bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition by Some Allelochemicals of Intake of Individual Meals by Meadow Voles1
Authors: Kendall W. A. , Hill R. R. , Shenk J. S. 
Published: July 2010

AbstractA large number of allelochemicals may occur in forage plants but only a few of them can be studied in detail with large animals. Therefore, studies with small animals are essential to provide information that may be common to many animals or contribute towards the justification of further research with large animals. The objective of these experiments was to determine the relative importance of allelochemicals that are common in forages as they affect feed intake by the meadow vole (Microtus pennsylvanicus). The allelochemicals were fed alone or together in single meals to meadow voles. Gramine, hordenine sulfate, and tryptamine‐HCl, which occur in reed canarygrass (Phalaris arundinacea L.) were diluted to various concentrations with potato starch. Crownvetch (Coronilla varia L.) plants were grown with adequate or limiting levels of N and irradiation to the lowermost leaves to provide plants with different levels of β nitropropionic acid (NPA). Semisynthetic diets with various levels of NPA or combinations of NPA with one of the alkaloids were prepared by mixing the test chemicals with potato starch.Intakes of semisynthetic diets by the voles were inhibited by each of the allelochemicals. Inhibition by gramine and tryptamine were similar and greater than the inhibition with hordenine when measured on a weight basis. Inhibition by the three alkaloids was similar on a molecular basis. The intake of fresh leaves of crownvetch was probably limited by NPA and some additional inhibitor(s). The inhibitory effect of the alkaloids on intake was additive when they were fed in mixtures in synthetic diets. A synergistic effect on intake was obtained with diets that contained mixtures of gramine and NPA. We conclude that the biological activity of hordenine is of sufficient magnitude to warrant further work to determine its prevalence‐in the field and effects on animals.
Volunteer Legume Control in Legume Seed Crops with Carbon Bands and Herbicides. I. White Clover1
Authors: Rolston M. Philip , Lee W. Orvid , Appleby Arnold P. 
Published: July 2010

AbstractIn legume seed production, volunteer legumes from seed in the soil may result in contamination of seed lots. No herbicides are available which can selectively control volunteer legumes in seeded legumes when both are exposed to the herbicide. Greenhouse and field experiments on white clover (Trifolium repens L.) were conducted in western Oregon to determine the potential of using activated carbon applied in bands over the seed row, with nonselective herbicides, to selectively control volunteer legumes. A 25‐mm band of activated carbon was applied to the soil surface over the seeded row during planting and a nonselective herbicide was applied broadcast immediately. Weed control was visually evaluated, and stand and seed yield of the white clover was measured. The carbon: herbicide ratios required for protection with 0.5 kg/ha of diuron [3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea], atrazine [2‐chloro 4‐(ethylamino)‐6‐(isopropylamino)‐s‐triazine], and simazine [2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine] were 50:1, 200:1, and 200:1, respectively. This reduction resulted in seed yields of 80, 40, and 14% of the check at first harvest of fall‐planted white clover. Atrazine and simazine at 1.25 and 1.5 kg/ha, respectively, reduced seedling numbers to the same extent as diuron at 2 kg/ha. In the second harvest of these treatments, seed yields from plots established with diuron at 2 and 3 kg/ha were similar to those from the check plots. Seed yields from white clover established with carbon bands in the spring were not reduced by diuron. White clover injury was greatest when diuron was applied to soil that was wet on the surface. Seed germination and seed weight were not influenced by the herbicides used in these experiments. Weed control between the carbon bands was good but grasses and broadleaf weeds also were protected by the carbon band. With carbon banding, volunteer white clover and volunteer narrow birdsfoot trefoil (Lotus tenuis Waldst. & Kit) were both reduced 95% by diuron applied at 2 and 3.3 kg/ha. Individual circumstance will determine whether the increase in seed lot quality that results from the control of volunteer legumes will offset the reduction in the quantity of seed produced.
Compensatory Growth in the Crown Root System of Sorghum1
Authors: Jordan W. R. , McCrary Marion , Miller F. R. 
Published: July 2010

