bluuebunny/crossref_metadata_2025_split huggingface dataset:
Standard, Cold, and Tetrazolium Germination Tests as Estimators of Field Emergence of Mechanically Damaged Soybean Seed1
Authors: Mason S. C. , Vorst J. J. , Hankins B. J. , Holt D. A. 
Published: July 2010

AbstractSoybean [Glycine max (L.) Merr.] germination is routinely estimated from laboratory germination test results. However, differences in seed quality have caused variable germination performance both in the laboratory and in the field. The objective of this research was to determine ability of standard, tetrazolium, and cold germination tests to estimate average field emergence of mechanically damaged soybean seed. Damaged seeds were subjected to standard, tetrazolium, and cold germination tests and were planted in the field to determine field emergence and seed yield. Germination test accuracy was measured by analyzing the difference between field emergence and the germination test results.Increasing levels of mechanical damage significantly decreased percent laboratory germination in both years and generally decreased percent field emergence. The tetrazolium test indicated a significantly higher percent laboratory germination than did standard germination and cold tests, and the standard germination test resulted in significantly higher percent laboratory germination than did the cold test. The tetrazolium test was not sensitive in detecting recently induced mechanical damage, and the cold test showed more variability in percent laboratory germination.In 1975 the standard germination and cold test accurately estimated average field emergence within ± 8 and ± 12%. The tetrazolium test over‐estimated average field emergence from 0 to 20%. In 1976 the standard germination test estimated average field emergence within ± 12%, the tetrazolium test generally over‐estimated average field emergence from 0 to 18%, and the cold test under‐estimated average field emergence by 5 to 41%.
Physiological Response of Chile Pepper to Trickle Irrigation1
Authors: Horton R. , Beese F. , Wierenga P. J. 
Published: July 2010

AbstractThe present field studies were conducted to examine the response of chile pepper (Capsicum annuum L., var. New Mexico No. 6‐4) during one irrigation cycle, to different deficit trickle irrigation treatments.After applying four different water rates for 46 days, detailed measurements were made, over a 3‐day period between two irrigations, of the water content, the soil‐water pressure potential, the osmotic potential of the soil solution, the leaf water potential, and the stomatal resistance. Crop evapotranspiration was estimated from water balance measurements, and hourly potential evaporation, ET0, was calculated using meteorological information.There were four water treatments, consisting of a control treatment and three treatments receiving 80, 120 and 140% of the water applied to the control. There were considerable differences in water transpired from the different treatments, but only slight differences in plant water potentials and stomatal resistances. At any time the differences in plant water potential and stomatal resistances were less than 2 bars and 1 sec/cm, respectively. Chile appeared to adapt to the soil water supply by controlling its size. The plants in the dryer irrigation treatments displayed less leaf area, fewer leaves per plant and less aboveground dry mass production. Because of the large differences in plant size associated with relatively small differences in measurements of the plant water status of chile, it appears inadvisable to depend upon pressure chamber, or diffusion porometer measurements for irrigation scheduling of trickle irrigated chile.
Environmental Influences on Fiber Component Concentrations of Warm‐season Perennial Grasses1
Authors: Henderson M. S. , Robinson D. L. 
Published: July 2010

