bluuebunny/crossref_metadata_2025 huggingface dataset:
Relation Between Quality of Life of Mothers of Children With Cerebral Palsy and the Children's Motor Functioning, After Ten Months of Rehabilitation
Authors: Prudente Cejane Oliveira Martins , Barbosa Maria Alves , Porto Celmo Celeno
Published: July 2010

This study aims to analyze the quality of life of mothers of children with cerebral palsy, correlated with the evolution of their children's gross motor function after ten months of rehabilitation. An observational, longitudinal study was carried out in Goiânia, Goiás, Brazil, involving 100 mothers and children with cerebral palsy. The children's motor function was evaluated using the Gross Motor Function Measure (GMFM) and the mothers' quality of life using the Medical Outcomes Study 36-item Short Form Health Survey (SF-36). After ten months of rehabilitation, the children's gross motor function had significantly improved (p<0.001), while the mothers only presented a significant improvement (p<0.001) in the bodily pain domain. The improvement in the motor function of children with cerebral palsy did not influence the changes in the mothers' quality of life.
Prevalence of Pattern of Risky Behaviors for Reproductive and Sexual Health Among Middle- and High-School Students
Authors: Campo-Arias Adalberto , Ceballo Guillermo Augusto , Herazo Edwin
Published: July 2010

This research aimed to establish the prevalence and factors associated with the pattern of risky behavior for reproductive and sexual health (PRBRSH) among secondary education students in Santa Marta, Colombia. A cross-sectional study was done. The PRBRSH was defined as having had two or more out of four possible risky sexual practices across the lifetime. Logistic regression was calculated to control for confounding variables. In total, 804 students reported lifetime sexual intercourse. PRBRSH was reported by 36.1% of the sample. Illegal substance use (OR=11.4), alcohol drinking (OR=2.5), being a middle-school student (OR=1.7) and middle or high socioeconomic status (1.4) were associated with PRBRSH. Around one out of three adolescent students is at high risk for HIV infection or unwanted pregnancy. Safe sex practices need to be promoted in this population.
Restructuring the Nursing Staff and its Influence on Care Hours
Authors: Cucolo Danielle Fabiana , Perroca Márcia Galan
Published: July 2010

This descriptive study aimed to calculate and compare the nursing staff at the medical-surgical clinical units of a philanthropic hospital in current and projected situations, and to investigate how much time the nursing team delivers patient care in the current and projected situations. Gaidzinski's method was used to calculate the nursing staff, and the equation proposed by the Hospital Quality Commitment (HQC) to estimate care hours. The findings showed an increase of 33% in the staff, with a 68.4% increase in the number of nurses and 15.6% in the number of technicians / nursing auxiliaries. According to the projected situation, the care hours varied from 5.7 to 7.2. The number of nursing and the mean care time provided to the patients were inadequate according to the clientele's care needs. This could impair the quality of care.
Nurses’ Knowledge about the Insertion Procedure for Peripherally Inserted Central Catheters in Newborns
Authors: Lourenço Solange Antonia , Ohara Conceição Vieira da Silva
Published: July 2010

The right to practice the Peripherally Inserted Central Catheter (PICC) technique, mainly in neonatal intensive care units, was achieved by nursing and consists of efforts that lead to a new challenge: the improvement of the practice of this procedure. This study determined and evaluated the theoretical and practical knowledge acquired by nurses in qualification courses concerning aspects of PICC line insertion in the case of newborns. This descriptive and quantitative study used a questionnaire with nine questions to collect data. The study population was composed of 40 nurses qualified to insert a PICC line in newborns. According to the conceptual knowledge scale established for this study, the results reveal that the nurses have inadequate knowledge concerning the studied aspects, indicating the need for nurses to constantly update and improve their knowledge about this practice so as to better the quality of care delivered to newborns.
Hardening Behavior of Sweetclover (Melilotus Spp.) Varieties in a Subarctic Environment1
Authors: Hodgson H. J. , Bula R. J.
Published: July 2010

Synopsis

Eleven sweetclover varieties were evaluated for winter survival, carbohydrate reserves, trends of cold resistance development, and nitrogen content of root tissue. Arctic, Brandon dwarf, Erector, and Alpha were the only varieties to give any appreciable winter survival. Carbohydrate reserves were adequate in all varieties. Arctic, Brandon dwarf, and Erector showed significantly higher cold resistance and content of various nitrogen fractions. The possible role of various nitrogen fractions in cold resistance development is discussed. Water soluble protein appeared most closely associated with cold resistance.
Flowering Response and Winter Survival in Seedling Stands of Medium Red Clover1
Authors: Smith Dale
Published: July 2010

Synopsis

Date of seeding influenced markedly the number of medium red clover plants that flowered during the seedling year. Plants that flowered were winterkilled more than nonflowering plants, and certain plant types winterkilled more than others. The variability in plant types occurring in spaced populations following certain seeding dates may aid in selection programs.
Competition and Natural Selection in Soybean Varietal Composites1
Authors: Mumaw C. R. , Weber C. R.
Published: July 2010

Synopsis

Composites of pure line varieties grow at the same location showed marked varietal changes during 5 seasons. Varieties having taller height, later maturity, more lodging and greater branching habit increased in proportion suggesting a limitation in the bulk hybrid method of plant breeding. Composites of unlike varieties exceeded the mean yield of their pure lines by more than Composites of similar varieties. Seed number was more important than seed size in the yield advantage of composites. Branching types yielded more than non‐branching types in composites.
The Effect of the Mammoth Gene on Certain Quantitatively Inherited Characters of Flue‐Cured Tobacco1
Authors: Mann T. J. , Chaplin J. F.
Published: July 2010

