bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relationship between Number of Independent Variables and Number of Observations in Plant Analysis Calibration Studies1
Authors: Walker W. M. , Carmer S. G. , Peck T. R. 
Published: July 2010

AbstractData were presented indicating that the number of data points in plant analysis calibration studies should be 5 to 10 times as large as the number of potential variables in the regression model. This criterion was valid for the quadratic polynomial and the square root transformation of the quadratic polynomial in these studies. This kind of information should assist researchers in planning the number of plant samples to be obtained for calibration studies after a regression model has been selected.
Effect of Soil Temperature on the Growth of Spring Wheat With and Without Wheat Straw Mulch1
Authors: Brengle K. G. , Whitfield C. J. 
Published: July 2010

AbstractSpring wheat (Triticum aestivum L. vat. ‘Lee’) was grown in pots in the greenhouse in water baths controlled at 12.8 ± 0.3 and 18.3 ± 0.3 C. Wheat straw was applied on an area basis at rates equivalent to 0 and 5,040 kg/ha. Selected groups of pots were shifted between temperature baths at specific growth stages. Soil temperatures measured continuously with thermocouples were lower with surface residue than without surface residue during the earlier stages of growth, with the greater difference occurring in the 12.8 C bath. There was a significant correlation between temperature at the 0–3 growth stage and the number of tillers, number of heads, and total grain yield. The percentage of heads to tillers ranged from 34 to 50 with no clearcut correlation with temperature or mulch treatment. There was no correlation between yield and mulch treatment. Significant correlation coefficients were also obtained for soil temperature during the 10–10.5 stage of growth and weight per kernel, number of kernels per head and weight of grain.
Dieldrin Translocation and Accumulation in Corn1
Authors: Beestman G. B. , Keeney D. R. , Chesters G. 
Published: July 2010

AbstractThe translocation and sites of accumulation of dieldrin in corn were investigated in greenhouse experiments using C14‐dieldrin. Surface and subsurface horizon soil samples from three catenal soils were treated with 1 and 5 ppm of dieldrin, and the corn was harvested 39, 69, or 90 days after emergence. At the final harvest, the corn had reached full maturity with normally developed ears. The stalks below the 5th node were the primary site of dieldrin localization, and contained 70 to 90% of the total dieldrin contained in the plant. Dieldrin accumulated in corn in the following order: Lower stalks > lower leaves > upper stalks > upper leaves > ears. Evidence was obtained of dieldrin translocation from the leaves and stalks into the developing ears. Dieldrin translocation within the plant was dependent throughout the growing season on dieldrin application rate and soil characteristics. Dieldrin concentrations in the mature ears were in the order: cobs > car leaves > kernels.
Atriplex polycarpa: II. Germination and Growth in Water Cultures Containing High Levels of Boron1
Authors: Chatterton N. J. , McKell C. M. , Goodin J. R. , Bingham F. T. 
Published: July 2010

AbstractA study of seed germination and growth of three populations of Atriplex polycarpa under greenhouse conditions using water cultures showed it to be very tolerant to high concentrations of boron in the growth medium. Germination was not affected by boron. Growth varied among populations but was generally not reduced by up to 40 ppm boron in the culture solutions. High levels of boron had no effect on root/top ratio or percent water in the top growth. Although growth was somewhat reduced in 80 ppm boron, no vsible morphological changes occurred or toxicity symptoms appeared.
Fixation of Atmospheric Nitrogen by Nonlegumes in Wet Mountain Meadows1
Authors: Porter L. K. , Grable A. R. 
Published: July 2010

AbstractMountain soils subjected to excessive irrigation and high water tables accumulate organic matter in sod mats. Meadow soils often contain two or three times more N than equal areas of adjacent dry soils. Symbiotic nitrogen fixation by legumes is one possible source of N for sod mat formation. Fixation of N2 by free‐living organisms has also been postulated and was verified by the laboratory studies reported here. Nitrogen fixation by sod mats containing no legumes was determined at 18C in atmospheres containing N215 Both photosynthetic and nonphotosynthetic organisms appeared to fix N2. In 10 days, mats in the dark fixed from 0.76 to 1.90 kg N2 ha−1 and illuminated mats fixed from 3.72 to 6.86 kg N ha−1.
Diurnal Variation in Growth Rate of Irrigated Winter Wheat1
Authors: Johnson Wendell C. 
Published: July 2010

