bluuebunny/crossref_metadata_2025_split huggingface dataset:
Leaf Angle, Leaf Area, and Corn (Zea mays L.) Yield1
Authors: Winter S. R. , Ohlrogge A. J. 
Published: July 2010

AbstractSince canopy structure can be an important factor in determining the productivity of a plant community, these studies were undertaken to determine the influence of upright leaves, at various leaf area indexes (LAI) on the grain yield of highly productive, field‐grown corn (Zea mays L.).Leaf area index was varied by changing plant population density. Leaf angles of the upper leaves were manipulated by mechanical means to change the leaf angle from roughly 45° to 10° or 15° from the vertical.The response to upright leaves depended upon the LAI. At low LAI (below 3 or 4), upright leaves tended to decrease grain yield. At high LAI (5 and above), upright leaves tended to increase grain yield. The optimum LAI (population) for grain yield was always lower with the normal canopy structure than with upright leaves. When canopy types were compared for maximum yield (i.e. each considered at its optimum LAI), upright leaves outyielded the normal by only 0.4, 5.7, and 5.8% in 1968, 1969, and 1970, respectively. These slight yield differences are not statistically significant and occurred with LAI above those commonly found under conditions of commercial corn production in Indiana.These results suggest that an upright leaf canopy similar to that tested would not be beneficial at present in Indiana or similar corn producing areas. If varieties are developed with a higher LAI at the population giving maximum yield and/or in an environment‐management situation capable of supporting a higher LAI, upright leaves might increase grain yield significantly.
Yield Response of Soybean Varieties Grown at Two Soil Moisture Stress Levels1
Authors: Mederski H. J. , Jeffers D. L. 
Published: July 2010

AbstractEight soybean [Glycine max (L.) Merrill] varieties in each of four maturity groups were grown to maturity at optimum and deficient soil moisture conditions to determine differences in varietal response to soil stress. A significant variety by stress level interaction on seed yield was detected among varieties in each of four maturity groups, indicating that the effect of soil moisture stress on yield varied among varieties.Under high moisture stress conditions, the yield of the most stress resistant varieties was reduced about 20%, while the yield of the least stress‐resistant varieties was reduced about 40%. The absolute reduction in yield for the most stress‐sensitive varieties was approximately 1000 kg/ha, while the yield of the least stress‐sensitive varieties was reduced about 200 to 400 kg/ha.Under conditions of optimum soil moisture, the difference in yield among varieties was large relative to the difference in yield produced under deficient moisture conditions. A low or nonstress soil moisture level permits greater genotypic expression, thereby increasing genotypic variance among varieties. A low soil moisture stress environment appears to be the optimum environment for selecting soybean yield attributes.
Effect of a Phytoplankton Culture on the Germination and Seedling Development of Barley, Sugar Beets, and Lettuce1
Authors: Davis Charles H. , Bigler E. Ray 
Published: July 2010

AbstractAlteration of soil properties and plant growth by phytoplankton cultures has been reported many times as separate phenomena. An investigation of the interrelationship of alteration of soil properties and plant growth by a phytoplankton culture was undertaken. This report is confined to seedling development, emergence, and related yields.The effect of various quantities of a Chlorophyta phytoplankton culture on seed germination, seedling development, and yield was evaluated in both the laboratory and field. In the laboratory, ‘Arivat’ barley (Hordeum vulgare L.) seedlings were grown in aqueous solutions of phytoplankton culture. Shoot length was increased by 102 and 103 ppm concentrations of the culture but was unchanged at 104 and 105 ppm. There was an inverse relationship between shoot length and shoot weight per unit length. In the field, barley seedling emergence was significantly increased by injecting undiluted phytoplankton culture with the seed at a rate of three liters per 240 m of row.Preplant irrigation with a 103 ppm dilution of phytoplankton culture in the field increased sugar beet (Beta vulgaris L.) and lettuce (Lactuca sativa L.) seedling emergence. Subsequent post‐plant applications of the phytoplankton resulted in additional increase in seedling emergence. Increased production was found for the sugar beets at all levels of treatment. This further increase could not be allocated to either growth regulator or soil modification but could be the result of both acting at once.
Evaluation of Vigor Tests for Sorghum Seed1
Authors: Vanderlip R. L. , Mockel F. E. , Jan Halim 
Published: July 2010

