bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Soil Fertility and Plant Competition on Grain Sorghum Panicle Morphology and Panicle Weight Components1
Authors: Blum A.
Published: July 2010

Panicle weight components (i.e., number of branch whorls per panicle, number of branches per whorl, number of grains per branch and grain weight) and rachis morphology were analyzed under different soil fertility and plant population treatments.

High soil fertility and low plant competition increased the 1000‐grain weight and number of grains per panicle. The latter component was affected by soil fertility through the number of branches per whorl and the number of grains per branch, and by plant competition through the number of whorls per panicle and the number of grains per branch. Higher soil fertility and lower plant competition promoted a longer panicle through the increase in rachis internode length and number of internodes, respectively. The degree of contribution of some components to the number of grains per panicle was not always equal throughout the length of the panicle.

A negative correlation, which became stronger as the number of grains per panicle increased, was found between weight of grain and number of grains per branch. Intra‐panicle competition between these components was suggested.
Emergence and Seedling Growth Related to Oxygen Content and Oxygen Diffusion Rate in Different Soils1
Authors: Kaack K. , Kristensen K. J.
Published: July 2010

Absract

Emergence and growth of winter wheat and emergence of mustard responded to oxygen concentration in the soil atmosphere. Winter wheat germinated at nearly zero oxygen and showed maximum emergence at about 10% oxygen. Mustard did not emerge at oxygen concentrations below 2% and emergence increased with oxygen content up to the highest concentration tried (atmospheric air). Emergence and growth correlated better with the oxygen content in the soil air than with the oxygen diffusion rate (ODR), measured with the platinum microelectrode. For comparable oxygen concentrations, emergence and growth were generally better at low (70 cm tension) than at high (5 cm tension) water content in the soils.
Differences among Plant Species in Selenium Accumulation from Soils Low in Available Selenium1
Authors: Ehlig C. F. , Allaway W. H. , Cary E. E. , Kubota J.
Published: July 2010

The uptake of Se by several plant species was compared with the uptake of Se by alfalfa under field and greenhouse conditions. Differences among plant species in Se accumulation from soils low in Se were small. Field samples of red clover (Trifolium pratense L.), orchardgrass (Dactylis glomerata L.) and bromegrass (Bromus inermis Leyss.) contained about one‐half the Se concentration of alfalfa (Medicago sativa L.). Astragalus bisulcatus (Hook) Gray, a noted Se accumulator in high‐Se soils, accumulated about five times as much Se as did alfalfa when grown in pots of Dalton silt loam (pH 7.0) which had been treated with 0.75 ppm Se labelled with 75Se. Of the other 22 species tested, the species with the highest Se concentration had only about three times that of the one with the lowest Se concentration. The Se concentration in grasses decreased with increases in the rate of dry matter production, whereas the Se concentration in dicotylendon species, except dandelion (Taraxacum officinale Weber), did not decrease with increase in the rate of dry‐matter production.

On soils low in Se, stage of growth had little effect on the Se concentration of alfalfa. Drying at 50 C did not cause postharvest losses of Se.
Persistence of Birdsfoot Trefoil, Lotus corniculatus L. as Influenced by Plant Growth Habit and Grazing Management1
Authors: Van Keuren R. W. , Davis R. R.
Published: July 2010

The persistence of birds foot trefoil as a pasture legume grown with Kentucky bluegrass was studied for a 6‐year period. The inclined point quadrat was used to measure changes in the trefoil stands as influenced by grazing system, species of grazing animal, and plant growth habit. Trefoil was shown to be a long‐lived perennial. Rotational grazing was necessary for trefoil persistence under grazing; the trefoil stand was sharply reduced under continuous grazing. The species of grazing animal was not a major factor in trefoil persistence. Semiprostrategrowing ‘Empire’ was found to persist slightly better than upright‐growing ‘Viking’.
Manganese‐Sulfur Fusions as a Source of Manganese for Crops1
Authors: Ludwick A. E. , Sharpee K. W. , Attoe O. J.
Published: July 2010

