bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy and CO2 Balance of an Irrigated Sugar Beet (Beta vulgaris) Field in the Great Plains1
Authors: Brown K. W. , Rosenberg Norman J.
Published: July 2010

The fluxes of latent heat and CO2 above an irrigated sugar beet (Beta vulgaris) field in the North Platte Valley of Nebraska were calculated by means of the energy balance. The advection of sensible heat to the field was large only when strong dry winds predominated or when the field acted as a leading edge of the irrigated river valley.

Little evidence was found of midday depression in sugar beet photosynthetic rate. Contrary to reported aerodynamic evaluations of CO2 flux in the field, the energy balance calculations do not reveal a relationship between wind speed and CO2 flux, except for a negative correlation during a dry windy period. This decrease was attributed to increased stomatal resistance.

The crop appeared to be light‐saturated at 0.8 cal cm‐2 min‐l short wave radiation. When CO2 flux is corrected for soil CO2 emission and plant respiration, agreement with plant sampling measurements of dry matter increase is good. Water use ranged from 171 g per g dry matter fixed on a cloudy day to an average of 365 g per g dry matter fixed on clear days. Since the sugar beet crop is saturated at less than full sunlight, water use is greater than is necessary for the production obtained.
Establishment of Crownvetch with Herbicides1
Authors: Peters E. J. , Lowance S. A.
Published: July 2010

A number of herbicides were evaluated preplant, preemergence, and postemergence as aids to the establishment of crownvetch (Coronilla varia L.) in the field. In five experiments, during the four years of the study, the degree of weed control and the density of the crownvetch stands were evaluated during the seedling year. Yields of crownvetch and weeds were determined the year following establishment.

Preplant applications of S‐ethyl dipropylthiocarbamate (EPTC), α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine (trifluralin), N‐butyl‐N‐ethyl‐α,α,α‐trifluoro‐2,6‐dinitro‐p‐toluidine (benefin), and a mixture of l,l‐dimethyl‐4,6‐diisopropyl‐5‐indanyl ethyl ketone and l,l‐dimethyl‐4,4‐diisopropyl‐7‐indanyl ketone (64‐296‐B) nearly eliminated all weed grasses and were somewhat better than preemergence and post emergence applications of 2,2‐dichloropropionic acid (dalapon) for controlling weed grasses. Mowing, in addition to the use of these herbicides, was necessary to control broadleaf weeds and to insure good stands of crownvetch. Stands of seedling crownvetch and yield the year following establishment were increased when herbicides and mowing were used during establishment.

Postemergence treatments with an amine and ester of 4‐(2,4‐dichlorophenoxy)butyric acid (2,4‐DB), 3,5‐dibromo‐4‐hydroxybenzonitrile (bromoxynil), and 3,4‐dichloro‐4‐hydroxybenzonitrile (chloroxynil) controlled broadleaf weeds but the herbicides injured seedling crownvetch and reduced its vigor. Bromoxynil and chloroxynil were more injurious to crownvetch than 2,4‐DB. Injury from 2,4‐DB, bromoxynil, and chloroxynil was such that use of the herbicides could be justified only where stands would be lost without practices to control broadleaf weeds.
Influence of Nitrogen Source on Phosphorus Uptake by Corn from Soils Differing in pH1
Authors: Blair Graeme J. , Mamaril C. P. , Miller M. H.
Published: July 2010

The objective of this study was to test the hypothesis that reduction of pH at the soil‐root interface when NH4+ ions were absorbed is the cause of the increased absorption of P in the presence of NH4+.

The influence of addition of (NH4)2SO4 or KNO3 to an MCP band on P absorption by corn was determined in a greenhouse study involving four soils ranging in pH from 4.2 to 8.2. The in‐situ activity of the corn plants was determined periodically during the growth, and the dry weight of tops and roots in the fertilizer zone as well as the nutrient content of the tops were determined after 17 days.

Application of (NH4)2SO4 with MCP was found to increase fertilizer P uptake when compared to MCP alone on soils of pH 8.2, 7.4 and 5.5. No difference was measured on a soil of pH 4.2. Accumulations of Ca and P were found on the root surface of the plants grown in the alkaline soils. Ca, Fe and P was found on the root surface in a soil with a pH of 5.5. No root surface accumulation was found at a soil pH of 4.2. Fertilizer P uptake at 9 days was greatest where NH4+ and least where NO3‐ accompanied the P. Changes in the soil‐root interface pH and resulting changes in the H2PO4‐/HPO4= ratio at the root surface which are modified by the inherent soil pH are implicated in these findings.
Residual Mineral N Accumulation in Soil and its Utilization by Irrigated Corn (Zea mays L.)1
Authors: Herron G. M. , Dreier A. F. , Flowerday A. D. , Colville W. L. , Olson R. A.
Published: July 2010

Field experiments on fine textured soils measured fertilizer and mineralized soil NH4‐N and NO3‐N accumulation in the rooting profile and the effectiveness with which this residual N was used by irrigated corn. At rates of 168 and 252 kg N/ha there were substantial N gains in the 180 cm soil profile with only limited losses apparent below that depth. Delayed fertilizer application resulted in greater crop use efficiency and more residual N than with preplant application, suggesting greater losses through leaching and gaseous evolution with the latter in early spring months when there are no crop roots for rapid absorption of N. Smaller amounts of residual N remained in soil after corn grown in 51 cm rows for 3 years than with 72 and 102 cm row widths, corresponding with the larger yields obtained and heavier N utilization with 51 cm rows. Corn grain yield was related to residual soil N when no additional fertilizer was used, the quantity from 60 cm depth being proportionately less than that in the 180 cm profile but still quite effective as indicator of yield potential from the N standpoint. Use of a nitrification inhibitor with an NH, carrier clearly served a useful purpose in preserving mineral N in irrigated fine textured soils to the eventual benefit of yield.
Influence of Soybean Production Practices on Lodging and Seed Yield in Highly Productive Environments1
Authors: Cooper Richard L.
Published: July 2010

The effect of planting date, variety, row spacing, and seeding rate on lodging and seed yield of soybeans (Glycine max (L.) Merr.) in highly productive environments was studied at Ashland and Chenoa, Illinois, in 1969. Three planting dates, seven varieties, two row spacings, and three seeding rates were used.

