bluuebunny/crossref_metadata_2025 huggingface dataset:
Ergopeptine Alkaloids in Grazed Tall Fescue
Authors: Belesky D. P. , Stuedemann J. A. , Plattner R. D. , Wilkinson S. R.
Published: July 2010

Endophyte (Acremonium coenophialum Morgan‐Jones et Gams) ‐infected tall fescue (Festuca arundinacea Schreb.) produces ergopeptine alkaloids (EP) that may be associated with fescue toxicosis symptoms in cattle (BOS taurus). A study was conducted during 1983 and 1984 at Watkinsville, GA, to determine the effects of endophyte infection, season, and N fertilization on EP concentration and steer average daily gain (ADG) in grazed 0.7‐ha tall fescue paddocks. Treatments included low (LF) and high (HF) endophyte infection frequency ‘Kentucky‐31’ (KY‐31) tall fescue fertilized with 134 or 336 kg N ha−1 (2✕2 factorial) replicated three times. The cultivars AU Triumph and Johnstone were also evaluated. Animals were managed using put‐and‐take grazing system. Ergopeptine alkaloid concentration (ergovaline was 80% of total) was greater in HF KY‐31 than LF KY‐31 in both years. Peak ergovaline concentrations occurred in spring and again in autumn (1984) when concentrations in HF KY‐31 approached 1 mk kg−1. Mid‐summer concentrations were about one‐third the autumn maximum for HF and LF KY‐31. Nitrogen fertilization had minimal effect on ergovaline concentration in the spring‐summer of 1983 but increased concentrations in LF KY‐31 in 1984. Ergopeptine alkaloids were not detected in endophyte‐free AU Triumph, and were detected in low amounts (< 0.1 mg kg−1) in a pre‐varietal release of Johnstone containing 7 to 10% endophyte. Increased ergovaline was associated with decreased ADG in the spring‐summer of 1983 and 1984; however, there was no significant association between ergovaline and ADG when the entire (April‐December) 1984 growing season was considered, suggesting that ergopeptine alkaloids may operate in conjunction with other environmental and nutritional factors to elicit fescue toxicosis symptoms.
Influence of Silt and Clay on the Physical Performance of Sand‐Soil Mixtures
Authors: Whitmyer R. W. , Blake G. R.
Published: July 2010

Small variations in component characteristics of materials used for soil mixtures for landscaped areas, such as sportsfields, sometimes result in unpredictable performance. The objective of this research was to determine the effect of variation in the relative amounts of silt and clay in soil mixtures having high sand content on soil physical properties of importance to mixture performance. Soil mixtures having sand contents ranging from 80 to 92% by weight and silt/clay ratios varying from 0.2 to 4.8 were formulated using seven soils. For 28 mixture combinations, determinations were made for shear strength, air‐filled porosity, saturated hydraulic conductivity, and hydraulic diffusivity. The extent and texture of particles migrating during saturated water flow were also determined. Sand content was the primary variable determining physical properties of the soil mixtures, the magnitude of measured differences being greater for variations in sand content compared to variations in the silt/clay ratio. Variations in the mixture silt/clay ratio did however result in significant differences in properties. As the silt/clay ratio increased from 0.2 to 4.8 in a soil sample having a sand content of 88%, shear strength decreased from 34 to 20 kPa (at a normal stress of 36 kPa), and air‐filled porosity increased from 12 to 24 m3/100 m3 (at a water potential of −2.9kPa). Saturated hydraulic conductivities and the volume of migrating particles increased as the silt/clay ratio increased at a given sand content.
Spring Establishment of Turf‐Type Tall Fescue Seed Crops with Cereal Companion Crops
Authors: Chastain T. G. , Grabe D. F.
Published: July 2010

Spring plantings of tall fescue (Festuca arundinacea Schreb.) for seed production are common in the Pacific Northwest, but seed yields are negligible in the year of planting. Planting tall fescue seed crops with cereal companion crops could increase the profitability of seed production. The purpose of this study was to determine the competitive effects of spring cereals on growth, seed yield, and economic return of turf‐type tall fescue. ‘Bonanza’ tall fescue was interplanted iin 45‐cm rows with ‘Waverly’ spring wheat (Triticum aestivum L.), ‘Steptoe’ spring barley (Hordeum vulgare L.), and ‘Cayuse’ spring oats [Avena fatua var. sativa (L.) Haussk.] in 15‐ and 30‐cm rows. Experiments were initiated in March 1985 near Corvallis, OR, and repeated in 1986. Cereals reduced the photosynthetic photon flux density (PPFD) available for tall fescue seedlings, which caused transient increases in chlorophyll content and reduced soil temperature by 1.8 °C. Soil water content was decreased by competition from cereals, causing greater stomatal resistance and lower transpiration rate. Reduction in PPFD and soil water by cereals was responsible for low tall fescue tiller and dry matter production. Following cereal harvest, tall fescue regrowth and new tiller initiation were delayed until spring as a consequence of competition with cereals, resulting in fewer fertile tillers and a 61% reduction in firstyear (after planting) seed yield compared with no companion crop. Tall fescue growth and seed yield were similar with all cereals, row spacings, and combinations of row spacings and cereals. Second‐year (after planting) seed yield was 15% greater when fescue was established with cereals than when no companion crop was used. Dry conditions caused low grain yield and increased competition by cereals, and was partly responsible for poor economic returns; however, fescue planted with spring oats earned $139.00 ha‐1 more than monoculture over a 3‐yr period because of compensatory increases in second‐year seed yield. This suggests that turf‐type tall fescue establishment with cereals could be more profitable in spring with irrigation or in fall when water is not limiting.
Nitrogen Economy and Canopy Carbon Dioxide Assimilation of Tropical Lowland Rice
Authors: Schnier H. F. , Dingkuhn M. , De Datta S. K. , Mengel K. , Wijangco E. , Javellana C.
Published: July 2010

