bluuebunny/crossref_metadata_2025 huggingface dataset:
Response of Sorghum, Sesame, and Groundnuts to Plant Population Density in the Central Sudan1
Authors: Gerakis P. A. , Tsangarakis C. Z.
Published: July 2010

Two varieties of sorghum (Sorghum bicolor L. Moench) and sesame (Sesamum indicum L.) and one of groundnuts (Arachis hypogaea L.) were grown at different population densities with and without nitrogen and phosphorus fertilizers, under 578 mm rainfall in a Sand Sheet (“goz”) soil. Sesame and groundnut yields increased when the maximum plant populations presently utilized in the area were increased by 50%. Further density increases were ineffective for those two crops. Grain sorghum did not respond to any increases in the density. The difference in response between sorghum and the other two crops was attributed to differences in type of root system, which in turn affected the pattern of soil moisture depletion in the soil profile. No interaction between varieties, either unfertilized or fertilized, and population densities was noted. Soil moisture rather than soil nutrients seemed the limiting growth factor in these trials.
Survey of Maize Strains for Lysine Content1
Authors: Paez A. V. , Ussary J. P. , Helm J. L. , Zuber M. S.
Published: July 2010

Whole kernel lysine content was determined on inbred lines and Plant Introduction strains of corn (Zea mays L.). The lysine values ranged from 0.16 to 0.45%. The largest values are comparable to whole kernel lysine contents of opaque‐2 mutants. The distribution was normal with a mean of 0.30% and a standard deviation of 0.04%. A significant correlation (r=0.48) was obtained between whole kernel lysine and protein for a selected group of high‐lysine lines. Little variability in lysine content was noted for six inbred lines grown at different stations in different years.
Photo‐ and Thermo‐Control of Pretransplant Floral Induction in Burley Tobacco1
Authors: Kasperbauer M. J.
Published: July 2010

Burley tobacco was exposed to controlled variations of light and temperature in growth chambers during the pretransplant period to determine combinations that lead to more uniform growth and development during the post‐transplant period. Exposure of plants to certain photoperiod, light intensity, and temperature combinations resulted in floral induction before the plants attained transplant size. Although such plants did not have macroscopic floral buds at time of transplanting, many of them flowered within 3 or 4 weeks after being transplanted to the field. Early induction of flowering resulted in development of fewer leaves per plant, exclusive of those on suckers.

Burley tobacco plants became ready for floral induction after they had developed five or six leaves. Plants exposed to high intensity, short photoperiods at 18 C or low intensity, “natural” (13.5‐hour) photoperiods at 18 C became florally inducted during the pretransplant period. Inductive effects of both of these environmental combinations were counteracted by exposing the plants to several hours of low intensity light from incandescent‐filament lamps, each night. Also, maintaining plants at 28 C instead of 18 C had the effect of opposing the inductive process.
Effect of Corn Hybrids, Row Spacing, and Plant Population on the Yield of Corn Silage1
Authors: Lutz J. A. , Jones G. D.
Published: July 2010

A number of corn (Zea mays L.) hybrids differing in maturity were grown in varying plant populations and row spacings at two locations in Virginia over a three‐year period to determine silage yield and chemical composition.

In 1966, yields from the alternated 25 and 125 cm spacings were lower than from the other uniform spacings at both locations, with no differences in yield among the other spacings. Yields were not increased with increased population in 1966. In three of four location‐year tests in 1967 and 1968, yields were higher with the 40 than with the 100 cm spacings. Yields were higher with the late maturing hybrid and with the highest plant population. Stalk diameter was affected by row spacings but not by populations or hybrids. The N, P, and K contents of leaf samples were not differentially affected by hybrids, populations, or spacings in 1966. The P content of leaf samples decreased with increased population in 1967 but was unaffeced by hybrids and row spacings.
Occurrence of Atypical Flowers and Some Associated Bees (Apoidea) in the Peanut, Arachis hypogaea L.1
Authors: Leuck D. B. , Hammons R. O.
Published: July 2010

Presence of atypical flowers in the peanut, Arachis hypogaea L., which could facilitate insect cross‐pollination by a large bee (Apoidea) species complex is investigated. Observations show that off‐type flowers are present among total flowers of at least two cultivars, that they are a complete fertile flower, that their numbers increase with increased flower production, and that they are a possible source of cross‐pollination contamination often observed among varieties in connection with pure line breeding studies in field nurseries.

Six additional new records of wild bee species are identified in the flower visiting bee complex. They are: Augochloropsis metallica fulgida (Smith) (Halictidae), Chalicodoma (Chelostomoides) georgica (Cresson) (Megachilidae), Megachile (Delomegachile) addenda Cresson (Megachilidae), Melissodes (Melissodes) comptoides Robertson (Anthophoridae), Ceratina (Ceratinula) cockerelli Smith (Anthophoridae), and Ceratina (Zadontoemrus) dupla floridana Mitchell (Anthophoridae). The bee species found to be most abundant on peanut flowers in the vicinity of Tifton in 1967 were Pyrobombus impatiens Cresson (Apidae), Megachile (Litomegachile) mendica Cresson (Megachilidae), Apis mellifera L. (Apidae), and Lassioglossum (Dialictus) versatum (Robertson) (Halictidae).
Growth Response of Merion Kentucky Bluegrass to Fertilizer and Lime Treatments1
Authors: Juska F. V. , Hanson A. A. , Hovin A. W.
Published: July 2010