AbstractEvaluation and management of warm‐season perennial grasses are complicated by seasonal fluctuations in forage quality. Field studies have indicated that a significant proportion of this seasonal variation is due to environmental conditions. Due to confounding effects under field conditions the variation cannot be directly attributed to specific environmental factors. In this study, Coastal and common bermudagrass [Cynodon dactylon (L.) Pers.], Pensacola bahiagrass (Paspalum notatum Flugge), and dallisgrass (Paspalum dilatatum Poir.) were grown in an artificial medium under 4 day/night temperatures (35/24, 32/31, 29/18, 26/15 C), 4 photon flux densities (1,050, 840, 630, 420 µE m−2 sec−1 PAR) and two soil moisture levels (high and low) in growth cabinets to evaluate the relative influence of each factor on fiber component concentrations. Grasses were harvested at 14 and 21 days and analyzed for neutral‐detergent fiber (NDF), acid‐detergent fiber (ADF), cellulose (CEL), hemicellulose (HEM), permanganate lignin (LIG), and silica (SIL) concentrations. multiple regression analysis was used to obtain reduced prediction equations for evaluating responses of all measured variables to temperature (T) and photon flux density (L) at each soil moisture level. Prediction equations for fiber component concentrations of each grass included T effects at both soil moisture levels but did not consistently include L effects. Coefficients of determination (R2 values) for the prediction equations indicated that T and L effects on fiber component concentrations varied with the fiber component, grass, and soil moisture level.Concentration of NDF increased in the Cynodon species and decreased in the Paspalum species as T increased. In all grasses, predicted concentrations of ADF, CEL, LIG, and SIL increased with increasing T at both soil moisture levels, while HEM concentrations decreased. In all grasses L effects consistently influenced ADF, LIG, and SIL concentrations at both soil moisture levels and CEL concentrations at the low moisture level. Concentrations of ADF, CEL, and SIL decreased slightly, while LIG concentrations increased with increasing L. Although T effects consistently had greater influence in this study, both T and L and their interaction effects significantly influenced predicted fiber component concentrations. The data emphasize the importance of considering environmental influences when evaluating forage quality differences of warm‐season perennial grasses.
Morphological and Physiological Variation in Wild Oat1
Authors: Miller S. D. , Nalewaja J. D. , Mulder C. E. G. 
Published: July 2010

AbstractWild oat (Avena fatua L.) is well adapted to grow and persist under a wide range of climatic and edaphic conditions. The present study was conducted to evaluate the variation within the wild oat population in North Dakota and Minnesota as to morphology, dormancy, and herbicide response. Growth characteristics of 230 wild oat accessions and their response to several herbicides for wild oat control were determined. Research was conducted in the glasshouse with potting soil (2:1:1 v/v/v Fargo silty clay, sand, and compost) or field on a Fargo silty clay (fine, montmorillonitic, frigid, Vertic Haplaquolls) or Barnes loam (fine‐loamy, mixed Udic Haploborolls). The wild oat accessions differed in plant height, number of tillers, days to panicle emergence, grain yield, and response to diclofop {2‐[4‐(2,4‐dichlorophenoxy) phenoxy]propanoic acid}, difenzoquat (1,2‐dimethyl‐3,5‐ diphenyl‐1H‐pyrazolium‐ion), flamprop [N‐benzoyl‐N‐(3‐chloro‐4‐fluoropheny1)‐DL‐alanine], and MSMA (monosodium methanearsonate). The accessions were classified into four botanical varieties (ecotypes) based on caryopsis (seed) characteristics; but magnitude classes within the measured traits showed no relationship to the ecotype classification.Wild oat seed dormancy varied between accessions and was influenced by location and season. The variation in wild oat indicates a potential within the natural population for certain accessions to become more weedy than others especially those possessing high dormancy, herbicide resistance, and seed production.
Quantitative Characterization of Vegetative Development in Small Cereal Grains1
Authors: Klepper Betty , Rickman R. W. , Peterson C. M. 
Published: July 2010

AbstractThe number of headed tillers is an important yield component in cereal grain production. Studies are needed to assess effects of environmental stress and genetic factors on tiller production and abortion in the field. The system for quantifying cereal leaf and tiller development described in this paper permits such studies to be done more definitively than was previously possible because each leaf and tiller on the plant is given a unique designation. The system developed on wheat [Triticum aestivum (L.) em. Thell.] is suitable for other cereals.Leaves are numbered acropetally, with the first foliar leaf being L1 and the coleoptile L0. Tillers are named for the leaf with which they are associated, e.g., T1 and TO. Subtillers have two digit designations, and third order tillers have three digit designations.Culm development is described by counting the number of fully expanded leaves and the fraction of the length the newest developing leaf measures relative to its predecessor. A stem with 6.2 leaves has six fully developed leaves and a seventh leaf one‐fifth as long as the sixth.The developmental time or phyllochron for each leaf on the plant is the same in any given environment, and leaves and tillers unfold in a set and orderly pattern. The rate of this unfolding is primarily determined by environment. Stress causes tillers to be omitted or delayed, compared to unstressed plants.
Cultivar and Seeding Rate Effects on Several Physical Characteristics of Kentucky Bluegrass Turf1
Authors: Brede A. D. , Duich J. M. 
Published: July 2010