Highly significant date, variety, spacing, rate, and interaction effects were obtained on lodging and yield at both locations. Seed yield was generally unaffected by seeding rate where no lodging differential occurred, but tended to be significantly lower where the higher seeding rates caused severe early lodging. These results indicated that early lodging was a major factor contributing to the yield decrease that occurred at the higher seeding rates. Whether a lodging differential occurred between seeding rates was dependent on location, date, variety, and row spacing used. These data also suggested that lodging may be an important factor in preventing yield increases from earlier planting and from narrower rows. At Ashland, in absence of a lodging differential between dates, the highest yields were obtained from the earliest planting, but at Chenoa, where the first two planting dates were more severely lodged than the latest planting date, there was no yield advantage. The yield advantage of narrow rows was greatest for the third planting date, at both locations, where lodging was essentially the same in both row spacings. At the earlier planting dates, 17‐cm rows tended to be more severely lodged than 50‐cm rows, cancelling out potential benefits from more uniform plant distribution. This was attributed, in part, to the less effective natural thinning that occurred in the 17‐cm rows.
Grain Filling Period of Corn as Influenced by Phosphorus, Potassium, and the Time of Planting1
Authors: Peaslee D. E. , Ragland J. L. , Duncan W. G.
Published: July 2010

Grain production of field‐grown corn (Zea mays L.), as it related to the degree‐days3 occurring between initiation and maturity of the grain, was evaluated at O, 22, and 112 kg/ha of P and O, 56, and 224 kg/ha of K nutrition and with planting dates of April 7 and May 26. High levels of P accelerated development to silking but had little effect upon maturity of the grain. High levels of K accelerated development to silking and delayed grain maturity. Without added P and K, silking was delayed a maximum of 7 days in plots planted May 26, whereas maturity of the grain was accelerated 7 days. The number of degreedays between emergence and silking and between emergence and maturity were correlated (R2 = 0.58 to 0.87) with levels of applied P and K. The degree‐days between silking and maturity were also correlated with applied P and K (R2 = 0.61 and 0.81) and with grain yields (r2 = 0.62 and 0.71). These data indicate that nutrition influenced the rates at which corn plants developed through certain stages, and that the changes in these rates of development were associated with differences in grain yields.
Effects of Shading and Nitrogen on Growth of Grass‐Alfalfa Pastures1
Authors: Chan Wing‐To , MacKenzie A. F.
Published: July 2010

The relative competitiveness of alfalfa under varying nitrogen and shade conditions must be known to manage grass‐legume mixtures for maximum yield and quality of hay. Therefore, the growth of a grass‐legume mixture (predominantly Phleum‐pratense L. and Medicago sativa L.) under artificial shading and with added nitrogen was studied under field conditions in Quebec in 1967 and 1968. At low N levels, the alfalfa was a stronger competitor in the mixture under full sunlight, irrespective of the stage of growth. At high N levels, alfalfa yields were decreased due to increased grass growth. However, shading had very little effect on the competitive ability of the alfalfa at high N levels. Grass with upright leaves should permit more effective competition by alfalfa.
Harvesting Vernonia Anthelmintica (L.) Willd. to Reduce Seed Shattering Losses1
Authors: Massey John H.
Published: July 2010

Results from four methods of harvesting Vernonia anthelmintica (L.) Willd. seed indicated that the highest yield (1,369 kg/ha) was obtained by cutting and windowing plants before seedheads opened. When harvest was delayed until all seed had ripened, yields were reduced to 264 kg/ha by shattering. Other methods gave intermediate yields.
Effect of Potassium and Nitrogen Fertilization on Lysine, Methionine, and Total Protein Contents of Wheat Grain, Triticum aestivum L. em. Thell.1
Authors: Hojjati S. M. , Maleki M.
Published: July 2010

An irrigated, split‐plot field experiment was conducted at Pahlavi University, Shiraz, Iran to study the effects of N and K fertilization on the lysine, methionine, and total protein contents of wheat (Triticum aestivum L. em. Theil., var. ‘Roushan’). The soil was calcareous silty clay loam. The area was flood irrigated once before seeding and four times during the growing season. Rainfall totaled 49 cm. The amino acids were assayed microbiologically.

Yield of grain was not affected by application of 50 or 100 kg/ha of N, but decreased at the 200‐kg level. The ratio of grain to total dry matter decreased consistently with increasing application of N, showing that N stimulated the vegetative growth much more than seed production. Application of K did not show any significant effect on the yield of grain or on total dry‐matter production.

Protein content of the grain was consistently increased by each additional increment of N, and so were the lysine and methionine contents. The increase in protein was about 1% for each addition of 50 kg N/ha. Percentage of lysine in the protein showed an inverse relationship with the N applied or the protein content of the grain. However, K significantly increased the lysine percentage in the protein. Percentage of the methionine in the protein did not change with varying rates of N or K.
Critical Levels of Sulfur in Bur Clover1
Authors: Jones M. B. , Ruckman J. E. , Lawler P. W.
Published: July 2010

Sulfur deficiencies are widespread in areas of California annual grassland where bur clover (Medicago hispida) is an important legume. The growth of this species is greatly increased by applications of S where S is deficient. The purpose of this study was to obtain information useful in assessing the sulfur status of annual grasslands in which bur clover occurred.