The performance of ‘Merion’ Kentucky bluegrass to 10 fertilizers, applied at three rates, at two pH levels, is herewith reported. Carriers incorporated with fertilizers had little or no effect on grass growth; however, the carrier used in one fertilizer (24‐4‐6) with 23.19% watersoluble nitrogen mixed with reed sedge peat may have absorbed soluble nitrogen to cause slower nitrogen release. Highest total grass yield was obtained from ammonium nitrate and lowest from urea‐form. The lower yields were obtained from less soluble sources of nitrogen while the soluble urea source (45‐0‐0) was intermediate. Loss of nitrogen in the form of ammonia may have accounted for the relatively low yield from this soluble nitrogen source. All fertilizers significantly increased yield of Merion Kentucky bluegrass at pH 4.8 and pH 7.0, but the interaction between fertilizers and pH levels was not significant. There was a highly significant difference in yield among fertilizer sources. Selection of a fertilizer source or form of nitrogen fertilizer should be based on the relative importance of convenience, safety, cost, and response of grass growth.
Nitrogen Recovery from a Soil Profile by Bromus inermis1
Authors: Ogus Lufti , Fox R. L.
Published: July 2010

Nitrogen recovery was estimated as a function of depth of placement and time from nitrate fertilizer placed at various depths in brome grass (Bromus inermis, Leyss) sod at the beginning of spring growth. The soil was a Crete silty clay loam with a clay B horizon which severely restricted root penetration. About 43% of the N placed in the C horizon (105 cm) was recovered in two growing seasons. Per unit mass, roots in the C horizon took up over 300 times more N than did roots in the surface soil. Total N in the grass reached a maximum then declined rapidly as the plants matured.
Competition among Adjacent Rows of Grain Sorghum of Different Height Genotype1
Authors: Kern J. J. , Atkins R. E.
Published: July 2010

A 2‐year study was conducted at Ames, Iowa, to evaluate the role of plant height as a factor affecting interrow competition in grain sorghum (Sorghum bicolor (L.) Moench) performance tests. A secondary objective was to determine the effect of height genotype on several agronomic characters of sorghum. Hybrids having 3✕3‐ and 4✕3‐dwarf height genotypes were bordered by themselves and, in turn, by each other. Grain yields of 3✕3 hybrids were enhanced about 4% when 4✕3 border rows were used, and yields of 4✕3 hybrids were depressed about 3% when bordered by 3✕3 hybrids. Row spacings, female parents, and pollinators did not exert pronounced or consistent effect on the competition attributable to height differences. Hybrids having a 3✕3 height genotype usually exceeded the 4✕3 hybrids in number of seeds/head, 100‐seed weight, and grain yield, but they produced fewer heads/plant and bloomed later than the short hybrids.
Establishment of Perennial Forages II. Subsequent Root Development1
Authors: Buxton D. R. , Wedin W. F.
Published: July 2010

The effect of interspecies competition during establishment of three perennial forage grasses and three perennial legume species on subsequent root development was investigated in two similar field experiments.

Interspecies competition had a greater effect on the upper 15‐cm root yield of the legume and upper 10‐cm root‐rhizome yield of the grass species than on forage yields.

During the year after seeding, when fertility and moisture were limiting factors, lowest carbohydrate levels occurred in weeded swards with heavier root weights (g/m2). Highest carbohydrate levels in unweeded treatments probably resulted because a low quantity of minerals and water was supplied by the smaller root systems, which limited growth and resulted in carbohydrate accumulation. When moisture and fertility were adequate, little difference existed in carbohydrate levels among treatments, although large differences existed in root weights. This observation can explain the more pronounced treatment effects on forage yields that were observed when moisture and fertility were low.
Internode Lengths at Different Developmental Stages on Corn (Zea Mays L.)
Authors: Hanway J. J.
Published: July 2010

Internode lengths were measured on six single‐cross corn hybrids at development stages 2 to 5.5. Lengths did not show extreme variability among hybrids and can serve as a means of identifying the stage of plant development before silking.
Influence of Soil Incorporation on Herbicide Performance in Sorghum1
Authors: Wicks G. A. , Burnside O. C. , Fenster C. R.
Published: July 2010

Experiments were conducted at Lincoln, North Platte, and Alliance, Nebraska, during 1965 and 1966 to determine the effect of herbicides, herbicide incorporation, and rotary hoeing on ‘Nebraska 505’ sorghum [Sorghum bicolor (L.) Moench.] grown in 50.8‐cm rows. Preplant soil incorporation and preemergence herbicide applications were superior to preemergence + shallow incorporation with a rotary hoe in weed control and grain yields. Postemergence rotary hoeing improved weed control and sorghum yields on herbicide treatments. The best treatments were atrazine (2‐chloro‐4‐ethylamlno‐6‐isopropylamino‐s‐triazine) at 2.24 kg/ha and atrazine norea [3‐(hexahydro‐4,7‐methanoindan‐5‐)y‐ll, l‐dimethylarea] at 0.84 + 1.68 kg/ha (1.12 + 2.24 kg/ha in 1965) + two rotary hoeings at Lincoln, atrazine at 2.24 kg/ha at North Platte, and rotary hoeings but no herbicide at Alliance. Only at Lincoln did sorghum yields on herbicide‐treated plots approach that on handweeded checks. On the low organic matter soils at North Platte and Alliance, atrazine injury limited sorghum yields.
Response of Pisum sativum L. to Gibberellic Acid Seed Treatment1
Authors: Teare I. D. , Law A. G. , Wilson V. E.
Published: July 2010

