bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performance of Bluegrass Varieties at Two Cutting Heights and Two Nitrogen Levels1
Authors: Goss Roy L. , Law Alvin G. 
Published: July 2010

AbstractDwarf type Poa pratensis L. selections (‘Merion,’ ‘Newport,’ and Washington State University selections 602, 402, 104, and 205) and “tall” or erect types (‘Park’ and ‘Delta’) were planted in replicated plots 2.5 ✕ 3.1 m on a Caldwell silt loam soil. Levels of P, K, and Ca were considered adequate for normal turfgrass growth. The plots were allowed to establish for 1 year and were then split into four subplots of two cutting heights (1,27 and 2.54 cm) and two nitrogen levels (3.6 and 1.1 kg/92.9 m2 per season). The plots were mowed once weekly for 20 weeks and all clippings were saved for yield and nitrogen analysis. Cores of soil 10.2 cm in diameter and 20.3 cm deep were analyzed for roots at the end of the season each year.There were significant differences (P = .05) in yield of shoots among varieties in the first but not the second treatment year. Significant differences were found in root yield among varieties both years. Cutting heights produced significant differences both years. Most shoots in 1957 were produced at the 2.54‐cm cutting height, but more shoots in 1958 were produced at the 1.27‐cm height.Significantly more shoots were produced both years from the highest N rate. The same treatment produced significantly fewer roots both years. The high N treatment resulted in higher tissue nitrogen content, but the greatest percentage nitrogen was recovered by the grass with the low N treatment.Shoot:root ratios were computed and are shown.
Winter Cover Crops for Sod‐Planted Corn: Their Selection and Management1
Authors: Moschler W. W. , Shear G. M. , Hallock D. L. , Sears R. D. , Jones G. D. 
Published: July 2010

AbstractWinter cover crops for sod‐planted corn (Zea mays L.) were studied in 11 location‐year field experiments in Virginia during the 1962–1966 period. Conventionally tilled corn with cover crop turnplowed and sod‐planted corn were also compared. Rye (Secale cereale L.) was the most satisfactory because of superior winter hardiness, susceptibility to herbicidal killing, and the production of relatively large amounts of persistent mulch. Wheat (Triticum aestivum L.) and oats (Avena sativa L.) were comparable as mulches except at higher elevations where oats winterkilled. Barley (Hordeum vulgare L.) was the least satisfactory winter grain tested because of resistance to herbicides. Inclusion of crimson clover (Trifolium incarnatum L.) or hairy vetch (Vicia villosa Roth.) in winter grain seedings slightly increased mulch forage but not corn yields.In general, highest corn yields occurred where largest amounts of cover crop mulch occurred, except for Italian ryegrass (Lolium multiflorum Lam.). The additional mulch produced by late versus early killing of particular cover crops tended to increase corn yields, though not always significantly. Planting corn in rye stubble after removal of forage for hay or silage reduced corn yields an average of 47% in three of seven comparisons with rye left as mulch, while yields in the remaining four were comparable.Yields of sod‐planted corn in rye sod averaged 44% higher than conventionally tilled corn in 4 of 13 comparisons and were comparable in the remaining nine. More soil moisture was found under sod‐planted corn than under conventionally tilled corn, especially during the first half of the growing season.Corn yields were increased or at least maintained, in comparison to conventional tillage, by sod‐planting in rye over a wide range of soil and moisture conditions, with the added advantages of improved soil and water conservation.
Weed Root Profiles1
Authors: Davis R. G. , Johnson W. C. , Wood F. O. 
Published: July 2010

AbstractThe spatial extent of the root systems of Xanthium Pennsylvanicum Wallr. (cocklebur), Tribulus terrestris L. (puncturevine), Kochia scoparia (L.) Schrad. (kochia), Digitarius sanquinalis (L.) Scop. (large crabgrass), Solanum rostratum Dunal. (buffalobur), Salsola kali L. var. tenuifolia Tauch (Russian thistle), Amaranthis retroflexus L. (redroot pigweed), and sorghum was determined at 10 weeks after transplanting and at maturity by digging and exposing the roots. The plants were grown without competition under favorable moisture conditions. At maturity, the root profile areas varied from 5.20 m2 for pigweed to 17.93 m2 for cocklebur. Plants within the extremes in increasing order of root profile area were sorghum, Russian thistle, buffalobur, crabgrass, kochia, and puncturevine.
Soil Degradation of Diazinon, a Phosphorothioate Insecticide1
Authors: Konrad J. G. , Armstrong D. E. , Chesters G. 
Published: July 2010