Increased irrigated areas, availability of short‐duration modern rices (Oryza sativa L.) and herbicides, and increasing labor cost have motivated Asian farmers to shift from transplanting to direct seeding of lowland rice. Information on cultural requirements of direct seeded lowland rice in Asia is limited. Thus, two field experiments were conducted during the dry season on a Vertic Tropaquept soil to evaluate various cultural practices of direct seeded rice, and to compare the growth characteristics of direct seeded and transplanted rice. Direct seeding increased vegetative growth and shortened crop duration by more than 1 wk. Broadcast seeded rice gave the highest tiller number, followed by row seeded and hill‐wise dibbled rice. Relative tillering rate was significantly correlated with relative growth rate. Greater vegetative growth of direct seeded rice decreased tissue N concentration which in turn impeded sink formation. Grain yield of direct seeded rice was significantly correlated with spikelet number per panicle but not with panicle density, while the reverse trend was observed in transplanted rice. Band placement of fertilizer N gave significantly higher canopy CO2 assimilation rates and grain yield than did conventional fertilizer application methods in both direct seeded and transplanted rice. By increasing N availability to the plant, band placement allowed the use of a one‐third to two‐thirds N split application which increased plant N concentration during the reproductive stage, particularly in direct seeded rice. Leaf area index (LAI) was higher in direct seeded than in transplanted rice. Canopy photosynthesis was limited by LAI during the vegetative growth stage and by foliage N concentration during the reproductive stage.
Evaluating a Model for Predicting Nutrient Uptake by Rice During Vegetative Growth
Authors: Teo Y. H. , Beyrouty C. A. , Gbur E. E.
Published: July 2010

Since submerged soils create a unique chemical environment from which roots take nutrients, models that estimate nutrient uptake for upland crops may differ from those for rice (Oryza sativa L.). A mathematical model that had been used to predict nutrient uptake by corn (Zea mays L.), soybean [Glycine max. (L.) Merr.], and sorghum (Sorghum bicolor L.) was evaluated for predicting uptake by rice under flooded soil conditions. Our objectives were to evaluate such a model for rice and to conduct greenhouse and growth chamber studies to measure the soil and plant parameters required by the model. Sensitivity analyses were also conducted to determine the parameter most influencing N, P, and K uptake. Two soils (Crowley silt loam (Typic Albaqualfs) and Calhoun silt loam (Typic Glossaqualfs)] and three rice cultivars (Lemont, Katy, and Mars) were selected for this study. Linear regression of predicted vs. observed uptake for N, P, and K gave satisfactory fits to the data with R2 values of 0.48, 0.99, and 0.88, respectively. The slopes of the lines for predicted vs. observed uptake for N and K were 1.01 and 0.94, respectively, and the relationships did not depend upon either soil or cultivar. However, the prediction of P did depend on cultivar. The slopes of the lines for predicted vs. observed P uptake by Mars, Lemont, and Katy were 1.81, 1.08, and 1.02, respectively. The parameters most affecting N uptake were root growth rate, N concentration in the soil solution, and the half‐distance between root axes. However, parameters most influencing P and K uptake were root growth rate, root radius, and maximal influx rate.
Developing Guidelines for Replanting Grain Sorghum: III. Using a Plant Growth Model to Determine Replanting Options
Authors: Heiniger Ronnie W. , Vanderlip Richard L. , Williams Jeffrey R. , Welch Stephen M.
Published: July 2010

The adaptability of grain sorghum [Sorghum bicolor (L.) Moench] complicates decision making regarding the replacement of damaged stands. Our objective was to construct replanting guidelines for a broad range of situations by using a sorghum growth model to project yields for both original and replanted stands. Sorghum yields were simulated for 33 seasons for every combination of seven planting dates, six plant populations, and three hybrid maturity classes at three Kansas sites representative of Midwest sorghum producing areas. The outputs were tabulated to obtain yield distributions for both original and replanted crops. Net returns for replanting were calculated from yield differences, input costs, and harvest prices. Increases in both mean yields and net returns were associated with greater variability. The choices of replant timing, hybrid maturity, and planting density therefore depend on the grower's risk preferences. In western Kansas, an area with soils and climate representative of most of the Great Plains, risk‐neutral producers should replant with an early‐maturity hybrid at 50 000 plants ha−1 if the original population declines to less than 20 000 plants ha−1. In eastern Kansas, an area representing western Corn Belt sorghum production, replanting with a medium‐maturity hybrid at 200 000 plants ha−1 is a good option when a medium‐ or late‐maturity hybrid falls below 20 000 plants ha−1 or an early hybrid drops beneath 100 000 plants ha−1.
Direct Measurement of Arbuscular Mycorrhizal Phosphorus Uptake into Field‐Grown Winter Wheat
Authors: Schweiger P.F. , Jakobsen I.
Published: July 2010