AbstractDuring the 2‐week period before heading, a continuous growth record of irrigated winter wheat (Triticum aestivum) was obtained using a growth sensor attached to a leaf emerging from the whorl and a strip chart recorder. The growth rate was typically the greatest in the afternoon, with a maximum point usually occurring around sunset. The minimum growth rate usually occurred at the time of the minimum temperature, which on days without moisture condensation was around sunrise. The normal decrease in growth rate at night was arrested, or there was an increase in growth rate, when an increase in temperature or humidity occurred.A continuous growth record of a plant was obtained during a 6‐day period that included a cold front passage followed by a late freeze and several days of subnormal temperatures. The temperature below which growth ceased was in the range 1 to 1.5C. On the day with the coldest morning, minimum temperature −0.5C (31F), considerable growth was made in the afternoon when the temperature rose to 23.5C (74F).
Simultaneous Cycling of Peltier Thermocouple Psychrometers for Rapid Water Potential Measurements1
Authors: Hoffman G. J. , Herkelrath W. N. , Austin R. S. 
Published: July 2010

AbstractAn automatic system was built to record the output from Peltier‐effect thermocouple psychrometers. The system consists of a scanner, capacitors, voltmeter, and a recorder. The scanner, built from inexpensive commercial components, is of solid‐state circuitry and contains only one moving mechanism, a stepping relay. The system automatically reads and stores the initial emf, cools as many as six psychrometers simultaneously, reads and stores the final emf, and heats the measuring junction of the psychrometers. For a 30‐second cooling period, six psychroneters can be read in 2½ minutes. By adding a stepping relay, as many as 150 psychrometers can be read in an hour. The standard deviations for recorded calibration outputs were ±0.04 µv for soil and intact leaf thermocouple psychrometers. Under actual experimental conditions, the values obtained with the automatic system were as accurate as measurements made manually.
A Modified Dye‐Binding Method for Estimating Soybean Protein1
Authors: Hymowitz T. , Collins F. I. , Gibbons S. J. 
Published: July 2010

AbstractKjeldahl values that indicated 27 to 51% protein (N ✕ 6.25) were obtained in 95 soybean meal samples. A linear regression with modified dye‐binding values as independent variables was fitted to the percent protein data obtained by the Kjeldahl method. The correlation coefficient was 985.Analysis of variances of modified dye binding and Kjeldahl values showed that high drying temperature reduced the percent protein obtained by the dye‐binding method, but had little effect on the protein determined by Kjeldahl. At room temperature, there were no significan differences in values among the Kjeldahl, modified dye‐binding and Smalley soybean check series.The modified dye‐binding method can be used to estimate the protein fraction of soybean meal, or to obtain equivalent Kjeldahl values for protein estimation.
Fruiting Pattern of Vernonia Anthelmintica (L.) Willd1
Authors: Massey John H. 
Published: July 2010

AbstractKinkaoil ironweed (Vernonia anthelmintica (L.) Willd.) seed yield and components of yield were determined for successive 5‐day intervals throughout the fruiting season. The average yield per plant was 19.45 g, or 5,021 seeds, which ripened over a 40‐day period. Seed weight decreased from the beginning to the end of the season. There was an average of 151 heads per plant, each containing 29 to 40 seeds. The peak yield occurred 21 to 30 days after the first head matured.
Influence of Nitrogen Fertilizers on Washington Creeping Bentgrass, Agrostis palustris Huds. I. Growth and Mineral Composition1
Authors: Markland F. E. , Roberts Eliot C. 
Published: July 2010

Abstract‘Washington’ Creeping Bentgrass turf (Agrostis palustris Huds.) clipped at 0.635 cm (1/4 inch) was fertilized with seven nitrogen sources applied at two rates over a 5‐year period. Differences in nitrogen response were noted and correlated with fresh and dry weight yields, with percentage dry weight, and with mineral analysis of leaf tissue. Activated sewage sludge, inorganic nitrogen sources, and urea produced similar growth responses. Processed tankage and ureaformaldehyde were less effective in promoting growth than other nitrogen fertilizers.
Effects of Spacing Arrangement and Anthracnose on Cassia occidentalis L.1
Authors: Massey John H. , Sowell Grover 
Published: July 2010