Sypnosis

Mammoth selections of flue‐cured tobacco produced fewer pre‐topping suckers, more leaves, fewer post‐topping suckers, higher yields, greater acre values, and lower values per hundredweight than did their dayneutral recurrent parents. In certain families yield increases were obtained through the use of the mammoth gene without loss in quality.
The Nutrient Content of Fescue and Orchardgrass and Amino Acids in Other Grassland Species1
Authors: Kik M. C. , Staten R. D.
Published: July 2010

Sypnosis

Samples of several grasses and legumes were collected throughout the growing season and analyses were run to determine the amount of vitamins, minerals and amino acids contained in fescue and orchardgrass and the amino acid content in 20 other herbage species. The average values for all species are presented. The amino acid values are in percent of total crude protein. The vitamin content for fescue and orchardgrass includes all known members of the vitamin B complex.
The Effect of Different Fertility Levels on Yield, Persistence, and Chemical Composition of Alfalfa1
Authors: Gerwig John L. , Ahlgren Gilbert H.
Published: July 2010

Synopsis

Potash was the most important factor in maintaining high yields and persistence of an alfalfa stand. The “critical percentage” for potassium content varied from season to season and probably lies somewhere between 1.42 and 1.84%. Nitrogen fertilization tended to decrease yields and stands whereas phosphorus had no significant beneficial effect.
Responses of Resistant and Susceptible Wheats to Hessian Fly Attack1
Authors: Cartwright W. B. , Caldwell Ralph M. , Compton Leroy E.
Published: July 2010

Synopsis

Hessian fly resistant wheats infested at first leaf stage, unlike susceptible wheats, undergo little stunting of subsequently developed leaves. Larvae migrated normally downward, but were constantly carried upward by the elongating second leaf. Four days after hatching, most larvae had died in the sheath column and were subsequently carried upward and above the enclosing leaf sheath.

Normal growth of resistant leaves appears detrimental to larvae, but its relationship to the initial lethal effect is not understood.
Effect of Harvest Dates and Location on the Genetic Composition of the Syn1 Generation of Pilgrim Ladino Clover1
Authors: Stanford E. H. , Laude Horton M. , Enloe J. Alton
Published: July 2010

Synopsis

Parental clones of Pilgrim Ladino clover differ in their seed producing ability. The relative amounts of seed produced by individual clones vary with harvest dates and areas of production. Pollen contributions of the individual clones also differ. If genetically uniform lots of breeders’ seed are to be produced, they must be produced under similar environmental conditions.
The Distribution of Normal and Toxic Amounts of Boron in Leaves of Rough Lemon
Authors: Oertli J. J.
Published: July 2010

Synopsis

The distribution of boron in rough lemon leaves is non‐uniform. Concentrations can be found in areas near the tip a hundred times higher than that in the petiole. Symptoms of disorders in boron nutrition are reflected in the boron distribution in the tissues.
Effect of Irrigation and Deep Fertilization on Yields and Root Distribution of Selected Forage Crops1
Authors: Boehle John , Kardos Louis T. , Washko John B.
Published: July 2010

Synopsis

Irrigation was effective in increasing total forage production in 1957 but not in 1958. In both years, however, irrigation prior to the first harvest did not increase yields. Deep fertilization was ineffective in increasing forage production. Alfalfa, alone and with orchardgrass, was the only species whose root yield was increased by deep fertilization. Alfalfa, alone and with orchardgrass, made the best use of available subsoil moisture; orchardgrass made the least use of this moisture.
Trends of Cold Resistance and Chemical Changes Over Winter in the Roots and Crowns of Alfalfa and Medium Red Clover. I. Changes in Certain Nitrogen and Carbohydrate Fractions1
Authors: Jung G. A. , Smith Dale
Published: July 2010

Synopsis

Cold resistance increased from late September to mid‐December. A high level was maintained until February or early March. Resistance was lost slowly until early April and rapidly thereafter. In general, each nitrogen and carbohydrate fraction increased in content during the fall, was at its highest level sometime during the fall or winter, and then decreased during the spring. Correlation coefficients of the trends of the chemical fractions with the trend of cold resistance were significant in many cases.
Influence of Oxygen Diffusion Rate on Sunflower Growth at Various Soil and Air Temperatures1
Authors: Letey J. , Stolzy L. H. , Valoras N. , Szuszkiewicz T. E.
Published: July 2010

Synopsis

Oxygen diffusion rates increased 1.8% per degree centigrade rise in soil temperature for a given surface oxygen concentration. When diffusion rates are low, higher soil or aerial temperatures are more detrimental to shoot growth than lower temperatures. Regardless of temperature, roots did not grow when oxygen diffusion rates were less than 20 × 10−8 g. cm.−2 min.−1. A higher diffusion rate was required to maintain optimum root growth under higher aerial temperatures but was affected very little by soil temperature.
Vegetative Development of Alfalfa Seedlings under Varying Levels of Shading and Potassium Fertilization1
Authors: Matches Arthur G. , Mott G. O. , Bula R. J.
Published: July 2010

Synopsis

Two levels of shading imposed 6 weeks after planting had more apparent effect upon the root and top dry weight accumulation of 3 alfalfa varieties than upon their height, root length, or root/top ratio. Root dry weight accumulation was much more sensitive to shading than top dry weight accumulation. Potassium fertilization affected plant height, root length, root dry weight accumulation, and the root/top dry weight ratio. Interactions of the second and third order were noted in several cases.
Yield Response Surfaces, Isoquants, and Economic Fertilizer Optima for Coastal Bermudagrass1
Authors: Welch L. F. , Adams W. E. , Carmon J. L.
Published: July 2010