The aim of the study was to measure hyphal P uptake by native arbuscular mycorrhizal fungi using a test system designed for field conditions. Phosphorus uptake by external hyphae of a native arbuscular mycorrhizal (AM) fungal community was studied in the winter wheat (Triticum aestivum L. cv. Stava) crop of an organic cropping rotation. Mesh containers containing a soil volume accessible only to external hyphae were buried in the ground. The soil inside these hyphal compartments (HCs) was labeled with 32P to distinguish P taken up from inside the HCs from overall P uptake. As an additional control treatment, half of the HCs received the fungicide carbendazim [methyl benzimidazol 2‐y carbamate] at a rate known to disrupt AM hyphal P uptake. Wheat tillers were harvested throughout the experimental period to monitor the time course of hyphal P uptake. Final harvest was at plant maturity, at which time the HCs were excavated and the soil inside was analyzed for hyphal length, NaHCO3–extractable P and specific activity of the extracted P. External hyphae of the native AM fungi grew into the HCs without added carbendazim and took up substantial amounts of P. Addition of carbendazim at a rate known to inhibit hyphal P uptake resulted in no P uptake from inside those HCs. This is due to the design of the HCs used in this study, which successfully prevented P uptake by plant roots and root hairs from inside the HCs. The HCs are therefore well suited for field measurements of plant P uptake via external hyphae of the native AM fungi. Estimates for length‐specific hyphal P uptake per unit time (37.8 ± 5.2 fmol P m−1 s−1) were similar to published estimates obtained in growth chamber studies with cultured isolates of AM fungi (1–430 fmol P m−1 s−1). The results of this study demonstrate the considerable contribution of native AM fungi to overall P uptake of field‐grown winter wheat, even at typical field soil fertility levels (28 μg NaHCO3–extractable P g−1 soil).
Evaluation of Tillage and Poultry Litter Applications on Peanut
Authors: Wiatrak P. J. , Wright D. L. , Marois J. J.
Published: July 2010

Detrimental levels of poultry litter (mixture of manure and bedding material) and concurrent effects of tillage need to be determined for peanut (Arachis hypogaea L.) production. Two field trials with ‘Georgia Green’ peanut were conducted in 2001 and 2002. The objective of the first study was to evaluate the influence of seven tillage treatments (chisel, conventional, disk, fall moldboard plow, moldboard plow + chiselvator, ripper bedder, and strip‐till) and three poultry litter applications (0, 4.5, and 9.0 Mg ha−1) before tillage. The objective of the second study was to evaluate four application timings (0, 1, 2, and 3 wk before planting) of high poultry litter rate (13.4 Mg ha−1) on peanut. In the first experiment, the application of 4.5 and 9.0 Mg ha−1 poultry litter decreased peanut yields in disk and moldboard plow + chiselvator treatments in both years. However, no detrimental effect of poultry litter was noted with 4.5 Mg ha−1 on treatment with fall moldboard plow or strip‐till. Due to tomato spotted wilt tospovirus severity, peanut yields were less with the application of 4.5 and 9.0 Mg ha−1 (1844 and 1643 kg ha−1, respectively) compared with treatment without poultry litter application (2037 kg ha−1) in 2002. In the second experiment, the least yield decrease was observed with high litter application at 1 wk before planting peanut (1059 kg ha−1) compared with control (1669 kg ha−1). These studies indicate that the detrimental effect of poultry litter may be reduced with less poultry litter (up to 4.5 Mg ha−1) applied to strip‐tilled peanut.
Pathology of Winter Injured Grasses and Legumes In Western Canada1
Authors: Lebeau J. B.
Published: July 2010

Winter killing of turfgrass and forage crops is seldom due to subzero temperatures alone but is also caused by desiccation or attack by psychrophilic fungi. In Western Canada snow mold is caused by an unidentified basidiomycete. Cold‐hardy varieties of turfgrass and forage crops were more resistant to this pathogen than non‐hardy varieties. Investigations on snow mold in Alberta showed that damage on turfgrass and alfalfa was consistently associated with accumulation of HCN in the host tissues. The effect of low temperature on cell permeability appears to be the important factor making a cyanogenic glycoside from the host available to beta‐glycosidase secreted by the fungus. Snow mold on turfgrass was controlled in southern Alberta by raising the temperature of the soil a few degrees during cold periods in the winter. Minimum temperatures were maintained in experimental plots by soil‐heating cables controlled by thermostats. The temperature required for control was critical. No snow mold was found in plots with minimum controlled temperature of 0 C. The grass grew slowly during the winter in these heated plots and was lush and green in the early spring. Regulation of temperature in conjunction with the application of fungicides should ensure complete protection of turfgrass from damage caused by psychrophilic pathogens. The extended use of this method will depend largely on the future cost of supplying heat energy.
Germination of Vicia Species and Interspecific Lines as Affected by Temperature Cycles1
Authors: Elkins D. M. , Hoveland C. S. , Donnelly E. D.
Published: July 2010

Temperature cycles of 4.5–21, 21–4.5, 21–32, and 32–21 C were used in germinating scarified and unscarlfied seed of vetch species and advanced generation interspecific hybrids.