The clover was grown in nutrient solution with varying levels of available S. Total S and SO4‐S concentrations in immature and mature leaves and in middle and lower stems were studied in relation to dry matter production. The concentration of total S where yields were 95% of maximum (“critical concentrations”) was 0.225% for both immature and mature leaf blades and was 0.080% for middle and lower stems. The “critical concentrations” for SO4−S were 160, 140, 100, and 160 ppm for immature and mature leaves and middle and lower stems, respectively. Organic S (total S minus SO4−S) reached a maximum at about 0.250% in leaves and about 0.100% in the stems. Where S was applied in luxury amounts unmetabolized sulfur accumulated as SO4−S. Highest concentrations were found in the lower stems, lesser amounts in the upper stems, and least SO4−S was found in the leaves.
Effects of Tillage Method and Incorporation on Trifluralin Carryover Injury1
Authors: Fink Rodney J.
Published: July 2010

A Bolivia silt loam soil was spring plowed in 1969 and preplant treatments of trifluralin (a,a,a‐trifluoro‐2, 6‐dinitro‐N, N‐dipropyl‐P‐toluidine) were incorporated with a power rotary tiller operating 2.54 cm and 10.16 cm deep and with a disk‐harrow operating 7.62 cm and 15.24 cm deep and plante d to soybeans [Glycine max (L.) Merr.]. Soil samples were taken at three intervals following application at 0‐ to 5.08, 5.08‐ to 10.16; and 10.16‐ to 15.24‐cm layers of the soil profile. These soils were analyzed for trifluralin and were used for a plant bioassay using a sorghum‐sudan hybrid. The field plot area was divided into three sections with each section divided into a disked and a plowed area, and was planted to wheat (Triticum aestivum L.), corn (Zea mays L.), and grain sorghum [Sorghum bicolor (L.) Moench]. Depth of incorporation did not affect total amount of trifluralin remaining II months after application but did affect concentrations at different intervals in the soil profile. Trifluralin carryover injury to corn, grain sorghum, and wheat occurred on field plots.
Crown‐freezing and Natural Survival Comparisons in Winter Wheat1
Authors: Warnes D. D. , Johnson V. A.
Published: July 2010

Survival from artificial crown‐freezing and field nurseries was compared for 31 winter wheat (Triticum aestivum L.) varieties. Both —8.9 C and —11.6 C crownfreezing temperatures were required to adequately differentiate all 31 wheat varieties into coldhardiness levels. Crown‐freezing survival percentages were lower at each later reading date following crown freezing. Delayed crown‐freezing survival readings correlated better with natural survival from the uniform regional nurseries than readings taken soon after the freezing cycle. The general level of correlations of crown‐freezing survival with natural survival was lower for winter wheat than previously presented by the authors for winter barley (Hordeum vulgare L.). Contributing factors may have been the wide range of winterhardiness in winter wheat and inadequate locations of tests for differential natural survival. The crown‐freezing technique would enable the winter wheat plant breeder to evaluate material for cold‐hardiness every year instead of only those few isolated winters that produce differential natural field survival.
Nitrogen Fertilization and Clipping Effects on Green Needlegrass (Stipa viridula Trin.): I. Development, Growth, Yield, and Quality1
Authors: White Larry M. , Cooper Clee S. , Brown Jarvis H.
Published: July 2010

More information is needed about fertilization and management of green needlegrass (Stipa viridula Trin.) to increase its relative prevalence in the northern Great Plains. We applied N and imposed clipping treatments on green needlegrass to determine the effects of these treatments on the initiation and growth of tillers, and on the yield and quality of forage. Ammonium nitrate was broadcast at 0, 70, and 140 kg of N/ha in November 1968. The two clipping treatments were unclipped and clipped to a 5‐cm height five times during 1969 at approximately 21‐day intervals. Studies were conducted in 1969 and 1970 on a dryland site which normally receives 32.6 cm annual precipitation.

In 1969 N increased dry matter yield, percentages of crude protein and P, but did not affect the rate of successive plant development. Residual N in 1970 increased dry matter yield, decreased percentage of P, and had no effect on the percentage of crude protein. Doubling the N fertilization rate had little effect on the plant factors measured.

In 1969 clipping decreased dry matter yield, increased percentages of crude protein and P, and extended the plant growth period by 26 days. Clipping in 1969 reduced dry matter yield in 1970, but did not affect percentages of crude protein and P.

There were 30% floral and 70% vegetative tillers on nonfertilized plots, and two‐thirds of the floral tillers present in July 1969 were initiated the previous autumn. Nitrogen fertilization increased the number of spring‐initiated tillers, which were 15% floral and 85% vegetative and matured 4 weeks later than autumn‐initiated tillers.
Effects of Soil‐injected Ethylene on Yields of Cotton and Sorghum1
Authors: Freytag A. H. , Wendt C. W. , Lira E. P.
Published: July 2010

Virtually no results have been reported on the use of ethylene in the root zones of intact plants. This report is unique because of the increase of yield on cotton and sorghum through the use of soil‐injected ethylene.

