bluuebunny/crossref_metadata_2025_split huggingface dataset:
Soybean Plant Damage and Yields as Affected by Metribuzin and Seed Quality1
Authors: Gossett B. J. , Morgan L. F. , Murphy T. R. 
Published: July 2010

AbstractCrop safety is a concern when metribuzin [4‐amino‐6‐tert‐butyl‐3‐(methylthio)‐as‐triazin‐5(4H)‐one] is used as a preemergence for weed control in soybeans [Glycine max (L.) Merr.] on coarse textured soils having a low organic matter content. Six field experiments were conducted on soils that were Typic Hapludults, Typic Udifluvents, and Typic Paleudults. In each experiment three soybean cultivars were used to determine if excessive metribuzin rates interact with various seed quality factors to influence the margin of safety to soybean plants. The cultivars were ‘Bragg’, ‘Bossier’, and ‘Hampton 266A’. Seed quality factors included 1 and 2‐year‐old seed with different germination percentages, physically damaged vs. nondamaged seed, and large vs. small seed sizes. Metribuzin was applied at 0.0, 0.84, and 1.68 kg/ha to the soil surface immediately after planting.In most experiments, both metribuzin and seed quality factors affected plant damage ratings, final stands, mature plant heights, and grain yields. In seed germination and seed damage experiments, none of the seed quality ✕ metribuzin interactions were significant for any of the measured parameters. However, in the seed size experiments, metribuzin caused more plant damage and a greater reduction in final stands and heights of plants from small than from large seed, but grain yields were not affected. From a practical standpoint, this may be of little or no importance since seed size extremes in these studies probably do not occur in normal seed lots, and plant performance differences did not appear to warrant separating specific seed sizes from a given lot. Our results suggest that metribuzin ✕ seed quality interactions do not frequently result in increased plant damage, reduced stands and height of plants, and lower grain yields, but their effects are additive. Therefore, uneven stands and apparent herbicide damage symptoms may be diagnosed only as herbicide damage when actually seed quality factors may be contributing to the problem.
Kentucky Bluegrass Seed Production Characteristics as Affected by Residue Management1
Authors: Hickey V. G. , Ensign R. D. 
Published: July 2010

AbstractSeed productivity of Kentucky bluegrass (Poa pratensis L.) is usually improved by open field burning of post‐harvest residue. This field study compared the effects of field burning and mechanical removal of post‐harvest residue on Kentucky bluegrass plant growth and seed yields. ‘Merion’, ‘Nugget’, ‘Baron’, ‘Glade’, and ‘South Dakota’ Kentucky bluegrass cultivars were seeded on a Latahco soil, (fine‐silty, mixed, frigid argiaquic Agrialboll) in 1976. Residue removal treatments were stripped across the cultivars in 1977, 1978, 1979, and 1980. Seed yields where residue was removed by burning were 1.5 times greater in 1979,1.6 times greater in 1980, and 1.7 times greater in 1981 than yields where residue was mechanically removed to 2.5 cm. Seed yields where residue was removed by burning were 2.0 times greater in 1979, 1.9 times greater in 1980, and 2.6 times greater in 1981 than yields from plants where residue was mechanically removed to 7.6 cm. Panicle and tiller numbers were reduced where residue was mechanically removed to 2.5 or 7.6 cm compared to panicle and tiller numbers where residue was burned. Tiller leaf sheath lengths were not different where residue was burned or removed to 2.5 cm and were shorter than where residue was removed to 7.6 cm. Rhizome weights were reduced where residue was burned compared to weights where residue was clipped at 2.5 or 7.6 cm height in both 1980 and 1981. Root weights, when averaged across all five cultivars, were not affected by residue removal method. A significant cultivar × treatment interaction was noted for Glade, which produced more roots when clipped to 2.5 cm than when burned or clipped to 7.6 cm in both years. Significant cultivar × treatment interactions occurred in 1980 in tiller number which were reflected in panicle numbers and seed yields for Glade and South Dakota. Increased tiller production was associated with decreased rhizome weights. Since tiller apices have been found to control the upturning of rhizomes to produce new tillers, it was concluded that burning functions to reduce tiller apical control of rhizomes. The increased length of tiller leaf sheaths under decreasing heights of residue removal was concluded to be in response to decreased light penetration into the canopy.
Yield and Quality of Soybean Hay as Influenced by Stage of Growth and Plant Density1
Authors: Munoz A. E. , Holt E. C. , Weaver R. W. 
Published: July 2010

