bluuebunny/crossref_metadata_2025_split huggingface dataset:
Response of Wheat Cultivars to Liming in Some High Al Oxisols of Rio Grande do Sul, Brazil1
Authors: Martini J. A. , Kochhann R. A. , Gomes E. P. , Langer F. 
Published: July 2010

AbstractThe objective of this field study was to determine the yield response of wheat (Triticum aestivum L.) to the direct and residual effects of liming in relation to variety, soil acidity, Al toxicity, P availability, and disease incidence in five Oxisols of Rio Grande do Sul, Brazil under successive wheat‐soybean (Glycine max L. Merrill) cropping.This work was carried out under field conditions using various limestone treatments arranged in a randomized block design and replicated four times. Plots were 6 m long ✕ 2.4 m wide with 12 rows planted 20 cm apart at the rate of 90 kg/ha. The soils used in this investigation were in the suborder Udox.While Brazilian wheat varieties developed under acid soil conditions tended not to respond to liming due to their tolerance to exchangeable Al and possibly Mn, wheat varieties from other countries, developed under less acid soil conditions, did respond significantly to liming because of their susceptibility to soil Al and possibly Mn. Some Brazilian wheat varieties did respond to liming under high soil acidity and exchangeable Al levels. Liming to bring soil pH between 4.8 and 5.7 and reduce toxic Al levels below 1.5 meq/100 g was a more valid criterion than raising soil pH to neutrality in order to maximize yields. Liming to pH 5.7 or higher increased the incidence of Ophiobolus graminis and a soil‐borne mosaic.
Influence of Management and Season on Fate of N Applied to Golf Greens1
Authors: Brown K. W. , Duble R. L. , Thomas J. C. 
Published: July 2010

AbstractBecause golf greens are constructed of very sandy soil mixtures over a gravel and tile drainage system and subjected to heavy irrigation schedules, there is a high potential for loss of applied N through leaching. This study was undertaken to determine the influence of management practices during different seasons on the fate of N applied to golf greens. Small isolated golf greens (3 m on a side) were constructed according to USGA specifications and equipped with drainage and runoff collection systems. Mixtures of sand and Houston black clay soil (Udic Pellusterts) were used in some plots while others were made of a Tabor sandy loam soil (Udertic Paleustales). All plots were planted with Tifdwarf Bermudagrass (Cynodon dactylon L). N sources were applied at various rates during different seasons. The golf greens were irrigated at three different rates. Leachate and runoff samples were analyzed for NO3 to evaluate the influence of management practices on N losses from the golf greens. The results show that N losses and concentrations of NO3 in the leachate immediately after application of soluble sources were a function of the rate of N and water applied. When the irrigation rate was kept at or near the evapotranspiration rate, the loss of NO3 from inorganic soluble sources was minimized. The irrigation rate did not affect the NO3 losses from organic sources. Seasonal studies indicated that losses and concentrations of NO3 were highest in winter. This appeared to be associated with the large volume of water which leached from the plots during the season. It was concluded that N losses and NO3 concentrations could be lowered by: using organic sources of N; reducing irrigation rates to equal the evapotranspiration rate; and decreasing fertilizer rates during periods of slow growth.
Evaluation of Seed Treatments to Enhance Pima Cotton Seedling Emergence1
Authors: Buxton D. R. , Melick P. J. , Patterson L. L. , Godinez C. A. 
Published: July 2010

AbstractPrevious research has shown that germination of cottonseed (Gossypium spp.) can be improved during low temperature by treating seed with gibberellic acid (GA3), kinetin, or by elevating the seed moisture level. The work reported here was conducted to evaluate these seed treatments as aids to improving seed germination of G. barbadense L. (‘Pima S‐4’) and to determine if they enhance seedling emergence in fields with low soil temperatures. Soaking seed in water for 6 hours before chilling at 5 C significantly reduced visual chilling injury. Both kinetin and GA had little effect on % germination, but vigor of germinating seed was increased in the laboratory when seed were soaked for 3 hours in 0.1 or 1.0 mg/liter kinetin, or 100 or 500 mg/liter GA.When similar seed treatments were evaluated in several field plantings with low soil temperatures, neither chemical improved the number of seedlings emerged or the time required for emergence. GA at the level that promoted seed vigor in the laboratory resulted in greatly reduced emergence because of spindly growth. Soaking seed in water before planting generally reduced emergence with the degee of reduction directly related to length of soaking. Seed that were soaked for 3 hours showed abnormal development of cotyledons and reduced dry wt. compared to nonsoaked seed. Thus these seed treatments cannot be recommended as aids to enhance Pima cotton seedlings emergence.
Regulation of Grain Yield by Photosynthesis in Maize Subjected to a Water Deficiency1
Authors: McPherson H. G. , Boyer J. S. 
Published: July 2010