AbstractDegradation of the insecticide diazinon was followed in acid soil‐free systems and in soil systems. The mechanism of diazinon degradation in soils is a partial chemical hydrolysis with formation of 2‐isopropyl‐4‐methyl‐6‐hydroxypyrimidine and diethyl thiophosphoric acid; hydrolysis in soils is adsorption rather than acid catalyzed. Degradation rates were 11, 7, and 6% per day for Poygan sicl, Kewaunee c, and Ella Is, respectively, and these rates were related to organic matter content and pH of the soil.
Effect of Mulches and Bed Configuration. I. Early‐Season Soil Temperature and Emergence of Grain Sorghum and Corn1
Authors: Adams John E. 
Published: July 2010

AbstractClear plastic film, petroleum mulch, and two bed configurations (ridge and 20° south slope) were used on Austin and Houston Black clay to evaluate their effects on soil temperature (7.6‐cm depth) as compared with flat surface (conventional planting).All treatments caused some increase in soil temperature as compared with conventional planting. Mulches had a highly significant effect (1% level) on soil temperature during seedling emergence. Average daily soil temperature (7.6‐cm depth) was increased from 0.6 to 2.2 C by petroleum mulch and from 1.1 to 4.4 C by clear plastic. Bed configuration caused a small (0.3 to 0.6 C) but nonsignificant increase in the average daily temperature of bare soil during emergence.Mulches had more effect on initial emergence than bed configuration. Grain sorghum (Sorghum vulgare) and corn (Zea mays L.) emergence was fastest on clear plastic‐mulched plots and slowest on bare plots. Treatments with earliest emergence also had the densest stand. Both mulches and bed configuration had a highly significant effect (1% level) on seedling emergence. Emergence time for grain sorghum decreased 1 day for each 0.9 C increase in average daily (7.6‐cm depth) soil temperature between 12.8 and 20.6 C (r = −0.94).Results indicate that the soil is too cool at normal planting time for maximum emergence and stand of grain sorghum and corn in the Texas Blackland area.
Effects of Clipping on the Performance of Spring Barley (Hordeum vulgare L. emend Lam) Seeded in October1
Authors: Day A. D. , Thompson R. K. , McCaughey W. F. 
Published: July 2010

AbstractA 4‐year experiment was conducted to study some of the effects of clipping on the yield and quality of simulated pasture forage and grain from ‘Harlan’ spring barley planted in October and grown under irrigation at Mesa, Ariz. Four treatments (0, 1, 2, and 3 clippings at the onset of jointing) were evaluated in a replicated randomized complete block design. Forage and grain harvests were made with small‐plot equipment. Clipping two times by late January reduced plant height, eliminated lodging, and produced maximum yields of quality grain. In addition, the pasture forage provided an economical source of protein and digestible laboratory nutrients (D.L.N.).
Effect of Soil Nutrients and pH on Nitrate Nitrogen and Growth of Pearl Millet [Pennisetum typhoides (Burm.) Staph and Hubbard] and Sudangrass [Sorghum sudanense (Piper) Staph]1
Authors: Smith D. T. , Clark N. A. 
Published: July 2010

AbstractPearl millet [Pennisetum typhoides (Burm.) Staph and Hubbard] and sudangrass [Sorghum sudanense (Piper) Staph] were compared in 1963 on a mineral‐deficient, low pH Monmouth sandy loam under four rates each of K and P, and three rates each of Ca and Mg with one element varied per plot. In 1964, pearl millet was grown on a Sassafras sandy loam under three pH levels and four potassium levels. A greenhouse experiment was conducted the following winter with pearl millet grown in soil from the low‐K plots of the first experiment. Treatments were three pH levels and four K levels. Plant samples from each experiment were chemically analyzed. Although K fertilization had no effect on nitrate N in sudangrass, nitrate N in pearl millet tended to incrtase with K applications. Concentrations of 3 to 6% K in plant tissue were common. P and Mg fertilization showed no effect on nitrate N concentrations in plant tissue. Nitrate in millet increased with soil pH increases. Millet was less sensitive to soil fertility than sudangrass was and extracted greater amounts of N, P, and K.
Effects of Plant Parts on the Grain Yield, Kernel Weight, and Plant Height of Wheat and Barley1
Authors: Saghir A. R. , Khan A. R. , Worzella W. W. 
Published: July 2010