AbstractThe effects of spacing arrangement and anthracnose, caused by Colletotrichum sp., on Cassia occidentalis L., a potential seed‐gum crop, were studied at Experiment, Ga. Row widths of 30, 46, and 91 cm and within‐row plant spacings of 10, 20, and 41 cm did not affect seed yield or plant height. Anthracnose caused very serious reduction in seed yield and was found to be seed‐borne. Hot water treatment of 30 min at 55 C apparently inactivated the pathogen but reduced seed germination. Anthracnose resistance was found among available Cassia spp. introductions.
Influence of Herbicides on Plant Growth and Agronomic Characteristics of Soybean Varieties1
Authors: Johnson B. J. 
Published: July 2010

AbstractThe effect of selected herbicides on soybean growth and other agronomic characteristics was studied for four soybean varieties with different maturing dates. There were no interactions when amiben ester + dinoseb, trifluralin, chloroxuron, or chlorpropham + dinoseb herbicides were applied to soybean varieties on plant growth, seedling vigor, date of maturity, lodging, seed size, seed quality, or seed yield. The growth of soybean seedlings was retarded when treated with amiben ester + dinoseb or trifluralin in 1967 and trifluralin in 1968, but the difference in height of soybeans was nil at maturity. Seedling vigor was affected by amiben ester + dinoseb or trifluralin in 1967 and by chloroxuron in 1968. Seed yields were significantly reduced in 1968 when soybeans were treated with chloroxuron or chlorpropham + dinoseb. Soybeans treated with amiben ester + dinoseb had less lodging in 1968 than when treated with trifluralin, chlorpropham + dinoseb or when no herbicide was applied.
Radiation Exchange in Controlling Leaf Temperature1
Authors: Aston A. R. , Millington R. J. , Peters D. B. 
Published: July 2010

AbstractAn experimental study has been made of the energy balance of a dry artificial leaf under controlled radiative and convective heat loads.The exchange coefficients found for free and forced convection agreed with calculated values. This study has provided insight into problems of assessing energy budgets at the single leaf level and indicated the need for study of transient coupled exchange phenomena.
Management Factors Influencing Viability of Castorbean (Ricinus communis L.) Seed1
Authors: Williams J. H. , Kittock D. L. 
Published: July 2010

AbstractGermination samples of castorbean (Ricinus communis L.) seed were taken from 1,100 truck loads delivered to 11 collection points in Nebraska during 1962 and 1963. Information on variety, seed moisture content at harvest, seed weight, and time from frost to harvest was obtained both years. Data on date of planting, seed yields, number of irrigations, and amount of N applied were also obtained on 104 samples in 1963. Data were analyzed by a covariance analysis to permit estimation of multiple regression equations of germination percentage and seed yield on the independent variables. The regressions for each covariate were determined with effect of all other variables held constant.Quality of seed varied significantly between the 11 designated areas included in the sampling. Irrigated dwarf‐internode varieties gave lower germinability than nonirrigated hybrids. Effect of genotype and irrigation was confounded and could not be accurately separated. Germination increased with increased seed weight, lower moisture content of seed at harvest, earlier planting date, and early harvest after first frost. Higher seed yields were associated with early planting, increased irrigation, and early harvest after frost. Lower germinability resulted from increased rates of nitrogen application.
Head Size of Sunflower as an Indicator of Plot Yields1
Authors: Burns Robert E. 
Published: July 2010

AbstractThe accuracy of plot yields of sunflower is often reduced by bird depredation. To find a substitute for harvested yields of plots, the head size of two varieties of sunflower was correlated with yield per head. The high correlation obtained (r = 0.95) indicates that, in plots which have considerable bird damage, yield estimates based on head size would be more accurate than actual seed weights.
Response of Six Diverse Genetic Lines of Soybeans to Different Levels of Soil Fertility1
Authors: Caviness C. E. , Hardy Glenn W. 
Published: July 2010

AbstractExperiments were conducted at the Rice Branch Experiment Station, Stuttgart, Ark. on a Crowley silt loam soil for a 6‐year period to evaluate the response of four soybean varieties (‘Lee,’ ‘Hood,’ ‘Ogden,’ and ‘Arksoy’), a strain (R56‐49), and a plant introduction (PI‐91,120) (to three levels of soil fertility. Significant increases in seed yield were obtained each year from the application of 49 kg/ha of P and 93 kg/ha of K. However, when this rate of fertilizer was doubled, yields were not significantly higher than those obtained from the moderate rate.Each year certain of the genetic lines produced increased yields when grown at the high fertility level, but when this line was evaluated in a different environment the following season, it usually did not produce this unusual yield response. The commercial varieties were just as responsive as the lines which had been selected for their ability to produce increased yields with high fertilizer rates. There was some indication that the Arksoy variety failed to respond to fertilizer application as much as other entries.
Factors Affecting Stalk Strength and Flexibility in Sugarcane
Authors: James Norman I. , Smith Garry A. 
Published: July 2010