Synopsis

Yield data from a 4 by 4 by 4 NPK factorial experiment with Coastal bermudagrass on Cecil soil are used to obtain a yield equation by multiple regression. The yield equation is then used in calculations for response surfaces, isoquants, and economic fertilizer optima.
Root Activity Distribution Patterns of Sorghum and Soil Moisture Conditions1
Authors: Nakayama F. S. , van Bavel C. H. M.
Published: July 2010

Synopsis

Relative root activity measurements using P32 uptake and soil‐water depletion data show that approximately 90% of root activity of sorghum plants occurred in the top 3 feet. Root growth rates were from 0.75 to 2.0 inches per day.
Comparative Effects of Flooded and Unflooded Soil Conditions and Nitrogen Application on Growth and Nutrient Uptake by Rice Plants1
Authors: Chaudhry M. S. , McLean E. O.
Published: July 2010

Synopsis

Unflooded conditions caused delayed flowering, high percentage sterility, and consequent low yields. Nitrogen increased the cation exchange capacity of the roots and increased the yields when applied to the flooded soil at tillering stage. Plant P and Mn contents were low under unflooded conditions, but this did not appear to be the basic cause for the abnormal growth under these conditions.
Effect of Date of Planting on Yield, Plant Height, Flowering, and Maturity of Rape and Turnip Rape1
Authors: Gross A. T. H.
Published: July 2010

Synopsis

In 2 out of 3 years a significant negative correlation was obtained between seed yield and sowing date. Yield was highest when seeded on May 8. Delay in seeding resulted in later maturity, reduction in plant height, and reduction in time required for vegetative and reproductive development.
Relationship Between Rate of Stocking and Per Animal and Per Acre Performance on Pasture1
Authors: Petersen R. G. , Lucas H. L. , Mott G. O.
Published: July 2010

Synopsis

Quantitative theory indicates that gain per animal is constant as stocking rate is increased to a “critical” point. Beyond this point gain per head is inversely related to stocking rate. Gain per acre increases linearly as stocking rate is increased to the “critical” point, then decreases linearly with further increases in stocking rate.
Sulfur and Nitrogen Content of Alfalfa Herbage During Growth1
Authors: Pumphrey F. V. , Moore D. P.
Published: July 2010

Synopsis

Sulfur fertilization increased the sulfur and nitrogen content and yield of alfalfa herbage. Percent sulfur was highest in the young growth and declined at a near linear rate for both deficient and nondeficient plants. The use of a critical level of sulfur in alfalfa herbage needs to be associated with a definite stage of growth. The nitrogen to sulfur ratio in the herbage was nearly constant at all stages of growth and was much narrower in the nondeficient than in sulfur‐deficient herbage.
Chemical Fallow Studies in Winter Wheat Fallow Rotations in Western Nebraska1
Authors: Fenster C. R. , Burnside O. C. , Wicks G. A.
Published: July 2010

Synopsis

Rates of 2 lb./A. or more of 2‐chloro‐4‐ ethylamino‐6‐isopropylamino‐s‐triazine (Atrazine) or 2‐ methoxy‐4,6‐bis (isopropylamino) ‐s‐triazine (Prometone) were necessary to give satisfactory weed control during the fallow period in an alternate wheat fallow rotation. However, these rates frequently injured the following wheat crop. Climatic and edaphic factors affected phytotoxicity and soil persistence of the herbicides.
Soil and Alfalfa Plant Characteristics as Affected by a Decade of Fertilization1
Authors: Hanson Roger G. , MacGregor John M.
Published: July 2010

The 10‐year field study indicates annual top‐dressings of K are needed to maintain a dense stand for high yields of quality alfalfa on sloping Port Byron silt loam. Total yield increases were related to total quantities of P or PK applied, with largest increases obtained from annual K with P top‐dressings.

Contents of P and K in 10‐year‐old alfalfa were related to quantities of these elements applied. The P and K concentrations generally were highest in the third cutting and lowest in the second.

There appeared to be little movement of P below the surface 3 inches and little movement of K below 6 inches in Port Byron silt loam during the ten years of the experiment.
Mixtures of Hard Red Winter Wheat Cultivars1
Authors: Shaalan M. I. , Heyne E. G. , Lofgren J. R.
Published: July 2010

Four hard red winter wheat (Triticum aestivum L. em. Thell.) mixtures of three components each, two of adapted cultivars and two of similar phenotypic strains, were studied with component lines for 7 years at two locations. Equal portions of three adapted cultivars or similar phenotypic strains were used to form an original mixture the first year and a reconstituted mixture in succeeding years. Components of each mixture were selected to allow ease of identity to ascertain what ratio changes occurred in a mixture. Yield, test weight, and ratio change were the characteristics evaluated. Data indicate that the annually reconstituted mixture was more stable in performance than the original mixture or the component strains. Year‐to‐year variation apparently can be reduced by employing annually reconstituted mixtures. However, the average performance of mixtures of adapted cultivars or mixtures of similar phenotypic strains was not superior to that of the best component.
Wind and Sandblast Injury to Seedling Green Beans1
Authors: Skidmore E. L.
Published: July 2010