AbstractThe number of crown roots which develop on grain sorghum (Sorghum bicolor (L.) Moench) plants under field conditions is often reduced far below the genetic potential. As a first step toward understanding the significance of the number of crown roots to total function of the root system, we conducted experiments to determine the capacity for growth when root numbers were restricted by clipping treatments and water and nutrients were not limiting. When grown in hydroponics, ‘RS610’ sorghum plants developed an average of 20.6 crown roots by 50 days after planting (DAP). Root clipping treatments, initiated when plants were young, gave groups of plants in which 3, 6, and 10 crown roots were allowed to develop. For plants with at least six roots, leaf areas, shoot, and root dry weights were not different from controls. Plants maintained with only three roots had reduced leaf areas and lower shoot and root dry weights by 50 DAP; however, branching and growth of second and third order lateral roots were promoted. When compared at equal leaf areas, total root lengths and root volumes were equivalent for all treatments. Thus, compensatory growth within the existing root members was capable of maintaining root length and volume, but not root dry weight when crown root numbers were severely reduced.
Managed Soil Moisture System for Studying Plant Water Relations under Field Conditions1
Authors: Reetz H. F. , Hodges H. F. , Dale R. F. 
Published: July 2010

AbstractA Managed Soil Moisture System (MSMS) was installed at the Purdue Univ. Agronomy Farm for plant water relations research. Sixteen plots, each 6.1 m ✕ 9.8 m, can be controlled individually for water application and removal. The MSMS was designed on the principle of the Prescription Athletic Turf (PAT) system developed at Purdue. The area was excavated and lined with a moisture barrier. After the drainage/irrigation system was installed, the plots were filled to a depth of 40 cm with dune sand. During normal. “non‐moisture stress” operation a water table is maintained at a depth of 35 cm. Each plot has its own supply tank for monitoring the water use. An overflow allows drainage of excess rainfall, and a pump can be used to hasten drainage. Given a period of dry weather, this facility allows rapid adjustment of soil moisture for studying the effect of drought stress on plant growth. The plot size permits plant measurements and periodic destructive sampling without significantly affecting the crop canopy environment. In preliminary experiments in 1974, corn (Zea mays L.) grew normally to maturity with a water table at 35 cm. During a hot, dry period, severe leaf curling began on the stress plots 4 days after the drainage system was opened. Coupled with meteorological and soil water data, plant growth, and water potential measurements, this facility provides a relatively low cost means for studying environmental‐plant response data under near‐natural environments.
Tolerance of Cotton to the Herbicide Glyphosate1
Authors: Jordan T. N. , Bridge R. R. 
Published: July 2010

AbstractAn increasing group of weed pests in U.S. cotton (Gossypium hirsutum L.) are the perennial grasses which can be controlled with glyphosate [N‐phosphonomethyl) glycine], but cotton is also sensitive to this herbicide. Field studies were initiated to determine if certain cotton genotypes could be selected with sufficient tolerance to glyphosate to allow its use in a cotton‐weed control program. In 1974,405 genotypes were evaluated for tolerance to glyphosate at rates of 0.84, 1.68, and 3.36 kg/ha applied as an over‐the‐top treatment in the early bloom stage. In 1975, 24 genotypes selected from 1974 studies were screened at rates of 0.56 and 0.84 kg/ha of glyphosate ap lied over‐the‐top of cotton plants. Six genotypes selected from previous studies were evaluated with glyphosate applied over‐the‐top or directed under cotton plants 50 to 62 cm in height in the very early square stage. Glyphosate toxicity varied with cotton genotypes and increased with increasing rates. In 1976 and 1977, all genotypes that received an over‐the‐top treatment of glyphosate yielded significantly less seed cotton than the untreated checks. Glyphosate applied as a directed post‐emergence treatment did not cause significant injury symptoms in treated cotton, however, none of the treated genotypes produced seed cotton yields equal to their untreated controls. Cotton injury was only 10% or less when the herbicide was directed to the base of the plants as compared with 65 to 80%, injury when the herbicide was applied over‐the‐top. Two genotypes (DES 04‐11 and DES 04‐606) yielded over 100% of their untreated controls when one or two separate applications of 0.56 kg/ha of glyphosate was directed to the base of the cotton plants in 1977. The increase in yield of these two genotypes was not significant, but indicated a level of glyphosate tolerance which could be used in the development of commercial cultivars possessing enough tolerance to glyphosate to allow its use for perennial weed control in cotton.
Relationship of Stelar Lesions to Radicle Growth in Corn Seedlings1
Authors: Cohn Marc Alan , Obendorf R. L. , Rytko G. T. 
Published: July 2010