The initial temperature of a cycle had marked effects on both the rate and final germination percentage of certain entries. Variation in response to temperature cycles was found between Vicia species and within V. sativa and V. angustifolia. Scarified seed of parents of the interspecific hybrids differed greatly; the V. sativa parent (Ala. 1894) germinated faster at high temperatures, whereas the V. angustifolia parent (P.I. 121275) germinated faster at low temperatures. The behavior of interspecific hybrid progeny indicated a recombination of genes that conditioned the physiological requirements for germination. Unscarified seed of V. grandiflora and an interspecific hybrid germinated more rapidly at low temperatures. Unscarified seed of another hard‐seeded species, V. angustifolia, responded in a reverse manner, germinating more rapidly at high temperatures. Germination response to temperature was found to be controlled by hard seedcoat in addition to a physiological response of the embryo.
Interception of Solar Radiation and Dry Matter Production by Various Soybean Planting Patterns1
Authors: Shibles R. M. , Weber C. R.
Published: July 2010

Solar radiation interception and dry matter production were studied in soybeans (Glycine max (L.) Merr.) grown in various planting patterns (4 populations of 26, 52, 104, and 209 thousand plants per acre within each of 4 row widths – 5, 10, 20, and 40 inches).

Increased population resulted in increased leaf area index (LAI) and a reduction in the number of days from emergance to 95% (daily basis) solar radiation interception (D95). At corresponding populations of 52,000 or above, D95 was considerably higher for the 40‐inch row pattern than for the other spatial arrangements, which differed in reaching D95 by only a few days.

Dry matter production was a functin of percent solar radiation interception regardless of planting pattern. However, the efficiency of utilization of intercepted energy differed between years for the mean of all treatments, and was significantly lower for the 208,000 plant population in 1962. These differences were attributed to a limitation imposed by moisture stress.

Seed yield was not correlated with total dry matter produced, dry matter produced during seed formation, or solar radiation intercepted. As determined by differences in harvest index, seed yield was a function of differential utilization of photosynthate between vegetative and seed production. In general, high population or close plant spacing in any one direction tended to result in a low harvest index. Thus, while full interception during seed formation is required for maximum seed yield, conditions resulting in a high seasonal interception may not result in highest seed yield.
Quantitative Presentation of the Systematic Relationships Among Twenty‐one Sorghum Species1
Authors: Liang George H. L. , Casady A. J.
Published: July 2010

Twenty‐one species in the subsection ArundinaceaS nowden, subgenus Eu‐Sorghum Stapf, genus Sorghum Moench, were studied to obtain the pattern of interspecific variation. A statisical taxonomic method which employs numerous but unweigbted characters was used to derive the quantitative index of affinity between any two species. The indices of association then were exploited in establishment of a diagram suggestive of phylogenetic relationships.

A tree‐like diagram was constructed from between species correlations and the resultant correlation matrices. The diagram shows the interspecific relationship amongth e species studied, and indicates that the species may be divided into three series consisting of 14, 6, and 1 species, respectively.
Tillering and Carbohydrate Contents of Orchardgrass as Influenced by Environmental Factors1
Authors: Auda Hamid , Blaser R. E. , Brown R. H.
Published: July 2010

Three experiments were conducted in the greenhouse and environment chambers to study effects of nitrogen rates, light intensity, daylength, temperature, and defoliation, and their interrelationships on tillering, growth, and water‐soluble carbohydrates in orchardgrass. Tillering, growth, and carbohydrates increased as light intensity was increased from 25% to normal sunlight. Tillering was associated with light energy rather than photoperiod. Extending the photoperiod with low light intensity reduced tillering, but not carbohydrates.

Tillering and growth was low at 50 to 60 F as compared with 70 to 80 F night‐day temperatures; carbohydrates were much higher for the lower temperature, this was attributed to rapid carbohydrate utilization at the higher temperature.

Tillering and plant weights increased as defoliation was relaxed. Such improved tillering was attributed to more carbohydrates in stubble bases where new tillers formed. Root growth trends were similar to those for tillering.

Nitrogen stimulated tillering and growth, which lowered carbohydrates. Root weights decreased with added nitrogen.

The single order interactions of the factors mentioned above on tillering and carbohydrates were generally significant. High tillering appeared to be associated with factors that have potentially high photosynthesis and carbohydrate storage, but environmental factors must also favor rapid growth and utilization of carbohydrates in a dynamic biological system.
Inbreeding Depression in Diploid, Tetraploid, and Hexaploid Crested Wheatgrass1
Authors: Dewey Douglas R.
Published: July 2010

The effects of inbreeding on vegetative vigor and fertility were evaluated on 2 diploid, 164 tetraploid, and 30 hexaploid S1's progenies of crested wheatgrass represented by 252, 13,770, and 1,543 plants, respectively. Forage yields of S1 progenies averaged 64.1, 49.6, and 32.6% of comparable O.P. progeny yields in the diploid, tetraploid, and hexaploid populations, respectively. Open‐fertility of diploid, tetraploid, and hexaploid S1 progenies averaged 47.8, 57.9, and 31.0%, respectively, of that of their O.P. counterparts. Mean self‐fertility of S1 diploids and tetraploids was not reduced by one generation of selling; however, self‐fertility of hexaploid S1s was 23.1% of that of the O.P. plants. The effect of inbreeding on forage yield and self‐ and open‐fertility was highly variable from progeny to progeny within each population. The tetraploid and hexaploid populations suffered much greater inbreeding depression than was expected on the basis of the theoretical approach to homozygosity associated with selling in autoploids. The severe inbreeding depression of the tetraploid and hexaploid populations was attributed to chromosome abberations that accumulate in species buffered by autoploidy. Relatively self‐fertile progenies were found at each ploidy level. The most self‐fertile diploid, tetraploid, and hexaploid progenies averaged 5.0, 22.3, and 29.6 self seeds per spike, respectively. Self‐fertile populations of diploid, tetraploid, and hexaploid crested wheatgrass can apparently be obtained by simple selection procedures.
Death of Smooth Bromegrass (Bromus inermis Leyss.) on Organic Soil1
Authors: Myhr K. E. , Tesar Milo B. , Davis R. A. , de Zeeuw D. J.
Published: July 2010