AbstractStandard germination tests often overestimate field performance of sorghum [Sorghum bicolor, (L.) Moench] seed. Seed from 60 seed lots were germinated following NH4CI treatment, NaOH treatment, and no treatment. Results from these tests, seed size, and tetrazolium staining were correlated with field stand establishment under four sets of conditions. Germination following NH4CI treatment gave highest and most consistent correlations with field stand establishment. Seed size and tetrazolium tests were poorly related to field stand establishment. Correlations among vigor tests, in general, were high, even with those that did not correlate well with field stand establishment. Thus vigor tests should be related to field stand establishment rather than to another vigor test.
Effects of Fertilizer on Root Strength of Sherman Big Bluegrass (Poa ampla Merr.)1
Authors: Haferkamp M. R. , Currie P. O. 
Published: July 2010

AbstractPulling of plants by grazing animals animals has been a common problem on ‘Sherman%’ big bluegrass (Poa ampla Merr.) pastures in Colorado. Fertilizers were applied to individual plants in a greenhouse study to evaluate their influence on plant resistance to pullup. The fertilizer treatments were 56 kg/ha N, 56 kg/ha P, or 56 kg/ha of each element as an N+P combination. Fertilizer treatments were applied to vernalized and nonvernalized plants grown in two soils.Tensions required for pullup in the greenhouse were correlated with total root weight (r = .75**) and significantly increased with N fertilization. Plants fertilized with N produced more vegetative and reproductive shoots, tillers, foliage weight, and root system weight and length. Phosphorus fertilization produced a significant increase in vegetative and reproductive shoots, and a significant interaction between N and P was found for root system size and the amount of roots that were pulled from the soil with the plants.
Short Note on the “Wilting Phenomenon in Crop Plants”
Authors: Tomar V. S. , Childyal B. P. 
Published: July 2010

AbstractIn a greenhouse study diurnal variation in water deficit, resistance to water transport and the internal plantwater relations of rice (Oryza saliva L., Var. IR‐8) plants were determined to understand the phenomenon of wilting in rice plants. It seems that wilting occurs at a definite value of turgor pressure rather than the complete absence of turgor pressure and is associated with a marked change in the elastic property of the leaf tissue. The wilting may also be affected by the resistance to water movement in plant tissues. Wilting phenomenon is not related directly with the 15 bars soil moisture suction.
Phosphate Uptake and Distribution in Bush Bean Plants as Affected by Foliar Application of Naphthenate1
Authors: Severson John G. , Wort D. J. 
Published: July 2010

AbstractA 0.5% solution of potassium naphthenates (KNap) was applied to the foliage of hydroponically grown 14‐ day‐old bush bean (Phaseolus vuigaris L., cultivar ‘Top Crop’) plants to determine the effect of this chemical mixture on the uptake and distribution of root‐fed 32P among leaf blade, stem, and root tissues. The plants were grown in eiither a phosphate‐free (−P plants) or a complete nutrient solution. The uptake of 32P was not changed by KNap treatment. The percentage distribution of 32P among the various plant organs, however, was markedly affected by the presence or absence of phosphate in the nutrient solution and by treatment. The enhanced translocation of 32P observed, especially in −P plants, may be associated in a casual way with the characteristic stimulation of metabolic processes in the aerial portions of naphthenate‐treated plants.
Effects of Temperature and Nitrogen Supply on Four Nitrogen Fractions in Barley1
Authors: Chowdhury I. R. , Zubriski J. C. 
Published: July 2010

AbstractDistribution of four nitrogen fractions in tops and roots of 4‐ and 8‐week‐old barley (Hordeum vulgare L.) plants as influenced by two rates of nitrogen and three ambient temperatures during the latter half of growth period was studied in pot experiments. All plants were initially grown at 15.6 to 18.3 C for 4 weeks under two nitrogen treatments. Temperature variables were established on the plants during the last 4 weeks of growth. Temperatures tested in two sets of experiments were 7.2 to 8.9 C and 15.6 to 18.3 C, and 15.6 to 18.3 C and 26.6 to 27.7 C. Samples were analyzed for total, alcohol‐insoluble, alcohol‐soluble, and nitrate nitrogen. Highest dry matter was produced at 15.6 to 18.3 C. The 400‐mg N/pot yielded more total, alcohol‐insoluble, alcohol‐soluble, and nitrate nitrogen than the 20 mg N/pot. Yields of total and protein nitrogen in plants were approximately proportional to yield of dry matter, and percent total nitrogen in plants was inversely related to yield of dry matter. Alcohol soluble nitrogen yield was greater in plants grown at higher ambient temperatures in both experiments. In plants supplied with 400 mg N/pot, an above optimum temperature (26.6 to 27.7 C) caused a significant portion of the total nitrogen to be in alcohol‐soluble form. A large part of this alcohol‐soluble nitrogen was nitrate nitrogen. This alcohol‐soluble nitrogen is highly mobile and can be easily translocated to grain. These results corroborate field observations that temperatures above 27 C during the heading stage of barley plant restrict grain yields, even though protein percent remains high.
Effect of Level Terraces on Soil Moisture Content and Utilization by Corn1
Authors: Miller E. L. , Shrader W. D. 
Published: July 2010