Seedling green beans were subjected to various combinations of windspeed (20, 30, and 40 mph), abrasive flux (0, 0.2, 0.4, and 0.6 ton per rod width per hour of sand), and duration of exposure (5, 10, and 15 minutes) in a wind tunnel. Wind alone with speeds up to 40 mph caused only slight damage, Introduction of as little as 0.2 ton per rod width per hour of sand into the windstream greatly increased plant injury. However, additional increases in abrasive flux causesd no proportionate increase in plant injury. Plant damage increased linearly and bean yields decreased almost linearly with increase in windspeed and duration of exposure. Although the plants abraded at 20 mph sustained injury, they recovered sufficiently to yield well. The yield of plants abraded at 30 and 40 mph decreased with increased sand flux.
Influence of 2‐Chloroethyltrimethylammonium Chloride (CCC) on Wheat (Triticum aestivum L.) When Applied as a Seed Treatment1
Authors: Appleby A. P. , Kronstad W. E. , Rohde C. R.
Published: July 2010

The growth of wheat seedlings from seed treated with a .5% CCC solution was studied under greenhouse conditions. Length of coleoptile, length of culm to first leaf blade, total shoot length, and dry weight of shoots were reduced by the seed treatment. Length of longest root and dry weight of roots were not reduced appreciably after the initial week of growth.

A method of applying CCC as a dust treatment to wheat seed was developed and used in field experiments. Considerable differences in varietal response for a number of agronomic characteristics were found in replicated field experiments over a 2‐year period. The stand of ‘Gaines,’ a semidwarf variety, was reduced, the stands of ‘Omar’ and ‘Golden’ were increased, and the stand of ‘Brevor’ was not affected. Yield increases were found in the three tall varieties while a reduction in yield was noted for the semidwarf variety. Straw‐grain ratio was reduced in all four varieties. Effect of CCC on lodging resistance could not be evaluated.
Nitrogen and Dry Matter in Five Spring Wheat Varieties at Successive Stages of Development1
Authors: McNeal F. H. , Berg M. A. , Watson C. A.
Published: July 2010

Dry weight and nitrogen content of leaves, stems, kernels, and roots were determined for five spring wheat varieties on seven dates.

Maximum leaf development occurred by July 19 (flowering), and maximum stem development ocurred by July 29 (filling). By August 19 (maturity) the top weights were similar for all varieties except ‘Mindum’, which was significantly higher. The average ratio of root (to 5‐ft depth) to top growth on August 19 was 1:14.9.

Uptake of nitrogen continued until harvest, although the rate was much slower after July 19. Nitrogen content in the roots was low at all sampling dates, indicating rapid translocation to aboveground parts. If all root nitrogen had been translocated to the kernels, the effect on kernel nitrogen would have been insignificant. The average ratio of root to top nitrogen on August 19 was 1:23.4.

The r value of 0.95 between pounds of kernel nitrogen and pounds of top dry weight indicates that 90.2% of the variation in kernel nitrogen in this experiment is due to differences in plant dry weight. This leaves only 9.8% of the variation in kernel nitrogen which the plant breeder might be able to manipulate.

We suggest that if wheat varieties which will translocate as much as 70% or more of leaf and stem nitrogen to the kernels can be found, they might be useful in breeding programs.
Conditioning Dry Bean Seed (Phaseolus vulgaris L.) for Better Processing Quality and Seed Germination1
Authors: Dexter S. T.
Published: July 2010

Bean windrows were sprayed with water to prolong or induce seedcoat toughening that protected the beans from cracking during combining without appreciably increasing their percentage moisture. After combining, the desired amount of moisture was added by mixing a suitable quantity of dampened sawdust with the beans and screening after various intervals. This would protect the beans during the processes of unloading, conveying, screening, and binning. With undesirably dry beans in the bin, moisture was added by circulating warm air at a relative humidity of about 75%. Seed beans, too dry to be drilled without damage to germination, were toughened with damp sawdust and seedling emergence was greatly improved. Damage incurred during combining was not nullified by later conditioning, but further damage could be prevented.
Some Interrelationships between Fertility Levels and Ophiobolus Patch Disease in Turfgrasses1
Authors: Goss Roy L. , Gould Charles J.
Published: July 2010

Ophiobolus patch disease developed rather quickly on young bentgrass turf after an initial methyl bromide fumigation. The disease occurred at random in 1961, but generally was much worse on plots receiving 9.8 kg of N per 100 m3 per season, regardless of P and K levels, than on plots receiving less or no N. However, by 1964, Ophiobolus patch was much more severe in the 5.9 kg of N plots than in those receiving 2.9 or 9.8 kg of N. Phosphorus had little effect on the disease in 1961, but by 1964 plots treated with 0.86 kg of P had only 15% as much infection as those receiving 0 P. Potassium exhibited a suppressing effect on the amount of disease throughout the experiment regardless of the P level. There was about five times as much disease in the 0 P and 0 K plots in 1964 as in the 0 P and 1.6 kg of K plots at all N levels. Interactions between P and K probably account for some of this difference, since this does not occur when P is added.
Influence of Limestone and Nitrogen on Soil pH and Coastal Bermudagrass Yield1
Authors: Adams W. E. , Pearson R. W. , Jackson W. A. , McCreery R. A.
Published: July 2010

‘Coastal’ bermudagrass was grown on an extremely acid Cecil sandy loam soil in order to study the influence of limestone rate (0, 7,846, and 40,349 kg/ha), limestone placement (surface and mixed), and N levels (0, 224, 448, 896, and 1,793 kg/ha) on forage production, rooting, and changes in soil properties.

Without limestone, annual forage production declined with time at the 448‐kg/ha N level and above, and Coastal bermudagrass plants exhibited a severe chlorosis. At the two highest N levels (896 and 1,793 kg/ha), up~o 90% of the plants died.

Limestone increased annual forage yields at N rates of 896 kg/ha and above. Mixing the limestone with the surface soil resulted in significantly higher forage yields at the 1,793‐kg/ha level. The movement of Ca and Mg into all soil zones down to the 30‐ to 45‐cm zone confirmed the changes in soil pH.