AbstractSince the physiological mechanisms responsible for yield losses under dry conditions are unknown, especially for grain crops, we attempted to identify them in maize (Zea mays L.) subjected” to a water deficiency during most of the grain filling period. The plants were grown in a controlled environment capable of providing yields comparable to the field. Grain yield, dry weights of shoots and roots, apparent photosynthesis, and leaf water potentials (Ψw) were determined. Shortly after tasseling, water was withheld from the soil of half the plants until Ψw had decreased to —18 to —20 bars, where Ψw remained until maturity. Apparent photosynthesis became virtually zero at these Ψw. However, grain yield was 47 to 69% of the control yield. At low Ψw, the grain developed partly at the expense of photosynthate accumulated prior to the desiccation period. Since grain development is dependent entirely on translocation in maize, this indicated that translocation continued despite the cessation of apparent photosynthesis. The parameter most closely related to yield was dry matter accumulated during the entire growing season rather than that accumulated during grain fill alone. We conclude that translocation it less inhibited than photosynthesis during drought, and that the total photosynthetic accumulation for the growing season controls yield during a drought that does not disrupt the flowering process.
Effects of Snowmobile Traffic on Several Forage Species and Winter Wheat1
Authors: Ryerson D. K. , Schlough D. A. , Foresman C. L. , Tenpas G. H. , Pendleton J. W. 
Published: July 2010

AbstractExperiments to determine the effects of snowmobile traffic on plant species, frequently grown in heavy snow‐belt regions, were conducted over 3 years in northern Wisconsin. Plant species tested during the trials were: alfalfa (Medicago sativa L.); birdsfoot trefoil (Lotus corniculatus L.); red clover (Trifolium pratense L.); bromegrass (Bromus inermis Leyss.); orchardgrass (Dactylis glomerata L.); and winter wheat (Triticum aestivum L,). The soil is classified as a Typic Eutroboralf, very fine Illitic (mixed). Designated areas of each crop species received varying amounts of snowmobile traffic when snow depths were > 7.5 cm. Soil temperatures, snow compaction, and frost depths were measured. Forage dry matter or grain yields were taken during the following summer. Soil bulk density was determined during two growing seasons as a measure of soil compaction.Stands of alfalfa, birdsfoot trefoil, and alfalfa/bromegrass treated for two winters with snowmobile traffic showed no detrimental effects on forage yield. Grain yields from winter wheat stands exposed to snowmobile traffic were not reduced below that of check areas. Red clover and birdsfoot trefoil/orchardgrass yields were decreased during 1 year of the trials but were unaffected by snowmobile traffic during 1 other year.Snow was found to be compacted by snowmobile traffic and soil temperatures colder and more erratic under these areas. Frost penetrated deeper under areas subjected to snowmobile traffic. Soil compaction was not found to be increased by snowmobile traffic.
Estimation of Individual and Total Leaf Areas of Safflowers1
Authors: Sepaskhah A. R. 
Published: July 2010

AbstractThe rapid, nondestructive, and relatively accurate measurement of safflower (Carthamus tinctorius L.) leaf area for physiological and agronomic studies is important. Regression analysis of measurements of leaf length and width were used to develop prediction equations involving three independent variables for estimating individual and total leaf area. Leaf area of plants grown in greenhouse conditions was measured by an optical planimeter. Statistical analysis revealed that a common prediction equation should not be used for both local and non‐local cultivars.Prediction equations derived from independent variables involving length ✕ width (LW), length squared (L2), or width squared (W2) were satisfactory for estimating total leaf area of both local and non‐local cultivars. Furthermore, the predictive ability of equations for individual leaf area of local cultivars was lowered as the independent variables changed from LW to L2 or W2. Total leaf area could be predicted for all cultivars by measuring only length or width with no loss of accuracy. The variability associated with only width measurements was extremely large compared to length meassurements.
Influence of Soil pH on the Phytotoxicity of Three s‐Triazine Herbicides1
Authors: Adams R. S. , Pritchard D. J. 
Published: July 2010