A greenhouse experiment was conducted to study the availability of manganese to ryegrass (Lolium perenne L.) from manganese‐sulfur fusions. Total yields of eight successive cuttings were not appreciably affected by the various manganese treatments, but the concentration of manganese in the tissue was directly related to the solubility of the compounds used and inversely related to granule size and soil pH. The 20 to 40 and the 40 to 80 mesh fusions of MnCO3 with sulfur (1:2) gave an sample and fairly steady supply of manganese for the eight cuttings. The coarser granule sizes were less effective. The total manganese content of the cuttings was about two to five times higher for the MnCO3‐S fusions than for comparable MnO2‐S fusions. It was also about two to four times higher at a soil pH of 6.0 than at 7.2. Total crop recovery of applied elemental sulfur and soil sulfate was inversely related to granule size and ranged from 22 to 112%.
Effect of Varied Rates of Atrazine and Simazine on the Establishment of Several Zoysia Strains1
Authors: Engel R. E. , Funk C. R. , Kinney D. A.
Published: July 2010

Two triazine herbicides, atrazine and simazine, were applied over freshly planted stolons of five different strains of zoysia. Herbicide rates ranged from 1.4 to 8.4 kilograms active chemical per hectare (1 1/4 to 7 1/2 lb/A). The variety ‘Meyer’ and the two experimental selections B52‐22(24) and B21‐15(4) showed good tolerance to herbicide treatments with excellent stolon survival and only moderate growth reduction at chemical rates needed for good weed control. The variety ‘Midwest’ and the selection B21‐15(22) were substantially less tolerant and showed severe damage from treatment at this stage. Atrazine was more phytotoxic than simazine, especially on the less tolerant zoysia types.
Effect of Seaweed on the Levels of Available Phosphorus and Nitrogen in a Calcareous Soil1
Authors: Caiozzi Mario , Peirano Pedro , Rauch Eduardo , Zunino Hugo
Published: July 2010

The objective of the present investigation was to study changes in levels of phosphorus and nitrogen in soils supplemented with dry, ground seaweed, KNO3, and KH2PO4 After intervals of 21, 42, 76, and 105 days, phosphorus, nitrate, and ammonium were determined. The results showed that the seaweed affected the status of total inorganic N and P in the soil

In all systems the levels of available inorganic phosphorus increased. However, part of the N that was added as nitrate or that was originally present in the soil was immobilized. The results further indicated that inorganic P of seaweed origin was probably in a form other than simple phosphate.
Influence of Mineral Nutrition on Pigmentation in Sorghum1
Authors: Doak K. D. , Miller Paul R.
Published: July 2010

Five sorghum arieties, ‘Dwarf Yellow ’ milo, KB2 512; ‘Atlas ’ sorgo. FCI 9112; ‘Feterita, ’ SPI 51991; ‘Fargo Straightneck’ milo, CI 809; and Feterita, KB 2563 were grown in nutrient and cultures with nitrogen levels from 0.01 to 2.0, in five steps in the phosphorus series and four steps in the potassium series. The amount of purple pigmentation in the five sorghum varieties was influenced by both phosphorus and nitrogen. This feature does thus not serve correctly as a deficiency indicator for phosphorus at low nitrogen levels. These varieties also differed widely in the amount of pigmentation produced at comparable nutrient levels.
Estimation of the Tasseling Date of Corn (Zea mays L.)1
Authors: Stauber M. S. , Zuber M. S. , Decker W. L.
Published: July 2010

