bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some Factors Affecting Development and Longevity of Leaves of Corn1
Authors: Eik K. , Hanway J. J. 
Published: July 2010

SynopsisPlanting dates had small effects on the numbers, sizes, rate of emergence, and longevity of corn leaves. There were differences among hybrids in the numbers, sizes, rates of emergence, and longevity of leaves. Longer‐season (later) hybrids developed and maintained larger leaf areas per plant than the shorter‐season hybrids. Increasing the availability of nutrients, particularly of N, early in the season generally increased the numbers of leaves formed per plant, increased the sizes of leaves more consistently than the numbers, and increased the rates of leaf emergence and leaf area expansion.
Relative Turgidity Technique for Scheduling Cotton (Gossypium hirsutum) Irrigation1
Authors: Namken L. N. 
Published: July 2010

SynopsisCotton irrigations were adequately scheduled according to variations in the relative turgidity of the plant leaves sampled between 2:30 and 3:00 p.m. Cotton plants were able to endure short periods of severe plant moisture stress (66 to 62% relative turgidity) without significant yield reductions. Long periods of moderate to severe plant moisture stress (70 to 62% relative turgidity) during the bloom stage of plant growth caused significant yield reductions.
Effect of Soil Moisture Depletion on Crop Yield and Stomatal Infiltration1
Authors: Fuehring H. D. , Mazaheri A. , Bybordi M. , Khan A. K. S. 
Published: July 2010

AbstractYields of potatoes and maize were considerably reduced as the irrigation interval exceeded one week. Partial closure of stomata as early as two days after irrigation indicated stress on plant growth even when most “available” soil moisture was still present. A linear relationship between degree of stomatal opening as measured by the oil‐drop penetration technique and the length of time after irrigation of various crops was established under field conditions.
Fate of White Clover Axillary Buds at Five Intensities of Sunlight1
Authors: Trautner James L. , Gibson Pryce B. 
Published: July 2010

AbstractThe developmental fate of axillary buds and the frequency of nodal rooting of white clover growing at four reduced intensities of sunlight were determined by suspending plastic shade screens over field plots of spaced plants. Moderate shading as compared to full sunlight resulted in an increase in (1) growth as measured by number of nodes produced, (2) frequency of axillary buds developing into branch stolons, and (3) number of nodes that rooted. The results support the concept that slight shading by a companion grass favors the persistence of white clover stands.
Sorghum Foliar Responses to Changes in Soil Water Content1
Authors: Ehrler W. L. , van Bavel C. H. M. 
Published: July 2010

AbstractPlant response to differences in water availability in the field was measured in grain sorghum during July in centra1 Arizona. During two 24‐hours periods, systematic measurements were made of meteorological factors, transpiration resistance, leaf thickness, leaf temperature, and evaporation, first in dry soil and then in wet soil, after irrigation.Limited soil water availability partially counteracted the normal, light‐induced stomatal opening and led to increased daytime values of leaf diffusion resistance, decreased evapotranspiration, and leaf temperatures that exceeded air temperature, in contrast to plant reactions with water freely available.On the other hand, leaf thickness, as measured by a beta‐ray gauge, decreased negligibly from the dawn reference value, even when the soil water content approached the 15‐bar percentage. The absence of significant leaf response in this regard appears to be a failure of the beta‐ray gauge technique to assess the water content of sorghum leaves.
Test for Drought Resistance in Pearl Millet (Pennisetum typhoideum)1
Authors: Fanous Mamdouh A. 
Published: July 2010

AbstractIn tests for drought resistance in pearl millet, three methods were used: (1) growth in pots under different soil moisture tension regimes, (2) germination of seeds and growth of seedlings in mannitol solutions of different osmotic pressures, and (3) stability of extracted chlorophyll under heat treatment. The pearl millets studied represented a considerable range of ecological adaptation varying from types grown at the edge of the Rajasthan desert in India to commercially available varieties developed at Tifton, Georgia. The results showed that as the soil moisture tension increased, the growth responses for the pearl millet varieties studied decreased in the same general pattern. Differences in magnitude of responses were also observed among the varieties. It was concluded that more progress might be made by selection for early maturity in order to avoid drought than by selection for physiological drought resistance.
Influence of Plant Population on Yield and Other Characteristics of Soybeans1
Authors: Johnson B. J. , Harris H. B. 
Published: July 2010