AbstractThe bioactivity of s‐triazine herbicides is known to vary with soil pH. The purpose of this study was, on one soil type and under similar climatic conditions, to determine the influence of soil pH on the phytotoxicity of atrazine (2 ‐ chloro ‐ 4 ‐ (ethylamino) ‐ 6 ‐ (isopropylamino) ‐ s ‐ triazine), prometryn (2, 4 ‐ bis (isopropylamino) ‐ 6 ‐ (methylthio) ‐ s ‐ triazine and secbumeton (N ‐ ethyl ‐ 6 ‐ methoxy ‐ N ‐ (1‐methylpropyl) ‐ 1, 3, 5 ‐ triazine ‐ 2, 4 ‐ diamine). Greenhouse and field bioassays were used with chemicals applied at four rates ranging from 0 to 4.5 ppm. Soybeans (Glycine max L.) was the bioassay plant in the greenhouse and maize (Zea mays L.) in the field. The soil was Port Byron sil (Typic Hapludolls) and had been in a long term lime study (five rates) for 19 years prior to these studies. Soil pH varied from pH 5.4 to pH 7.4. Soil pH demonstrated the dominant influence on the phytotoxicity of prometryn and secbumeton, but demonstrated much less influence on atrazine toxicity. Organic carbon variation did not effect the phytotoxicity of prometryn or secbumeton, but was the principle factor influencing atrazine phytotoxicity. In the field studies maize was injured severely by high rates of prometryn and secbumeton in the calcareous soil samples, but not in the acid treatments. Maize was not affected by any rate of atrazine or at any pH examined. The influence of pH on s‐triazine toxicity appeared due to differential adsorption or differential hydrolysis by the soil.
Yields and Response of Cereal Crops to Phosphorus Fertilization under Changing Rainfall Conditions1
Authors: Matar A. E. 
Published: July 2010

AbstractResponse of cereal crops to N and P fertilization, grown under the semi‐arid conditions of southern Syria, has been variable and somewhat related to climatic conditions. Two long‐term fertilizer experiments were initiated in 1966 at Ezraa Experimental station, to study some of the P fertilization problems. The first studied interactions between fertilizer use and crop rotation and the second studied direct and residual effects of P on yields of wheat (Triticum aestivum L.) and lentil (Lens esculenta). Response to P depended upon climatic conditions. Data for 1966 to 1972 were used to correlate yields of wheat and lentil or the relative response to P fertilization with rainfall in each month of the growing season or the total of 2 or more months during the respective period. The following results were obtained: (a) A high positive correlation between yields of lentil and amount of rainfall in December (r = +0.90) or March (r = +0.80) and that of wheat with total rainfall in December and January (r = +0.97) was observed. Early predictions of yields should be of great importance to agricultural planning under dry land farming conditions. (b) The relative response of either wheat or lentil to addition of P fertilizers was largely dependent on rainfall distribution. The correlation coefficient (r) between crop response to P and rainfall distribution was opposite in signs to that observed between yields of crops and rainfall distribution. A negative linear relation was found between relative response of lentil to P an amount of rainfall in December (r = −0.89) or in March (r = −0.72). The coefficient of correlation between response of wheat to P and amount of rainfall in December and January was −0.95). In general, greater response to P fertilization was found in the dry and unproductive years, and a negative linear relationship was found between the relative response to P and the absolute yields of wheat or lentil (r = −0.98). It is postulated that P improved cereal crops' tolerance to aridity.
Estimating Leaf Water Potential in Safflower1
Authors: Sepaskhah A. R. 
Published: July 2010

AbstractThe pressure chamber technique is used for rapid measurements of plant water potential. Comparison of this method with thermocouple psychrometer technique is required at various stages of growth for different crops. Xylem water potential estimated by pressure chamber and leaf water potential measured by thermocouple psychrometer were correlated for safflower (Carthamus tinctorius L.) leaves at vegetative and flowering stages of growth in greenhouse conditions. The results of the two methods were linearly related for both growth stages but the equations were different at the 1% level. The values of ordinate intercept were nearly equivalent to the xylem sap osmotic potentials at the both stages of growth.
Tolerance of Bermudagrass Selections to Acidity. I. Effects of Lime on Plant Growth and Mine Spoil Material1
Authors: Lundberg P. E. , Bennett O. L. , Mathias E. L. 
Published: July 2010