Weather records and data from a 10‐year date‐of‐planting study of corn (Zea mays L.) conducted near Columbia, Missouri, were used to estimate the length of period from planting to tasseling. The accumulated maximum daily temperature for the first 35 days after planting was found to be very effective in predicting tasseling dates. The linear statistical model used resulted in a coefficient of determination of 0.96 and standard error of estimate of 2.05 days. The relationship between temperature and length of the period from planting to tasseling was curvilinear. Increases in temperature resulted in decreases at a decreasing rate in the number of days in the period from planting to tasseling. Delays in planting resulted in reductions in the length of the period from planting to tasseling at a rate of approximately a 1‐day reduction for a 5‐day delay in planting. Differences in the length of the period from planting to tasseling were slight for hybrids of different relative maturity classes. The model for predicting tasseling date of corn should prove useful to producers and agronomists interested in scheduling of cultural or experimental operations sensitive to the tasseling of the crop.
Effects of Lime and Phosphorus Treatments in Specific Horizons of Acid Soil on Growth and Chemical Content of Corn (Zea mays L.)1
Authors: Estrada Jose , Cummings George A.
Published: July 2010

The effect of phosphorus and lime applications to the Ap and/or A2 horizon of a Norfolk loamy sand upon the growth and P and A1 content of corn were determined under greenhouse conditions. Increasing the supply of P in either horizon resulted in significant increases in top growth. This increase was of greater magnitude when P was supplied to the Ap than when supplied to the A2 horizon. The growth response of roots in each horizon to P application followed the same trends as top growth except when high levels of P were applied in both horizons the relative increases were much less than with top growth. Applications of lime to the A2 horizon resulted in increases in root growth in that horizon which were not increased further by lime application to the Ap horizon. Lime application in the A2 horizon resulted in slight increases in weight of tops and of roots from the Ap horizon. However, only when lime was applied to the Ap horizon was maximum top growth and root growth in the Ap horizon realized. Significant effects upon phosphorus concentrations in tops and in roots from the Ap horizon were not observed with the first increment of phosphorus in either horizon. A marked increase in phosphorus content was obtained from the second increment of phosphorus. Lime application resulted in a decrease in P and A1 concentration. The decrease in AI concentration was much less from the lime than from the P treatment.
Influence of Method of Planting and Nitrogen Fertilizer on the Establishment of Birdsfoot Trefoil1
Authors: Watson H. , Matches A. G. , Peters E. J.
Published: July 2010

Stands, root lengths, root weights, and root−top ratios of birdsfoot trefoil, and botanical composition of orchardgrass−birdsfoot trefoil swards were not significantly influenced by 28 kg/ha (25 lb/A) of nitrogen starter fertilizer. In general, there was no significant influence of method of planting on “established” stands of birdsfoot trefoil. Seeding trefoil alone resulted in larger individual plants than when seeded with a grass.
Nitrogen Content of Grain as Influenced by Water Supplied to the Plant1
Authors: Stone J. F. , Tucker B. B.
Published: July 2010

Results of independent studies involving wheat (Triticum aestivum L.) and grain sorghum (Sorghum bicolor (L.) Moench) indicate that a linear relationship exists between nitrogen fraction in the grain and the quantity of water applied to the soil surface just prior to and through vegetative growth of the plant. The effect was noted consistently in studies in Oklahoma and Texas. The designated purpose of these studies was to determine effects of fertilizer amounts and irrigation amount and timing on the production of crops. The studies were conducted at widely separated locations over eight growing seasons. The effect was noted by chance during evaluation of one of the studies and was found to exist in data found in the literature and in data from other studies of the authors.
Nutrient Distribution During Development of Three Market Types of Peanuts. II. B, Cu, Mn, and Zn Contents1
Authors: Martens D. C. , Hallock D. L. , Alexander M. W.
Published: July 2010