AbstractAn investigation was conducted at Experiment, Georgia, during the period 1964 through 1966 to study effects of plant population on soybean (Glycine max (L.) Merr.) yield and other agronomic characteristics of varieties of different maturity. The 6.6 plants per meter of row (2 plants per foot) produced maximum yields (that point at which there were no further significant increases) of ‘Bragg’; all other varieties required 26.2 plants per meter (8 plants per foot). Plant height increased as populations increased through 26.2 plants per meter of row for all varieties except ‘Hardee’, which required only 13.1 plants. Lodging was a serious problem only in Hardee during 1966, and this was apparently associated with stem breakage due to stem girdling and excessive height. Weed populations and development of lower pods closer to soil level occurred in populations below 13.1 plants per meter of row. An inverse relationship between seed size and plant population was observed for Lee only.
Differential Tolerance of Dry Bean, Snapbean, and Lima Bean Varieties to an Acid Soil High in Exchangeable Aluminum1
Authors: Foy C. D. , Arminger W. H. , Fleming A. L. , Zaumeyer W. J. 
Published: July 2010

AbstractVarieties of dry beans, snapbeans, and lima beans differed widely in their top and root growth on acid Bladen soil (pH 4.4) and in their yield response to lime. Previous evidence that Al toxicity is the primary growth‐limiting factor in this soil led to the conclusion that certain bean varieties differ in their specific tolerance to Al. With few exceptions, varieties that originated in the South (Florida, South Carolina, Tennessee) or East (New York) showed greatest tolerance to the acid soil. Varieties developed in the Midwest (Michigan) or West (Idaho, California) showed least tolerance. Results suggest the possibility of breeding bean varieties with greater tolerance to Al. Such varieties would root more deeply in acid, Altoxic subsoils and make better use of subsoil water and nutrients.
Effect of Phenylmercuric Acetate on Growth and Water Use of Spring Wheat1
Authors: Brengle K. G. 
Published: July 2010

AbstractSpring wheat (Triticum aestivum L. var. ‘Lee’) was treated with two concentrations of phenylmercuric acetate (PMA). In one test the treatments were applied at tillering, boot, and flowering stages of growth. In a second test, PMA was applied at tillering and heading stages of growth with a soil water variable for a 10‐day period following treatment. The soil water suction was kept between 1 bar and 1/3 bar in one series of treatments and permitted to go to 9 bars in another series. PMA applied at the heading or flowering stages of growth, reduced plant growth and water use. Plant damage or reduced water use were not apparent at the other stages of growth. Water use efficiency was not increased by any PMA applications used in these studies. Water use during the period of treatment was affected by soil water regimes but not by PMA treatment.
Effects of Environmental Factors on the Development of the Crown Node and Adventitious Roots of Winter Wheat (Triticum aestivum)1
Authors: Ferguson Hayden , Boatwright G. O. 
Published: July 2010

AbstractRates of surface straw litter were shown to influence the location of the crown node in four varieties of winter wheat (Triticum aestivum). As the rate of surface straw was increased, the node formed farther from the seed; however, there was a strong variety ✕ straw rate interaction. At low straw rates, winter‐hardy varieties formed their nodes closer to the seed than did nonhardy varieties.Both light and temperature influenced the location of the crown node. As light decreased or temperature increased, the node formed farther from the seed, but the node location was strongly affected by a variety ✕ temperature ✕ light intensity interaction.Adventitious roots formed but did not elongate when the soil water content around the crown node was air dry; however, at water contents at or above 15 bars adventitious root growth appeared normal.
Effect of Nitrogen Fertilizer on Yield, Nitrogen Content, and Yield Components of Safflower
Authors: Jones J. P. , Tucker T. C. 
Published: July 2010

AbstractNitrogen fertilization produced large increases in safflower seed yield when amply irrigated, a lesser effect with moderate irrigation, and none where irrigation was severly restricted.Total nitrogen in above ground plant portions increased with N fertilization rate, doubling from first bloom to maturity at all N rates. Percentage recovery decreased as applied N rates increased.Nitrogen fertilization increased safflower seed yield with more heads in the tertiary position and increased weight per head in the secondary and tertiary position. Increased head weight resulted from increased weight per seed in secondary head position and increased number of seeds per head in the tertiary position.
Establishment of Tall Fescue and White Clover: Effects of Seeding Method and Weather1
Authors: Hart Richard H. , Carlson G. E. , Retzer H. J. 
Published: July 2010