AbstractField experiments were conducted to determine the effect of sod‐stabilized backslope level terraces on soil moisture content and the utilization of moisture by corn (Zea mays L.). Plots were located in the terrace interval and in terrace channel positions up‐slope from 9 different terraces, on a watershed, in the Ida‐Monona soil association area of southwestern Iowa. Periodic measurement of soil moisture in the root zone, daily observation of weather variables, and corn development and yield measurements were made for each plot and were used to evaluate soil moisture content and utilization by corn. Soil moisture amounts in the rooting zone were greater in terrace channels than in terrace interval positions on all sample dates, with differences ranging from 1.98 to 6.27 surface cm and averaging 5 cm in the surface 1.83 m of soil. Significant yield differences between positions occurred, and moisture‐stress intensity was a significant factor in explaining yield variation. Other factors that were significant in explaining the variation in yield were plant density and plant nitrogen and phosphorus contents. A yield‐response curve was developed, which characterized the relationship between corn yield and moisture stress intensity.
Management Effects on Persistence and Productivity of Birdsfoot Trefoil (Lotus corniculatus L.)1
Authors: Taylor T. H. , Templeton W. C. , Wyles J. W. 
Published: July 2010

AbstractOne of the deterrents to the use of birdsfoot trefoil (Lotus corniculatus L.) is the maintenance of acceptable stands after establishment. The principal objective of this study was to test the hypothesis that birdsfoot trefoil stands may be maintained through natural reseeding. Other objectives were aimed at evaluating varieties and determining the quality and quantity of herbage produced under different systems of management. Birdsfoot trefoil seed, represented by ‘Dawn,’ ‘Viking,’ and a Kentucky ecotype, were drilled into an old Kentucky bluegrass (Poa pratensis L.) sod in 1967, and the plantings were observed through the 1972 growing season. The second herbage crop of the natural‐reseeding plots was permitted to set seed in 1969 and 1970, but not in 1971 or 1972. Those plots had excellent trefoil stands at the end of 5 years, in contrast to plots that were prevented from reseeding (approximately 100 plants/m2 versus 20/m2, respectively). The hypothesis that good stands of trefoil may be maintained through natural reseeding was accepted. Losses in yields during the 2 years that reseeding was permitted were recovered during the following 2 years. Herbage produced during the reseeding process was of acceptable quality and could be especially important as pasturage for certain classes of livestock in midsummer. The ecotype was superior to Dawn and Viking in yield and persistence.
Comparative Phytotoxicity of Nitrapyrin and its Principal Metabolite, 6‐Chloropicolinic Acid
Authors: Geronimo J. , Smith L. L. , Stockdale G. D. , Goring C. A. I. 
Published: July 2010

AbstractPrevious laboratory studies have shown that nitrapyrin (2‐chloro‐6‐(trichloromethyl) pyridine) can produce phytotoxicity in certain plants. Nitrapyrin hydrolyzes in soil to 6‐chloropicolinic acid; however, the phytotoxic properties of the latter compound have not been compared with those of the former. Therefore, studies were conducted to compare the relative toxicity of nitrapyrin and 6‐chloropicolinic acid to the seedlings of various crop plants, to compare their phytotoxicity in a variety of soils, and to estimate if the soil concentration, of either chemical, required to produce significant growth reduction is less than recommended field application rates for nitrapyrin. Nitrapyrin was more toxic than 6‐chloropicolinic acid to the graminaceous species tested which included corn (Zea mays L.), sorghum (Sorghum vulgate L.), wheat (Triticum aestivum L.), and rice (Oryza sativa L.). 6‐Chloropicolinic acid was more toxic than nitrapyrin to the dicotyledenous species tested which included cotton (Gossypium hirsutum L.), sugar beet (Beta vulgaris L.), tomato (Lycopersicon esculentum L.), alfalfa (Medicago sativa L.), and soybean (Glycine max L.). The dicotyledenous species were more sensitive to both compounds than were the graminaceous species. All species tested except alfalfa and tomato tolerated soil concentrations of nitrapyrin estimated to be greater than the highest recommended field application rates. Nitrapyrin was more highly adsorbed and therefore detoxified to a greater extent than 6‐chloropicolinic acid when soil organic matter increased.
Effects of Copper Sources on Wheat and Soybeans Grown on Organic Soils1
Authors: Barnes J. S. , Cox F. R. 
Published: July 2010