Soil pH was reduced by annual applications of 448 kg/ha of 1N and forage yields of Coastal bermudagrass were severely restricted.

Coastal roots penetrated to 120 cm in soil with a range in pH from 4.0 to 4.5, emphasizing the extreme tolerance of this grass to very low soil pH.
Effect of Leaf Removal at Four Stages of Growth on Yield of Castorbeans1
Authors: Kittock D. L. , Williams J. H.
Published: July 2010

Removal of castorbean (Ricinus communis L.) leaves at four growth stages at the rates of 1/4, ½, 3/4, and total defoliation resulted in lower yields than the check. Differences between most partial defoliation treatments were not large enough to be significant. Stage of growth when partial defoliation treatments were applied had no significant effect on yield. Total plant defoliation at each of the four dates resulted in yields that were significantly lower than the check. Differences between dates were also significant. Regrowth following the first two total defoliations produced yields that were adequate to justify continuation of fields under farm conditions. Best yield recovery occurred following defoliation at the bloom stage of the primary raceme.

Alternaria leaf spot [Alternarla ricini (Yoshii) Hansford] infection occurred after tertiary racemes started blooming but before quaternary racemes started blooming.
Physical State of Water in Plant Xylem Vessels1
Authors: Cary John W. , Jensen Marvin E. , Fisher Herbert D.
Published: July 2010

The vapor pressure psychrometer was used as a tool to study the physical state of water in plant xylem vessels. The experimental procedure involved measuring the change in diffusion pressure deficit (DPD) of corn and tomato plants when the stem was cut. When the DPD was greater than 4 bars in tomatoes and 28 bars in corn, the water in xylem vessels no longer appeared to flow in response to hydrostatic pressure gradients. The limiting value of DPD increased as the xylem radius decreased. A mechanism is suggested which describes the physical state and the movement of water through xylem tissue under high DPD. The proposal is based on the pressure difference across a curved air‐water interface and on the concept of an electrostatic double layer with its associated osmotic pressure.
Downy Brome Competition and Control in Dryland Wheat1
Authors: Rydrych D. J. , Muzik T. J.
Published: July 2010

Competition between downy brome (Bromus tectorum) and winter wheat causes serious economic losses to growers in the Pacific northwest. On a site which received 25 cm average annual rainfall and had a light soil (very fine sandy loam) winter wheat yields were reduced 28% by fewer than 54 downy brome plants per m2 (5 plants/ft2). On a site which received 55 cm average annual precipitation and had a silt loam soil, winter wheat yields were reduced 92% by more than 538 downy brome plants per m2 (50 plants/ft2). Downy brome seed‐to‐straw ratios were indicative of a tremendous yield potential. Seed‐straw ratios of 1:4 are probably an exception but ratios of 1:1 and 1:2 were common.

Chemical fallow studies at three sites showed that nonselective downy brome control can be obtained by the use of herbicide combinations such as 3‐amino‐l‐2, 4‐triazole‐ammonium thiocyanate (amitrole‐T), plus chloro‐4‐ethylamino‐6‐isopropylamino‐s‐triazine (atrazine) or amitrole‐T plus 2,4‐dichlorophenoxyacetic acid (2,4‐D). Amitrole‐T plus atrazine was more effective when used as a fall treatment. Amitrole‐T plus 2,4‐D was more effective in the spring. These chemicals reduced tillage requirements and decreased downy brome growth by 90%.
Cumulative Effects of Irrigation and Fertilizer on Soil Fertility1
Authors: Vittum M. T. , Lathwell D. J. , Gibbs G. H.
Published: July 2010

Irrigating Lima and Kendaia silt loam soils with an average of 10.7 cm of water each year for 13 years caused no change in soil pH, organic matter, or available P, Ca, and Mg. Irrigation significantly reduced available K from an average of 109 kg/ha in nonirrigated plots to an average of 97 kg/ha in irrigated plots.

Applying an extra 30 kg of P and 54 kg of K per hectare each year for 14 years significantly reduced soil pH, had no effect on organic matter, Ca, or Mg, and significantly increased available P and available K. At the end of the experiment, normal fertility level plots contained 25 and 96, and high fertility level plots contained 37 and 109 kg of available P and K per hectare, respectively.
Effect of Early‐Summer Seeding of Winter Wheat on Yield, Soil Moisture, and Soil Nitrate1
Authors: Dewey W. G. , Nielson R. F.
Published: July 2010

Winter wheat was planted at monthly intervals from June through October at four irrigated and three dryland sites in northern Utah over a 4‐year period. The effects of planting date on grain yield, soil moisture and soil nitrate were studied.

At the dryland locations the June and July plantings exhausted most of the available moisture and nitrate to the greatest depths sampled (150 and 90 cm, respectively) by fall of the establishment year, thus largely negating the benefits of the fallow summer. Yields of the June‐seeded plots averaged approximately 1/10 those of plots planted in August, September, or October.