AbstractChilling during imbibition of Zea mays L. kernels resulted in anatomical lesions across the stele of radicles, and subsequently in reduced growth of radicles. The objective was to determine if stelar lesion formation accounted for the radicle growth reduction. Inheritance patterns, source of seedstodrs, maturity of kernels, and surgical treatments of pericarp and endosperm were used to compare lesion occurrence and radicle growth in laboratory evaluations of field‐grown seedstocks. Chilling injury of 5% (low) moisture kernels was measured as radicle growth reduction after a 48 hour hydration treatment at 5 C followed by 4 days at 25 C when compared to Similarly treated controls with 13% moisture kernels. Chilling injury was also measured as stelar lesion formation. In cresses between the sensitive inbred ‘Oh51A’ and the injury resistant inbred ‘B8,’ both radicle growth reduction and stelar lesion formation were receive characters. While the inheritance of either character was not altered substantially by the maternal parent in studies of intact kernels, pericarp damage in chilling sensitive crosses resulted in more severe radicle growth reduction without increasing lesion frequencies. Removal of the endosperm prior to imbibitional chilling resulted in lower lesion frequencies in sensitive inbreds and hybrids. Various sources of the Oh51A inbred had markedly different sensitivities to imbibitional chilling. Maximum sensitivity occurred before kernel maturation. Increasing kernel moisture to 13% before hydration at 5 C reduced or avoided injuries caused by imbibitional chilling of 5% moisture kernels. The embryo, pericarp, and endosperm each influenced the severity of imbibitional chilling injury. While the stelar lesion may contribute to radicle growth reduction, it was not the only factor responsible for imbibitional chilling injury of corn.
Effects of Crop Sequence and N Fertilizer Levels on Soil Bulk Density
Authors: Hageman N. R. , Shrader W. D. 
Published: July 2010

AbstractThe effect of intensive corn (Zea mays L.) production on soil properties and on the productive capacity of soils is a matter of continuing concern. A 20‐year comparison of continuous corn (CCCC) and a corn‐oats (Avena sativa L.)‐meadow‐meadow (COMM) rotation with various N rates on Webster silty clay loam, a Typic Haplaquoll, in north‐central Iowa, provided the opportunity to measure soil changes induced by these two widely differing cropping systems.It was found that, at the 15 cm depth, the soil bulk density in the CCCC and COMM rotations was 1.17 and 1.13 g/cm8, respectively. The difference was attributed to less machinery travel and greater organic matter production on the COMM rotation. When the N fertilizer treatments were compared at the 15 cm depth, the soil bulk density of the 134 kg N/ha treatment was 1.10 g/cm8, and the 0 kg N/ha treatment was 1.20 g/cm8. The difference here was attributed to greater production of organic matter in the higher N treatment.The organic matter content was 5.02 and 5.52% in the CCCC and COMM rotations, respectively. In the 0 kg N/ha treatment and the 134 kg N/ha treatment, the organic matter content was 5.21 and 5.33%, respectively. As the soil organic matter increased, the soil bulk density decreased.
Rate of Fill and Length of the Grain Fill Period for Nine Cultivars of Spring Oats1
Authors: McKee G. W. , Lee H. J. , Knievel D. P. , Hoffman L. D. 
Published: July 2010