AbstractA field study was conducted on dry land to determine the contribution of different plant parts to the kernel development of wheat and barley. Shading of the spike proved to be the most effective treatment in reducing the grain yield and 1000‐kernel weight of wheat and barley. The least significant effect was obtained by the removal of the lower leaves. Treatments made 1 week before anthesis caused maximum reductions in grain yield and 1000‐kernel weight. Plant height was least affected by shading or removal of the different plant parts.Clipping full awns at anthesis had the most significant effect on the grain yield and 1000‐kernel weight of wheat, reducing the yield 20.8% and the weight 13.4%. This reduction corresponded to the proportion of the awns clipped and the advancement of the stages of growth studied. The plant height was not affected by clipping the awns.
Carbowax 6000, Mannitol, and Sodium Chloride for Simulating Drought Conditions in Germination Studies of Corn (Zea mays L.) of Strong and Weak Vigor1
Authors: Parmar M. T. , Moore R. P. 
Published: July 2010

AbstractThe investigations concerned the influences of simulated drought conditions on germination and early nonphotosynthetic stages of seedling growth of two lots of dent corn differing in energy. Carbowax polyethylene glycol 6000, (C6M), mannitol, and NaCl were used osmotic substrates to prepare aqueous solutions having 0 to 10 atmospheres of osmotic pressure (O.P.), corresponding to different drought conditions. The tetrazolium test was used to evaluate seed energy.Water absorbed by seeds decreased with increasing O.P. levels. Increased O.P. levels progressively delayed and reduced germination. Linear regression coefficients were ‐3.45, ‐1.09, and ‐0.49% germination per 1 atm O.P. for the above three substrates, respectively. The rapidity of gernfination and the seedling vigor in growth tests of the two lots tended to parallel the vigor ratings obtained from tetrazolium tests.Trends were noted indicating more adverse effects of increasing O.P. levels on the low than on the high energy lot, and on the shoot than on primary root elongation. Correlation steadies indicated that shoot growth alone was an acceptable measure of evaluation for the simulated influence of drought conditions.
Efficiency of Rape, Oats, Soybeans, and Flax in Absorbing Soil and Fertilizer Phosphorus at Seven Stages of Growth1
Authors: Kalra Y. P. , Soper R. J. 
Published: July 2010

AbstractA greenhouse experiment was conducted in an attempt to determine the phosphorus requirements of rape, oats, soybeans, and flax at various stages of growth. Radioactive phosphorus was used in order to differentiate between the amount of phosphorus derived from the fertilizer and from the calcareous soil used. Phosphate fertilizer was applied as a band about 1.3 cm below the seeds at the time of planting.“A” values differed amongst these crops and at different stages of growth for the same crop. The “A” values decreased in the order soybeans, flax, oats, and rape. Soybeans were much more efficient than rape, oats, and flax in extracting soil phosphorus. For most of the growth cycle rape and flax were similar in absorbing phosphorus from the soil and in this respect oats were less efficient than these two crops except for the last two stages. It would appear that the differences amongst the “A” values of rape, oats, and flax are largely due to differences in their abilities to extract fertilizer phosphorus. The “A” values of soybeans were very high, which would seem to be largely due to their greater efficiency in absorbing soil phosphorus.
Kernel Color and Shape as Guides to Potential Flour Performance in Wheat Marketing1
Authors: Barmore Mark A. , Bequette Robert K. 
Published: July 2010

AbstractA 16‐year summary of flour quality data for important Pacific Northwest wheat varieties is used to illustrate that primary responsibility for maintaining an orderly wheat marketing system rests with plant breeders and associated cereal technologists.The exact rate at which flour strength increases as protein content increases is an inherent varietal property which influences the suitability of hard‐endosperm wheat flours for yeast‐leavened products, and of soft‐endosperm flours for chemically leavened baked goods. The U. S. Grain Standards group varieties having visibly similar identifying kernel characters into classes (or subclasses) which represent inherent differences in flour properties and use potential. Subclasses (except White Club and Western White) are based on kernel vitreousness as an estimate of protein content, which is in turn an estimate of flour strength.The grading and marketing problems created by a hard‐endosperm bread wheat variety with a white bran coat suggest that until a quick quality test is developed, varietal quality should be defined as: “the suitability for the end‐use normally associated with the market class (or White Wheat subclass) in which a variety is automatically placed because of kernel color and shape”.
Effect of Soil Salinity on Water Potentials and Transpiration in Pepper (Capsicum frutescens)1
Authors: Ehlig C. F. , Gardner W. R. , Clark M 
Published: July 2010