In the irrigated trials soil moisture and nitrate levels were maintained near optimum through frequent irrigation and the addition of nitrogen fertilizer; yet, as in the dryland tests, yields in the early‐seeded plots were significantly below those of plots seeded at the later planting dates. Disease, winterkill, and possibly physiological old age appeared to be the major factors limiting yields of early‐seeded winter wheat grown under irrigation.
Mineral Composition of Six Tropical Grasses as Influenced by Plant Age and Nitrogen Fertilization
Authors: Gomide J. A. , Noller C. H. , Mott G. O. , Conrad J. H. , Hill D. L.
Published: July 2010

This study was conducted in central Brazil on a sandy loam soil which under normal conditions receives no fertilizer. The K, P, Ca, Mg, Cu, Mn, Fe, and Zn contents were determined on six grasses: Meilinis minutiflora Beauv., Digitaria decumbens Stent., Pennisetum purpureum Schum., Pennistetum clandestinum Hochst., Cynodon dactylon Pers., and Panicum maximum Jacq. var. ‘Gondlyodes Doell’

Significant decreases in K, P, Mg, Cu and Fe in the forages (P < .01) occurred with advance in plant age from 4 to 36 weeks. The average K content for all grasses at 4 weeks of age was 1.42% and at 36 weeks of age 0.30%. Kikuyugrass had the highest K content at 36 weeks of age (0.54%). The average P content for all grasses was 0.26% at 4 weeks and 0.12% at 36 weeks. Pangolagrass appeared to be a poor source of P at all ages studied (average 0.12%).

Nitrogen fertilizer had no effect on any of the minerals studied except for Mn which increased with N fertilization.

Under the conditions of the experiment, the forages could be deficient in K and P for cattle and borderline in zinc.
Long‐Term Fertility Requirements of Coastal Bermuda. II. Nitrogen, Phosphorus and Lime1
Authors: Woodhouse W. W.
Published: July 2010

Data are presented on the effect of N, P and L variables applied over a 14‐year period on growth and chemical composition of coastal bermudagrass grown on a Eustis sand. N response was around 45 kg of hay per kg of N for rates up to 224 kg/ha with recovery of applied N in the range of 75 to 90%. Yield response flattened off rapidly beyond the 224 kg rate and N recovery declined rapidly beyond this point. The continued application of higher rates of N, 448 and 672 kg, produced a strongly acid reaction in the soil profile throughout the 30 to 240 cm zone, and this appears to have contributed to the relatively poor response at these levels of applied N. The application of only 1120 kg/ha of dolomitic limestone after 11 years of crop removal on an unlimed treatment produced an immediate and rather dramatic yield response. This appeared to be related to Mg supply. Around 25 ppm of soluble P in the plow layer appeared to be adequate, with critical level of P in the plant between 0.11 and 0.14% and optimum between 0.15 and 0.20%.
Factors Affecting the Alkaloid Content of Tall Fescue (Festuca arundinacea Schreb.)1
Authors: Gentry C. E. , Chapman R. A. , Henson L. , Buckner R. C.
Published: July 2010

The alkaloid content of tall fescue (Festuca arundinacea Schreb.) was investigated in seed and different stages of maturity during plant growth from seed to mature plants by paper and thin‐layer chromatography. Eleven alkaloids were found in a selection of Ky 31.

No alkaloids were found in seed of Alta, Goar, or NK 36, whereas 3 alkaloids were present in seed of ‘Kenwell’ and ‘Ky 31’. The initial rate of alkaloid synthesis was much higher in Ky 31 than in ‘Alta’. In young seedlings of both varieties perloline, the predominate alkaloid, was detected in the seed and roots as early or earlier than in the shoot. Leaves from mature plants, contained 44% as much perloline and 61% as much total alkaloid as stems.

Significant differences occurred in alkaloid content among and within varieties, and among various plant parts. Potassium and phosphorus greatly reduced perloline whereas nitrogen increased perloline synthesis. Perloline and total alkaloid content were reduced as the plant approached maturity. Pasture plants contained the largest concentration of alkaloids, whereas alkaloid content was drastically reduced when the plant material was field‐cured as hay.
Crop Seedling Uptake of DDT, Dieldrin, Endrin, and Heptachlor from Soils1
Authors: Beal M. L. , Nash R. G.
Published: July 2010

In greenhouse experiments, soybean, wheat, corn, alfalfa, bromegrass, and cucumber seedlings took up various amounts of DDT, dieldrin, endrin, and heptachlor residues from five soils treated with 0.5 or 5.0 ppm insecticide. Residue concentrations in plants were usually well below the soil treatment rates, though endrin and heptachlor residues in alfalfa and bromegrass exceeded the treatment rate of some soils. The order of residue uptake in increasing amounts was DDT < dieldrin < endrin < heptachlor.

Correlations calculated between residues in seedlings and several soil characteristics revealed that organic matter negatively affected the uptake of DDT, dieldrin, and heptachlor. Silt negatively affected endrin uptake. Soil moisture content at 0.33 bar tension negatively affected DDT and dieldrin uptake by alfalfa. No significant correlations were found between uptake and soil pH, cation exchange capacity, or clay content.

Soil analysis, 14 or 20 months after insecticide application, revealed residues of the insecticides, in increasing order of persistence, to be heptachlor < dieldrin ≈ endrin < DDT. Correlations calculated between residues in soils and the soil characteristics above, revealed that persistence was positively correlated with soil organic matter.
Effects of Tillage, No Tillage, and Mulch on Soil Water and Plant Growth1
Authors: Jones J. Nick , Moody J. E. , Lillard J. H.
Published: July 2010

Seedbeds for corn (Zea mays L.) were prepared by both conventional tillage and the no‐tillage method, each with and without surface mulches. The mulches consisted of killed grass sod on the no‐tillage plots and straw applied on plots with conventional tillage. No‐tillage plots without a mulch were obtained by removing the killed sod. Mulched treatments, whether of undisturbed killed sod on the no‐tillage plots or of straw on conventional plots, gave the lowest values for runoff and the highest values for soil water content and yield of corn. Soil water conserved by the mulches was reflected in an average grain yield increase of 1,932 kg/ha. Differences in total soil water among treatments were significant to a depth of 30 cm. The effect of tillage was minor, but the data indicate the value of the killed sod mulch in the no‐tillage system.
Effect of Soil Gas Composition and Flooding on Growth of Nicotiana tabacum L1
Authors: Williamson R. E.
Published: July 2010

The responses of Nicotiana tabacum L. to flooding and to soil treatments consisting of combinations of O2, CO2) and N, gases were determined from leaf area and plant height changes and from final root weights. Leaf area and plant height were measured before treatment and after a 5‐day recovery period following treatment; root weights were obtained after the recovery period. The plants were grown in acrylic containers of soil located in an artificially lighted, controlled environment room.