AbstractThe growth habit and plant dimensions of Kentucky bluegrass (Poa pratensis L.) can be affected by the management factors imposed. This study was initiated to learn the effects of seeding rate and cultivar on several physical characteristics of Kentucky bluegrass turf and to develop and evaluate techniques for measurement of these characteristics under turf field conditions (a fine, mixed, mesic, Hapludalf soil). An optical enlargement technique was used to measure leaf angle, leaf‐fold angle, sheath‐axis width, leaf width, and leaf length of ‘A‐34’, ‘Baron’, ‘Bonnieblue’, ‘Newport’, and ‘Pennstar’ Kentucky bluegrasses. An overhead projector (the type commonly used in classrooms), mirror, and protractor screen enlarged the plant image 10 to 20 times enabling 1‐degree and 0.05‐mm resolution. A Noer profile sample3 (inner dimension, 13 ✕ 76 mm) was compared to three, round tools and found acceptable for sampling population densities if the loose tillers were included in the count. Because counting was easier and quicker, and plugs were returnable to the plots with minimal disturbance, the Noer tool proved advantageous. A technique was developed for estimating seedling blade density, given a few standheight measurements.Seeding rate had a positive effect on leaf angle, while the percent loose tillers per sample plug (an indicator of nonvertical tiller orientation), green leaves per tiller, sheath‐axis width, and leaf widths were negatively affected by seeding rate in the year after establishment. Stand densities converged to a mature density over five growing seasons. The convergent density was affected by cultivar and cutting height.Of the cultivars examined, A‐34 had the highest tiller density throughout the test, fewest green leaves per tiller, and narrowest leaf angle and blades. Baron possessed the most brown leaves per tiller, and widest sheath‐axis width (equal to Bonnieblue). Bonnieblue had the most green leaves per tiller, and lowest mature tiller density (equal to Pennstar). Pennstar had the most loose tillers per sample plug, widest leaf angle, and the most narrow sheath‐axis width.
The Effects of Anhydrous Ammonia at Planting Time on Spring Wheat and Barley1
Authors: Varvel G. E. 
Published: July 2010

AbstractAnhydrous ammonia has become the main N source used in the northern Great Plains on small grains, but most of it is applied in the fall preceding the crop year. This practice has been used for convenience, to avoid moisture loss which can occur in the spring due to the depth of placement, and to avoid possible germination damage from the anhydrous application if small grains are planted immediately after injection.The present studies were conducted to determine the effect of anhydrous ammonia on spring wheat, Triticum aestivum L., and barley, Hordeum vulgare L., at planting time.Field experiments were conducted 1979‐1981 on a Wheatville loam (coarse‐silty over clayey, frigid Aeric Calciaquolls) soil. The treatments consisted of three rates of N as anhydrous ammonia (45, 90, and 135 kg/ha) in 1979 and four rates of N (0, 45, 90, and 135 kg/ha) in 1980‐1981 at three depths (8,16, and 24 cm) in all combinations. Spring wheat and barley were then seeded at three different times. Seedling stand counts, grain yield, and protein were used to determine the effect of the treatments.Seedling stands were reduced in some cases, but no reduction in grain yield or protein was obtained due to the reduction in stand. The most important factor in spring anhydrous application was the depth of application, which caused greater moisture loss and seedbed disruption at the 24‐cm application depth. Significant responses to N were obtained, but N as anhydrous ammonia did not cause reduction in seedling stands of agronomic importance.
Differential Response of Sunflower Hybrids to Planting Date1
Authors: Owen D. F. 
Published: July 2010

AbstractDate of planting studies are often conducted using only one cultivar as a measure of performance. When different cultivars do not respond alike to differing planting dates then results of planting date studies in which only one cultivar is used may lead to false conclusions. In an effort to determine if different sunflower (Helianthus annuus L.) hybrids responded alike to varying planting dates, five oilseed sunflower hybrids were planted at monthly intervals from late April through late July during 1977–1979 at the Texas Agric. Exp. Stn., Halfway, Texas, on a Pullman clay loam (fine, mixed thermic Torrertic Paleustoll). Major differences were found between years for yield and oleic and linoleic acid concentration, between dates for yield and concentrations of oleic and linoleic acid; and between hybrids for oil percentage. All of the interactions with years were significant. The date by hybrid interactions were not significant for yield, percent oil, and concentration of oleic and linoleic acid when averaged over years. Difference in yields among dates (α = 0.10) indicated that mid‐ to late‐July plantings produced less than late May and mid‐ to late‐June plantings. One hybrid was significantly higher in oil concentration than the others. Oleic acid concentration decreased and linoleic acid concentration increased linearly as planting dates were delayed. Planting hybrid sunflower after mid‐June as a primary crop is not recommended due to reduced yield potential and risk of frost damage. Early planting could be advantageous if higher oleic acid concentration were desired, and conversely, later planting if higher linoleic acid concentration were considered more important.
Plant Growth‐Regulating Effects of Systemic Fungicides Applied to Kentucky Bluegrass1
Authors: Kane R. T. , Smiley R. W. 
Published: July 2010