AbstractWe drilled and broadcast‐seeded tall fescue (Festuca arundinacea Schreb.) and white clover (Trifolium repens L.) on three soil types, on 29 dates in 1963 and 1964. Tall fescue yields of the spring after seeding were generally higher from drilled than from broadcast stands. Although drought in the spring of 1965 reduced yields from most of the 1964 seedings, fescue yields were mainly limited by soil moisture supply immediately after germination. If drought occurs in this critical period, the fescue should be reseeded, because future forage yields will be greatly reduced. However, irrigation during this period should greatly increase potential yields the following year. The amount of white clover in the stand was limited by moisture and competition with fescue; there was more clover in broadcast stands, where competition with fescue for light and moisture was less severe, and in stands planted in summer, when more light could penetrate the stand.
Field Investigations of the Relationships of Leaf Angle in Corn (Zea mays L.) to Grain Yield and Apparent Photosynthesis1
Authors: Pendleton J. W. , Smith G. E. , Winter S. R. , Johnston T. J. 
Published: July 2010

AbstractField investigations were conducted at Urbana, III., concerning the relationship of leaf angle and canopy shape to grain yield and apparent photosynthesis of Zea mays L. A backcross‐derived isogenic single cross hybrid (‘C103’ ✕ ‘Hy’) carrying the lg2 gene for erect leaf produced 40% more grain than its counterpart with normal (horizontal) type leaf, when compared in rows 51 cm wide at 59,304 plants/ha. Mechanical manipulation of the leaves of a widely grown commercial hybrid. ‘Pioneer 3306’ into a more upright nature resulted in grain yields above that produced by the same hybrid in its normal leaf orientation and canopy shape. Apparent photosynthesis measurements on individual corn leaves showed the relative efficiency of CO2 fixation/unit of incoming sunlight to steadily increase as the leaf angle decreased. The results strongly support corn breeding programs in the area of plant geometry and crop canopy.
Reduction of Strontium‐85 Uptake in Field Crops By Deep Plowing and Sodium Carbonate Application1
Authors: Menzel R. G. , Eck H. V. , James P. E. , Wilkins D. E. 
Published: July 2010

AbstractDeep plowing reduced uptake of Sr85 by four irrigated crops on Pullman silty clay loam at Bushland, Texas. Uptake was further reduced when Na2CO3 was plowed under with the Sr85. The relative concentrations of Sr85 in mature soybean (Glycine max), sugar beet (Beta vulgaris), sudangrass (Sorghum sudanense), and cabbage (Brassica oleracea var capitata) plants grown with Sr85 applied in different treatments were: rotary tilled 20 cm deep, 100; plowed 90 cm deep, 25–50; plowed 90 cm deep with 22,400 kg/ha (10 tons/acre) of Na2CO3, 3–7. In the plowing treatments, 90% of both the Sr>85 and the Na2CO3 were banded in the furrow deeper than 75 cm. Crop yields were increased by deep plowing and were affected very little by the application of Na2CO3. This experiment demonstrates that a toxic chemical can be plowed under deeply with radioactive contamination to reduce the uptake of the radioactive material with little effect on yield from the chemical.
Desiccation and Defoliation of Plants by Different Herbicides and Mixtures1
Authors: Bovey R. W. , Miller F. R. 
Published: July 2010

AbstractGuava, hibiscus, sorghum, and cotton leaves were treated with 5 herbicides each at 10 dosages. Pentachlorophenol (PCP) and cis−2,3,5,5,5−pentachloro−4−ketopentenoic acid (AP−20) produced the most rapid desiccation at high dosages. The 6,7−dihydrodipyrido(l,2−α:2',I'−c)pyrazidünium salt (diquat) was usually as effective as PCP and AP−20 within 1 to 2 days after treatment, and it produced more extensive desiccation at lower dosages, especially on hibiscus, sorghum, and cotton. Diquat, l,l'−dimethyl− 4,4'−bipyridinium salt (paraquat), dimethylarsinic acid (cacodylic acid), and AP−20 produced complete defoliation of hibiscus within 5 days after treatment but diquat and paraquat were more effective at lower dosages than other defoliants. Diquat completely defoliated hibiscus at 19 µg regardless of placement on the leaf, but higher dosages were required for effective desiccation when applied non−uniformly over the leaf. Effective desiccation with PCP required uniform application to either upper or lower surfaces. Defoliation of leaves after treatment with PCP did not occur. Some herbicides increased the desiccation and defoliation of hibiscus synergistically when added to diquat. Hormone−type herbicides such as 2,4−dichlorophenoxyacetic acid (2,4−D) and 4−amino−3,5, 6−trichloropicolinic acid (picloram) were antagonistic to diquat.
Practical Suggestions on Pooling Variances for F Tests of Treatment Effects1
Authors: Carmer S. G. , Walker W. M. , Seif R. D. 
Published: July 2010