The B, Cu, Mn, and Zn contents of portions of ‘Virginia 61R,’ ‘Early Runner,’ and ‘start’ peanuts (Arachis hypogea L.) were determined at various sampling dates during the 1966 growing season. The main stem of the three cultivars generally contained higher amounts of B and Mn than the hypocotyl‐crown, the stemmy and leafy portions of the first and second lateral branches, or the fruit. The highest Cu contents were usually present in the fruit and hypocotyl‐crown and the highest Zn contents in the fruit and main stem. Significant differences among cultivars in B, Mn, and Zn contents of similar plant portions occurred on one or more sampling dates. Similar differences were not obtained for Cu. All plant portions sampled decreased in one or more micronutrients during the growing season, except the stemmy portion of the first and second lateral branches and the fruit.
Response of Soybean Plant Types to Planting Patterns1
Authors: Hicks D. R. , Pendleton J. W. , Bernard R. L. , Johnston T. J.
Published: July 2010

Four plant types—short determinate (dt1), tall determinate (Dt2), narrow leaflet (ha), and normal—in both ‘Harosoy’ and ‘Clark’ soybean [Glycine max (L.) Merr.] genetic backgrounds were compared in various planting patterns at Urbana, Illinois. The eight lines were seeded in 76‐ and 25‐cm row spacings with seeding rates of 84, 168, and 252 kg/ha in 25‐cm rows and 84 kg/ha in 76‐cm rows.

A greater leaf area index was provided earlier in the season when plants were spaced in 25‐cm rows. LAI increased as seeding rate increased. More light penetrated farther into the canopies of the narrow leaflet type than the normal type. Plant height increased with higher seeding rates and narrower row spacings. Stem diameter and number of pods per plant decreased as seeding rates increased. Lodging increased as row spacing decreased and plant population increased. Plants of the short determinate types did not lodge. Row spacing and seeding rate did not statistically affect seed yield. The tall determinate types yielded 4.6% more than the normal types. There was no difference in yield between the short determinate and normal or the narrow leaflet and normal plant types.
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

Data 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

Spring 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

The 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

A 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

Mountain 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

During 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

An 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

Kjeldahl 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

Kinkaoil 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

‘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

The 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

The 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

An 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

Germination 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

The 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

Experiments 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

The 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

Dry‐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

In 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

Absorption 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

Dry 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

Soybeans (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.
In‐the‐furrow Application of Root‐knot Larvae in Field Plots1
Authors: Banks Donald J.
Published: July 2010

A method of inoculating a small field plot with Northern root‐knot nematode, Meloidogyne hapla Chitwood, is described. An average of 11,353 nematode larvae that had been collected from tomato roots under a mist system in the greenhouse were distributed per 30.48 cm (foot) of row during planting. The larvae were dispensed in the furrow over peanut seeds by gravity flow through a glucose intravenous injection apparatus mounted on a garden planter.

Differences in plant growth and pod yields in the inoculated and uninoculated plots were not apparent the 1st year. Visual differences in growth and statistically significant differences in pod yield and plant height, but not in stand, occurred the 2nd year after inoculation. Pod yields and plant heights were reduced 66 and 29%, respectively, in the nematode infested plots.
Toxicity of 2‐Chloro‐6‐(Trichloromethyl) Pyridine in Soybean (Glycine Max L. Merr.) Seedlings1
Authors: Riley D. , Barber S. A.
Published: July 2010

Soybeans were grown for 18 days in a silt loam soil containing 0 to 20 ppm 2‐chloro‐6‐(trichloromethyl) pyridine (N‐Serve). Yield of shoots was reduced by concentrations of 8 and 20 ppm and their morphology was altered with concentrations as low as 1 ppm. Yield of roots was not greatly affected by up to 20 ppm, but their morphology was drastically altered with 8 and 20 ppm. Production of NO3 in the soil was reduced 90% by 8 and 20 ppm, 60% by 3 ppm and only slightly by 1 and 0.5 ppm of 2‐chloro‐6‐(trichloromethyl) pyridine.
Resistance to Greenbug in Three Millet Species1
Authors: Hackerott H. L. , Harvey T. L.
Published: July 2010