AbstractThe primary objective of this study was to determine the effect of distribution of fibrovascular bundles on stalk strength and flexibility in sugarcane (Saccharum spp.). Differences in distribution of fibrovascular bundles within the stalk accounted for less than 1% of the variation in strength of single stalks selected at random from 137 clones. About 76% of the variation in stalk strength was attributed to differences in diameter and percent fiber of stalks. Standard partial regression coefficients indicated that stalk diameter was more than twice as important as percent fiber in predicting stalk strength. Less than 1% of the variation in stalk flexibility was attributed to the combined effect of distribution of fibrovascular bundles, total number of fibrovascular bundles, stalk diameter, and percent fiber of stalks.
Dry Matter Production and Nutrient Uptake in Irrigated Cotton (Gossypium hirsutum)1
Authors: Bassett D. M. , Anderson W. D. , Werkhoven C. H. E. 
Published: July 2010

AbstractDry‐matter production of cotton (Gossypium hirsutum L.) plants in the irrigated San Joaquin Valley of California was slow for 40 to 80 days following seeding, with only 2 to 4% of the total seasonal aerial dry matter present at time of first square, and 7 to 10% at time of first flower (one‐fourth to one‐tenth of the percentages reported elsewhere for these stages). One‐third of the total seasonal dry matter was produced in a 2‐week period in August. Total dry matter ranged from 6,900 to 8,900 kg/ha, distributed in mature plants as stems, 23.1%; leaves, 17.4%; burs, 16.3%; seed, 25.3%; and lint, 17.9%. The proportion of lint was at least 50% higher than reported from early research in other areas.Amounts of N, P, K, Ca, Mg, and Na accumulated in the aboveground parts at first flower were less than 15% of the final amounts. Of total seasonal uptake, 45% of N and P occurred in July, and 67% of K in the 6 weeks beginning July 1. During these peak absorption periods, daily uptake per hectare was 1.5 to 2.0 kg N, 0.17 to 0.34 kg P, and 2.1 to 3.4 kg K.Mature plants contained 142 kg N, 19 kg P, and 127 kg K per hectare. About 70 kg N, 11 kg P, and 21 kg K per hectare were contained in the seed. The amount of dry matter needed to produce 100 units lint contained 10 units N, 1.5 P, and 9 K. More than half of the N and P was in seed, and more than one‐third of the K was in the bur.
Effect of Plant Density and Growth Duration on Grain Sorghum Yield under Limited Water Supply1
Authors: Blum A. 
Published: July 2010

AbstractIn one experiment, three experimental grain sorghum (Sorghum bicolor L. Moench.) hybrids (heading 55, 60, and 70 days from emergence) were planted at 12 plant densities (from 2.9 to 27.9 plants/m2) in a systematic design. Plants were grown under conditions of 302 mm available soil water, as determined at emergence, with no additional water supply.It was found that the grain yield of the late maturing hybrid was highest under the low plant density and that of an early maturing hybrid was highest under the high density. The superiority of low density in the late maturing hybrid and of high density in the early maturing hybrid was also consistent regarding yield per plant, number of heads per plant and number of grains per panicle.The highest yield in the experiment was obtained with the earliest maturing hybrid planted at the densest plant population. All grain yield components were operative in the determination of inter‐hybrid differences under moderate competition. The expression of components was suppressed by increased competition, and at the highest plant density grain yield was determined only through the interaction between the number of grains per panicle and the weight per grain. The superiority of the early maturing hybrid at the highest density was attained through its ability to maintain larger grains in spite of increased interplant competition for water.In a second experiment an early maturing hybrid used less water than a later maturing hybrid, at all stages of growth, beginning on 30 days from emergence. Water use was increased by increased plant density.
Absorption of Na, Cl, and B by Desert Saltbush in Relation to Composition of Nutrient Solution Culture1
Authors: Chatterton N. Jerry , McKell C. M. , Bingham F. T. , Clawson W. J. 
Published: July 2010