AbstractTotal leaf water potential, osmotic potential, turgor potential, and transpiration rate were measured on pepper plants irrigated with saline water having an osmotic potential of −2 bars. Results were compared with similar measurements on nonsaline treatments. Plants were allowed to extract water from the soil until the total water potential reached about −16 bars.The difference between the leaf water potential and the soil water potential was the same for both treatments. The relation between the leaf water content and component water potentials was that predicted from the nonsaline leaves, assuming an osmotic adjustment in the saline leaves of −2 bars. No further adjustment due to concentration of the soil solution was observed. The relative transpiration rate was reduced at a much higher soil water content for the saline than for the nonsaline case.
Use of Multiple Regression in Fertilizer Evaluation1
Authors: Engelstad O. P. 
Published: July 2010

AbstractThe application of standard Multiple regression programs to fertilizer evaluation via nutrient uptake is shown to be both feasible and convenient. A common intercept and regression coefficients are calculated for any number of fertilizers being compared, along with additional data needed for statistical comparisons. Statistical tests for determining significant differences among coefficients are provided. Linear segments of yield curves can also be used.
Photosynthesis Under Field Conditions. XI. Soil‐Plant‐Water Relations During Drought Stress in Corn1
Authors: Shinn J. H. , Lemon E. R. 
Published: July 2010

AbstractThe variation of leaf water potential at different heights in a corn crop canopy (Zea mays) and with time during a period of increasing drought stress were examined along with soil moisture tension and evapotranspiration. These measurements plus growth measurements permitted an evaluation of the soil‐plant‐water transport system and its effects on plant growth during drought.On clear summer days the upper leaves of the corn crop had higher water potentials with a bimodal tendency in contrast to the lower leaves which had lower and almost constant water potentials.On high stress days the magnitude of the maximum afternoon leaf water potential increased by an amount equal to the increase in soil moisture tension. On days of comparable evaporative demand, the gradient of water potential from the upper leaves to the soil increased regularly with an increase in soil moisture tension in the root zone.Since total transpiration was not bimodal even though upper leaves exhibited bimodal variations of water potential, it is concluded that if midday stomatal closure of the upper leaves occurred, it apparently was ineffectual or compensating transpiration must have been carried on by lower leaves.A 2‐week drought period was examined in detail. Computation of the “effective conductance” of liquid water in the plant was compared with the moisture conductivity of the soil. This permitted a calculation of the “effective root length” where the gradient of water potential from plant to soil was assumed to represent the gradient from the root surface to the ambient untapped soil moisture. This calculated length was small by comparison to those calculated by Slatyer (1957), but the computational error is large.Transpiration was not detectably changed by the decrease in effective plant conductance and soil conductivity, so it is. concluded that the plant was still able to keep pace by maintaining sufficient potential gradient to transport the needed amount of water. The growth processes, however, were slowed down with increasing leaf water potential and decreasing turgor of the tissues. This slowdown was evident even at the relatively low soil moisture tension of less than one bar and a leaf water potential of less than 3.5 bars.
Defoliation by Sheep‐Grazing Versus Mower‐Clipping for Evaluation of Pasture1
Authors: Cuykendall C. H. , Marten G. C. 
Published: July 2010

AbstractYields within three grass species and two alfalfa varieties defoliated by sheep‐grazing or machine‐clipping were nearly identical in a year of limited moisture. With adequate moisture, grazing caused higher yields of all forages, until extremely high levels of N (for grasses) and K (for alfalfa and grasses) were applied to both treatments. Sheep excreta significantly increased K levels of soil and plant tissue. Comparable heights of defoliation by the two methods left twice as much residual leaf and stem tissue after grazing, but this did not increase subsequent forage yields. Significantly more weeds invaded clipped plots in late summer. Regrowth of sod cores in darkness at the end of each season indicated more total reserves per unit area under grazing due to more tillers and roots per unit area. However, no differences in grams of top growth per gram of stubble and root appeared under the two methods of defoliation.
Effects of Rainfall and Temperature Interactions During the Growing Season on Corn Yield1
Authors: Runge E. C. A. 
Published: July 2010