AbstractA two‐part rule is given as a practical guide in preliminary tests of significance for determining whether or not to pool two or more variances for use as “error term” in subsequent F tests for treatment effects. Four examples involving commonly occuring analysis of variance tables are given to illustrate the use of the rule.
Root Growth Pressures of Cotton, Peas, and Peanuts1
Authors: Taylor Howard M. , Ratliff Larry F. 
Published: July 2010

AbstractThe root growth force that cotton (Gossypium hirsutum L. ‘Coker 413–68’), pea (Pisum sativum L. ‘Brunswick’), and peanut (Arachis hypogaea L. ‘Virginia Bunch’) seedlings developed was measured with an unbonded strain gage force transducer. Root growth pressure, defined as root growth force per unit root cross‐sectional area, averaged 9.4, 13.0, and 11.5 bars for cotton, peas, and peanuts, respectively, but values varied widely within each variety. Osmotic potential and root growth pressure results supported Pfetter's contention that cellular osmotic potential created the stress necessary for root growth pressure development.
Effects of Soil Temperature and Zinc Application on Yields and Micronutrient Content of Four Crop Species Grown Together in a Glasshouse1
Authors: Wallace A. , Romney E. M. , Hale V. Q. , Hoover R. M. 
Published: July 2010

AbstractFour species of plants were grown together in Dinubasandy loam in pots which were placed in temperature controlled tanks to give root temperatures of 14, 20, and 26C. Sugar beets had been previously grown and the residues incorporated in the soil to help induce a low zinc status. Zinc labeled with Zn65 had been added to half of the pots. Vegetative yields of two crops, Zn65 contents, and micronutrient and phosphorus contents of the plants were tabulated. Yields generally increased wih soil temperature with or without zinc application. Cotton yields responded to zinc at the low soil temperature, bush bean yields at the high soil temperature, and corn responded at all three temperatures used. Zinc content tended to increase with soil temperature; the increase was significant in cotton without added zinc and in soybean either with or without added zinc. The zinc application generally resulted in a higher zinc content of plants; the two cases when this was not significantly so were at the high soil temperature. Zinc content and evidently zinc needs varied considerably. The specific activity of the zinc in the four species was remarkably uniform, but for three of them there was a tendency for a decrease at the highest soil temperature. Plant phosphorus tended to increase with soil temperature, and there was a slight interaction with zinc contents. There was some tendency for copper and manganese in plants to increase with zinc; iron did also but to a much lesser extent. Copper tended to increase with soil temperature but manganese tended to decrease at the high temperature. Boron varied for species only and aluminum decreased with increasing temperature.
Row Spacing and Fertilization Influences on Forage and Seed Yields of Intermediate Wheatgrass, Russian Wildrye, and Green Needlegrass on Dryland1
Authors: Black A. L. , Reitz L. L. 
Published: July 2010

