bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Light Quality and Temperature on Fe3+ Reduction, and Chlorophyll Concentration in Plants1
Authors: Brown J. C. , Cathey H. M. , Bennett J. H. , Thimijan R. W.
Published: July 2010

Plant species differ in their response to light; some grow best in full sunlight, some in partial shade, and others in full shade. Inside, under growth chamber conditions, cool white fluorescent (CWF) lamps, in combination with supplemental incandescent (Inc) lamps, have been a satisfactory light source. Low pressure sodium (UPS) lamps have also been used. The spectral radiant power curve for the CWF lamps extends from 350 (includes UV and blue) to above 700 nm, whereas the spectral curve for LPS lamps is between 560 to 610 nm (no UV or blue) with no radiation below 550 nm. This study was conducted to determine affect of LPS and CWF lamps, alone and in combination with Inc lamps, on plant growth and reduction of Fe3+ to Fe2+. Lettuce (Lactuca saliva L. ‘Grand Rapids’), cotton (Gossypium hirsutum L. ‘M8’) and petunia (Petunia hybrida Vilm. ‘Pink Cascade’) were grown in environmental control cabinets at 22 and 28 C under LPS or CWF lamps, with and without Inc lamps. Reduction of Fe3+ to Fe2+ was determined as Fe2+ ferrorine [disodium salt of 3‐(2‐pyridyl)‐ 5,6‐bis(4‐phenylsulfonic acid‐l,2,4‐triazine] in solution under all light treatments to determine if chlorophyll concentration in plant tops was related to Fe3+ reduction in solution. We had observed that cotton was chlorotic under LPS, but not under CWF lamps. Only small amounts of Fe3+ were reduced to Fe2+ at wavelengths above 420 nm, and more Fe3+ was reduced to Fe2+ in solution under CWF than under LPS lamps. Chlorophyll concentration in lettuce and cotton leaves followed about the same pattern as Fe3+ reduced to Fe2+ in solution. Chlorophyll levels were greater in leaves grown under CWF than under LPS lamps, and generally greater in leaves grown at 28 than at 22 C. If we assume that CWF light mediates reduction of Fe3+ to Fe2+ in plant foliage as it does in ferric‐ferrozine solutions then it could make Fe2+ available for biochemical reactions related to chlorophyll synthesis. Petunia did not respond to the light regimes and temperature as did lettuce and cotton.
Residual Effects of MSMA on Sterility in Rice Cultivars1
Authors: Gilmour J. T. , Wells B. R.
Published: July 2010

In a study conducted in 1975, sterility in rice (Oryza sativa L.) cultivars grown on Crowley silt loam soil (Typic Albaqualf) amended with monosodium methanearsonate (MSMA) increased as cultivar susceptibility to straight‐head increased. A midseason drain and dry treatment was found to decrease MSMA induced sterility. This study was a continuation of the experiment initiated in 1975 to evaluate the residual effects of the 1975 MSMA application on rice growth and yield 2 and 4 years later for two water management schemes. Two rice cultivars (‘Lebonnet’ and ‘Nova 76’ or ‘Mars’) of different straighthead resistance were grown in rotation with ‘Lee 74‘ soybean (Glycine max L. Merr.). Two years after application of MSMA, sterility and decreased yield were observed under continuous flood for the 11.2 kg arsenic/ha rate with the straighthead susceptible cultivar (Nova 76) being damaged more severely. No damage was found at this arsenic (As) rate for the midseason draining and drying treatment, a common straighthead control practice, or for either water management at the 1.1 kg As/ha rate. Four years after MSMA application, no sterility or yield reduction were noted in any treatment. These data suggest that where rice production is desired on a silt loam soil previously treated with MSMA crop rotation, in addition to cultivar selection and water management, could be used to minimize yield loses due to sterility.
Effects of Tillage Practices on Soil and Wheat Spectral Reflectances1
Authors: Aase J. K. , Tanaka D. L.
Published: July 2010

The objective of the study, which was located on a Williams loam soil (fine‐loamy, mixed Typic Argiborolls) near Sidney, Mont., was to attempt to discriminate by reflectance determinations among varying degrees of wheat (Triticum aestivumL.) stubble and crop growth covering the soil surface. Spring and winter wheat were seeded no‐till (NT) into standing spring wheat stubble and after one tillage operation on stubble‐mulch fallow and on bare soil. Also included in the study were bare fallow, stubble‐mulch fallow, and chemical fallow. A handheld radiometer With bandpass intervals similar to those of the multispectral scanner aboard Landsat was used to measure radiances from the plots. Reflectances were calculated as the ratio of plot radiance to the radiance from a barium sulfate plate. Reflectance differences among fallow treatments were not consistent throughout the season, and it is questionable whether, with present techniques, we can discern among fallow treatments. Wheat that was seeded NT into standing stubble and wheat that was seeded after one tillage operation could be detected and separated from soil readings as early as wheat seeded on bare fallow. Sparse crop growth during a drought year could not be separated from soil background. The relationship between green leaf dry matter (DM) and IR/Red ratio suggests that reflectance measurements may substitute for manual measurements of green leaf DM.
Effect of Furrow Diking, Subsoiling, and Slope Position on Crop Yields1
Authors: Gerard C. J. , Sexton P. D. , Conover D. M.
Published: July 2010