Investigations were conducted in the field and under controlled conditions to determine why smooth bromegrass dies on organic soil during the growing season and its reaction to fungicide treatments and irrigation.

Isolations of fungi from decayed bromegrass roots in the field show that Fusarium spp. are frequent and, apparently, harmful parasites in muck soil.

Fusarium poae was particularly identified with killing of Lincoln bromegrass roots under controlled conditions. Pythium spp. appeared to be associated with similar, but lesser, injury.

Dying of Lincoln bromegrass in the field was detected in the third cutting near the end of the first harvest year.

Dexon fungicide, selected for its specific action against Pythium spp., only partly reduced dying of roots because the fungicide was ineffective against Fusarium spp. Dexon improved Lincoln bromegrass yields on irrigated plots in the third cutting and stands after the end of the first year in the field.

Yields of bromegrass in the field were reduced approximately 18% as a result of relatively heavy irrigation on a muck soil.
Estimating Harvest Date of Corn in the Field1
Authors: Schmidt J. L. , Hallauer Arnel R.
Published: July 2010

Moisture data for 12 years from the period 1940 to 1963 were summarized to determine the relation between kernel moisture and time. The rate of kernel moisture reduction was determined for five arbitrary moisture phases and used to predict when specified moisture levels would be attained from pollination date. Correlation studies were made between rate of kernel moisture reduction and four weather factors (air temperature, saturation deficit, wet bulb depression, and relative humidity).

The average daily rates of kernel moisture reduction varied considerably from year to year within the five phases of corn growth. Above 30% kernel moisture content the rate of moisture reduction was significantly related to the temperature of the air. Below 30% kernel moisture the reduction rate was significantly related to saturation deficit, wet bulb depression, and relative humidity of the air.

A curve, along with a 95% confidence band, was constructed to show the average number of days for corn to go from pollination to a given kernel moisture.
Carbohydrates in Grasses. I. Sugar and Fructosan Composition of the Stem Bases of Several Northern‐Adapted Grasses at Seed Maturity1
Authors: Smith Dale , Grotelueschen R. D.
Published: July 2010

Extraction of the stem base tissue of timothy, orchardgrass, and redtop at near seed maturity with concentrations of ethanol from 95 to 0% yielded steadily increasing percentages of carbohydrates, indicating a series of fructosans of increasing chain length. Reed canarygrass and Kentucky bluegrass tissue also yielded increasing percentages, but not continuously so. Fructosans in all of the above species were predominantly of long‐chain length. Bromegrass,t all rescue, ryegrass, and quackgrass tissue yielded no additional carbohydrate at low ethanol concentrations, indicating that the fructosans present were relatively short‐chain polymers.

Concentration of the ethanol must be considered in separating free sugars from low molecular weight fructosans, or otherwise some of the fructosans may De extracted along with the sugars. Thin layer chromatography showed that 85% ethanol was the most suitable concentration with which to extract the free sugars from the fructosans in those species containing predominantly long‐chain fructosans. With the species containing predominantly short‐chain fructosans, 90% ethanol was most suitable. More dilute ethanol solutions extracted short‐chain fructose polymers along with the glucose, fructose, and sucrose.

Glucose, fructose, and sucrose constituted only a small part of the total water‐soluble carbohydrates in all of the grass species. Fructosans were the predominant carbohydrates.
Directed Effects of Environment on Populations of Small Grain Varieties1
Authors: Grafius J. E.
Published: July 2010

Evidence was presented that the effect of environmental stress on a population of oat (Avena sativa L.) and barley (Hordeum vulgate L.) varieties is directed. if random subsets are drawn from a population, then it is expected that the subsets will respond to stress in a similar manner.I t appears, on the basis of limited evidence, that nonrandom subsets will also respond to stress in a similar way, providing the various subsets are not too divergent. Just how great a divergence is permitted before the subsets react differently can probably only be determined by tests. In the case of oats, varieties from Europe, Canada, and northern USA, and from the Corn Belt reacted in a similar manner, indicating a directed effect of environmenot n the subsets.

Subsets drawn from a barley population in a nonrandom manner showed diverse reaction in the case of a split into 6‐row and 2‐row groups. But when a nonrandom split of the 2‐row group into an early and late subset was made, fair agreement between the subsets in their response to environmental change was observed for several traits.