AbstractSystemic fungicides applied to Kentucky bluegrass (Poa pratensis L.) turf often cause visible alterations in plant morphology. Compounds derived from 5‐pyrimidinemethanol and 1,2,4‐triazole may induce changes in color, growth rate, and density of the stand while also providing outstanding disease control. Because plant growth and stress responses contribute to the severity of many turfgrass diseases, nontarget plant growth regulating effects could influence the disease control activity of systemic fungicides. Studies were conducted to determine the effects of several systemic fungicides on Kentucky bluegrass morphology and physiology. Fungicides were compared, when possible, to growth‐regulating compounds with similar chemical and/or biological properties. Commercially available or experimental formulations were applied as soil drenches to greenhouse‐grown seedlings and as foliar sprays to field‐grown sod of ‘Merion’ and ‘Fylking’ Kentucky bluegrass. Application rates of the fungicides were as recommended for controlling Fusarium blight. Growth regulators were applied at rates comparable to the fungicides or at rates previously reported to have an effect on plant growth. Oven‐dry root weights, shoot densities (tillers plus nonemerged rhizomes), and leaf growth rates were measured. The chlorophyll content of young leaves was determined by extraction with dimethylsulfoxide. Chlorophyll retention of excised, mature leaves was measured following dark incubation. Total nonstructural carbohydrate (TNC) content in mature foliage was determined using the anthrone method. When applied to greenhouse‐grown seedlings, pyrimidinemethanol and triazole derivative fungicides reduced leaf growth rates, shoot densities, and root weights of one or both cultivars. Pyrimidinemethanols increased the chlorophyll content of Fylking and increased TNC contents of both cultivars. Triazoles also increased TNC levels while increasing chlorophyll retention of excised leaves. Chlorophyll retention was also enhanced by cytokinin analogs, including a benzimidazole fungicide. Results obtained from field experiments were inconsistent although similar growth‐regulating effects were observed following certain treatments. Our results show that the systemic fungicides studied have nontarget plant growth‐regulating activity on Kentucky bluegrass. These effects could influence the severity of stress related diseases such as Fusarium blight.
Wetting and Maturity Effects on the Yield and Quality of Legume Hay1
Authors: Collins Michael 
Published: July 2010

AbstractInformation is needed on the effects of rain on the magnitude of yield and quality losses of field cured legume hay. Two experiments were conducted to evaluate the influence of wetting on yield and quality losses of hay of alfalfa (Medicago sativa L.) and red clover (Trifolium pratense L.) cut at two maturity stages. Three and one‐half kilogram samples of alfalfa and red clover forage grown on Plano silt loam soil (fine‐silty, mixed, mesic Typic Argiudoll) and harvested at early and late maturity stages were placed on wire screens and allowed to dry without wetting or were exposed to natural or artificial wetting in 1980 and 1981. A completely randomized design was used with three replications in 1980 and two in 1981. In 1980, 2.5 cm of water was applied to hay wetted during drying. In 1981, hay wetted during drying was exposed to 4.1 and 6.2 cm of precipitation, respectively. Mean dry matter (DM) losses during drying in 1980 were 8.1 and 17.0% from unwetted and wetted forage, respectively, but red clover harvested at the bud stage and wetted lost 25.8% of the total DM. In 1981 unwetted forage, forage wetted during drying and forage wetted after reaching 85% DM lost 10.5, 43.4, and 53.0% of the initial DM. Wetting did not change forage N concentration greatly in either year. Forage in vitro dry matter disappearance (IVDMD) was reduced by wetting in both years. In 1981 IVDMD was reduced from 66.4% for unwetted hay to 48.1% for hay wetted during drying. Mature forage of alfalfa was lower in IVDMD than bud stage alfalfa in both years regardless of wetting treatment. Neutral detergent fiber concentration was increased by wetting red clover forage in both years. Prolonged wetting in 1981 reduced the yield of N and TNC by 40.3 and 71.5%, respectively. Dry matter and quality losses due to wetting of legume forage during hay curing vary with legume species and the timing and duration of wetting. Results indicate that plant constituents differ in their susceptibility to loss due to wetting during hay curing.
Fall Sod‐Seeding of Ladino Clover into Tall Fescue as Influenced by Time of Seeding, and Grass and Insect Suppression1
Authors: Rogers D. D. , Chamblee D. S. , Mueller J. P. , Campbell W. V. 
Published: July 2010