AbstractNon‐fertile acid soils including many strip‐mined spoils are common in the Appalachian region of the USA. Strip mine spoils often have low water holding capacity, no soil structure, and various toxic materials, thus correction of pH and fertility problems may not be economical. Studies involving judicious use of lime and fertilizer and suitable plant species, however, are warranted. The objective of this research was to study the growth of several bermudagrass (Cynodon dactylon (L.) Pers.) selections on strip mine spoil treated with various lime rates. Three cultivars and five strains of bermudagrass were planted in 1 liter pots filled with low pH mine spoil (pH 2.9) treated with six rates of calcitic lime from 2.24 to 13.44 metric tons/ha (1.3 to 7.8 g/pot). All pots were given blanket applications of N, P, K, and Mg, as need was determined from soil analyses. Four harvests were made at approximately 6‐week intervals with oven dry weights of both forage and roots taken at the end of the study. All eight selections showed a significant increase in mean root and forage yields up to 6.72 metric tons/ha lime. Higher lime rates than this did not increase forage yields and resulted in lower root yields. Selections differed markedly in their growth response to various lime levels. ‘Tufcote’ outyielded all other selections at the 2.24 metric tons/ha lime rate, but its highest yield was lower than that of any other selection. ‘P.I. 315904’ and ‘Native 1’ grew best over the range of all lime treatments. Soils in which the various selections had grown had significant differences in pH and residual available nutrients. Bermudagrass was found to tolerate very acidic conditions (pH 3.4). The fact that yield made its most dramatic increase through the first three rates whereas pH increased little may indicate it is really the toxicity of certain elements rather than the low pH which limits bermudagrass growth. This study indicates that Tufcote would be a good choice if pH was as low as 3.4, however, at a nearly optimum pH of 4.5 P.I. 315904 or Native 1 would be a much better choice.
Mineral Utilization by Lambs and Guinea Pigs Fed Mg‐Fertilized Grass and Legume Hays1
Authors: Reid R. L. , Jung G. A. , Roemig I. J. , Kocher R. E. 
Published: July 2010

AbstractHypomagnesemic tetany, in both spring and winter forms, is a serious metabolic problem in beef cow herds in the northeast U. S. Control of the syndrome may be achieved by Mg supplementation of the diet, by selecting or breeding plants with the ability to accumulate Mg, or by increasing the concentration of Mg in forages by Mg fertilization or foliar application. The present study was designed to determine whether fertilization of forages with a moderate level of an available Mg fertilizer would effectively increase the concentration of Mg in the forage and improve the Mg status of ruminant animals. A number of grasses and legumes were grown in Pennsylvania and West Virginia, fertilized with kieserite (MgSO4·H2O) at the rate of 112 kg Mg/ha, and harvested as hays in 1973 and 1974. Magnesium concentration in the forages was determined by chemical analysis, and utilization of minerals evaluated with growing wether lambs in balance trials. The use of the guinea pig (Cavia porcellus) as an assay animal for mineral studies with ruminant species was examined in a limited number of trials. Magnesium fertilization increased the concentration of Mg in hays, from a mean value of 0.17 to 0.20% for all forages studied. Fertilization had no significant effect on dry matter digestibility (DMD) of the hays by lambs, and had a variable effect on apparent absorption of Mg. Apparent absorption of Mg was increased significantly, from 24.4 to 29.5%, by fertilization of the grass hays, with no effect (31.8 vs. 31.9% for non‐fertilized and fertilized treatments) in the legume hays. Apparent absorption of Mg, Ca, and P was higher in legumes than in grasses, but there were no differences in absorption of K and S due either to type of hay or to fertilization. Magnesium fertilization resulted in a highly significant increase in Mg retention by lambs, 0.17 vs. 0.28 g/day for non‐fertilized compared to fertilized treatments, for all forages. Retention of Mg, Ca, and P was markedly higher from the legume than from the grass hays. Fertilization had no effect on retention of Ca or P. Fertilization resulted in the most marked improvements in Mg retention from orchardgrass (Dactylis glomerata L.) when harvested (1974) at a vegetative stage in West Virginia and Pennsylvania. DMD values of forages were lower, and apparent absorption and retention of Mg much higher, in the guinea pig than in the lamb in comparative trials. Substantial species differences in the degree and nature of Mg utilization of alfalfa (Medicago sativa L.) hays fertilized with different levels of MgSO4 suggest that the guinea pig would not be a suitable essay animal for mineral availability studies with the ruminant.
Influence of N Stress on Leaf Senescence and N Redistribution in Soybeans1
Authors: Egli D. B. , Leggett J. E. , Duncan W. G. 
Published: July 2010

