bluuebunny/crossref_metadata_2025_split huggingface dataset:
Seed Size and Germination of Hulled and Unhulled Bermudagrass Seeds1
Authors: Ahring Robert M. , Todd Glenn W. 
Published: July 2010

AbstractGermination procedures used for testing bermudagrass [Cyndon dactylon (L.) Pers.] seed were developed primarily from studies with “common”. Seed of strains other than common, produced under different environmental conditions, may have different germination requirements. Nine strains and five hybrids of bermudagrass, were examined for: 1) differences in seed size, 2) germination capacity in eight different environments, and 3) effects of moist prechill on germination. The objective was to evaluate the differences among strains for seed size and germination requirements.Seed size among strains were essentially the same during both years of study. Five strains [9945, Guymon, 9958, 10981, and 9958(x)] consistently produce larger seeds. Seed‐set under field conditions would not have to be as high as it was in these strains to have good seed yield potential.Fresh seed germinated best in a temperature regime alternating between 20 and 30 C. Germination of seed 2 months old, both hulled and unhulled, was significantly greater on substrate moistened with KNO3 than with water. Light, alternating temperatures, and a substrate moistened with KNO3 promoted germination in the dormant or fresh seeds of all but one strain.Moist prechill treatments tended to reduce viability of the hulled seed, but unhulled seed remained firm and germinaated well after prechill. This finding and the fact that warm alternating temperatures promoted maximum germination suggests that early (February through April) field plantings of hulled seed would not be as successful as late (May through July) plantings. Unhulled seed did not deteriorate as rapidly as hulled seed under moist prechill situations and may find use in February through April plantings.
Herbage Yields and Levels of N and IVDDM from Five Alfalfa Strains of Different Ploidy Levels1
Authors: Arbi Nitza , Smith Dale , Bingham E. T. , Soberalske R. M. 
Published: July 2010

AbstractCultivated alfalfa (Medicago sativa L.) cultivars are primarily tetraplolds, and data are sparse about the performance of alfalfa strains of different ploidy levels. Related diploid, tetraploid, and hexaploid alfalfa strains and a ‘Vernal’ check were compared in seeded row plots at Madison, Wisconsin. The soil was a fertile Dodge silt loam (Typic Hapludalf). The alfalfas were harvested during 2 years with two, three, or four cuts annually,, and the forage was analyzed for concentrations of nitrogen and in vitro digestible dry matter (IVDDM). Herbage, N, and IVDDM yields averaged over alfalfa strains were similar for two and three cuts annually, and were lowest for four cuts. Percentages of N and IVDDMw ere in the increasing order of two, three, and four cuts annually and similar for all ploidy levels within a cutting schedule. The 4x strains produced higher yields of herbage, N, and IVDDM than the 2x and 6x strains within each cutting schedule. The 2x strain outyielded the 6x strain with two cuts annually, but the reverse was the case with three and four cuts annually. This same response of strains was apparent in the residual herbage yields, within each cutting schedule, which were in the descending order of two, three, and four cuts annually. It was concluded that among the materials tested the tetraploid level had the highest yield potential and that the experimental diploid was best suited to a two‐cutting schedule. The tetraploid that was synthesized to maximize heterozygosity [4x (70‐44)] outyielded the check cultivar ‘Vernal’ at all cutting frequencies. Lack of maximum heterozygosity in the hexaploid was a possible reason for its comparatively poor performance.
Effects of Annual Weed Control on Alfalfa Forage Quality1
Authors: Temme D. G. , Harvey R. G. , Fawcett R. S. , Young A. W. 
Published: July 2010