For two consecutive years ethylene was applied to cotton (Gossypium hirsutum L.) as a soil treatment at 1.59 and 3.14 kg/ha, at three different stages of plant development and in three soil moisture tension regimes (0 to 30, 0 to 50 and 0 to 70 centibars). In the first study (1970) yield was increased 25% by ethylene treatment in the 0‐ to 30‐centibar moisture regime. While in the 0‐ to 50‐centibar and 0‐ to 70‐centibar regimes the yields from the ethylene treated plots were higher than those of the untreated plots the differences were not statistically significant. In th second study (1971) lint cotton yield was significantly increased 12% in the 0‐ to 70‐centibar moisture regime. Micronaire and staple length were not significantly affected by the ethylene treatments in the 1970 or the 1971 study.

In a similar study in 1970 on sorghum (Sorghum bicolor (L.) Moench.), ethylene was injected into the soil at a rate of 1.59 and 3.14 kg/ha at the 6 to 7‐ and 9‐ to 10‐leaf stages of growth. Although yields were higher in some cases, the differences were not significant at the 5% level of probability. The second study (1971) on sorghum gave a 13% significant yield increase when ethylene was injected into the soil at a rate of 1.59 kg/ha at the 6‐ to 7‐leaf stage.
Influence of Simazine on Yield and Quality Components of Reed Canarygrass1
Authors: Allinson D. W.
Published: July 2010

The use of the chloro‐substituted triazines as a tool for modifying plant growth has received increasing attention. The study reported herein evaluated the influence of 2‐chloro‐4,6‐bis(ethylamino)‐s‐triazine (simazine) as a growth regulator. In 1969 simazine was applied at rates of 0, 0.28, 0.56, and 1.12 kg/ha in both split and single applications to reed canarygrass (Phalaris arundinacea L.) supplied with either 224 or 448 kg N/ha. Three harvests were taken. Single applications of simazine at rates of 0.56 and 1.12 kg/ha significantly (P < 0.05) depressed dry matter yields; when applied in split applications, 0.56 kg/ha did not depress yields. Yields of crude protein were depressed by single applications of 1.12 kg/ha of simazine, while single applications of both 0.56 and 1.12 kg/ha of simazine depressed yields of in vitro digestible dry matter (IVDDM). However, split applications of simazine at 1.12 kg/ha did not significantly affect yields of crude protein or IVDDM. Percent crude protein, alcohol‐insoluble N, NO3‐N, and in vitro dry matter digestibility (IVDMD) were increased, while cell wall components were decreased by simazine application. The extent of these changes in composition varied with rate and method of simazine application. In 1970, simazine treatments of 0, 0.28 kg/ha applied as a single application, and 0.56 kg/ha applied ia split applications were made to reed canarygrass. Responses to simazine applications at these levels in 1970 were similar to those observed in 1969. The observed changes in composition suggest that the nutritive value of reed canarygrass was improved.
Effect of Soil pH on Element Concentration and Uptake by Maize: I. P, K, Mg, and Na1
Authors: Lutz J. A. , Genter C. F. , Hawkins G. W.
Published: July 2010

An understanding of soil‐plant relationships, plant nutrition, and fertilization requires a knowledge of the variability of the chemical composition and uptake of elements by plants. The availability of certain elements is related to soil pH and since many of the soils of the southeastern U. S. are acid, particularly in the subsoil, additional information is needed on the effects of soil pH on the growth, chemical composition, and uptake of elements by maize (Zea mays L.).

Greenhouse experiments were conducted on Greendale silt loam to investigate the effects of three soil pH levels, 3.9, 5.1, and 6.1, on the yield and certain chemical characteristics of selected maize inbreds and single crosses. Adequate plant nutrients were applied to all pots and two rates of dolomitic limestone were applied to increase the pH. Plants were harvested 36 days after planting, dried, and later analyzed for P, K, Ca, Mg, and Na.

Highly significant differences in yields; P, K, Ca, and Mg concentrations; and uptake among maize entries were observed. Response of entries at different pH levels was not consistent for either uptake or concentration of P, K, Ca, or Mg. There were no significant differences in Na concentrations among entries or pH levels.
Fertilizer Rates on Sugarcane for Sirup Production
Authors: Freeman Kelly C.
Published: July 2010

A series of experiments was conducted to compare fertilizer rates on yield and quality of two newer sugarcane (Saccharum spp. hybrid) varieties. Increasing rates (449, 673, 898, 1,122, and 1,346 kg/ha) of 5‐4.3‐13.4 (N‐P‐K) fertilizer applied to ‘C. P. 36‐111’ and ‘C. P. 52‐48’ sugarcane varieties increased yield of cane and generally decreased the Brix of the juice. When the standard rate (673 kg/ha) was doubled (1,346 kg/ha), an increase of only 159 liters of sirup/ha (20 gallons per acre) was obtained. Heavier rates of fertilizer encouraged continuous vegetative growth, resulting in increased tonnage of cane with a reduction of Brix in the stalk juice.
Protein Content of Rice Grain as Affected by Nitrogen Fertilizer and Some Triazines and Substituted Ureas1
Authors: De Datta S. K. , Obcemea W. N. , Jana R. K.
Published: July 2010

Field experiments were conducted to determine whether varietal differences in protein content exist and to study the use of cultural practices — plant density, time of N application, and application of chemicals —for increasing protein content of rices (Oryza sativa L.).

Results demonstrated that a high‐yielding improved line ‘IR480‐5‐9’ has high protein content in the grain. The protein content of brown rice of IR480‐5‐9 varied from 9.5 to 10.2% without application of N. The highest protein of ‘IR480,’ was about 12.5% while that of ‘IR8’ was 9.8%. In another experiment, the protein content of IR480 was 10.2%, while that of ‘IR22’ was 8.6%. Both rices had similar grain yields (7.8 metric tons/ha).