If a directed impact of environment on moderately divergent subsets, such as the change in breeding populations over a period of time, can be demonstrated it will be a means of establishing meaningful genetic correlations. These correlations would be a measure of constancy of a trait at a location over a period of years and would be of use in selection and prediction. It is expected that the hypothesis will apply more to polygenic traits than to traits such as rust resistance.
Comparative F2 and F3 Fertility in Partially Sterile Rice Hybrids
Authors: Jennings Peter R.
Published: July 2010

The association of fertility in the F2 and F3 of three indica ✕ japonica rice hybrids, having disparate degrees of sterility, was studied in relation to the effectiveness of early selection for fertility. As the results indicated a direct parent‐progeny association of fertility among the first three plant generations, it was concluded that early selection for fertility is desirable and effective in wide crosses. Breeding behavior in the F3 suggested the extreme complexity of intervarietal hybrid sterility.
Observed and Expected Response in Four Selection Experiments in Maize1
Authors: Moll R. H. , Robinson H. F.
Published: July 2010

Full‐sib family selection is being conducted in three populations of maize; viz. a hybrid population derived from a cross of inbred lines and two populations which are open‐pollinated varieties. Reciprocal recurrent selection is being conducted in the crossbred of the varieties. The results of the first several cycles of selection are compared with expectations based on estimates of variances.

There is good agreement between observed and expected selection response of the primary trait, yield, in three of the four experiments. Number of ears per plant showed a reasonably consistent increase associated with selection for high yield. Correlated responses of two other traits, ear height and days to tassel, were less consistent and generally in poor agreement with expectation.

Reciprocal recurrent selection for crossbred performance and full‐sib family selection for purebred performance were compared in their effectiveness for improving both purebred and crossbred performance. After 3 cycles of selection, it appears that full‐sib family selection was at least as effective as reciprocal recurrent selection in improving crossbred performance.
Inheritance of Plant Height, Yield of Grain, and Other Plant and Seed Characteristics in A Cross of Hard Red Winter Wheat, Triticum aestivum L.1
Authors: Johnson V. A. , Biever K. J. , Haunold A. , Schmidt J. W.
Published: July 2010

The inheritance mechanisms of seven plant and seed characters were studied in the F1, backcrosses and segregating generations from the cross of two winter wheat varieties differing in plant height and other characteristics.

Evidence for the control of plant height by three major gene pairs was obtained. Additive gene action accounted for most of the plant height variance. Maturity was controlled by a single dominant gene pair for earliness. A bimodal F2 frequency distribution for kernel weight indicated operation of a relatively few genes. Heterosis for high yield was evident. The 4380‐pounds‐per‐acre yield of the F1 exceeded the most productive parent by 12.9%. Heavy kernel weight and, to a lesser extent, number of spikes per plant contributed to the high yield of the F1. The genetic expression of spike length and number of rachis internodes was completely additive.

Heritability percentages for plant height, spike length, maturity, and kernel weight were sufficiently high to indicate that selection in the F2 for these traits could be effective. Selection for number of rachis internodes, number of tillers, or grain yield would be ineffective. Plant height was significantly correlated with kernel weight, spike length, maturity, grain yield, number of spikes per plant, and number of rachis internodes.
Outcrossing of Oat Plants (Avena sativa L.) Grown from Mutagen‐Treated Seeds1
Authors: Grindeland R. L. , Frohberg R. C.
Published: July 2010

The percent of outcrossing on oat plants from untreated and mutagen‐treated seeds was determined from four experiments. The mutagens used were thermal neutrons and ethyl methanesulfonate.

The year‐to‐year percent outcrossing varied from 2.4 to 6.0 in the mutagen‐treated populations and 0.5 to 2.4 in the checks. The mean outcrossing percents for all experiments were 4.0 and 1.4, in the mutagen‐derived and check populations, respectively. Both mutagens, when applied in proper dosages, were equally effective in causing outcrossing.
Production of F1 Seed in Castorbeans by Use of Sex Genes Sensitive to Environment1
Authors: Zimmerman L. H. , Smith J. D.
Published: July 2010

By growing castorbeans, Ricinus communis L., in different environments, genotypes were obtained with both the N‐pistillate gene ƒ for female racemes and environmentally sensitive genes for interspersed‐staminate flowers. These genotypes were homozygous for the ƒ gene, but not always for the genes for interspersed‐staminate flowers. With penetrance of the genes for interspersed‐staminate flowers at a location having high summer te~nperatures, a July average of 91 F, plants were propagated by selfing or sibbing. With nonpenetrance at locations having lower summer temperatures, July averages of 75 to 83 F, F1 hybrid seed was produced without roguing. Previous methods using the ƒ gene required roguing monoecious plants from the female parent, often involving more than 50% of the plants.

In test crosses, presence of interspersed‐staminate flowers was recessive to absence. There was wide variation among genotypes tested for frequency of interspersed‐staminate flowers, suggesting a polygenic system with considerable opportunity for selection.
Development and Selection of Productive S1 Inbred Lines of Corn (Zea mays L.)1
Authors: Genter C. F. , Alexander M. W.
Published: July 2010

Two recurrent selection series, originating from the same 153 S1 lines, were carried through two complete cycles. Selection was based on testcross yield in one series and on S1 progeny yield in the other. The mean S1 yield increased 31.4% with 2 cycles of selection for S1 yield and 17.9% with 2 cycles of selection for testcross yield. The more productive S1 lines tended to produce the more productive crosses, but the correlation between S1 and testcross yields decreased with each cycle of selection. Four S1 lines from the second cycle synthetic of the series selected for progeny yield were more productive than the original cross‐pollinated population. In a second experiment, lines that were derived from the more productive S1 progenies were most frequently maintained under visual selection. Nine of the 10 S1 lines that were still represented after selection in S3 progenies were above average in yield. Seven of the 31 S1 lines that were still represented after selection in S2 progenies produced testcrosses which ranged from 105 to 110% of the trial mean and 6 of these 7 were above average in S1 yield.
Location of Genes Conditioning Resistance in Corn to Leaf Feeding of the European Corn Borer1
Authors: Scott Gene E. , Dicke F. F. , Pesho G. R.
Published: July 2010

Chromosomal interchanges were used to determine which chromosome arms of resistant corn inbreds, C.I.31A and B49, carry genes for resistance to European corn borer leaf feeding. All corn plants were infested manually with corn borer egg masses in field studies conducted in 1961 through 1964.