AbstractGrass competition and insect damage may detrimentally influence establishment of forage legumes sod‐seeded into perennial grass swards. The objective of this study was to quantify and evaluate the effects of seeding date, grass suppression, and insects on fall establishment of ‘Tillman’ ladino clover (Trifolium repens L.) into tall fescue (Festuca arundinacea Schreb.) sods. Four field experiments were conducted during 3 years on a Typic Hapludult or an Ultic Hapludalf soil in the North Carolina Piedmont. Paraquat (1, 1′‐dimethyl‐4,4′‐bipyridinium ion) for sod suppression and granular carbofuran (2,3‐dihydro‐2, 2‐dimethyl‐7‐benzofuranyl methylcarbamate) for insect control were not applied or were applied at 0.28 and 3.7 kg ha−1, respectively, at two seeding dates (early‐September or mid‐October) in a 23 factorial combination. Measurements were made of clover stand, insect damage, and dry matter production. Prevalent insects were identified. Much more insect damage was observed from September than from October seedings. During a 9‐day period shortly after the September seeding in Exp. 4 an 82% reduction in clover density was measured in plots not treated with insecticide. Clover establishment and 1st‐year dry matter production were often greatly increased by combining sod suppression with insect control at seeding compared with use of either practice alone. In Exp. 1 for example, seasonal yields of September‐seeded clover were 2564 and 1079 kg ha−1 for paraquat and carbofuran used alone, respectively, and 5568 kg ha−1 when used in combination. Check plots yielded 183 kg ha−1. Good winter survival was obtained from October sod seedings although the majority of clover seedlings (75 to 83%) had developed only one trifoliolate leaf by early December in three of the four trials. We conclude that the use of both an insecticide and a grass suppressant may be necessary for successful establishment of ladino clover into a tall fescue sward under some conditions and that mid‐October is a good alternative to early‐September as a seeding date during years of low moisture and high insect populations in September.
Soil Fertility and Defoliation Effects with Arrowleaf Clover and Nitrogen Fertilizer Equivalence of Crimson‐Arrowleaf Clover Combinations
Authors: Lynd J. Q. , Hanlon E. A. , Odell G. V. 
Published: July 2010

AbstractArrowleaf clover (Trifolium vesiculosumSavi) has promise as an improved forage legume that is compatible with both warm and coolseason grass species. The objective of these studies was to evaluate factors influencing the potential of ‘Yuchi’ arrowleaf clover for high forage productivity with desirable symbiotic N2fixation. Effects of soil fertility and defoliation on arrowleaf clover growth, tillering, nodulation and nitrogenase activity (C2H2reduction) were determined for a 3‐year period. Relative N2fixation as fertilizer N equivalence (FNE) was determined with a combination of arrowleaf and crimson clover (Trifolium incarnatumL.), interseeded with rye (Secale cerealeL.). Arrowleaf top growth, number of tillers, nodule mass, and nitrogenase (C2H2reduction) increased with defoliation and P, K, and Ca fertility treatments in 3 years of field experiments on a Port silt loam (fine, silty, mixed, thermic Cumulic Haplustoll). Phosphorus was the first limiting factor. Fertilizer N equivalence of arrowleaf alone was 50 kg N ha−1, with combined arrowleaf and crimson clover having an FNE of 89 kg N ha−1compared to NH4NO3fertilization for increased rye yield. Residual N fixed by the clovers increased subsequent monocultured rye yield equivalents to an FNE 111 kg N ha−1for arrowleaf clover alone and an FNE of 121 kg N ha−1for combined arrowleaf and crimson clovers.