In another experiment, the protein content of several rice cultivars was significantly higher when 150 kg/ha N was applied half at planting and half at heading than when all N was applied at planting.

Simetryne [2,4‐bis (ethyl amino)‐6‐(methyl thio)‐S‐triazine], at 0.5 kg/ha active ingredient, applied either as granular or liquid formulation at panicle initiation or at heading stage of the rice crop, significantly increased the protein content and protein yield of IR22 compared with the fertilized control. Three chemicals, tenoran [N′‐4 (4‐chlorophenoxy) phenyl‐N,N‐dimethyl urea], CP 17029 [2,4 bis (3 methoxy‐propyl amino)‐6‐(methyl thio)‐Striazine], and benzomarc (N‐benzoyl‐N‐dichloro‐3,4‐phenyl N′‐N′‐dimethyl urea) also increased protein content of rice grain without significantly affecting grain yields and yield components.
Dry Land Research in Northwest India: I: Effect of Variable Pre‐Planting Tillage on Soil Moisture, Growth, and Yield of Pearl Millet (Pennisetum typhoides, S. and H.)1
Authors: Malik A. S. , Kumar Vijay , Moolani M. K.
Published: July 2010

Four preplanting tillage methods including turn plowing, chiseling, double disking — all followed by a light cultivation — and no tillage were tried on pearl millet (Pennisetum typhoides, S. and H.) under dry land conditions. Turn plowing resulted in the highest infiltration rate and lowest bulk density values. In consequence, it showed maximum profile soil moisture throughout the growing period of the crop. Variation in soil moisture was more marked in the 60‐ to 90‐cm depth than the upper layers. Grain yield from turn plow plots was about 29% higher than that from the no tillage. Root growth was comparatively poor, but weed yield was more than double on the nontilled plots than on those that were turn plowed. Most of the plant and soil observations showed little difference between turn plowing and chiseling, while double disking was close to no tillage.
A Model for Estimating Desired Levels of Nitrate‐N Concentration in Cotton Petioles1
Authors: Grimes Donald W. , Dickens W. L. , Yamada H. , Miller R. J.
Published: July 2010

Field studies were conducted on two widely different soils over a 3‐year period in a semiarid irrigated region to establish functional relations between responses of cotton (Gossypium hirsutum L.) plants and the major production input factors: water, nitrogen, and plant density.

The nitrate‐nitrogen concentrations of petioles from the most recently matured leaves were influenced by N‐fertilization level, time of sampling in the season, and water management. Plant population did not alter the nitrate‐N levels of petioles. High concentrations were associated with large amounts of N applied in side‐dress soil applications. On a fine‐textured soil with a high water‐retention capacity N side‐dressed after emergence was not taken up by the plant until the first irrigation was added.

Concentrations of nitrate‐N in petioles at critical times in the season were characterized by a 2nd‐degree polynomial model having water and nitrogen quantities as independent variables (0.54≤2R≤0.94). A second model was subsequently developed that incorporated time as an independent variable in addition to water and nitrogen quantities. Using a yield equation and model 2, a procedure was developed that enables time‐dependent “desired” levels of plant nutrient concentrations to be established that are dependent on commodity price and production factor costs. This model is sensitive to changing price levels for commodity and/or production factors.
Blendability of Phenotypically Similar and Dissimilar Winter Barley Cultivars1
Authors: Palvakul Monope , Finkner Verne C. , Davis D. L.
Published: July 2010

The objectives of the reported research were to compare the performance of winter barley (Hordeum vulgare L. emend. Lam.) and to determine if overcompensation would be associated with blends of similar or dissimilar phenotypes. The performance of 28 bi‐line blends, each in a 1:1 genotypic ratio, was compared with the performance of the eight component lines grown in monoculture. The eight component lines of winter barley were chosen to provide a gradient in the phenotypic expressions of heading date, plant height, grain yield, and awnness. Significant overcompensation or undercompensation for grain yield was not found in any combination of like or unlike phenotypes; however, several blends did show a trend for overcompensation. Nineteen of the 28 blends were higher yielding than the midcomponent. Eight of the blends had higher yields than the higher‐yielding component grown in monoculture. The 28 blends averaged 2% higher yields than the midcomponent. Grouping into small, intermediate, or large phenotypic differences did not result in groups exhibiting significant overcompensation or undercompensation. Phenotypic selection was not effective for identification of lines whose blends would exhibit overcompensation.
Gains and Ruminal pH, NH3 and VFA of Beef Steers Fed Molasses or Molasses‐Urea on Tall Fescue Pasture1
Authors: Hart Richard H. , Bond James , Rumsey T. S. , Carlson G. E.
Published: July 2010

Molasses or molasses + urea supplements were fed free‐choice to steers grazing tall fescue (Festuca arundinacea Schreb.) to determine the effects of supplemental energy and nitrogen on carrying capacity, animal gains, and rumen parameters. Carrying capacity, average daily gain, and gain per hectare were not increased by either supplement. Molasses alone depressed ruminal volatile fatty acids (VFA) and NH3 concentrations, but molasses + urea increased ruminal NH3. Ruminal pH and the molar percentages of the different ruminal VFA's were not substantially affected by either supplement, except for a temporary increase in butyrate, and a slight depression in iso‐acids.
Effect of Phosphorus Nutrition and Soil pH on “Physiologic Spotting” of L8 Burley Tobacco1
Authors: Lowe R. H. , Bortner C. E.
Published: July 2010