Flooding and pure N2 treatments for 24 hours almost prevented further growth. After 48‐hour treatments with pure N2 and flooding, roots and shoots were almost dead. Growth of plants treated with 1% O2 or 1% O2 + 20% CO2 was significantly less than that of the control. The 1% O2 + 20% CO2 treatment reduced leaf growth significantly more than did 1% O2. Although 1% O2 and 1% O2 + 20% CO2 caused injury, plants treated with these gaseous mixtures exhibited near normal growth at the end of a 5‐day recovery period. Permanent injury of tobacco by flooding is primarily due to lack of O2 in the root zone and not to excess CO2. Results obtained in the soil system were similar to those previously obtained in spray nutrient solution culture.
Effect of Phosphorus on Nitrate in Sugar Beet (Beta vulgaris L.)
Authors: Hills F. J. , Sailsbery R. L. , Ulrich Albert , Sipitanos K. M.
Published: July 2010

Culture‐solution and field experiments indicate that P‐deficient sugar beets, particularly young plants, do not take up nitrate as well as plants adequately supplied with P. The increase in concentration of NO3‐N in whole tops of young seedlings, cotyledons, or petioles of first true leaves with increased P supply is greater than can be accounted for by a concomitant decrease in percent dry‐matter of these plant parts. The decreased absorption of NO3 by P‐deficient plants in aerated culture‐solution, with all roots exposed continuously to high concentrations of NO3 indicates that the phenomenon reflects not merely increased root extension but a physiological aberration brought about by P‐deficiency.
Nitrate and Ammonium as Sources of Nitrogen for Corn and Their Influence on the Uptake of Other Ions1
Authors: Blair Graeme J. , Miller M. H. , Mitchell W. A.
Published: July 2010

No yield differences in tops or roots were measured between ammonium and nitrate nitrogen sources in flow ‘United 108’ grown for 14 or 28 days in constant flow culture solution. There was a greater uptake of N from the nitrate source but approximately 25% of the total uptake remained as nitrate within the plant. Higher plant levels of phosphorus and sulphur were measured in the ammonium treatment and higher Ca++ and Mg++ in the nitrate treatment indicating a predominately cation‐anion balance effect.
Nitrogen Increases in a Non‐nodulating Soybean Genotype Grown with Nodulating Genotypes1
Authors: Vest Grant
Published: July 2010

Seeds of non‐nodulating soybean (Glycine max (L.) Merrill) genotype A62‐8 were mixed in a 1:1 ratio with seeds of nodulating genotypes ‘Delmar’ and ‘Scott’. Prior to planting, the mixtures were inoculated with 7 different strains or combinations of strains of Rhizobium japonicum. A62‐8 mixed with Delmar yielded significantly more with certain inoculum treatments than when the mixture was uninoculated. However, when mixed with Scott the yields of A62‐8 did not differ with inoculum treatments. The seed protein of A62‐8 was higher when the mixtures were inoculated than when uninoculated. The yield and protein percentage of inoculated Delmar and Scott were also significantly higher than the uninoculated checks. The amount of nitrogen fixed in each mixture‐inoculum combination was estimated by using yield and protein data from each genotype.
Nitrogen Accumulation in Fescuegrass Sod1
Authors: Giddens Joel , Adams W. E. , Dawson R. N.
Published: July 2010

Tall fescuegrass (Festuca arundinacea) was seeded in Cecil sandy loam for 5 years in separate plots. Established fescuegrass plots were plowed and planted to corn during the same period. In 1968 both areas were plowed and planted uniformly to corn (Zea mays). Total N, carbon, organic residues, bulk density, and aggregation were determined on the soils of both areas. Soils from both areas were planted to sudax in the greenhouse.

Yields increased from 2,728 kg/ha for continuous corn to 5,940 kg/ha for corn following 5 years of fescuegrass. After destruction of sod, corn yield decreased in 5 years from 5,018 kg/ha to 3,205 kg/ha. Sudax yields showed similar trends. Topsoil N increased from .047% to .088% as result of grass, and decreased from .078% to .054% as result of turning the grass. Soil carbon showed similar relationships. Soil bulk density and aggregation were not significantly affected by treatments. It was concluded that nonsymbiotic N fixation accounted for part of the nitrogen increase in fescuegrass sod and nitrogen conservation the remainder.
Kinetics of P Absorption by Excised Roots and Leaves of Corn Hybrids1
Authors: Phillips James W. , Baker D. E. , Clagett C. O.
Published: July 2010

The kinetics of phosphate uptake was studied using H332PO4 to determine if the observed differences in accumulation of inorganic phosphate by corn hybrids could be explained on the basis of genetic differences in the mechanism of absorption. The absorption of phosphate by corn roots was found to be similar to that for barley roots in that two independent mechanisms of ion absorption were observed. Vmax for the absorption at high concentration was 40 × 10−8 mole P/Mg root × hour, while that of the low concentration reaction was 1× 10−8 mole P/Mg root × hour. The Km for the high and low concentration reactions were 2 × 10−1 and 10−4 mole P/liter, respectively.