Gibberellic acid (GA) was applied to seed of Alaska peas to determine effects on rate of emergence, stem elongation, flowering, and yield. The effect of GA on the rate of emergence was dependent upon the temperature of the environment. Emergence of GA treated seedlings was 4 to 6 days earlier than non‐treated seedlings under cool conditions. At high temperatures, GA treated seedlings emerged one day earlier than the control, but emerged plants were susceptible to heat damage. Stem elongation was directly related to GA concentration and appeared to be inversely related to development of the root system. Date of blooming and maturity were not enhanced by GA treatment, but GA increased the number of flowers in the May 1 planting. Dry weight at maturity and seed yield were significantly lowered by seed application of GA.
Influence of Sublethal, Foliar Applications of 2,4‐D on Burley Tobacco Yield and Composition1
Authors: Atkinson W. O. , Kasperbauer M. J.
Published: July 2010

Low dosages (0.5 to 10 mg per plant) of 2,4‐D were sprayed on field‐grown burley tobacco plants during rapid vegetative growth, or immediately after topping (removal of inflorescenses and small upper leaves). The plants were left in the field for a normal 3 to 4‐week ripening period before conventional harvesting and aircuring. Yields of cured leaf from plants treated during rapid vegetative growth were more severely reduced than were those of plants treated immediately after topping. Decreased alkaloid content and increased content of soluble phenolic compounds were associated with 2,4‐D treatments.
Coefficients for Computing Leaf Area in Type 41, Pennsylvania Broadleaf, Tobacco1
Authors: McKee Guy W. , Yocum John O.
Published: July 2010

Measurements of 765 leaves from five different varieties of Type 41, Pennsylvania broadleaf, tobacco indicated that varieties differed significantly in leaf shape. Leaf area per plant could be calculated to an accuracy of ± 1% by multiplying the accumulated sum of length by width of individual leaves by a coefficient of 0.64. For greater precision, coefficients of 0.66 for leaves of Pennleaf 1, 0.65 for leaves of Swarr‐Hibshman, and 0.61 for leaves of Pennbel 69 should be used. Leaf area per plant could also be calculated with a lesser degree of precision (± 10%) by multiplying accumulated leaf length per plant by a coefficient of 21.45. For greater precision, specific varietal coefficients of 19.79 for Pennbel 69, 22.87 for Swarr‐Hibshman, and 21.70 for Pennleaf 1 should be used.
Relationship of Hybrid Sudangrass Plant Populations to Plant Growth Characteristics1
Authors: Holt Ethan C.
Published: July 2010

The number of plants established was not directly proportional to the number of seed planted in a seeding rate and row spacing study with a hybrid sudangrass (Sorghum bicolor (L.) Moench ✕ S. sudanense (Piper) Stapf.). At a fixed seeding rate more plants were established in narrow rows than in wide rows. Within a row spacing, percentage establishment decreased as seeding rate increased. Within a row spacing, plant size was inversely related to plant population so that yield per ha at maturity did not differ greatly. The largest plants were in wide rows; but at a fixed population level, plant size was greater in narrow than wide rows. LAI did not increase with increased plant numbers within a fixed row spacing. Within at least a two‐fold difference in plant numbers, yield was not significantly influenced by seeding rate.
Effect of Light and Temperature on Stimulation of Vegetative and Reproductive Growth of Bean Plants by Naphthenates1
Authors: Fattah Q. A. , Wort D. J.
Published: July 2010

Bush bean plants, Phaseolus vulgaris L., cultivar Top Crop, were grown from seed for 14 days at 26/21 C day/ night, and 16.1 k‐lux (1500 ft‐c) light with a photoperiod of 14 hours. At the end of this time half the plants were sprayed with a 0.5% potassium naphthenates (KNap) solution. Treated and control plants were then grown 1) under the original light/temperature conditions, 2) at a constant temperature of 26 C with light of 16.1, 10.76, or 5.38 k‐lux, and 3) at a constant temperature of 15 with the three fight intensities. Juvenile growth (plant height; fresh and dry weights of roots, stems, and leaves; number of leaflets; leaflet area) and reproductive growth (number and weight of green pods per plant) were measured 21 and 35 days, respectively, after treatment. The stimulative effect of KNap on both types of growth was evident at all light/temperature combinations, but it was greater at higher temperatures and light intensities. Increments under these conditions were consistently significant at the 0.05 level. The results are consonant with a previous finding that the foliar application of KNap is followed by augmented rates of photosynthesis and greater activity of enzymes of nitrogen metabolism. The larger number of pods may have been the result of more vigorous pollen germination and reduced abscission of young fruits.
Regression of Nitrogen Uptake on Nitrogen Added from Four Sources Applied to Grass1
Authors: Scarsbrook C. E.
Published: July 2010

Research was conducted to evaluate efficiencies of N fertilizers by comparing slopes of N uptake on N applied regression equations. Ammonium nitrate (33.5‐0‐0), diammonium phosphate (21‐23‐0), urea (45‐0‐0), and ureaammonium phosphate (33‐9‐0) were surface applied at four rates of N to Coastal bermudagrass on Norfolk sandy loam and to Pensacola bahiagrass on Boswell fine sandy loam. Relative efficiencies for N recovery were determined by comparison of the slopes (b) of the equations. The highest average efficiency (b = 0.80) was obtained with ammonium nitrate on bermudagrass. Values of b were similar for all sources of N on bahiagrass. There was a straight line relationship when dry forage produced (y) was plotted against N uptake (x). The equations were y = 1,500 ‐f 48x and y = 3,000 ‐j‐ 34x for bahiagrass and bermudagrass, respectively. These differences in slopes of the equations reflect the differences both in N contents and yields of the forage.
Dates and Rates of Seeding Fall‐planted Spring Barley (Hordeum vulgare L. emend Lam.) in Irrigated Areas1
Authors: Day A. D. , Thompson R. K.
Published: July 2010