The physiological spotting factor of the black shank resistant variety of burley tobacco, ‘L8,’ (Nicotiana tabacum L.) is related to phosphorus nutrition, and the disorder is accentuated by a low soil pH. This variety accumulated approximately the same amount of phosphorus as two other varieties (‘Burley 21’ and ‘Experimental 4’) with which it was compared but apparently has a malfunction in its phosphorus metabolizing system. Reciprocal grafts indicate that the disorder is associated with the aboveground portion of the plant. Raising either soil pH or soil phosphorus content partially eliminated the spotting. The spotting was completely eliminated, however, only when both soil phosphorus content and pH were high.
Producing Mature Plants from Embryos Excised from Dry Corn (Zea mays L.) Caryopses1
Authors: Amos F. B. , Wassom C. E.
Published: July 2010

Embryos excised from dry corn (Zea mays L.) kernels were planted several ways to determine the best method of stand establishment. Embryos of 20 sources were (i) planted in peat pots, and seedlings were transplanted to the field while still in the pots; (ii) germinated in petridishes, transferred to peat pots with seedlings later transplanted to the field; (iii) planted directly in the field; (iv) planted directly in the field, surrounded by ground endosperm of other seeds from the same ear; and (v) whole kernels of the same sources were planted in the field as controls. Treatments (i) and (iii) were most successful, each producing about ½ as many mature plants as the control; (ii) and (iv) each produced about 1/5 as many mature plants as the control. Treatment (iii) produced faster, more vigorous growth than (i), while (ii) and (iv) were about equal to each other but considerably behind (i) and (iii) in speed and vigor of growth. All seedlings from excised embryos grew less rapidly and less vigorously than those from whole kernels.
Cutting Height Effects on the Competitive Ability of Annual Bluegrass (Poa Annua L)1
Authors: Bogart J. E. , Beard J. B.
Published: July 2010

Annual bluegrass (Poa annua L.) plants were grown in a mature Merion Kentucky bluegrass sod and in monostands to determine the optimum cutting height for annual bluegrass in terms of shoot competition. Shoot dry weight and tiller number measurements were made on annual bluegrass plants maintained at cutting heights of 1.25, 2.54, 3.75, 5.08, and 6.25 cm. Cutting height significantly influenced the shoot dry weight and tiller number of annual bluegrass with 2.54 cm being the optimum cutting height. In addition, mowing annual bluegrass at a height of 2.54 cm significantly increased the shoot density over both higher and lower cutting heights when grown in a monostand. The optimum cutting height for annual bluegrass in terms of shoot competition was 2.54 cm.
Coadministration of Gibberellin and Auxin‐Type Herbicides on Sugarcane
Authors: Yates R. A.
Published: July 2010

Combinations of gibberellic acid (GA) and 2‐methyl, 4‐chlorophenoxyacetic acid (MCPA) were applied to the foliage of greenhouse‐grown sugarcane (interspecific hybrids of Saccharum), as part of a program of screening potential ripening agents. GA induced the typical growth stimulation, lasting about 4 weeks in these trials. MCPA induced a transient growth stimulation (lasting only one week) followed by growth retardation. The coadministration of MCPA sharply curtailed the growth response to GA. Suitable combinations increased stem weights without reducing the concentration of total sugars, and induced “ripening” by causing the conversion of reducing‐sugars to sucrose. Such coadministration appears worthy of field‐testing under conditions which favor high levels of reducing‐sugars in the cane; in contrast to the probable effects of growth retardants, this mixture should not introduce any penalty of reduced weight of cane.
Tolerance of Rice (Oryza Sativa L.) to Salt during Boot, Flowering, and Grain‐Filling Stages1
Authors: Kaddah M. T. , Lehman W. F. , Robinson F. E.
Published: July 2010

The effect of soil salinity on rice (Oryza sativa L.) development at the boot, flowering, and grain‐filling stages was tested for three varieties transplanted in a greenhouse. The irrigation waters used had electrical conductivities of 1.4, 3.0, and 6.0 mmho/cm at 25 C. The last two irrigation waters were introduced at the three stages of development and used until harvest. Weights of grain and straw and lengths of plants and panicles did not differ significantly between the treatments, indicating that rice is not sensitive to salt after the boot stage.
Yield and Chemical Characteristics of Corn (Zea mays L.) Types1
Authors: Jellum M. D. , Cummins D. G. , Young C. T.
Published: July 2010

The severe southern corn leaf blight epiphytotic in 1970 caused by Race T of Helminthosporium maydis Nisikado and Miyake resulted in a seed shortage of adapted hybrids with disease resistance for planting in 1971. This shortage led to alternative choices for the use of seed of F2 generation of adapted hybrids, imported hybrids, cytoplasmic blend hybrids, and open‐pollinated varieties. Fifteen tests were conducted throughout Georgia to determine grain yield, silage yield, and chemical characteristics of these corn (Zea mays L.) types. Adapted hybrids produced the highest grain yields followed by blends with a high proportion of resistant plants, and then by the F2 generation types. The imported hybrids and the open‐pollinated variety were low in grain yields. Healthy plants in a mixed population of healthy and diseased plants did not yield more per plant than healthy plants in a pure stand. The rank of corn types for silage yields was similar to grain yields, but the differences were not as great. Dry matter digestibility of the grain did not differ among the corn types. The imported dent × flint hybrid and flint hybrids were higher in protein and oil than the other types. Fatty acid composition of oil was different among entries, but differences among corn types were not distinct. Growing conditions such as irrigation, planting dates, and locations had significant effects on certain chemical characters, but these effects were of little importance. These results should assist in better choices in the future, if a similar disease situation occurs.
Influence of Applied Nitrogen and Clipping Treatments on Winter Survival of Perennial Cool‐Season Grasses1
Authors: Jung G. A. , Kocher R. E.
Published: July 2010

A study to determine the extent to which winter injury of cool‐season grasses was related to genetic variation in cold tolerance, nitrogen fertilization, or previous spring and summer clipping treatments was completed at Rock Springs, Pennsylvania. Visual estimates of the percentage of winter injury sustained during the winter of 1971–72 were made in mid‐May.