AbstractEstablishment of alfalfa (Medicago sativa L.) alone rather than with an oat (Avena sativa L.) companion crop usually results in a reduction in dry matter production. Use of herbicides for weed control during alfalfa seedling establishment also reduces yield since weeds are harvested along with the alfalfa and contribute to forage yield. Thus, if there are benefits from seeding alfalfa alone using herbicides for weed control they would only be expressed in terms of animal consumption, nutritional value, digestability, and finally animal growth or milk production. Consequently, a study was conducted to determine the benefits of annual weed control during alfalfa establishment. Alfalfa was sown into field test plots (Plano silt loam, 3.5 to 4% organic matter, Typic Argindoll, fine, silty, mixed mesic) in April 1976 with an oat companion crop and alone with and without herbicide treatments. Herbicide treatments included were S‐ethyl dipropylthiocarbamate (EPTG) + 4‐(2,4‐dichlorophenoxy) butyric acid (2,4‐DB), and Nbutyl‐N‐ethyl‐α,α,α‐trifluoro‐2,6‐dinitro‐p‐toluidine (benefin). Weeds were also allowed to grow in the absence of an alfalfa or oat seeding. The oat companion crop was harvested at the early dough stage and the alfalfa treatments at first flower, all as chopped hay. The stand of weeds was harvested at the same time as the alfalfa.The oat hay, weeds, and alfalfa established with and without herbicides, were analyzed in laboratory studies for in vitro digestible dry matter (IVDDM), neutraldetergent fiber (NDF), aciddetergent fiber (ADF), crude protein, and nitrate. A sheep feedingdigestion trial was used to determine the palatability, digestible dry matter (DDM), digestible crude protein (DCP), digestible neutraldetergent fiber (DNDF) and digestible aciddetergent fiber (DADF) of the forages, and N balances of the sheep fed the forages. The four forages were ranked as follows in order of increasing quality as measured by animal intake and digestible dry matter: oat, hay, weed forage, untreated alfalfa, herbicide‐treated alfalfa. The lower quality of the untreated alfalfa in comparison with the herbicide treated alfalfa was attributed to the fact that weeds constituted 50% of the dry weight of the untreated alfalfa stituted 50% of the dry weight of the untreated alfalfa forage. Chemical analysis of the weeds indicated that the Pennsylvania smartweed (Polygonum pensylvanicum L.), shepherds‐purse (Capsella bursa‐pastoris (L.) Medic), and yellow foxtail (Setaria lutescens (Weigel) Hubb.) had the greatest influence in lowering the forage quality. These three weeds, which composed 25% of the untreated alfalfa forage, had the lowest % crude protein and IVDDM and the highest % CWC and ADF. The digestion trial also showed the annual weeds, as a whole, to be the lowest in DCP, DNDF, and DADF. These results confirm that seeding alfalfa alone using herbicides for weed control is beneficial, and that feeding forage thus produced will improve livestock performance.
Evaluation of Legume Mixtures for Hay Plantings1
Authors: Cooper Clee S. 
Published: July 2010

AbstractNumerous studies have been conducted with grasslegume mixtures for hay and pasture production but few studies have been conducted with legume mixtures. Legume mixtures may be of value in forage production because nonbloating legumes planted with bloating legumes may lessen bloat hazard. Legume mixtures may also be advantageous for use in special purpose mixtures, such as those used for haystockpiling management regimes. We evaluated legume mixtures for irrigated hay production over a 4‐year period in comparison with legumes grown alone. Plantings were made into a Bozeman silt loam (Argic‐Pachic Cryoboroll) soil. Legumes evaluated were sainfoin (Onobrychis viciifolia Scop), birdsfoot trefoil (Lotus corniculatus L.), cicer milkvetch (Astragulus cicer L.), alfalfa (Medicago sativa L.), and red clover (Trifolium pratense L.). Legumes were seeded in 30‐cm row spacings on 1.2 ✕ 6.1 m plots. Legumes in mixtures were seeded in alternate rows. Herbage was harvested twice each year as hay.Highest yield for the 4‐year period was 36.61 tons/ha for the sainfoin‐birdsfoot trefoil mixture and lowest yield was 26.34 tons/ha for cicer milkvetch grown alone. Yields of other Iegumes grown alone or in mixtures were intermediate. Mixing other legumes with cicer milkvetch increased yields above those obtained with this species grown alone. The contribution of each legume to a mixture was dependent upon the competitiveness of the legume associate. A sainfoin‐alfalfa mixture yield was similar to that for each species grown alone. The merits of growing legume mixtures is discussed.
Gaseous Nitrogen Loss from Soybean Foliage1
Authors: Stutte C. A. , Weiland R. T. , Blem A. R. 
Published: July 2010