November and December plantings of ‘Harlan’ and ‘Arivat’ spring barley Hordeum vulgar L. emend Lam., generally gave maximum yields of quality grain in Arizona. In November plantings, seeding rates from 11 to 45 kg/ha produced as much or more grain than rates up to 123 kg/ha. Grain volume weights of Harlan were similar for all dates and rates of planting. Volume weights of Arivat decreased in late plantings.
Influence of Soil, Management, and Climatic Factors on the Yield Response by Corn (Zea mays L.) to N, P, and K Fertilizer1
Authors: Voss R. E. , Hanway J. J. , Fuller W. A.
Published: July 2010

Quantitative evaluations of applied fertility, indigenous soil properties, management, and weather variables in field experiments were all necessary to develop a satisfactory relationship between corn grain yield and the responsible factors. Experimental sites were selected that provided a sufficiently wide range in each uncontrolled variable to permit inferences concerning the entire Marshall and Monona soil areas. At each site, 19 different N‐P‐K fertilizer combinations were applied in a composite type design, with 6 of the treatments replicated. Each plot was characterized for soil test N, P, K, and pH, stand level, and barrenness. Variables evaluated on a site basis were past cropping, subsoil fertility, planting date, soil yield potential, and soil moisture stress. A multiple‐regression equation for yield, fitting data from 575 plots, contained 40 terms and achieved an R2 of 0.80. It contained interactions among applied fertility, indigenous fertility, management, and climatic factors. Response to applied N was influenced most by past cropping and soil moisture stress. Response to applied P was not influenced by environmental factors as much as was response to N, but “available” soil P, soil N, and soil moisture stress influenced P response. These soils, which rate “medium” or “high” in exchangeable K, responded only slightly and negatively to applied K fertilizer. Significant interactions were measured between soil moisture and plant population and between soil moisture and planting date. The necessity for this type of field experimentation is discussed. Methods of interpretation and practical applications of yield prediction equations are suggested and exemplified.
Soil Analysis of Trifluralin: Methodology and Factors Affecting Quantitation1
Authors: Harrison R. M. , Anderson O. E.
Published: July 2010

A simplified soil extraction procedure was evaluated for the recovery of trifluralin (a,a,a,‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine). Soil recovery values for the herbicide compared favorably with those reported in the literature. Recoveries of 90 to 93% of soil‐incorporated trifluralin were obtained over a 7‐day period, regardless of soil moisture conditions, ranging from 0 to 200% of field capacity, and whether treated soils were exposed to the atmosphere or maintained under airtight conditions. After 14 days, herbicide recovery for all treatments was approximately 64%.

Trifluralin in methanol or N‐hexane solution was rapidly degraded by ultraviolet light. In a 24‐hour U.V. exposure study, seven degradation products were observed using gas‐liquid chromatography (GLC). Under laboratory conditions trifluralin solutions were maintained in the dark for 30 days without degradation but exhibited a 1.4% loss per day when maintained under laboratory light conditions.

Linear electron capture detector response was shown to be related to injection volume of trifluralin solutions when analyzed quantitatively.
Responses of Nematode Infected Peanut Plants to Maleic Hydrazide1
Authors: Banks Donald J.
Published: July 2010

Gall formations on the roots of plants that are susceptible to root‐knot nematodes may be due to the presence of an auxin. Maleic hydrazide (MH), an antiauxin, has produced nematode and gall‐inhibiting effects in some plants. This chemical was tested on peanuts, Arachis hypogaea L., to determine if it would aid in preventing galling and nematode damage.

A seed soaking treatment at planting in 125 ppm and also foliar spray applications of 125 and 250 ppm of maleic hydrazide were applied to ‘Dixie Spanish’ variety peanuts that were in the two‐leaf stage. The plants were grown in the greenhouse at 21 to 29C for 42 days in soil that had been inoculated at planting with Northern root‐knot nematode, Meloidogyne hapla Chitwood.

Little stunting and slight chlorosis occurred in the seed treatment but severe stunting and chlorosis was observed early in the test in the foliar applications. At harvest, total plant green weights and plant heights were significantly reduced in the MH foliar treatments. Galling was not inhibited and microscopic examinations of the galls failed to reveal significant differences in giant cell formation, or nematode development or reproduction in the MH treatments.
Photo‐ and Thermo‐Control of Flowering in Tobacco (Nicotiana tabacum L.)1
Authors: Kasperbauer M. J.
Published: July 2010

‘Burley 21,’ ‘Ky 151,’ and ‘Hicks’ (burley, dark‐fired, and flue‐cured types, respectively) tobacco seedlings (Nicotiana tabacum L.) were started and grown to the 5‐ to 6‐leaf stage under long, warm days followed by exposure to controlled variations of light and temperature to determine combinations that cause these three types of tobacco to respond similarly and proceed from seed to flowering in minimum time. Tobacco plants became “ready for floral induction” after they developed 5 to 6 leaves. Long, warm days favored growth, while exposure of plants (that were “ready for floral induction”) to short, cool days favored floral induction. Uniformly early flowering of all three of the varieties occurred when they were grown under long, warm days to the 5‐ to 6‐leaf stage; exposed to short, cool days for 2 to 3 weeks; then returned to long, warm days after floral induction and initiation to hasten growth and development of the flowers.