No difference was observed in the kinetics of uptake of phosphate by roots of the corn hybrids studied. Phosphate absorption by excised leaves was found to be different for the high and low phosphorus accumulators. The difference in absorption rates suggests a difference between hybrids in the strength of the phosphorus‐carrier bond. The variation observed between hybrids was sufficient to account for a 1.6‐fold difference in accumulation of phosphate.
In Vitro Dry‐Matter Digestibility of ‘Midland’ Bermudagrass Grown at Several Levels of N Fertilization1
Authors: Fribourg Henry A. , Edwards Ned C. , Barth Karl M.
Published: July 2010

‘Midland’ bermudagrass [Cynodon dactylon (E.) Pers.] was grown at three locations without and with N fertilizer applied at several rates; four replications of a randomized complete block (RCB) design were used at each location. Dry‐matter yields of about 4 t/ha were produced by the no‐N treatment. This was doubled by adding 133 kg/ha of N and doubled again when 400 kg/ha of N were added. The 800 kg/ha of N treatment produced 2.5 t/ha more than the 400 kg/ha treatment. To ascertain the effects of N fertilization on in vitro dry‐matter digestibility (DDM), samples were composited from the four‐field replications of each harvest at each location. Four aliquots, one for each of four replications of a 9 ∗ 9 balanced lattice design (173% efficiency compared to RCB) were taken from each composite sample. Each replication was a run using one inoculum from a rumen‐fistulated steer fed Midland bermudagrass. The average DDM increased from about 37 to 46% over the range of applied N. The greatest increase occurred as the N rate was increased from 133 to 400 kg/ha. The yield of DDM was increased from about 1.5 to 9.0 t/ha with increasing N applications.
Double Cropping Following Winter Barley Harvest in Eastern Virginia1
Authors: Camper H. M. , Genter C. F. , Loope K. E.
Published: July 2010

Soybeans (Glycine max L.) for grain and sorghum (Sorghum vulgare L.) and maize (Zea mays L.) for both grain and silage were planted in late June and in July following winter barley (Hordeum vulgate L.) to evaluate these crops in a double cropping system in eastern Virginia. Soybeans have been widely grown after barley in that area. Production and harvest costs were estimated and net returns were calculated from these estimates and the values of the crops produced.

Grain yields were obtained over a 2‐year period. Both mid‐season and late maturity soybeans produced crops of satisfactory quality each year. Early or very early maturity sorghum and maize hybrids were planted and appeared to be satisfactory for grain when planted in June but one July planting was severely damaged by an early frost.

When the June plantings were harvested for grain, the net return from maize was significantly greater than from either sorghum or soybeans. Soybeans, however, appeared to be more dependable than maize or sorghum for grain if planted in July.

Maize and sorghum silage yields were obtained the second year of the experiment. Net returns from both crops for silage were consistently greater at each date of planting than from any grain crop. All but one of the differences were significant. Net returns were greater from sorghum silage than from maize at each date of planting and the difference was significant for the July planting.

Better adapted strains of all three crops are needed for use in a double cropping system.
Orientation and Distribution of Leaves Within Soybean Canopies1
Authors: Blad Blaine L. , Baker Donald G.
Published: July 2010

‘Chippewa 64’ and ‘Hark’ soybean [Glycine max (L.) Merr.] varieties were studied at Lamberton and St. Paul, Minn. The average leaf sizes, numbers, and total leaf area index were determined during the growing season. The distribution of leaf area with height was obtained in the field and in a controlled environment chamber. The chamber‐grown plants exhibited a distribution similar to the area distribution of a cylindrical cross‐section. The field‐grown soybeans had most of the leaf area near the upper portions of the plant canopy and did not have a cylindrical distribution. These variations in leaf area distributions are largely explained by differences in the light intensities at the lower canopy levels with the different growing conditions.

Measurements of the azimuth directions of the soybean leaflets revealed that soybean leaves do not show any preferred direction. Leaf inclination distributions showed that soybean canopies were planophile through most of the growing season, except in the early and lategrowth stages, when the leaves were almost evenly distributed among all inclination classes. The Hark variety had smaller and slightly more vertically oriented leaves than the Chippewa 64 variety, which would allow greater penetration of light to the lower canopy levels.
Dryland Evaporative Flux in a Subhumid Climate: III. Soil Water Influence1
Authors: Ritchie Joe T. , Burnett Earl , Henderson R. C.
Published: July 2010

This investigation was conducted to determine the relationship between evaporative rates of field‐grown cotton (Gossypium sp.) and grain sorghum [Sorghum bicolor (L.) Moench] and the soil water status for use in predicting evaporation on watersheds.

Soil water content and soil water matric potential of Houston Black clay were measured throughout complete growing seasons for cotton and grain sorghum concurrently with measurements of the daily evaporation rate. Evaporation rates were independent of the soil water status until soil water was depleted beyond a threshold value. This threshold, termed the lower limit for potential evaporation (LLE0), was reached when approximately 18.2 cm of water had been removed from a soil profile initially wet. Another 6.5 cm of soil water was extracted at a decreasing rate before evaporation practically stopped. Evaporation rates after the LLE0 threshold was reached were practically independent of the energy available for evaporation and depended on the rooting distribution and the water movement to the roots. An analysis of the soil water transmission characteristics after the threshold LLE0 was reached showed that practically all the water extracted by plant roots was moving from the volume of soil immediately surrounding the roots. This result points out the need for growing crops with deep, dense root systems in dryland for maximum utilization of stored soil water.