Pearl millet, Pennisetum typhoides (Burn.) Stapf and C. E. Hubb.; foxtail millet, Setaria italica L.; and proso millet, Panicum miliaceum L. were evaluated for resistance to the C‐biotype greenbug, Schizaphis graminum (Rondani), a recent serious pest of sorghum, Sorghum bicolor (L.) Moench. All trials were conducted in growth chambers at 27 C. Survival and reproduction of adult greenbugs confined to seedling and mature plants were greater on sorghum than on the millet species. The millets were also more resistant than sorghum on the basis of plant injury scores. Pearl millet seedlings were slightly more resistant than mature plants. Pearl millet supported the most greenbugs and proso the least in seedling trials with greenbugs confined to the three millet species individually and in all possible paired combinations. Since the millet species evaluated were highly resistant, they could serve as substitute crops for sorghum until greenbug‐resistant sorghum cultivars become commercially available.
Release of Nitrogen from Sulfur‐coated Urea in Flooded Soil1
Authors: Giordano P. M. , Mortvedt J. J.
Published: July 2010

Laboratory and greenhouse experiments were conducted to investigate the release of N in Mountview sil from sulfur‐coated urea (SCU) and the subsequent uptake of N by rice (Oryza sativa L. var. ‘Nato’). The rate of N release was much greater in moist than in flooded soil. Granules of SCU became coated with FeS after 2 weeks in flooded soil. When the flooded soil was dried to about field capacity, oxidation of the FeS coatings appeared to seal the granules so that very little N was released. In general, the release of N was slightly greater from SCU applied to limed soils fertilized with P

Dry matter production and uptake of N by rice from SCU was similar to that from uncoated urea when both N sources were incubated in moist soil for at least 2 weeks prior to planting and flooding. Urea applied to the soil immediately before flooding was also effective, but SCU was not.
Response of Plants to Naphthenic and Cycloalkanecarboxylic Acids1
Authors: Wort D. J. , Patel K. M.
Published: July 2010

The application of a 5 × 10‐2 M solution of potassimu naphthenates (KNap) to the foliage of 14‐day‐old plants of maize, spring wheat, sugar beet, bush bean, and radish resulted in 8 to 21% greater growth of the foliage determined 21 to 50 days after spraying. Fresh weight of the radish taproot was greater by 13.5%. Treatment increased the weight of green pods per bush bean plant, harvested 35 days after KNap application, by 23%. Soaking spring wheat seeds in a 0.01 or 0.001% KNap solution for 12 hours immediately prior to planting, resulted in increases of 9 and 12% in weight of kernels per plant. The foliar application of 1 × 10‐2 M and 2 × l0‐2 M solutions of the potassium salt. of cyclopentane‐, cyclohexene‐, or cycloheptanecarboxylic acid was followed by an increase in weight of pods per bush bean plant, but the increases lacked statistical significance (0.05 level). The use of potassium cyclohexanecarboxylate invoked significant increases of 24 and 35% in pod yield. Results suggested that the presence of a 6‐carbon saturated ring in the molecule of the lower molecular weight eycloalkanecarboxylic acids is required for effective stimulation of plant growth. This may also be true of the naphthenic acid mixture extracted from petroleum.
Relationship Between Grain Yield and Leaf N, P, and K Concentrations for Corn (Zea mays L.) and the Factors that Influence this Relationship1
Authors: Voss R. E. , Hanway J. J. , Dumenil L. C.
Published: July 2010

Corn grain (Zea mays, L.) yield and leaf N, P, and K concentrations were measured for 575 plots at 23 sites in western Iowa on Marshall and Monona soils. Variables included applied N, P, and K, indigenous fertility, plant population, soil yielding potential, past cropping, and soil moisture. The multiple‐regression equations for yield, as a function of linear and quadratic leaf concentrations, resulted in an R2 of only 0.24. A satisfactory equation contained linear, quadratic, and interaction terms for leaf N and P, several environmental factors, and the interactions among the leaf and environmental factor terms. The R2 of this equation was 0.71. Because of the general adequacy of leaf K, its addition to the above model did not improve the relationship. Leaf nutrient concentrations at predicted maximum yield and concentrations at 95% of predicted maximum yield varied with past cropping, plant population, soil yielding potential, and soil moisture. These experiments suggest that interpretation of leaf analyses should include consideration of soil, management, and climatic factors.
Growth of Sudan and Tall Fescue Grasses as Influenced by Irrigation Water Salinity and Leaching Fraction1
Authors: Bower C. A. , Ogata G. , Tucker J. M.
Published: July 2010