Resistant inbred C.I.31A was found to possess a gene or genes contributing to resistance on the short arm of chromosomes 1, 2, and 4, and on the long arm of chromosomes 4 and 6. Resistant inbred B49 appears to have genes for resistance on these same chromosome arms (possibly allelic to those of C.I.31A) plus an additional gene for resistance on the long arm of chromosome 8.
Transfer of Resistance to Erysiphe graminis f. sp. tritici from Khapli Emmer and Yuma Durum to Hexaploid Wheat1
Authors: Briggle L. W.
Published: July 2010

‘Khapli’ emmer is resistant to those cultures of Erysiphe graminis f. sp. tritici with which it has been inoculated. ‘Yuma’ durum, which had Khapli as one parent, is resistant to the same E. graminis tritici cultures. Both Khapli and Yuma are tetraploids.

A dominant gene for resistance to the powdery mildew fungus, herein designated as Pm4, has been transferred from Khapli into the genetic background of the hexaploid wheat variety Chancellor. The new line of Chancellor (Khapli ✕ Chancellor8) is homozygous for resistance and appears identical to Chancellor in morphological characters.

A dominant gene for resistance to E. graminis tritici has been transferred from Yuma into Chancellor. Present evidence indicates that this gene is identical with that in Chancellor from Khapli.

The gene from Khapli (Pm4) has been shown to be at a locus different from Pm1, Pm2, and Pm3.
Three Loci in Wheat Involving Resistance to Erysiphe graminis f. sp. tritici1
Authors: Briggle L. W.
Published: July 2010

With the advent of high yielding, strong straw, semi‐dwarf varieties of wheat, growers have increased rates of fertilizer, particularly nitrogen, and are producing more wheat under irrigation. Consequently, losses caused by Erysiphe graminis tritici have increased. Breeding for resistance is the only practical means of control.

Of 23 resistant varieties or selections studied, 11 apparently had in common a gene designated Pml (formerly Ml1). Four had Pm2 (formerly Mlu) and eight had Pm3 (formerly Mls, Mla, or Mlc). Some varieties or selections within each group could be differentiated by appropriate Erysiphe graminis f. sp. tritici cultures. Either a series of multiple alleles occurred at each of the three loci or other genes for resistance were present but not revealed by cultures 3, 22, and 27. Additional tests designed to establish or refute presence of multiple alleles are underway.

Data from intercrosses between varieties or selections representing the three loci indicate independence of genes for resistance.

A multiple allelic series presents restrictions on combining specific genes for resistance under conventional breeding methods. Utilization of two alleles simultaneously is possible with hybrid wheat.
Factors Affecting Foams with Forage Legumes1
Authors: Kendall W. A.
Published: July 2010

Foam production in vitro with red clover leaves and milk protein was inhibited by tannins, and this inhibition was overcome by polyvinyl pyrrolidone (PVP). PVP enhanced foam production of lespedeza, trefoil, and crownvetch. Large volumes of foam were also obtained at relatively high pH values with lespedeza and trefoil samples, but not with crownvetch.
Factors Involved in Seed Production of Red Clover Clones and Their Polycross Progenies at Two Diverse Locations1
Authors: Taylor Norman L. , Dade Eugene , Garrison C. S.
Published: July 2010

To assess the role of differential seed‐producing capacity as a factor in genetic shifts during seed multiplication, we examined seed production of red clover (Trifolium pratense L.) clones and their progenies at Lexington, Ky., and at Prosser, Wash.

Number of heads was the primary factor in governing seed yields per clonal plant. Number of seeds per head and seed weight were of less importance within each of the locations.

Clonal and progeny seed yields within and between locations were not correlated. Significant correlations indicated that, at Prosser, early clones produced the most heads and the highest seed yields. Progenies of these clones also produced the highest seed yields. Some evidence suggested that the high yielding progenies were also earlier than average to flower. Although this earliest to flower‐high seed yield relationship was not significant at Lexington, we inferred that it might have been present if seed had been harvested throughout the season rather than from only the regrowth following the harvest of the first crop as hay.