AbstractThe redistribution of nitrogen from vegetative to reproductive plant parts of soybeans (Glycine max (L.) Merr.) may be one of the factors causing leaf senescence and, consequently, it may have a direct influence on yield. Experiments were conducted for 2 years in a greenhouse hydroponics system to investigate the influence of N removal from the nutrient solution at various intervals during pod filling on the redistribution of N from vegetative plant parts to the seed and on leaf senescence. Plants were harvested at early podfill and at maturity, and all abscised leaves and petioles were collected. Subsequently, total N determinations were made on the abscised leaves and petioles, roots, pods, stems, and seed, thereby permitting an estimation of the redistribution of N. Removal of N early in the pod‐filling period reduced yield, primarily as a result of smaller seed. It hastened maturity and increased the proportion of N in the seed that came from redistribution. Early N removal resulted in earlier leaf and petiole abscission, but none of the N removal treatments had a major effect on the concentration of N in the abscised material. The portion of the N in the seed that came from redistribution ranged from approximately 20% (controls) to approximately 60% (early N removal treatments). Leaves and pod walls were the major sources of redistributed N. Raising the N level in the nutrient solution above that of the control during the filling period had no effect (relative to the control) on any of the parameters measured. The data suggest that the redistribution of N from vegetative to reproductive plant parts influence plant senescence; however, other factors are involved.
Seasonal Log of the Flowering and Podding Activity of Field‐grown Soybeans1
Authors: Hansen Wayne R. , Shibles Richard 
Published: July 2010

AbstractLittle is known about the seasonal and nodal distributions of flowering and podding in soybeans (Glycine max (L.) Merr.). This study was initiated to determine the fruiting activities of two Midwestern cultivars (‘Hark’ and ‘Hawkeye’). They were planted in 102‐cm rows on 18 May at Ames, Iowa, and thinned to appropriate spacings after emergence. Ten plants, spaced equidistant within a row of each of the four replications, were tagged for logging. Pods present at harvest maturity represented 37% of flowers produced in both cultivars. Thirty‐five and 40% of the flowers, and 44 and 40% of the pods abscised in Hawkeye and Hark, respectively. Proportionately greater loss of reproductive structures occurred on branches and on lower main stem nodes in both cultivars. Above node 6 the percentage pod set was virtually constant. Flowering, podding, and seed production were greatest in the lower middle portions of the plant — nodes 6 to 15 on plants with 22 to 26 nodes per main stem. Although flowering differed on a per plant basis, on a land area basis flowering, number of seeds produced, and yield were virtually identical for the two cultivars.
Fruiting in Cotton as Affected by Controlled Boll Set1
Authors: Patterson L. L. , Buxton D. R. , Briggs R. E. 
Published: July 2010

AbstractEnvironmental stress and boll load have both been suggested as responsible for the fruiting cessation (cut out) that occurs in cotton (Gossypium hirsutum L.) in mid‐summer in the hot, desert southwestern USA. This study was conducted to examine the influence of boll load on the flowering hiatus. Two cultivars differing in growth habit were planted in the field on an Avondale clay loam soil, a member of the fine, loamy, mixed Hyperthermic Torrifluventic Haplustolls. ‘Deltapine Smooth Leaf’ (DpSL) has a more determinate growth habit than ‘Acala 44–10’ (A‐44). Fruiting was limited during a 90‐day period within each year. Flowers in excess of one flower per plant per time interval, ranging from 2 to 5 days, were removed. Flowers left on plants were tagged and used to calculate boll retention curves. Limiting the number of flowers retained increased total flower production with DpSL more responsive than A‐44. Defloration resulted in cycling of the flower production curve which appeared to be related to relief of moisture stress either from irrigation or rain. Defloration increased both total and percent boll retention during the normal period of cessation of new vegetative and flowering growth with DpSL being more responsive than A‐44. We conclude that boll load exerts a large influence on fruiting behavior of cotton and is the major controlling factor of the cut out period in the cultivars tested.