Varietal differences were evident when plants were kept on long days and/or warm temperatures. Under such conditions, Burley 21 flowered later and at a larger size than did Ky 151 and Hicks.
A Growth Sensor for Sugarbeet Roots1
Authors: Davis Ronald G. , Johnson Wendell C.
Published: July 2010

Attachment and design of two types of growth sensors for obtaining a continuous record of circumference change of sugarbeet (Beta saccharifera) roots are described.
Comparison of Male Sterile and Male Fertile Corn for Silage1
Authors: Cummins D. G. , McCullough M. E.
Published: July 2010

A comparison of male sterile and male fertile corn (Zea mays L.) for dry matter production, total available carbohydrates (TAC), silage digestibility, and volatile fatty acid (VFA) production from the silage during rumen dermentation was made at Experiment, Georgia in 1968 to 1969. Dry forage yields were similar for the male literile and male fertile corn in 1968, but the male sterile vielded more than the male fertile in 1969. The male fertile hybrid contained a higher percentage TAC than did the male sterile hybrid. There were no significant percentage differences between the silages in individual VFA production, or digestibility of dry matter, crude protein, crude fiber, cellulose, ether extract, and nitrogen iree extract. The data indicate that at the maturity studied male sterile corn plants (without kernel development) are comparable to male fertile corn plants (with kernel development) for making silage.
An Evaluation of Two Methods for Obtaining Leaf Transmissivity from Leaf Reflectivity Measurements1
Authors: Carlson Richard E. , Yarger Douglas N.
Published: July 2010

Two methods for calculating values of leaf transmissivity from leaf reflectivity measurements are evaluated. These methods gave nearly identical results for the spectral range 500‐2,600 mμ. Two species with dissimilar leaf structures, cota, and soybeans, were tested. The results indicate that values of leaf transmissivity can be calculated within a relative error of 5% of the measured values. The method proposed by the authors is based upon a quadratic equation, which is simpler to apply than the cubic equation form of the other method which was tested.
Effectiveness of Zn Frits for Corn (Zea mays L.) as Influenced by Zn Concentration, Granule Size and Method of Application1
Authors: Hoeft R. G. , Walsh L. M.
Published: July 2010

A greenhouse experiment was conducted to study the influence of Zn concentration, particle size, and methods of application on the effectiveness of Zn frit‐concentrated superphosphate (CSP) mixtures3 in relation to ZnSO4. Two crops of sweet corn (Zea mays L.) were grown on a neutral loamy sand soil and a calcareous sandy loam soil. The effect of Zn concentration and particle size of the Zn frits on the solubility of these materials in water and in an acid solution was studied.

Zinc frits mixed with CSP were as effective as ZnSO4 on a neutral soil, but tended to be less effective than ZnSO4 on a calcareous soil. Effectiveness of granular Zn frit‐CSP mixtures decreased as the concentration of Zn increased, and the fine material was more effective than the granular material at the 12% Zn concentration on the calcareous soil. In the laboratory study no difference in solubility was found between the fine and granular 12% Zn frit carriers. Therefore, it was concluded that the reduced effectiveness of the 12% granular Zn frit was due to fewer particles and reduced surface area rather than to decreased solubility.
Susceptibility of Wisconsin Havana Tobacco Cultivars to Air Pollutants
Authors: Hodges G. H. , Menser H. A. , Ogden W. B.
Published: July 2010

Wisconsin Havana cigar tobacco cultivars were tested for susceptibility to air pollutants in a plant exposure chamber and in a tobacco field. Gases used in the chamber were ozone, sulfur dioxide, and a mixture of the two. Ozone was the principal air pollutant to affect field grown plants. ‘Havana 142’ was the most susceptible cultivar to ozone fumigations and to ozone induced, field disorder, weather fleck. ‘Havana 501’ exhibited about half the leaf injury of Havana 142 when exposed to the same ozone conditions. Other cultivars that showd intermediate response were ‘Havana 307,’ ‘Havana 425,’ and ‘Havana 503’ No injury resembling “Target Spot”, a nonpathogenic syndrome observed in Wisconsin on Havana 503, was produced in any of the tests. All injury resembled the ozone fleck consisting of punctate lesions on upper surfaces of mature leaves. A low concentration mixture of ozone (0.03 ppm) and sulfur dioxide (ca. 0.45 ppm) caused from 5 to 15% injury but individual gases used at the same rates caused no symptoms. Mixed gas injury differed very little from ozone flecks.
Effect of Seaweed on Phosphorus Availability of a Soil Derived from Volcanic Ash1
Authors: Zunino H. , Peirano P. , Aguilera M. , Gonzalez R. , Caiozzi M.
Published: July 2010

A volcanic ash‐derived soil was incubated up to 93 days with different amounts of seaweed. P was then extracted using an anion exchange resin method, and it was found that extractable P increased with increasing amounts of seaweed, which was added in proportions of .1, .5, 1.5, and 4.0%. Radishes grown in the same soilseaweed mixtures absorbed more P than from the control and increased their yield with the increase of seaweed.

On adding seaweed and KH2PO4 simultaneously to the soil, an interaction between seaweed, soil and KH2PO4 occurs which results, at .1 and .5% of seaweed, in a decrease in P fixation. This could be due to the presence of alginates and alginic acids in the seaweed, since these compounds could be binding exchangeable Ca of the soil and therefore diminish P fixation by the Ca‐bonding mechanism.
Effect of Freezing on Hydrocyanic Acid Release from Sorghum Plants1
Authors: Loyd Robert C. , Gray Elmer , Shipe Emerson
Published: July 2010

abstract

Freezing of sorghum (Sorghum bicolor (L.) Moench) leaves and stems resulted in release of hydrocyanic acid (HCN). The amount of HCN released by freezing was less than the amount released by treatment of fresh tissue with chloroform.
Effects of Rates of N and P on the Accumulation of NO3‐N in Wheat, Oats, Rye and Barley on Different Sampling Dates1
Authors: Baker J. M. , Tucker B. B.
Published: July 2010