The grasses received 0, 60, 120, or 240 kg N/ha in spring and summer of 1971 and spring 1972. Half the plots at each rate of N were clipped at vegetative growth stages in spring, and in early June, late July, and early October. The other half were clipped after head emergence in spring, and in late August and early October. Average winter injury ranged from less than 1% for reed canary‐grass (Phalaris arundinacea L.) to 83% for two perennial ryegrass (Lolium perenne. L.) cultivars. Kentucky blue‐grass (Poa pratensis L.) and smooth bromegrass (Bromus inermis Leyss.) were injured slightly (2 to 8%) more than reed canarygrass, and timothy (Phleum pratense L.) and redtop (Agrostis alba L.) sustained even more winter injury (12 to 18%). Average winter injury ranged from 14 to 57% for orchardgrass (Dactylis glomerata L.), 20 to 48% for tall fescue (Festuca arundinacea Schreb.) and 33 to 83% for perennial ryegrass. Nitrogen fertilization decreased winter survival of orchardgrass, tall fescue, and perennial ryegrass to a greater extent than it did other species. Kentucky bluegrass, smooth bromegrass, and reed canarygrass were not severely injured by either clipping regime. One or more cultivars of orchardgrass, timothy, tall fescue, perennial ryegrass, and redtop sustained winter injury when clipped at immature growth stages but were not injured when clipped at mature growth stages. Differential injury associated with the clipping regimes increased as rate of N increased.

The large differences in winter injury among cultivars of orchardgrass, tall fescue, and perennial ryegrass suggest that tolerances to environmental stresses ought to be more thoroughly tested if we are to use new cultivars most effectively.
Control of Midland Bermudagrass (Cynodon dactylon L. Pers.)1
Authors: Duell R. W. , Ilnicki R. D. , Furrer A. H. , Taylor B. B.
Published: July 2010

Shallow fall and spring tillage and 2,2‐dichloropropionic acid (dalapon) were evaluated for 3 years in field experiments for the control of ‘Midland’ bermudagrass (Cynodon dactylon L. Pers.). This high‐potential forage grass bears the stigma of common bermudagrass, a difficult widespread weed, and its use depends, in part, on developing practical control measures. Thorough fall rototilling to a depth of 8 cm exposed rhizomes to below‐freezing temperatures during winter months and resulted in a high degree of control in each of 3 years. Spring tillage was not effective. High rates of dalapon controlled Midland bermudagrass somewhat, but did not enhance control in fall‐tilled plots.
Two General Computer Programs for Drawing Graphs of Histograms, Data Points, and Linear and Quadratic Functions on Calcomp Drum Plotters1
Authors: Wallingford G. W. , Vanderlip R. L. , Meiners J. H. , Kemp K. E.
Published: July 2010

Mechanical plotting machines can present data rapidly and inexpensively if the available computer programs are general enough to handle a wide variety of data. Two FORTRAN IV, level G, programs were written for use with CALCOMP drum pen‐plotters. One program plots functions of the form Y=AX2+BX+C, including the individual data points. The other program plots histograms, which the user designs by dividing the bottom axis into subdivisions and stating the number of bars with different thatch designs to appear in each subdivision. Both of these programs allow the user to create graphs of any rectangular size with extensive labeling. Numerous options and the generality of the programs permit most data, without alteration, to be plotted in a final, publishable form.
Comparison of Banded and Broadcast Fertilizer Applications in Relation to Compaction and Irrigation in Maize and Wheat
Authors: Chaudhary M. R. , Prihar S. S.
Published: July 2010

For maximum utilization of applied nutrients, the zone of nutrient concentration and root activity must synchronize. Since irrigation and compaction influence nutrient mobility and root configuration, their effect on growth and nutrient uptake were studied under different methods of fertilizer application in deep sandy loam and loamy sand soils. In studies with maize (Zea mays L.) and wheat (Triticum aestivum L.), fertilizer was banded or broadcast with and without irrigation and interrow compaction.

Because seedling growth was faster when fertilizer was placed 20 cm below the seed, this treatment ultimately resulted in higher grain yield than when fertilizer was broadcast. In 1970, placement of fertilizer P was banded alone and increased corn yield by 40% while in 1971, placement of NPK increased maize yield by 170% over broadcast. The differences were greater with, than without, interrow compaction. Compared with broadcast, band placement of NPK increased the yield of irrigated wheat by 48% and 26% and that of unirrigated wheat by 288% and 150% with and without compaction, respectively. Treatment effects on nutrient uptake followed the same trends as those on grain yield. Fertilizer should not be broadcast where root growth in the surface layers is likely to be restricted due to surface drying or compaction.