AbstractThe loss of non‐elemental N from plant foliage was verified, and the significance of this loss was investigated. Soybean (Glycine max (L.) Merr.) leaf vapors were condensed (–50 C) using a calibrated test tube tra in a closed system. Subsequent N analysis of this condensate revealed water soluble N forms. Since the pyrochemiluminescent technique that was used for N analysis does not detect elemental N, the N present must be in chemically bound forms; preliminary research indicates the N in both oxidized and reduced forms.Significant losses of N from the determinate cultivar ‘Davis’ were positively correlated to temperature and to transpiration rate under field conditions. These losses, which like transpiration followed a diurnal trend, were greater in early vegetative growth stages than during flowering and pod‐fill. The amount of N lost is significant under the high temperatures of field Conditions and may account for much of the reduction in potential seed yields under this stress condition.
Osmotic Stability of Mannitol and Polyethylene Glycol 20,000 Solutions Used as Seed Germination Media1
Authors: Thill D. C. , Schirman R. D. , Appleby A. P. 
Published: July 2010

AbstractSolutions of mannitol and high molecular weight polyethylene glycols (PEG) of different osmotic potentials are often used to simulate water stress in seed germination studies. However, little has been reported about the osmotic stability of these solutions. The objectives of this study were to determine the osmotic stability of mannitol and PEG 20,000 solutions, to examine the biological significance of any observed instabilities, and to compare osmotic vs. matric water potential effects on germination of winter wheat (Triticum aestivum L., ‘Nugaines’). Four solutions of mannitol, PEG, and KC1 (standard) with water potentials ranging from −3.5 to −18.0 bars were incubated at 10, 20, and 30 C and water potentials were measured periodically with thermocouple psychrometry. In addition, comparisons were made of the percent and rate of germination of wheat seeds placed in 28‐day‐old and freshly prepared solutions of mannitol and PEG and the percent and rate of seedling emergence from a watered soil media. The osmotic potential of different mannitol solutions and of the −9.1‐ and −17.4‐bar PEG solutions did not change with time. However, the osmotic potential of the −4.0‐ and −6.4‐bar PEG solutions decreased 1.0 bar. Percent and rate of germination of wheat was the same in the 28‐day‐old and in freshly prepared mannitol and PEG solutions; but at equal potentials, the germination rate was most rapid in the mannitol solutions. Wheat emergence rate from watered soil was linearly related to the germination rate in PEG, but not in mannitol solutions.Hence the slight instability of PEG solutions appears to be of no biological consequence in seed germination studies, and wheat seed emergence rates at different soil matric potentials can be approximated from germination rates in PEG osmotic solutions.
Carbohydrate Sampling in Kentucky Bluegrass Turf1
Authors: Sheffer K. M. , Watschke T. L. , Duich J. M. 
Published: July 2010

AbstractThe percent total nonstructural carbohydrate (TNC) is often used as an indicator of the physiological status of cool season turfgrasses. However, the time of sampling during the day and the plant parts used for analyses may influence results. Growth habit differences of cultivars may also influence the TNC level of plant parts and the rate of accumulation at different times during the day. The purpose of this research conducted on Kentucky bluegrass (Poa pratensis L.) was to determine 1) TNC of five cultivars over three mowing managements, 2) whether TNC of leaf parts (blade or sheath) or the entire leaf (blade plus sheath) provided the best statistical separation of treatments, and 3) diurnal fluctuation of leaf blade TNC in cultivars of diverse leaf blade orientation.Five Kentucky bluegrass cultivars (‘Merion’, ‘Pennstar’, ‘Baron’, ‘Bonnieblue’, and ‘K‐150A’) maintained at three cuttings heights (1.3, 2.5, and 5.1 cm) in the field were utilized in these experiments. These cultivars were art of the 1972 Northeastern Regional Test established in 1972 on a Hagerstown soil (fine, mixed, mesic Typic Hapludalf). Upper canopy leaf blades (reel mower clippings), leaf sheaths, and entire leaves (blade and sheath) were analyzed for TNC. Blade tissues from intact tillers of Merion were analyzed for TNC and compared with upper canopy leaf blade TNC. Upper canopy leaf blades of Merion and two cultivars (‘Brunswick’ and ‘K‐183’) having diverse leaf blade orientation were sampled diurnally on 2‐hour intervals for TNCCuttings heights significantly affected TNC regardless of the tissue fraction analyzed. The 2.5‐cm height had significantly higher TNC than the 1.3 and 5.1 an heights. Entire leaf TNC provided a greater statistical cultivar separation than did sheath or blade tissue alone. K‐150A had significantly higher entire leaf TNC than Pennstar, Baron, and Bonnieblue, while Merion was also higher than Pennstar and Baron. Upper canopy leaf blade tissue of Merion had a much higher TNC level than leaf blade samples which included lower blades. The TNC of blade tissue was found to fluctuate significantly within 2 hours. Cultivars with different blade orientation exhibited similar diurnal TNC patterns. On the basis of these results, future TNC analyses should utilize the entire leaf (blade and sheath) for optimum statistical separations.
Temperature Effects on Growth and Manganese Tolerance in Tobacco1
Authors: Rufty Thomas W. , Miner G. S. , Raper C. D. 
Published: July 2010