AbstractWe hypothesized that yield differences among cultivars of spring oats, Avena saliva L., can be partially explained by differences in the daily rate of grain fill and length of the grain fill period. To obtain information on these factors, nine cultivars of spring oats were sampled three times weekly in the field in 1975. The time between anthesis and physiological maturity was considered to be the fill period. Physiological maturity was considered to be the date beyond which there were no differences in grain yield significant at the 5% level of probability and half of the glumes and kernels no longer took up a red water soluble dye. In 1975, the mean grain fill period for nine spring oat cultivars, planted and fertilized at recommended rates, was 23 days with a range of 20 to 24 days. In 1976, for eight of the same nine cultivars, the mean grain fill period was 24 days with a range of 23 to 26 days. One variety, ‘Pennfield,’ was tested over a 3 year period. Lengths of the grain fill period were 22, 26, and 25 days, respectively, in 1975, 1976, and 1977. In 1975, the mean daily rate of grain fill at 0% moisture was 95 kg/ha with a range of 88 to 100 kg/ha. Data on rate of grain fill were not secured hi 1976. Grain yield in 1975 was significantly correlated at the 1% level with rate of grain fill, length of the grain filling period, leaf area duration, and accumulated heat units and solar and sky radiation during the grain fill period. Multiple correlation and regression analysis indicated that low rates of grain fill and short leaf area duration limited grain yield in 1975. These data suggest that it may be easier to increase spring oat yields by altering the rate of grain fill than to greatly increase the length of the fill period.
Nitrogen Rate‐Yield‐Precipitation Relationships and N Rate Forecasting for Corn Crops1
Authors: Isfan Daniel 
Published: July 2010

AbstractThe purpose of this study was to determine relationships between precipitation, N rate, and yield, and to develop a criterion that would permit to forecast in the spring the most probable optimum N rate. The study was carried out on a chernozem soil, in a continental temperate climate, characterized by an average annual precipitation of about 500 mm that vanes greatly between years and between seasons. Regression analysis of 14 years of data has shown that optimum N rate was more highly correlated with November to February inclusive; accumulated precipitation (r=0.77**) than with May to August precipitation (r=0.41). The multiple correlation coefficient of optimum N rate and the two precipitation periods was highly significant (r=0.94**). In years with roughly normal summer precipitation, November to February precipitation was more important (I=0.86**). In years with less than 100‐120 mm in November to February, the applied N was less efficient even when the summer precipitation was greater than normal. The May to August precipitation had a higher direct effect on the N rate only in wet winter years, (with precipitation of over 200 to 220 mm in November to February); here, the simple correlation of the N rate with the winter precipitation decreased (r=0.50) and that with May to August precipitation increased (r=0.84**; 0.01 level), but the interaction effect of winter and summer precipitation was still significant (R=0.89**). This suggests that in all cases, winter precipitation can be used to predict the optinum rate of N fertilizer. To calculate the optimum N rate in March,the following equation is proposed:

N rate = 19.53 + 0.2854X1 + 0.0066X1X2 (R=0.90)
If the November to December precipitation exceeds 220 mm and the spring continues to be wetter than normal, the N rate can be calculated again in June, using the following equation:

N rate = 28.37 + 0.0021X1X4 + 0.0032X3X4 ‐ 0.2538X4 (R=0.97)
where: X1, X2, and X4 are the November to January, February and May‐ July precipitation (mm), respectively. Estimating the N rates in March and reestimating in June with the above two regressions gives an average yield increase of 69% and a profit 200% greater than with annual application of the long‐term average N rate. The yield increase was also more highly correlated with November to Februay (r=0.63; 0.05 level) than with May to August precipitation (r=0.59*; 0.05 level), and the interaction effect of these two variables was high (r=0.92**; 0.01 level). Yields can be predicted in summer using both winter and summer precipitation.
Fescue Yield Response to Sewage Sludge Compost Amendments1
Authors: Sikora L. J. , Tester C. F. , Taylor J. M. , Parr J. F. 
Published: July 2010