The NO3‐N concentration of wheat, oats, rye, and barley forage was found to be a function of rate of N fertilization, P fertilization, and date of sampling. The crops were not very different with respect to NO3‐N accumulation, though barley and wheat appeared to accumulate more nitrates than rye or oats during periods of highest concentration. Nitrate‐nitrogen concentrations were highest in samples collected March 18 and 24 when the plants were in the “joint” or “preboot” stage of growth. Concentrations greater than 3,500 ppm were not uncommon in barley and wheat samples collected at these stages of growth, whereas oat and rye samples rarely exceeded 3,500 ppm. The NO3‐N concentrations rarely exceeded the potentially toxic level of 2,100 ppm when 90 kg/ha or less N was applied, a rate that is as high as is typically applied to dryland winter wheat. The NO3‐N concentration declined sharply after the March 24 sampling date and continued to decline through the April 13 sampling date. A slight increase in concentration appeared late in the season, especially in oats.

The tendency for NO3‐N accumulation to be increased by a deficiency of P was also found. The concentration in wheat forage was reduced from 1,300 ppm to 300 ppm NO3‐N with the application of 15 kg/ha P. P rates beyond that necessary for maximum grain production did not further reduce the NO3‐N content of the forage.
Dry Matter Accumulation in Soybean (Glycine max (L) Merrill) Plants As Influenced by N, P, and K Fertilization1
Authors: Hanway J. J. , Weber C. R.
Published: July 2010

Dry matter accumulation in the different parts of soybean plants grown on plots with different fertilizer treatments was determined at successive developmental stages throughout the growing season. Moderate applications of P and K fertilizers had relatively small effects on weights of the different plant parts or seed yields, but heavy applications of KC1 significantly reduced plant weights and seed yields. N fertilizer markedly increased yield of non‐nodulated soybeans. With adequate N (672 kg N/ha), seed yields of nodulated and non‐nodulated soybeans were similar. To produce a final plant weight of 10,000 kg/ha, the average daily increase in dry weight of plants was 186 kg/ha/day between stages 5 and 9. Rapid increase in seed yield began at about stage 8 and continued to stage 10. Other plant parts lost weight after stages 8 or 9. At maturity, dry matter consisted of 28% fallen leaves, 15% fallen petioles, 17% stems, 11% pods, and 29% beans.
Physiology of Oil Seeds III. Response of Initially High and Low Germinating 1,2 Spanish‐type Peanut Seeds to Three Storage Environments
Authors: Ketring D. L.
Published: July 2010

Two lots of Spanish‐type peanut seeds (Arachis hypogaea L. var. Starr) were compared for their ability to remain viable under three environmental treatments. Temperature and relative humidities for treatments A, B and C were 21 ± 3C and 50 ± 5%, 3 ± 2C and 80 ± 15% and 3 ± 2C and 20 ± 10%, respectively. Initial germination of seed lots 1 and 2 were 81 ± 3% and 30 ± 8%. Seeds from both lots were exposed to treatments for up to 7 months. At monthly intervals .454 to .908‐kg samples were placed in sealed containers. After about 8 months of storage, total germination, vigor, organic constituents and ethylene production by the seeds were compared for seeds from the sealed containers.

Relative to their initial germniation, lot 1 seeds were reduced 4, 63, and 5% and lot 2 seeds 43, 93, and 57% in total germination within 2 months of storage when placed in treatments A, B and C, respectively. The proportion of vigorous seedlings were reduced 19, 81 and 33% for lot 1 and 50, 100 and 50% for lot 2 seeds after the same time and treatments.

Inorganic analyses showed that lot 1 seeds contained more calcium, potassium and zinc than lot 2 seeds. Organic analyses indicated that there was a decrease in total extractable nucleic acids when the seeds were stored in treatment B. Ethylene production by the seeds at 48 hours of germination was reduced 80% and 90% for lot 1 and lot 2 seeds, respectively, in treatment B. The deleterious effects on germination, vigor, nucleic acids and ethylene production of the seeds was apparently caused by high relative humidity, since a lower relative humidity at the same or a higher temperature did not cause these effects.
Sugarbeet Response to Deep Tillage, Nitrogen, and Phosphorus on Pullman Clay Loam1
Authors: Mathers A. C. , Wilson G. C. , Schneider A. D. , Scott Paul
Published: July 2010

This experiment included tillage to 15, 20, 30, 40, 60, and 80 cm depths and N and P fertilizer rates to provide an adequate plant nutrient level. The experiment was performed with both level border and graded furrow irrigation to determine the effect of deep tillage on yield of sugarbeets (Beta vulgaris L. variety ‘HH‐10’).

Sugarbeet yields were increased by deep tillage and added N with adequate irrigation, but there was no yield increase from applied P. Deep tillage increased yields more where N was applied. Also, the response to N was greater after deep tillage to 40 cm in two of three years. Deep tillage increased the water intake rate, thus favoring good root development during wet seasons. Higher sugar yield after deep tillage was attributed to increased water intake, improved aeration, reduced bulk density, less root rot, and increased response to N.
Variation in Growth Curve Increments1
Authors: Stroh James R.
Published: July 2010

This note relates what is thought to be sampling variation in increment growth curves to phenomena occurring in plants at different stages of growth. Increment growth curves were constructed for six grass species grown under irrigation at Bridger, Montana, in 1967. Vegetative, heading to bloom, and bloom to seed‐ripe growth stages were related to the wavy line growth curves. Similar growth curve humps were associated with each of the phenological stages in three species whose curves are termed typical. Different patterns of growth curves found in the other three species were associated with growth phenomena peculiar to each and are described as atypical.