AbstractSymptoms of Mn toxicity in tobacco (Nicotiana tabacum L.) are often observed in the mountain region of North Carolina at soil acidity and soil test levels of Mn which do not produce toxicity in the piedmont. Although genotypic differences between tobacco types grown in the regions may contribute to the differential response, variations in temperature between the regions may also be involved. To investigate the effects of temperature on plant growth and Mn tolerance, tobacco plants of a prevalent cultivar (‘Coker 347’) for the piedmont region were grown in sand culture at day/night temperatures of 22/18, 26/22, and 30/26 C. Manganese was applied daily at rates of 10, 20, 40, 80, and 120 mg/liter in a complete nutrient solution. Plants were sampled weekly during a 6‐week growth period and evaluated for visual toxicity symptoms, dry weight. Mn concentration, relative growth rate (RGR), and relative accumulation rate (RAR) of Mn.Plant tolerance to high rates of applied Mn increased with increasing temperature despite significantly greater tissue concentrations of Mn during early growth. Tissue levels of Mn in leaves associated with the appearance of visual toxicity symptoms were 700 to 1,200 mg/kg dry wt at 22/18 C, 2,000 to 3,500 mg/kg at 26/22 C, and 5,000 to 8,000 mg/kg at 30/26 C. Mn toxicity symptoms were more severe in immature leaves and often decreased as the leaves matured even though the concentration of Mn in the leaves increased. The RGR of leaves during the exponential growth phase increased with increasing temperatures at each Mn rate, but the RAR of Mn was unaffected by either temperature or applied Mn rate. It is proposed that the increased tolerance to high levels of tissue Mn by plants grown in warm temperatures is associated with more rapid rates of leaf expansion accompanied by increased vaculor capacity for disposal of accumulated Mn.
Assimilate Redistribution from Soybean Pod Walls During Seed Development1
Authors: Thorne John H. 
Published: July 2010

AbstractAccumulation of dry weight by soybean seeds occurs at a linear rate in spite of daily fluctuations in photosynthate production. This suggests a possible role for assimilate redistribution from storage in maternal fruit tissues to developing seeds. Because of their proximity to the seed, pod walls were suspected as temporary storage organs for photosynthate and nitrogenous assimilates.Populations of Norman (OO maturity) and Amsoy 71 (II maturity) soybeans [Glycine max (L.) Merr.] were field‐grown in 1977 on Cheshire fine sandy loam (Typic Dystrochrept). Weekly during reproductive growth, developing fruit were harvested and assimilates in pod walls extracted and colorimetrically determined. At midpodfilling, pods from three canopy strata were also harvested diurnally and analyzed. From the examination of dry weight and assimilate levels within these samples, evidence of storage and redistribution from pod walls was obtained.Prior to mid‐podfilling stage both cultivars accumulated maximum pod wall dry weight; Norman 290 mg pod wall‐1 on 11 August and Amsoy 71 170 mg pod wall‐1 on 25 August. Pod walls of Norman redistributed 112 mg of previously accumulated dry matter, occurring when incipient canopy senescence probably would have otherwise precluded continued linear seed growth. Assuming that these pod wall assimilates were transported to the enclosed seeds and an efficiency of conversion to seed of 41%, the redistributed materials accounted for 12.7% of the final seed yield per plant in Norman while only 1.8% in Amsoy 71.Pod walls were found to store and later redistribute starch, reducing sugars, and nitrogenous materials. The sucrose present was almost entirely in the major pod vascular bundles. Starch was a major storage product, but there was no significant diurnal variation in the amount. However, significantly more starch was accumulated by Norman pod walls in the upper third of the canopy. Glucose and fructose accumulations were depleted by redistribution in approximately the same time period as starch and nitrogenous materials.The data suggest that, in extremely short season cultivars such as Norman, assimilate storage and later redistribution by pod walls to the developing seeds may serve to effectively lengthen the period of podfilling and thus contribute significantly to final seed yield.
Salinity‐Induced Modifications in the Response of Maize to Water Deficits1
Authors: Stark J. C. , Jarrell W. M. 
Published: July 2010