Sudan (Sorghum sudanense P. Stapf) and tall fescue (Festuca arundinacea Schreb.) grasses were grown in outdoor lysimeters with various irrigation water salinity levels and leaching fractions to determine the steady‐state salt profiles that developed and to relate the salt profiles to yield. Yields of both grasses were highly related to the average salinity of the root zone in spite of marked differences in vertical distribution of salt. The first increments of leaching were the most effective in preventing salt accumulation in the root zone. These results agree with those previously reported for a similar study with alfalfa (Medicago sativa L.). The observed leaching fractions required to achieve 90% of maximum yields of all three crops with 2‐ and 4‐mmho/cm irrigation waters agreed reasonably well with values calculated by the equation: LF = EC1w/ECe‐50 per cent, where LF is leaching fraction, and EC1w and ECe‐50 per cent are the electrical conductivities of the irrigation water and of the soil saturation extract at 50% yield decrease, respectively.
Nitrogen and Phosphorus in Jaraguagrass (Hyparrhenia rufa (Nees)Stapf) During the Dry Season in a Tropical Savanna as Affected by Nitrogen Fertilization1
Authors: Tergas L. E. , Blue W. G.
Published: July 2010

The effect of N fertilization during the latter part of the rainy season on yield and N and P composition of jaraguagrass (Hyparrhenia rufa (Nees) Stapf) during the dry season in the wet‐dry Guanacaste Province of Costa Rica was studied. The dry season persists from approximately December 1 through May. A split‐plot experiment with N rates as main plots and harvest dates during the dry season as subplots was established on October 13 on a newly mowed grass sward. Forage production increased with N fertilization through January 13 and decreased erratically as the plants dried. Forage N concentrations and contents were increased by N fertilization, but decreased after the initial harvest on November 30 as the dry season progressed. Forage P concentrations and contents also decreased. The decreases in forage N and P concentrations and contents were significantly correlated for each N treatment. Root N concentrations and contents generally increased as forage N decreased with time into the dry season. Forage regrowth during the subsequent rainy season was higher when the dry season harvest was delayed. Apparently these elements were lost from the forage by translocation to the roots. The beneficial effect of N fertilizer on forage quality persisted only for a relatively short time after initiation of the dry season.
Laboratory Methods for Estimating Plant Available Nitrogen in Soil1
Authors: Ryan J. A. , Sims J. L. , Peaslee D. E.
Published: July 2010

Biological and chemical methods for obtaining an index of soil N availability to a test crop under different levels of N fertilization were evaluated on 15 Kentucky soils having a range of organic matter contents of 0.72 to 2.79%. Organic matter, N mineralized during aerobic incubation at 30C or 40C for 7 or 14 days, and extractable NH4+− ‐ 3 times after incubation under waterlogged conditions for 7 or 14 days at 30C and 14 days at 40C were all significantly related to N uptake and relative increase in N uptake by ‘X‐1605’ grain sorghum (Sorghum vulgares) during 18 weeks of growth in the greenhouse.

When the soils were amended in the laboratory with P and K or P, K, and Ca and incubated under waterlogged conditions, the relationship between extractable NH4+‐N and N uptake by sorghum improved greatly over unamended soils. Nitrogen mineralized during aerobic incubation and NH4+‐N after incubation of amended soil under waterlogged conditions were among the better predictors of both N uptake and relative increase in N uptake.