AbstractSoybeans [Glycine max (L.) Merr.] are known to have potential for hay production but additional cultural and harvest practice information is needed to optimize production and forage quality. Nodulating ‘Lee’ cv. of soybeans was grown on Ships clay (very fine, thermic, Udertic Haplustolls) at densities of 97,100, 194,200 and 291,300 plants/ha in 68‐cm row widths to evaluate the effect of stage of maturity at harvest and planting density on the quality (percent digestibility and crude protein) and dry matter yield of the soybean hay. The plant tops were separated into leaflets, stems plus petioles, and pods plus grain. Dry weight, in vitro dry matter digestibility (IVDMD) and crude protein (percent N ✕ 6.25) were determined for each sample. Plant density had a small negative effect on IVDMD, a large positive effect on dry matter (DM) yield and no significant effect on the percent crude protein of the soybean plant. Age had a significant effect on the proportion and DM production of plant components, IVDMD of leaves and stems but not pods and total plant, and protein content. When the pods were filled and leaves were beginning to turn yellow, the percentages of leaves, stems, and pods were 28, 36, and 36, respectively with a total DM yield of 12.4 metric ton/ha. The highest protein (20.2%) and IVDMD (62.2%) values for the total plant were at the pod‐filled stage. For optimum yield, crude protein and digestibility, the best time to cut soybean for hay appears to be when pods are filled and some leaves are starting to turn yellow.
Automated Seeding Rate Selector1
Authors: Stewart B. A. 
Published: July 2010

AbstractThere are instances when crop production could be enhanced if the plant population was changed within the field to correspond with changes in water or nutrient availability. Therefore, a device for changing seeding rates during planting operations was designed and tested. The device reported allows for three seeding rates, but the number could be changed to meet specific needs. The rate is changed by simply dialing an electric switch which engages the respective electromagnetic clutches. There is no need to stop or slow the planter to make the desired change. while the need that led to the equipment was to reduce plant densities down the field to correspond with decreased amounts of irrigation water, there are many other potential uses. Plant population studies could be more easily and precisely implemented. The concept could also be used to change fertilizer or pesticide rates in instances where the materials are applied by chain‐ or belt‐driven assemblies. The device can be readily constructed at moderate cost.
First Harvest Phenological Stage Effects on Production of Eight Irrigated Grasses1
Authors: Fairboura Merie L. 
Published: July 2010

AbstractPhenological development stage at the first harvest affects seasonal dry matter production of some grass species. This field experiment was done to determine the effect first harvest phenological stage has on seasonal dry matter production of eight grasses under irrigation on the Central High Plains. Grasses were ‘Latar’ orchardgrass (Dactylis glomerata L.), ‘Fawn’ tall fescue (Festuca arundinacea Schreb.), ‘Regar’ bromegrass ( Bromus biebersteinii Roem. and Schult.), ‘Manchar’ bromegrass (B. inermis Leyss.), ‘Garrson’ creeping foxtail (Alopecurusarundinaceus Poir.), meadow foxtail (A. pratensis L.), ‘Luna’ pubescent wheatgrass Agropyron trichophorum (Link) Richt.], and ‘Greenar’ intermediate wheatgrass p. [intermedium (Host) Beauv.]. Soil of the study area was an Altvan fine sandy clay loam, an Aridic Argiustoll. First harvests of the grasses were made at the vegetative, boot‐heading, and anthesis stages of development. In 24 species by year combinations, dry matter production was greater for first harvest at the boot‐heading stage than for vegetative and anthesis stages by eight and five harvests, respectively. First harvest at the anthesis stage had greater dry matter production than for boot‐heading in only one instance. First harvest at the vegetative stage depressed seasonal dry matter production. Crude protein and in vitro dry matter digestability (IVDMD) production generally followed the dry matter yields of the forages. Since the foxtail grasses have an indeterminate heading stage, a forage height of 25 to 30 cm appeared to be the best guide for first harvest of the growing season. The foxtail grasses, Latar orchardgrass, Fawn tall fescue, and Regar meadow bromegrass gave consistent season long production. The wheatgrasses and Manchar smooth bromegrass produced little regrowth and can be used to the best advantage in a forage program where hay harvest at the flowering stage is practiced.
Russian Wildrye Nutritional Adequacy and Chemical Composition1
Authors: Karn J. F. , Hofmann L. , Lorenz R. J. 
Published: July 2010