AbstractThe effects of contour row spacings of 76, 107, and 152 cm and N and N‐P fertilization on forage and seed production of intermediate wheatgrass (Agropyron intermedium [Host] Beauv.), Russian wildrye (Elymus junceus Fisch.), and green needlegrass (Stipa viridula Trin.) were evaluated over a 5‐year period.With 45 or 67 kg/ha of N applied annually, forage and seed yields of all species increased 1.5‐ to 2.0‐fold regardless of row spacing, independent of added P. The need for N and N‐P fertilization increased with age of stand regardless of row spacing. Without N or N‐P fertilization, row spacings had no significant influence on forage or seed production of intermediate wheatgrass or Russian wildrye. Forage and seed yields of green needlegrass decreased progressively as row spacing increased regardless of N or N‐P fertilization.Nitrogen recoveries by the three grasses ranged from about 20 to over 50%. In general, N fertilizer recovery was highest from plots with the highest yields and greatest water‐use efficiencies. Russian wildrye grown in 76‐ or 107‐cm rows recovered more than 50% of the N fertilizer applied.Considering all factors involved—forage and seed yields, water‐use efficiencies, and plant N and P uptake—intermediate wheatgrass, Russian wildrye, and green needlegrass should be grown in 107‐ 76‐, and 76‐cm row spacings, respectively, with annual applications of 40 to 60 kg/ha of N with P added.
Seasonal Patterns in Evapotranspiration by Irrigated Alfalfa in the Central Great Plains1
Authors: Rosenberg Norman J. 
Published: July 2010

AbstractEvapotranspiration (ET) by irrigated alfalfa in eastern Nebraska, as determined with precision weighing lysimeters during 1967, varied qualitatively and quantitatively with season. ET in early spring may exceed the net radiation. Low temperature, however, induces a strong canopy resistance and ET can then be significantly lower than atmospheric conditions suggest possible, Maximum ET measured during this season was approx. 6.5 mm day−1.Strong local and/or regional advection may prevail in late spring and ET rates may be as high as 12 mm day‐1. ET may exceed Rn by 80% during this season which is often characterized by very low humidity when winds stem from SW through N.Mid‐summer is characterized by hot and humid conditions under predominantly S and SE winds. ET exceeds Rn only little during this season. Maximum ET rate is about 7.5 mm day‐1.Nocturnal ET is common during the alfalfa growing season. Strong temperature inversions account for a downward delivery of sensible heat sufficient to explain this effect. As much as 1 mm per night can be transpired by alfalfa.The Energy Balance Bowen ratio method estimated hourly ET more closely than did an aerodynamic method uncorrected for atmospheric stability conditions. Neither method gave estimates more reliable than ±0.151y rain‐1.The Penman method underestimates ET under potential evaporation conditions by as much as 30%, particularly when advection is strong. The van Bavel method for estimating potential evaporation is very sensitive to the value assigned the roughness parameter. With Z0 = 2 cm this method estimates potential evaporation of 8 to 28% more than with Z0 = 1 cm. The van Bavel method is also sensitive to windiness, underestimating ET on calm days and overestimating on windy days.
Some Effects of Soil Moisture Stress on the Growth of Wheat (Triticum aestivum L. em Thell.)1
Authors: Day A. D. , Intalap Suhbawatr 
Published: July 2010

AbstractInvestigations were conducted in 1966 and 1967 at Tucson, Ariz., to study some effects of soil‐moisture stress, at three different stages of development (jointing, flowering, and dough) on the growth and grain yield of spring wheat (Triticum aestivum L. em Thell.) planted in December. A critical period in the growth of wheat was the jointing stage for moisture. Stressing wheat for water at jointing resulted in fewer days from planting to flowering, shorter plants, more lodging, lower grain yield, lower grain volume‐weight, fewer heads per unit area, and fewer seeds per head. Soil‐moisture stress at any stage of growth decreased grain yield. When wheat was stressed at jointing, reduced grain yield resulted from fewer heads per unit area and fewer seeds per head. However, when moisture stress occurred at the flowering and dough stages, lower grain yields were caused by lighter seed‐weight. Stress at the flowering and dough stages also hastened maturity.
Meso‐Scale Effects of Agriculture and a Large Prairie Lake on the Atmospheric Boundary Layer
Authors: Holmes R. M. 
Published: July 2010

AbstractThermal gradients were measured in the atmospheric boundary layer over an extensive agricultural region using an instrumented aircraft and a mobile ground station mounted on an automobile. It was noted that sharp changes in the temperature of the surface produce similar temperature changes in the atmosphere above. Near the surface the temperature discontinuities in the atmosphere were located almost immediately above the heat sources or sinks. But higher in the atmosphere, the cooled or heated air persisted for appreciable distances down wind. A large lake and an irrigated region produced 3.0 C and 2.0 C cooling, respectively at 20‐m elevation, and virgin prairie caused a temperature increase of 2.0 C in the atmosphere at 20 m. The temperature changes indicated are statistically significant compared to the temperature of prairie air 8 km up wind at the same elevation.