In compacted plots, heavy and infrequent irrigations appeared to be desirable because they resulted in significantly higher uptake of N. In the absence of compaction, nutrient uptake in the two irrigation practices was similar but grain yields were higher with frequent light irrigations than with infrequent heavy irrigations.
Susceptibility of Grain Sorghum to Water Deficit at Three Growth Stages1
Authors: Lewis R. B. , Hiler E. A. , Jordan W. R.
Published: July 2010

Susceptibilities of grain sorghum (Sorghum bicolor (L.) Moench. cv. ‘Oro’) to a moderately severe soil water deficit were determined for each of three growth stages. The crop susceptibility is expressed as the fractional reduction in yield caused by a given soil‐water potential at a particular growth stage as compared with a well‐watered control. The soil‐water potential was allowed to drop to −12 to −13 bars during one stage of growth only, while being maintained above −0.7 bar during the remainder of the growing season. This level of soil‐water deficit resulted in yield reductions of 17, 34, and 10% when the deficit occurred during the late vegetative to boot stage, the boot through bloom stage, and the milk through soft dough stage, respectively. These values are compared with values calculated from data reported in the literature and are discussed in terms of applicability in irrigation timing.
Tolerance of Five Cool‐Season Perennial Grasses to Selected Herbicides1
Authors: Canode C. L.
Published: July 2010

Selective herbicides were applied in September or in April preceding production of the first or second seed crop of Kentucky bluegrass (Poa pratensis L.), smooth bromegrass (Bromus inermis Leyss.), orchardgrass (Dactylis glomerata L.), crested wheatgrass [Agropyron desertorum (Fisch. ex. Link Schult.)], and red fescue (Festuca rubra L.).

Seed yield of these species was not reduced by isopropyl carbanilate (propham) or isopropyl m‐chlorcarbanilate (chlorpropham) at 3.4 and 4.5 kg/ha applied in September. Seed yield was significantly reduced by 5.6 kg/ha of propham applied in September to orchardgrass and chlorpropham applied in September to red fescue. Seed yield was not reduced by 3,6‐dichloro‐o‐anisic acid (dicamba) at rates as high as 4.5 kg/ha applied to Kentucky bluegrass in September, but was reduced by lower rates applied in April. Other species were less tolerant than Kentucky bluegrass to dicamba, applied in both September and April. Seed yield of Kentucky bluegrass was reduced by 4‐amino‐3,5,6‐trichloropicolinic acid (picloram) at 0.6 kg/ha applied in September before production of the first seed crop, but this species tolerated as much as 2.2 kg/ha applied to older stands. Other species were less tolerant than Kentucky bluegrass to picloram as they were to dicamba. Application of 2,4‐dichlorophenoxy)acetic acid (2,4‐D) up to 2.2 kg/ha in September did not significantly reduce seed yield of any of the species, but applications of 1.7 or 2.2 kg/ha in April reduced seed yield of smooth bromegrass and red fescue.

Applications of propham, chlorpropham, or 2,4‐D did not reduce seed germination of any species. Application of picloram in September also did not reduce germination of grass seed, but application of 1.7 kg/ha or more in April reduced germination of smooth bromegrass seed in 1969 and red fescue seed in 1966 and 1969. Of all the herbicides, dicamba, particularly when applied in April, appeared to be the one most likely to reduce germination of seed of certain grass species.
Cation Concentrations and K to CA + MG Ratio of Nine Cool‐Season Grasses and Implications with Hypomagnesaemia1
Authors: Thill James L. , George J. R.
Published: July 2010

Reports of hypomagnesaemia, a Mg deficiency in ruminants, occur most frequently when livestock graze the spring growth of grass pastures. To minimize these animal losses it is important to know whether differences exist among forage grasses for potential risk of Mg deficiency in ruminant livestock. The objectives of this study were 1) to determine if several cool‐season forage grasses accumulate K, Ca, and Mg in the same proportions during the spring period of growth and 2) to observe the effect of temperature fluctuations on changes in K, Ca, and Mg concentrations of these grasses.

Nine cool‐season forage grasses were harvested on a daily basis during mid‐ to late‐spring. Cation concentrations in the forage were determined, and the K to (Ca + Mg) cation ratios were calculated.

This study provides for the classification of reed canarygrass, (Phalaris arundinaceae L.), orchardgrass (Dactylis glomerata L.), tall oatgrass [Arrhenatherum elatius L. (Mert. and Koch)], and Canada wildrye (Elymus canadensis L.) as forage grasses with K to (Ca + Mg) cation ratios exceeding 2.2, and thus may be classified as those more likely to cause grass tetany in ruminants. On the other hand, smooth bromegrass (Bromus inermis Leyss.), Kentucky bluegrass (Poa pratensis L.), crested wheatgrass [Agropyron cristatum L. (Gaerta)], tall wheatgrass [Agropyron elongatum Host. (Beauv.)], and meadow foxtail (Alopecurus pratensis L.) generally have K to (Ca + Mg) cation ratios of less than 2.2 and appear to be less likely to cause grass tetany in ruminants.

For all grasses except meadow foxtail, a sudden increase in mean daily air temperature above 14 C was associated with a corresponding rise in cation ratio, with values reaching a peak approximately 5 days later. This suggests that the risk of hypomagnesaemia in grazing ruminants increases during these periods of temperature fluctuation. However, those grasses that initially had K to (Ca + Mg) cation ratios exceeding 2.2, presumably would continue to offer a greater risk compared to grasses initially found to have ratios less than 2.2.

Potassium concentration was the primary factor responsible for grass species having either a high or low cation ratio throughout the spring season, whereas fluctuations in Ca and Mg concentrations were responsible for the short‐term variation in ratios as influenced by temperature. With the exception of Canada wildrye and meadow foxtail, forage grasses having higher cation ratios also contained higher absolute concentration of Mg.
Simple Controlled‐Atmosphere Welding of Thermocouples1
Authors: Spomer L. Art
Published: July 2010

A simple jig is described for controlled‐atmosphere welding of small diameter thermocouple wire junctions for use in thermocouple psychrometers.