AbstractOptimum rates for and the residual effects of several new copper fertilizer materials have not been determined. Because the copper in these sources is complexed, usually with an organic ligand, it has been implied that they are more effective than copper sulfate.The immediate and residual effectiveness of copper sulfate and several new chelated and/or complexed copper materials were compared to determine the optimum rate of application for each source. Field experiments were conducted on four acid, organic soils, each of which was severely deficient in copper. Wheat (Triticum aestivum L.) yields were increased with an increase in the rate applied to 2.8 kg Cu/ha at three locations and to 5.6 kg Cu/ha at the fourth. There was no difference in the nature of the response obtained among sources so all sources were considered equally effective when equivalent amounts of copper were used.Soybeans [Glycine max (L.) Merr.] were double‐cropped behind wheat to determine the residual effect of these sources. Grain yields showed the same patterns of response to copper sources as were obtained with wheat. Plant analyses also revealed the same effects of copper applications as were obtained with grain yields. Distinct symptoms of copper deficiency developed in the control and low copper treatments in both crops.
Recovery, Residual Effects, and Fate of Nitrogen Fertilizer Sources in a Semiarid Region1
Authors: Power J. F. , Alessi J. , Reichman G. A. , Grunes D. L. 
Published: July 2010

AbstractInformation on recovery and eventual fate of fertilizer N applied to dryland crops in the northern Great Plains is needed to optimize economic returns and to minimize pollution hazards. In a field experiment at Mandan, N. Dak., four fertilizer N sources were applied to separate areas of corn (Zea mays L.) and bromegrass (Bromus inermis L.) for 4 years. From the fifth through seventh years, the two areas were uniformly seeded to barley (Hordeum vulgare L.) without additional N fertilization, until residual effects were no longer significant. Sources of N used were ammonium sulfate, ammonium nitrate, calcium nitrate, and urea, applied at either 55 or 110 kg/ha to Parshall fine sandy loam. Recovery of fertilizer N in corn plant tops was greatest for ammonium nitrate. Over 35% of the calcium nitrate and urea applied at 110 kg/ha of N to corn was leached below the root zone. Leaching of fertilizer N applied to bromegrass was insignificant. Except for urea, fertilizer N recovery by bromegrass from the other N sources was nearly equal and usually higher at 55 kg/ha. Residual growth responses were smaller from N applied to bromegrass than to corn. About 70 to 95% of the fertilizer N applied was accounted for by the end of the residual period, except for lower values for several of the urea treatments. Gaseous losses were probably high for urea surface broadcast on bromegrass at 110 kg/ha of N because only 47% could be accounted for and no residual effects were observed.
Relationships Between Seeding Dates and Environmental Variables, Seeding Methods, and Establishment of Small‐seeded Legumes1
Authors: Strand Rodney H. , Fribourg Henry A. 
Published: July 2010

AbstractPrecipitation, air and soil temperatures, soil moisture, and other environmental variables were measured daily for several weeks following the seeding of alfalfa (Medicago sativa L.), red clover (Trifolium pratense L.), and birdsfoot trefoil (Lotus corniculatus L.) on 52 occasions. Regression analysis was used to determine the significance of these variables to stand establishment. Environmental variables explained much of the variation in initial legume populations, but variability in stand counts several months after seeding was explained primarily by the classification variable “seeding date,” rather than by the specific environmental variables associated with seeding dates.
Relationship between Soil Oxygen Diffusion Rate and Yield of Oats in a Coastal Alluvial Soil at Critical Level1
Authors: Saini G. R. 
Published: July 2010