AbstractThe agronomic benefits of applying sewage sludge compost to land have yet to be defined. The study reported is part of a series designed to assess the benefits. It deals specifically with fescue yield response to sewage sludge compost and fertilizer. An Evesboro loamy sand (Typic Quartzipsamments) and a Fauquier silt loam (Ultic Hapudalfs) soil were amended with four rates of sewage sludge compost (0 to 6% equal to 0 to 134.4 metric ton/ha, dry weight), plus an additional lime control and two rates of N, P or N plus P (0 and 195 kg/ha) in a factorial greenhouse study. —Kentucky 31― tall fescue (Festuca arundinacea Schreb.) was grown and harvested at 40, 76, 120, and 167 days and the clippings were dried and weighed. A significantly greater grass yield was obtained from the compost amended Evesboro than the compost amended Fauquier which contained a vermiculite clay fraction. Yields were linearly related to compost amendment for both soils. Yields were significantly increased by the addition of N, P, or N plus P to compost amended soils. The largest yield increase was obtained by the addition of N plus P. The mineralization of compost organic N was the limiting factor in grass yield. Regression models were derived from the data using compost and days as independent variables for each soil, N, and P combination. In most cases, a quadratic term for compost amendment was necessary for explaining the variation in yield. Regression model equations based on cumulative yield data contained similar terms for each soil, N, and P combination except for the Fauquier soil with N and P added for which no model was obtained.
Air Pollution Oxidant Effects on Cool‐Season and Warm‐Season Turfgrasses1
Authors: Youngner V. B. , Nudge F. J. 
Published: July 2010

AbstractAlthough turfgrasses are grown extensively in urban areas where air pollution is a problem, little is known about their reaction to air pollutant oxidants. Cultivars of common turfgrass species were started in a greenhouse with charcoal‐filtered air. One lot of each was fumigated with 0.50 ppm ozone and another with 0.50 ppb peroxyacetyl nitrate (PAN) for 3 hours. A third lot was retained in the greenhouse as a control. Significant variations in leaf injury were noted among the species and cultivars. Injuries to a cultivar from ozone and PAN were often of different magnitudes. All Lulium perenne L. cultivars showed severe injury while Poa pratensis L. cultivars ranged in sensitivity between the extremes for both pollutants. Agrostis tenuis Sibth. and Festuca rubra L. cultivars had moderate injury. Warm‐season grasses, in general, were less sensitive than the cool‐season; only ‘Emerald’ Zoysiagrass and ‘Tifgreen’ bermudagrass showed injury.
Characteristics of the Occurrence and Some Factors Associated with Reduced Palatability of Pearl Millet1
Authors: Rouquette F. M. , Keisling T. C. , Camp B. J. , Smith K. L. 
Published: July 2010

AbstractDuring the prolonged drought conditions of 1978, cattle throughout the East Texas area abruptly refused to graze many fields of commercial pearl millet hybrids [Pennisetum americanum (L) K. Schum.]. This study was undertaken to characterize the occurrence of the lack of palatability, investigate some plant factors associated with reduced palatability, and verify that drought was involved in the development of the palatability problem. Forage was sampled from a pasture on an upland site where plants exhibited visual drought stress, and from a bottomland site where plants did not show drought stress symptoms. Analyses were conducted for total alkaloids and nitrate. Two management treatments, shredding and irrigation, were used in an effort to increase palatability of the drought stressed pearl millet. Total alkaloid concentration of non‐drought stressed forage, which was readily consumed, ranged from 10 to 20 mg/kg throughout the August sampling period. Drought stressed forage, which was not consumed, had total alkaloid contents of 180 to 460 mg/kg. The total alkaloid concentration in the drought stressed plants was reduced to 20 mg/kg 4 days after a 1.8 cm rain. Re‐growth forage from previously shredded areas in the drought stressed pasture was not consumed. Forage taken within the drought stressed pasture which was irrigated was readily consumed. The total alkaloid concentration of irrigated forage ranged from 10.0 to 16.7 mg/kg. Drought‐stressed plants contained 3% nitrate and non‐drought stressed plants contained 1% nitrate. Under extreme drought stress conditions, there appeared to be a negative relationship between both total alkaloids and % NO3, and palatability and total consumption.