AbstractApparent metabolic problems were observed in yearling steers grazing Russian wildrye (Elymus junceus Fisch.) in spring or early summer. This study was initiated to determine what factors were involved in these metabolic problems. Forage samples were obtained from small plots established in an existing 10‐year‐old stand of Russian wildrye, growing on Temvik silt loam (flne‐silty, mixed Typic Haploborolls) soils. The objective of the experiment was to examine the effect of sampling dates and N, P, and K fertilization on the chemical composition and subsequent nutritional adequacy of this forage for grazing cattle. Levels of N, P, K, and in vitro digestible organic matter (IVDOM) in Russian wildrye declined consistently between weekly sampling dates both years. Forage Ca and Mg levels increased (P < 0.05) between initial and final sample dates, but weekly changes were not consistent between years. The tetany hazard to cattle grazing Russian wildrye appeared greater when evaluated by the ratio of forage K/(Ca + Mg) than when evaluated by estimated blood serum Mg data. Regrowth forage, although morphologically similar to early cut forage, appeared quite different chemically. Nitrogen fertilization increased (P < 0.05) forage N and K and consequently the K/(Ca + Mg) ratio. Nitrogen fertilization decreased (P < 0.05) forage P, but the decrease was not progressive with higher N levels. Fertilization with P increased (P < 0.05) forage P, but effects on other parameters were inconsistent. Potassium fertilizer had little effect on any parameters measured. The data indicated substantial differences in forage chemical composition as affected by year, season, and fertility, but the results did not suggest a cause of the severe scours, excessive urination and depressed weight gains which had been exhibited by yearling steers.
Irrigation Regime Effects on Some Physiological Responses of Potato1
Authors: Shimshi D. , Shalhevet J. , Meir T. 
Published: July 2010

AbstractPotato is relatively sensitive to water stress, and therefore indices for characterizing the degree of water stress and its relation to tuber yield are sought. During a series of field irrigation experiments on potatoes (Solanum tuberosum L.) conducted on a calcic haploxeralf in the Negev region of Israel, data were collected on leaf permeability (LP), leaf and tuber water potential (Ψ1 and Ψ1, respectively) and photosynthetic rate, with the aim of relating the variables to a range of water stresses caused by the ratio irrigation/evaporation (Kp). Leaf permeability was linearly related to Ψ1, which ranged from −0.7 kJ kg−1 in well irrigated plants to −1.4 kJ kg−1 in severely water‐stressed plants. Tuber water potential, Ψ1, was higher by 0.4 to 0.7 kJ kg−1 than Ψ1, the difference increasing with water stress. In trickle‐irrigated plants, Ψ1 of tubers growing in dry soil was lower by 0.06 to 0.12 kJ kg−1 than Ψ1 of tubers growing in wet soil, even though the tubers were attached to the same stem. Photosynthesis increased with LP up to 0.8 mg CO2 m−2sec−1 and declined with plant age independently of LP. Marketable yield was well related to both seasonal LP and Ψ1, all three variables decreased when Kp dropped below 1.0. Leaf permeability seems to be a better index than leaf water potential for the characterization of water stress of potato in the field.
Grain Protein Response to Phosphorus Nutrition of Wheat1
Authors: Porter Michael A. , Paulsen Gary M. 
Published: July 2010