AbstractMaximum daily temperatures and rainfall were found to have a large effect on corn yield from 25 days before to 15 days after anthesis. This corresponds to the average calendar interval of June 30 through August 8 at Urbana. The maximum effect of temperature and rainfall on corn yield occurs approximately one week before anthesis and remains at a high level one week to either side of the maximum. The models solved in this investigation indicate that high temperatures (maximum daily temperatures between 32.2 and 37.8 C or 90 and 100 F) can be beneficial to corn yield if moisture available to the corn plant is adequate.
Effect of Soil Salinity on External Morphology of Cotton Leaves1
Authors: Gausman Harold W. , Cardenas Ruben 
Published: July 2010

AbstractFourth leaves from the apex of cotton plants were sampled in a field containing areas of low and high levels of soil salinity. Microscopic examination revealed that high salinity caused fewer epidermal cells and stomata per unit area, increased surface size of epidermal cells, and increased leaf thickness.
In Vitro and In Vivo Digestibility and Ad Libitum Intake of Mechanical Mixtures of Forages1
Authors: Monson W. G. , Reid J. T. 
Published: July 2010

AbstractWe determined in vitro digestible dry matter for two legumes (alfalfa and birdsfoot trefoil) and four grasses (smooth bromegrass, timothy, Reed canarygrass, and orchardgrass). Early‐ and late‐cut forage from each species was analyzed by a modified Tilley and Terry two‐stage digestion procedure. One‐third/two‐thirds mixtures were studied in all combinations within species and between each grass and legume. Certain mixtures of grasses and birdsfoot trefoil gave small, but consistent increases in dry‐matter digestibility over that calculated from the weighted mean of the mixture components. Dry‐matter digestibility and ad libitum intake of timothy and birdsfoot trefoil, separately and in mixtures, were determined in a feeding trial with sheep and steers. All forages in the in vivo studies had similar digestibilities. Average intake values of 117, 124, and 136% (timothy alone = 100) were obtained when forage fed was 33, 67, or 100% birdsfoot trefoil.
Rhizome and Tiller Development of Kentucky Bluegrass (Poa pratensis L.) as Influenced by Photoperiod, Cold Treatment, and Variety1
Authors: Moser L. E. , Anderson S. R. , Miller R. W. 
Published: July 2010

AbstractTwo controlled environment experiments were designed to study the effect of photoperiod and a cold treatment on rhizome and tiller development of ‘Merion’ and ‘Windsor’ Kentucky bluegrass (Poa pratensis L.) Evidence is given to support the following conclusions:

A cold treatment is not essential for rhizome formation. Cold treatments increased tillering but reduced the number of rhizomes.

Both initiation and elongation of rhizomes were favored by a 16‐ or 18‐hour photoperiod when compared to a 8‐ or 12‐ hour photoperiod.

Tillering showed little response to initial photoperiod, although more tillers were formed with a 12‐hour than with an 8‐ or 18‐hour photoperiod in one experiment.

Windsor generally produced more and longer primary and secondary rhizomes than Merion but the latter tillered more profusely than Windsor.
Effect of Plant Type and Nitrogen Level on the Growth Characteristics and Grain Yield of Indica Rice in the Tropics1
Authors: De Datta S. K. , Tauro A. C. , Balaoing S. N. 
Published: July 2010

AbstractOf the various factors affecting nitrogen response in rice, plant form or plant type is particularly significant. Experiments were conducted during two crop seasons to study the N response and the growth characteristics of some traditional leafy tropical indica varieties and two dwarf indicas of improved plant type. Most of the traditional tall varieties lodged at certain growth stages, and yielded the best when 30 to 60 kg/ha N was applied. One of the dwarf varieties developed by the Institute produced progressively higher yields (the highest being 9,477 kg/ha) up to 120 kg/ha N in the sunny dry season. The increase in dry matter production from panicle initiation to harvest was significantly correlated with grain yield.During the cloudy wet season when the grain yield response to fertilizer N is lower than during the dry season, the dwarf indica variety, IR8, produced 3,480 kg/ha more rough rice than the tall, weak‐strawed variety, Peta, indicating the importance of short stature and culm strength in obtaining high yields.