AbstractAbsorption of Na, Cl, and B ions by desert saltbush (Atriplex polycarpa (Torr.) S. Wats.) was investigated in relation to the concentration of these elements in water cultures. Plants were grown for 6 weeks in four different solution cultures containing sufficient NaCl to give osmotic potentials of —0.8, —10.0, —20.0, and —30.0 atm. Extremely large quantities of both Na and C1 (10 and 13%, respectively) were found in plants growing in the highest level of salinity. Although much salt is absorbed by desert saltbush, its adaptation to salinity may not be by virtue of a capacity to function with large quantities of salt within the photosynthetically active tissues. Instead, most of the absorbed salt may be localized in the trichomes and therefore essentially isolated from the mesophyll tissues. In contrast to Na and Cl, B was found to be absorbed relatively slowly. Tolerance of desert saltbush to substrates high in B may therefore be due to a selectivity mechanism at the site of absorption.
Extraction and Cleanup of 14C‐Chlorinated Insecticides from Cotton Grown in Treated Soils
Authors: Nash R. G. , Beall M. L. 
Published: July 2010

AbstractDry cotton hay or seed samples from plants grown in 0.5 ppm 14MC‐DDT, ‐dieldrin, ‐endrin, and ‐heptachlor treated soils were subjected to exhaustive Soxhlet extraction with chloroform/methanol (CM), hexane/acetone (HA), hexane/acetone/methanol (HAM), or hexane/acetone/ methanol/water (HAMW). Extracts further were fractionated by selective elution from Florisil columns and the 14C‐insecticide residues determined.The relative extracting power of the solvents was HAMW>HAM=CM>HA; this applied to all insecticides except DDT, whose residue was too low for reliable comparison. No solution removed all the 14C‐residue from plant tissue. HAM afforded greater simplicity and less time in cleanup compared to CM.One dieldrin degradation product, three endrin degradation products, and three heptachlor degradation products, which includes heptachlor epoxide, were believed extracted from cotton hay with HAMW.
Plant Uptake of Chlorinated Insecticides from Soils
Authors: Nash R. G. , Beall M. L. , Woolson E. A. 
Published: July 2010

AbstractSoybeans (Glycine max [L.] Merr., var. ‘Clark’) and cotton (Gossypium hirsutum L., var. ‘Acala 4‐42’) were grown in Lakeland sandy loam and Hagerstown silty clay loam soils treated with 0.5 ppm 14C‐DDT, ‐dieldrin, ‐endrin, and ‐heptachlor. Periodically, the top portion of one plant per pot was harvested and assayed for insecticide. At maturity, the seed and cotton lint were separated from the hay and assayed separately. Two methods of assay were used, i.e., gas‐liquid chromatography and 14C counting by liquid scintillation.Total 14C‐residue concentrations in soybeans for all four insecticides increased linearly during active growth stages, whereas highest 14C‐residues in cotton were found at the first harvest. No parent DDT or heptachlor was detected in any of the soybean or cotton samples by gas‐liquid chromatographic determination, though small amounts of unidentified DDT residues were detected by liquid‐scintillaton counting of plant extracts of both species. Heptachlor epoxide was present in soybeans at less than 0.1 ppm in hay and less than 0.04 ppm in seed. No heptachlor epoxide was detected in cotton, but unidentified 14C‐heptachlor residues were present at an equivalent of less than 0.065 ppm. Dieldrin residues ranged as high as 0.3 ppm in soybean hay and 0.09 ppm in seed. Endrin residues ranged as high as 0.5 ppm in soybean hay and 0.1 ppm in seed, though actual endrin was less than these values. Dieldrin and endrin residues in cotton hay were below 0.03 ppm and none was detected in seed or lint. The use of 14C‐labeled insecticides demonstrated that all 14C‐residues were not removed from plants. Furthermore, discrepencies between gas‐liquid chromatography and 14C determinations of plant extracts indicated endrin degradation products were present.Soil type influenced the plant uptake of these insecticides, especially endrin. Plants grown in the Lakeland s1 soil concentrated greater insecticide amounts than the Hagerstown sicl, presumably because of the lower organic matter content of the Lakeland soil. Cotton removed considerably more insecticides from soils than soybeans because of their greater mass. Based on these results, cropping would not be an efficient method of removing chlorinated insecticides from contaminated soils.