AbstractEfficacy of N fertilizer in increasing wheat (Triticum aestivum L.) grain protein is well recognized, but effects of P nutrition are unclear. Phosphorus nutrition of wheat in relationship to grain protein was investigated to ascertain differences among cultivars and interactions of P with N and K. Five hard winter wheat genotypes that differed in grain protein concentration were grown at two Kansas locations on Smolan Pachic Agriustolls and Parsons Mollic Albaqualfs soils with three P levels (0, 56, 112 kg P ha−1) as superphosphate and three K levels (0, 112,224 kg ha−1) as KCL to elucidate effects of P nutrition. Hydroponic studies with 0.005, 0.01, 0.05, 0.1, and 0.5 mM NaH2PO4, 5, 10, and 15 mM NaNO3, and 0.05, 0.5, and 5.0 mM KCI determined effects and interactions of P on nitrate reductase activity and soluble protein in seedling leaves. Other hydroponic studies determined effect of 0.01, 0.1, and 1.0 mM NaH232PO4 on grain yield, protein concentration, and 32P distribution. Field application of 56 and 112 kg P ha−1 increased mean grain yield 150 and 314 kg ha−1, respectively, over both locations and decreased grain protein 0.2 and 0.4% , respectively, at one location, an effect attributed to dilution of grain protein. Nitrate reductase activity of hydroponically grown seedlings was highest with 0.1 mM P and lowest with 0.005 and 0.5 mM P, whereas soluble protein was highest at the lowest P level. In plants grown to maturity in hydroponic cultures, 0.1 and 1.0 mM P increased plant tillers, vegetative N and P concentrations, grain yield, and grain protein and P concentrations. Time of application of 32P did not influence grain 32P concentration. We concluded that P fertilizer had no intrinsically detrimental effect on N metabolism and grain protein in wheat, but that it might indirectly affect grain protein concentration by influencing yield.
Fertilizer Nitrogen Utilization by Corn, Tomato, and Sugarbeet1
Authors: Hills F. J. , Broadbent F. E. , Lorenz O. A. 
Published: July 2010

AbstractDifferences in the abilities of crops to utilize fertilizer and soil N can contribute to the establishment of rotation systems to improve the efficiency of fertilizer use and reduce nitrate pollution groundwater. Field studies show considerable site variability in the utilization of fertilizer by individual crops. To compare fertilizer N use by corn (Zea mays L.), sugarbeet (Beta vulgaris L.), and tomato (Lycopersicon esculentum Mill.), several rates of fertilizer N were applied to replicated plots of each crop in the same field at Davis, Calif. A 2nd year study involved only corn and sugarbeet. The experiments were conducted at different sites, but both on the same soil, Yolo silt loam (a fine‐silty, mixed, nonacid, thermic, Typic Xerorthent). Nitrogen‐15 depleted ammonium sulfate was used as a labeled N source in the three‐crop experiment and ammonium nitrate of normal isotopic ratio was used for the two‐crop experiment. In both experiments, N was applied in bands on both sides of crop rows after seedling emergence in 56 kg increments from 0 to 280 kg N/ha. Fertilizer N required for maximum commercial yield in 1979 was: corn 194, tomato 131, and sugarbeet 92 kg N/ha; and in 1980: corn 280 and sugarbeet 70 kg N/ha. Average recoveries of labeled N from fertilizer in 1979 were: corn 57%, and tomato and sugarbeet 27%; and in 1980 without labeled N the apparent recoveries were: corn 52% and sugarbeet 37%. The ratios of fertilizer to soil N in the crops at fertilizer rates giving maximum commercial yields in 1979 were: corn 45/55, tomato 25/75, and sugarbeet 15/85; and in 1980 were estimated by the difference method to be: corn 54/46 and sugarbeet 10/90. Thus corn relied most heavily on fertilizer N, followed by tomato then sugarbeet. On average, over the 2 years, sugarbeet took up 95% more soil N than corn. These data indicate that fertilizer use efficiency may be improved by growing corn when residual N is lowest and tomato or sugarbeet when residual N is highest. With care to avoid residual N too high for depletion prior to harvest, sugarbeet can be used to scavenge soil N and thus conserve the use of fertilizer N.
Phosphorus Uptake by Six Plant Species as Related to Root Hairs1
Authors: Itoh Sumio , Barber S. A. 
Published: July 2010