AbstractThis note reports the effect of improved soil physical conditions, as characterized by oxygen diffusion rate (ODR), on the growth of oats (Avena sativa L.) at the critical soil salinity level (ECe = 5.0 mmhos cm−1).In a coastal alluvial soil at critical salinity level (ECe = 5.0 mmhos cm−1), the yield of oats increased from 0.55 g/pot to 10.88 g/pot as ODR increased from 7.3 ✕ 10−8 g cm−2 min−1 to 31.0 ✕ 10−8 g cm−2 min−1. The root elongation of the plant also appeared to be related to ODR.
Performance of Soybeans (Glycine max (L.) Merrill) in the Wet Tropics Affected by N, P, and K1
Authors: Chesney H. A. D. 
Published: July 2010

AbstractThe cultivation of soybeans [Glycine max (L.) Merr.] in wet, humid, equatorial countries that have short days is relatively new. Little is known of the agronomic requirements for maximum production of the few adapted varieties.Trials were set up on Arakaka clay loam (a yellow podzol, Typic Normudult) to determine soybean performance from 1) application of N, P, and K and 2) source of N. The variables were: nitrogen, 0, 22, and 44 kg/ha; phosphorus, 0, 29, and 58 kg/ha; and potassium, 0, 37 and 74 kg/ha. Urea, ammonium sulphate, and uramite were the sources of N.Nitrogen significantly influenced yields only during one particularly wet season, when it caused a decrease. Potassium significantly increased yields only during this same period of heavy rainfall, with the effect being greater at the higher application of N. Yields were increased by P at all harvests up to application rates of 58 kg/ha for the first two crops and 29 kg/ha for subsequent crops. The N × K interaction was the only two‐factor interaction that consistently had any significant effect on yield. Source of N had no effect on yield. Oil and protein contents of the seeds were not influenced by N, P, or K.Truog‐P in the soil was unaffected by the application of N or K. Fertilizer P and K increased their levels in the soil.Results indicated clearly that adapted soybean varieties can be successfully cultivated in the wet tropics.
Effect of Row Spacing and Seeding Rate on Yield of Buckwheat1
Authors: Ali‐Khan S. T. 
Published: July 2010

AbstractVery little experimental data are available on buckwheat (Fagopyrum sagittatum Gilib.) culture in North America. Therefore, to obtain information on the effect of row spacing and seeding rate a buckwheat cultivar, ‘Tokyo,’ and an experimental strain, CD 1370, were tested over a period of 4 years at two locations in Manitoba. Buckwheat was grown in rows 15, 30, and 45 cm apart at seeding rates varying from 22 to 60 kg/ha. The results indicate that varying row spacings and seeding rates did not affect appreciably the seed yields.
Competition of Common Milkweed with Sorghum1
Authors: Evetts L. L. , Burnside O. C. 
Published: July 2010

AbstractCommon milkweed (Asclepias syriaca L.) is a deep‐rooted perennial weed that has increased in occurrence in recent years and has caused much concern among landowners. Because it occurs frequently in dryland sorghum [Sorghum bicolor (L.) Moench], a 3‐year competition study using paired plots was conducted to determine the degree of yield loss caused by common milkweed. Sorghum yield and number of heads per hectare were significantly reduced by common milkweed competition each of the 3 years. Common milkweed reduced average yield by 21% and number of sorghum heads per hectare by 14%. Even low populations (less than 12,000 plants/ha) of common milkweed resulted in severe yield losses. Grain weight per head was significantly reduced by common milkweed competition in 1970 and 1972 but not in 1971. Competition had no effect on sorghum 500‐ seed weight in 1971 or 1972. Percentage protein (Kjeldahl method) of sorghum grain was significantly increased by competition in 1972 but not in 1971.
Sprinkler‐Induced Soil Temperature Changes Under Plant Cover1
Authors: Kohl R. A. 
Published: July 2010

AbstractAn experiment was conducted to determine the amount of soil temperature reduction to be expected from irrigating potatoes (Solanum tuberosum) at various intervals. Soil temperatures were measured at the 10‐cm depth under potato ridges with various amounts of plant cover. The mean daily soil temperature at the 10‐cm depth in a silt loam soil after 7 days following irrigation increased as much as 2 C above the daily irrigated plot with full cover and 4 C above the daily irrigated plot without cover. Similar soil temperature increases occurred in a loamy fine sand soil irrigated after 5 days which is the normal irrigation intervals for these soils.