The scattered data points found in either cumulative or increment growth curves are not necessarily errors due to sampling technique or heterogencity in the environment where the plants are grown. Close association between the scattering and phenological phenomena exists.
Effect of Injections of Propane into Soil on Microbial Activity1
Authors: Johnson D. R. , Frederick L. R.
Published: July 2010

Soil samples were incubated in air atmosphere containing 0, 10,000, 50,000, and 500,000 ppm propane gas (Ca3H8) by volume. Carbon dioxide evolution was used as a measure of soil microbial activity. Soil N immobilization was determined by measuring soil inorganic N. Carbon dioxide evolution and N immobilization were directly related to the C3H8 concentration. Carbon dioxide evolution over time was characterized by (1) an initial delay of 2 to 4 weeks, (2) an accelerated period, and (3) a decrease in activity caused by a shortage of N. Increasing the C3H8 concentration shortened the delay period and accelerated CO2 evolution and N immobilization. The C3H8 was used as a source of energy by microorganisms that immobilized the soil inorganic N. The use of C3H8 as an energy source for microorganisms has potential usefulness in studying basic soil microbiological problems relating to soil nutrient transformations because the C3H8 itself can be easily removed and does not interfere with subsequent analyses.
Light Quality under Saran Shade Cloth1
Authors: Pallas J. E. , Neves J. D. , Beaty E. R.
Published: July 2010

An earlier report based on optical pyrometry indicated that Saran shade cloth did not reduce visible sunlight uniformly. However, new radiometric measurements of green Saran shade cloth made at noon with 30, 47, 63, 73, 80, and 94% light reduction indicated that all the Saran shade cloths tested reduced light uniformly at all wave‐lengths.
Soil Heating Studies with Cool Season Turfgrasses. I. Effects of Watt Density, Protective Covers, and Ambient Environment on Soil Temperature Distribution1
Authors: Ledeboer F. B. , McKiel C. G. , Skogley C. R.
Published: July 2010

Electrical soil heating studies were conducted from 1967 to 1969 for the purpose of determining wattage and soil temperature requirements for establishment and growth of several turfgrasses during winter. Studies also included influence of Protective Covers, fertilization and heat distribution in the soil. Cables were installed 15.2 cm deep and 30.4 cm apart to provide wattages of 54,108 and 162/m2. Power was supplied from early December until normal spring green‐up. Thermostats located below the turf at the soil surface controlled cable operation. Heating densities of 108 W/m2 or greater were required to maintain soil temperatures near 8 to 10 C during the winter. Temperature distribution curves at several depths showed good thermoconductivity of the soil. Temperature changes near cables were closely linked to power input; near the surface, air environment had the greatest impact. In unheated soil, a lag occurred in diurnal temperature changes which were a function of soil depth. Heat losses were measured in deep soil strata. Block polypropylene screens of 55 and 73% shade used for protection increased heat retention and reduced heating requirements over unprotected turf.
Paraffin Oil and Granules as Carriers for Trifluralin1
Authors: Weaver D. N. , Meyer R. E. , Merkle M. G.
Published: July 2010

This study was conducted to determine the effects of the carrier on the stability of trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine) at the soil surface. Trifluralin concentrations were determined with a gas chromatograph equipped with an electron‐capture detector. In the laboratory, more trifluralin disappeared from wet soil (80% field capacity) after 24 hours when applied in water than when applied in paraffin oil. At 0 to 20% field capacity there was no difference between the carriers. Vapor sampling experiments showed no detectable volatilization of trifluralin from air dry soil over a 24‐hour period at 38C, and confirmed that less volatilization of the herbicide occurred from wet soil when applied in paraffin oil than when applied in water. About 20% less trifluralin was lost from granules than from aqueous sprays on wet clay soil, but no difference occurred on dry soil.

In field, paraffin oil delayed the loss of trifluralin from wet soil (60% field capacity), but under relatively dry field conditions there was little difference between the effectiveness of water and paraffin oil carriers.
Effects of Soil Water Tension on the Emergence and Growth of Cotton Seedlings1
Authors: Jensen R. D.
Published: July 2010

A laboratory study was conducted to determine the effects of soil water tension on the rate and percentage of emergence and the vigor of cotton (Gossypium hirsutum L.) seedlings in a soil environment. Pressure plate apparatus was used to bring the soil to the tensions desired. One hundred seeds were planted equal distance apart in a silt loam soil at a depth of 2.5 cm in a 30‐cm‐diameter enameled pan. The soil was compressed around the seeds to a bulk density of about 1.1 g/cm3. The pan was enclosed in a transparent plastic bag and placed in a constant temperature chamber at 25 C. The number, height, and a description of the appearance of the seedlings which had emerged were recorded daily for 4 weeks.