This work suggests that the higher seed production by early clones could account for some of the shifts found when red clover seed is multiplied. This indicated the need for further investigation of this possible relationship and the effect of different management practices on natural selection for undesirable forage characteristics.
Evaluation of Reserve Carbohydrates in Midland Bermudagrass (Cynodon dactylon L.)1
Authors: Burris J. S. , Brown R. H. , Blaser R. E.
Published: July 2010

Midland bermudagrass was grown at 35 and 30 C day and night temperatures with 300 and 30 pounds of nitrogen. The rhizomes were harvested at 7‐day intervals and reserve carbohydrates determined by 0.2 N H2SO4, 2% H2SO4, taka‐diasl:ase, alpha‐amylase, and perchloric acid extractions

The glucose extracted by either acid or taka‐diastase was compared with starch extracted by alpha‐amylase. It was found that at the 5% level the glucose extracted by 0.2 N H2SO4 and taka‐diastase was the same as the starch; while the 2% H2SO4 was higher. This correlation may not be applicable to other studies or other plant materials where weak structural materials may contribute glucose to the acid extractions.
Carbohydrates in Grasses. II. Sugar and Fructosan Composition of the Stem Bases of Bromegrass and Timothy at Several Growth Stages and in Different Plant Parts at Anthesis1
Authors: Smith Dale
Published: July 2010

The predominant fructosans in timothy varied in molecular weight with growth stage and plant part. At mature growth stages when the water‐soluble carbohydrate content was high, a series of fructosans was present in the stem bases and they were predominately of longchain length. Only short‐chain fructosans were found in the stem bases during periods of active vegetative growth when water‐soluble carbohydrates were low. Timothy plants at anthesis contained only short‐chain fructosans in the inflorescence, leaf blades, and in the upper sheaths and internodes, but the lower sheath, internodes, and roots contained predominately long‐chain units. Fructosans were of short‐chain length in all comparable samples of bromegrass. The chain lengths of fructosans were relative determinations based on their differential solubility in various elhanol concentrations and water.

The percentages of total free sugars, fructosans, and total water‐soluble carbohydrates in bromegrass at anthesis increased from the top to bottom leaf blade, sheath, and internode above the stem base. Such a gradient was noted only among the internodes of timothy for the later two fractions.

At anthesis, the stem (internodes plus the stem base) of both species contributed the largest proportion of the grams of total dry matter and total water‐soluble carbohydrates in the tillers, followed by the inflorescence. The contributions of the leaf blades atid sheaths were least and similar.
Mitochondrial Activity in Germinating New and Old Soybean Seeds1
Authors: Abu‐Shakra Salah S. , Ching Te May
Published: July 2010

Mitochondria isolated from dark‐grown seedling‐axes of new and old soybeans exhibited differential phosphorylative efficiency when identical cofactors and substrate were provided. The P/O ratio of mitochondria from aged material was 40 to 70% of the new material. Oxygen uptake per unit weight of mitochondrial nitrogen in aged material was 110 to 140% of the new seed.

Addition of serum albumin increased P/O ratio for both materials; sodium fluoride slightly unproved P/O ratio of the new material but had no influence on the old material; and 2,4‐dinitrophenol at 10−3M reduced P/O ratio of both materials and supressed oxygen uptake of the old material.

Experimental data indicated that mitochondria from aged seed seems to be endogenously uncoupled and the uncoupling is not due to loss of fatty acids or exogenous ATPase activity. Electron micrograph of the mitochondrial pellets showed a very dense matrix in the mitochondria of germinable but old seeds.
Genotype ✕ Environment Interactions in the Regional Testing of Soybean Strains1
Authors: Schutz W. M. , Bernard R. L.
Published: July 2010

Estimates of genotype ✕ environment interactions were obtained from seven regional Uniform Soybean Tests grown in 1954‐56. All of the second order and nearly all of the first order interactions were significantly different from zero at the .05 level of probability. Estimates of the genotype ✕ year interactions were generally smaller than estimates of the genotype ✕ location interactions but in practice will have a greater effect on the error variance of a line mean, since testing over a long period of time is seldom done.

Evidence was cited to suggest that locations may be effectively substituted for years in regional tests to permit a rapid turnover of breeding material and that data from 10 to 15 locations in a single year should be sufficient to eliminate low‐yielding strains.
Effects of Shade Applied at Different Stages of Plant Development on Corn (Zea mays L.) Production1
Authors: Early E. B. , McIlrath W. O. , Seif R. D. , Hageman R. H.
Published: July 2010

The effects of reducing the amount of sunlight at the vegetative, reproductive, and maturation phases on the morphology, grain yield, and chemical composition was determined for two corn hybrids.

The shade treatments exerted significant reductions inall components measured except those established prior to initiation of treatment. Shading for 21 days during the reproductive phase was more detrimental to grain production per plant than shading for longer periods during vegetative and maturation phases. When shaded at 60, 70, and 80% during the vegetative or reproductive phase, Hy2 ✕ Oh41 produced more grain per plant than WF9 ✕ C103, while the reverse was true during the maturation phase. The hybrids exhibited a differential response to shade treatments only during the vegetative phase. With respect to number of kernels and grain yield, shading during the vegetative phase was more detrimental to WF9 ✕ C103 than Hy2 ✕ Oh41 while the reverse was true during the reproductive phase. During maturation the reduction in grain protein was not proportionally as great as the reduction in grain yield for both hybrids.

Extensive vegetative growth during the first 54 days was not a prerequisite for a high grain yield per plant. These observations provide an explanation for the frequent failure of starter fertilizers to enhance grain yield and suggest management practices that might produce higher yields.

Plants shaded at 60% or higher during the reproductive phase had a full complement of normal leaves, but initiated and developed only a limited number of kernels. Weight per kernel and stover weight per plant at the end of the season were less than that of the control plant. Since these leaves were exposed to full sunlight from August 8 to the end of the season, they must have been essentially nonoperative during this period.