles fed control diets to which the ethanol extract was added. Weight gains and dry matter consumption of voles fed diets prepared with ethanol‐extracted forage were equivalent to those of the voles fed control diets containing purified cellulose.