Total emergence was not affected by changes in soil water tension between 1/3 bar and 3 bars. Emergence at 4 bars tension was significantly less than at lower tensions. The number of seedlings which emerged decreased slowly as the tension increased from 4 to 7.5 bars. A sharp decrease was observed in the emergence at a tension of 8 bars. No emergence occurred at tensions greater than 12 bars. The time required for emergence and the growth rate of seedlings was not significantly affected by changes in tension from 1/3 to 1 bar. The rate of emergence and the growth rate progressively decreased as tension increased from 2 to 4 bars. Thereafter, as tension increased, time requird for emergence increased rapidly and rate of growth simultaneously decreased sharply.
Influence of Nitrogen Nutrition and Suckering Practice on Content and Distribution of Certain Mineral Elements in Burley Tobacco1
Authors: Sims J. L. , Atkinson W. O.
Published: July 2010

Nicotiana tabacum L. cv. ‘Burley 21’ was grown in the field at Lexington, Ky., to determine the influence of N nutrition and suckering practices on concentration and distribution of principal mineral elements in different plant parts. Generally, total plant contents of K, Ca, Mg, and Mn all increased as the N fertilizer rate was increased from 112 to 224 kg N/ha, but increasing the rate to 448 kg N/ha provided no further increases in uptake with exception of Mn. The Mn content was nearly doubled by increasing the rate of N from 224 to 448 kg/ha. As an average of all treatments, total uptake of P, K, Ca, Mg, and Mn was 12, 211, 152, 26, and 0.8 kg/ha, respectively.

Practices to control suckers (axillary buds) and tops (seed heads), as well as the harvest date, influenced both total uptake and distribution of mineral elements among plant parts. Total uptake decreased with increasing degree of sucker control and was least for plants treated with maleic hydrazide. Data for harvest date indicated that considerable redistribution of elements occurred among plant parts between harvest dates. Elements generally considered to have the greatest mobility in plants, e.g., P, K, and to a lesser extent Mg, were present in relatively high amounts in tops and suckers and in relatively low amounts in leaves. The reverse was true for Ca and Mn.
Growth and Water Potential of Root Crops as Influenced by Salinity and Relative Humidity1
Authors: Hoffman G. J. , Rawlins S. L.
Published: July 2010

The interaction of relative humidity and salinity on garden beet, onion, and radish was studied in sunlit climate chambers at temperatures cycling daily between 26 and 10 C. Average daytime relative humidity (RH) was controlled at 45 and 90%. The root medium of each crop was maintained at four different osmotic potentials, the range depending on the crop's salt tolerance.

With a nonsaline root medium, increasing RH from 45 to 90% increased the yield of beet by 50% and radish by 15%, but did not enhance the yield of onion. In saline root media, high RH significantly raised the salinity level at which the yield was reduced to 50% of the nonsaline yield for onion and radish, but did not affect this level for beet.

Linear relationships between leaf water (ΨL) and osmotic (πL) potentials and the osmotic potential of the root medium (πS) were found for all three crops. Except low values of πS (high salinity), ΨL and πL were lower at 45% RH than at 90% RH. Leaf turgor potential was not affected by salinity in beet and onion but was reduced in radish.

The relationship between crop yield and ΨL was linear. The difference in ΨL for plants between full yield and almost no yield was only 13 bars for beet, 6 bars for radish, and 4 bars for onion.
Response of Corn to Residual and Applied Zinc as ZnSO4 and Zn‐EDTA in Field Investigations1
Authors: Schnappinger M. G. , Martens D. C. , Hawkins G. W. , Amos D. F. , McCart G. D.
Published: July 2010

Field investigations were conducted to evaluate the response of corn (Zea mays L.) to residual Zn in Litz silt loam and to determine the level of Zn required to correct Zn deficiency in corn on Westmoreland silty clay loam. Corn yields were increased on the Litz soil in 1969, where 7 and 14 kg Zn/ha as broadcast ZnSO4, and 4.4 kg Zn/ha as broadcast Zn‐EDTA were applied in 1968. A lower level of broadcast Zn‐EDTA of 2.2 kg Zn/ha was inadequate to increase yield. The residual Zn from application of 14 kg Zn/ha as ZnSO4 increased yield to a greater extent than residual Zn from application of 4.4 kg Zn/ha as Zn‐EDTA. Residual Zn from application of 7 kg Zn/ha as ZnSO4 was intermediate between these treatments in increasing yield. More than 13.6 kg Zn/ha as broadcast ZnSO4 was required to correct Zn deficiency of corn on a Westmoreland silty clay loam.
Yield Probabilities for Cotton and Grain Sorghum Grown Under Dryland Conditions on the Texas High Plains1
Authors: Bilbro J. D.
Published: July 2010

Yield probabilities were calculated for cotton (Gossypium hirsutum L.) and grain sorghum [Sorghum bicolor (L.) Moench] grown continuously and in rotations under dryland conditions on the Texas High Plains. The probabilities were calculated using the gamma function technique on data from three rotations (or cropping systems) of a 36‐year dryland study conducted at Lubbock, Texas during the period 1914‐1949. Differences in yields between rotations were also tested for statistical significance.

The mean lint yield of the continuous‐cotton cropping system was 19 kg/ha greater than that of the cotton in the cotton and grain sorghum rotation, but this difference was not statistically significant. Also, the shape parameter estimates (“g” values) for these two rotations were the same. Therefore, calculated yield probabilities for them were essentially equal. Yields of dryland cotton should exceed 150, 250, 400, and 600 kg/ha approximately 30, 50, 25, and 10% of the time, respectively.

The mean yield of grain sorghum grown in rotation with cotton was significantly higher than that from the continuous‐grain sorghum cropping system. Also, the “g” value obtained from the rotation was slightly higher than that obtained from the continuous‐grain sorghum cropping system. Therefore, the grain sorghum yield for a given probability level will be higher in rotations with cotton than from a continuous cropping system. A dryland, continuous‐grain sorghum cropping system should produce yields exceeding 750, 1,200, 2,000, and 2,750 kg/ha approximately 70, 50, 25, and 10% of the time, respectively. Slightly higher, yields can be expected when grain sorghum is grown m alternate years with cotton. Also, l0 to 20% higher dryland yields can be expected if hybrids are substituted for open‐pollinated varieties.