AbstractPlant species vary in the amounts of P they obtain from the soil. It was hypothesized that investigation of the differences among species with a mathematical model describing the processes involved in P uptake from soil, would both show why species varied and provide a more rigorous test of a model verified for corn (Zea mays L.). A controlled climate chamber experiment was conducted with six plant species varying in ability to grow in soils at low levels of soil P. The soil and plant parameters required to operate the model were measured and the agreement between predicted P uptake and observed P uptake evaluated. When the roots were considered to be smooth cylinders absorbing P from soil solution, several species absorbed more P than predicted by the model. The species varied widely in root hair length and density. When the contribution of root hairs to P uptake was included, predicted P uptake agreed with observed uptake. A linear regression gave an r of 0.89 and a slope of 0.89. In addition to root hairs, P uptake efficiency of the plant species was influenced by amount of root surface per gram of plant, rate of plant growth, and the P influx kinetics of the root.
Toxic Nitro Compounds in Lotus1
Authors: Williams M. C. 
Published: July 2010

AbstractToxic aliphatic nitro compounds were recently detected in species of the genus Lotus. Nitro‐bearing species, if used as forage, might be harmful to livestock. Therefore, this investigation was initiated in the greenhouse and laboratory to study the distribution, types, and concentration of nitro compounds in species of Lotus, and to determine the toxicity of cultivars of L. pedunculatus Cav. to 1‐week‐old chicks. Leaves of 83 species of Lotus, collected from herbarium specimens or plants grown in soil (Dagor series of fine‐loamy, mixed, mesic family of Cumulic Haploxeroll) in the greenhouse, were analyzed for nitro compounds. Nitro‐bearing species for which sufficient material was available were analyzed chromatographically for the type of nitro metabolite. The toxicity of cultivars of L. pedunculatus was determined by feeding dried plant and aqueous extracts of the foliage to 1‐week‐old chicks. Nitro compounds were detected in 17 of 83 species of Lotus. No nitro compounds were detected in three commercial cultivars of L. corniculatus L. Hydrolysis of nitro compounds yielded only 3‐nitropropionic acid (3‐NPA). Nitro levels in leaflets of L. pedunculatus averaged 27 to 29 mg NO2/g of plant. Dried plant or extracts of three cultivars of L. pedunculatus produced nitro poisoning in 1‐week‐old chicks. The data indicate that several species of Lotus synthesize toxic nitro compounds that yield 3‐NPA upon hydrolysis. Species of Lotus should be screened for nitro compounds before developing cultivars to prevent the seeding of potentially poisonous plants on grazing land.
Manganese Deficiency and Toxicity Effects on Growth, Development, and Nutrient Composition in Wheat1
Authors: Ohki K. 
Published: July 2010

AbstractWheat (Triticum aestivumL.) production areas have expanded to soils low in available Mn and to low pH soils with excess available Mn. The purpose of this study was to determine the effect of Mn deficiency and toxicity effects on ‘Stacy’ wheat growth components and to determine the Mn critical deficiency level (CDL) and critical toxicity level (CTL) in specific plant tissue in relation to top dry weight. The critical deficiency and toxicity values could be used as guidelines in tissue analysis to diagnose Mn deficiency and toxicity. Wheat plants were grown in nutrient solution containing 10 Mn rates from 0.09 μMto 9.1 mMin the greenhouse. Plants were harvested 26 days following treatment with Mn and tissue samples were analyzed for Mn and other elements in the wet ashed extract. Manganese deficiency and toxicity reduced top dry weight, root dry weight, plant height, and tiller number compared with plants supplied at adequate Mn levels. The CDL and CTL defined as the elemental concentration in the tissue associated with a 10% reduction in growth due to a deficiency or toxicity, respectively, were determined from the relationship of Mn concentrations in the tissue and top dry weight. The Mn CDL values for blades 1, 2, 3, and stem of Stacy wheat were 13,39,82, and 12 μg g‐1, respectively. Blade 1 is recommended for tissue sampling since the transition zone in the response curve is narrow and blade 1 is metabolically active and the most recently matured blade with a developed ligule. The Mn CTL values of the sampled tissues were 380, 900, 1100, and 200 μg g‐1for blades 1, 2, 3, and stem tissue, respectively. Maximum growth would be expected when tissue Mn concentrations are within the CDL and CTL of a specific plant tissue. The Mn concentration in tissues increased as Mn supply was increased. A reciprocal Fe/Mn and P/Mn concentrations existed in blade 1. Manganese deficiency and toxicity reduced K, Ca, and Mg concentrations.