AbstractIn many crop species, salinity induces physiological and morphological adjustments which assist in the maintenance of a favorable water balance. Adjustments such as these may also be effective in modifying the response of salinized plants to drought. This study was designed to evaluate the effect of salinity pretreatment on the response of maize to matric water stress.Maize (Zea mays L.) was grown in sand culture tanks at four levels of nutrient solution salinity, produced with an equivalent mixture of CaCl2 and NaCl: −0.4, −2.4, −4.4, and −6.4 bar osmotic potentials. When the plants were 35 days old, irrigation was stopped and a period of drought stress began. When predawn leaf xylem water potentials (Lψt in all but the highest salinity treatment had dropped below −15 bar, irrigation was resumed. Prior to, during, and after the drought period, rates of leaf blade elongation, Lψt, and relative water content (RWC) were measured.The lowest rates of leaf blade elongation prior to drought occurred in the high salinity treatments. However, 5 days after discontinuing irrigation, leaf blade elongation in the −0.4 bar treatment had nearly ceased, while the rate for the −6.4 bar treatment slowed considerably but continued to be measurable for 9 days. Plants from the high salinity treatment also did not show the rapid decreases in Lψt exhibited in the other treatments. This response was presumed to be due primarily to salinity‐induced reductions in the transpiration rate which prolonged the period of adequate water supply. Elongation rates partially recovered after the plants were rewatered, but the plants from the high salinity treatment again resisted rapid change.Salinity pretreatment altered the relationship between elongation and Lψt indicating that loss of turgor during drought may be partially moderated by preconditioning with osmotic stress. The water desorption characteristics of maize were significantly modified by any increase in salinity above that of the control solution.
Inheritancee of Tolerance or Resistance to Manganese Toxicity in Soybeans
Authors: Brown J. C. , Devine T. E. 
Published: July 2010

AbstractSoybeans (Glycine max L. Merr.) differ in their tolerance to Mn. The objective of this study was to determine the nature or mode of inheritance of Mn tolerance in soybeans. Test plants were Forrest (Mn‐intolerant, Fe‐inefficient), T203 (Mn‐tolerant, Fe‐inefficient) and their F2 progeny Forrest × T203 (F×T) and T203 × Forrest (T×F); and Bragg (Mn‐intolerant, Fe‐efficient), Lee (Mn‐tolerant, mod. Fe efficient) and their F2 progeny, Bragg × Lee (B×L), and Lee × Bragg (L×B). The plants were grown in Mn‐toxic soil and in nutrient solutions containing 0.35 and 0.65 mg Mn/liter. Only T203 did not develop some Mn‐toxicity symptoms under conditions of relatively high Mn. The order of symptom severity was Forrest ≥ Bragg > Lee > T203. Manganese toxicity symptoms also varied among the F2 progeny of reciprocal crosses. The leaves of both parents and progenies contained about 500 mg Mn/g dry matter. Some factor(s) other than Mn concentration in the plants appeared to cause the Mn‐toxicity symptoms. The Fe concentration in plant tops was related somewhat to Mn‐toxicity symptoms in that the Fe concentrations were usually greater in Mn‐intolerant than in Mn‐tolerant genotypes. Control of tolerance to excess Mn appeared to be multgenic rather than controlled by a single gene locus. Reciprocal differences in progeny suggested that cytoplasmic inheritance influenced Mn tolerance. Crop failure can be avoided by selecting a Mn‐tolerant soybean to be grown in a soil relatively high in available Mn.