The effects of furrow diking and subsoiling on runoff and crop yields were evaluated on gently sloping land in the Rolling Plains of Texas. Diking and subsoiling reduced runoff and significantly increased yields of sorghum [Sorghum bicolor (L.) Moench] and cotton (Gossypium hirsutum L.). Yields of diked sorghum and cotton were 108 and 32% higher than the check, respectively. Yields of sorghum on the diked treatments on an Abilene loam soil (fine, mixed, thermic Pachic Argiustoll) averaged about 2550, 3300, and 3590 kg/ha or about 302, 140, and 42% more than the check treatment on the upper, middle, and lower parts of the slope, respectively. In contrast, cotton yields on the diked treatment on a Miles fine sandy loam soil (fine‐loamy, mixed, thermic udic Paleustalf) averaged about 465, 515, and 475 kg/ha or about 57, 37, and 11% more than the check on the upper, middle, and lower parts of the slope, respectively. Response to subsoiling varied with years and crops. Results show that a determinant crop such as sorghum is more critically affected by loss of water due to runoff than the less determinant cotton crop. These studies show that furrow diking is effective in reducing runoff and increasing crop yields and that location on the slope has a significant effect on yields.
Sweet Potato Response to K and P Fertilization1
Authors: Nicholaides J. J. , Chancy H. F. , Mascagni H. J. , Wilson L. G. , Eaddy D. W.
Published: July 2010

Limited literature is available to provide recommendations of K source and rate and P rate for sweet potato [Ipomoea batatas (L.) Lam.] production. Many growers, therefore, continue to use the more expensive sulfate (SO4) source of K rather than chloride (Cl) and higher than recommended rates of K and P. Accordingly, on‐farm experiments were conducted during 3 years on North Carolina Paleudults to determine effects of K source and rate and Prate on sweet potato yield, grade, and quality. Potassium sources were KCl and K2S04. Fertilization rates of K varied over the five K experiments and depended on initial soil test levels which ranged from 0.04 to 0.12 cmol K L−1 by Mehlich‐I extractant. In the three P experiments, the various P rates were also dependent upon the initial soil test levels which ranged from 11 to 30 mg P L−1 also by Mehlich‐I extractant. As K source had no effect on yield, grade, or quality, it was concluded that the higher Cl concentrations, up to 22.8 g kg−1, in vegetative tissue with increasing KCl rates had no detrimental effect on sweet potato yield, grade, or quality. Total yield response to K applications was obtained where soil test K levels were ≤ 0.08 cmol L−1, although no. 1 yields increased only where soil test K levels were ≤ 0.05 cmol L−1. Phosphorus applications had no effect on yield, grade, or quality of sweet potato.
Growth, Development, and Thebaine Content of Papaver bracteatum Lindl. in Relation to Spacing1
Authors: Bare C. E. , Coffman C. B. , Gentner W. A.
Published: July 2010

Papaver bracteatum Lindl. is being investigated as an alternate source of the alkaloid thebaine, an industrial precursor of codeine and other analgesics. The effects of 0.15‐, 0.30‐, and 0.60‐m spacing on the growth, development, and thebaine content of P. bracteatum were investigated in the field on an Elkton silt loam (clayey, mixed, mesic Typic Ochraquult). The experiment was conducted for 2 yr at Beltsville, MD, using germplasm from the UNB‐4 collection from Iran. All treatments were replicated five times. Intraspecific competition greatly reduced plant growth and development at the 0.15‐m spacing, and, as a result, the number of flowering plants was reduced 75% in the second year relative to the first year. Second‐year increases were noted in capsule number and dry weight yield for both the 0.30‐ and 0.60‐m spacings, with the most capsules per plant for the 0.60‐m spacing. However, yield of phytomass per hectare was 130% greater for the 0.30‐m spacing than for the 0.60‐m spacing. Thebaine production per hectare for the duration of this investigation was highest for the 0.30‐m‐spacing treatments and lowest for the 0.15‐m treatment. Optimum spacing of P. bracteatum plants may be a function of the time plants are permitted to grow.
Responses of Maize to Plant Population Density. I. Canopy Development, Light Relationships, and Vegetative Growth
Authors: Tetio‐Kagho F. , Gardner F. P.
Published: July 2010

Understanding of maize (Zea mays L.) canopy structure and light transmission over a wide range of plant population densities (PPD) is necessary in the formulation of maize intercrop associations. Experiments using a systematic (fan) design were conducted on Lake fine sand (hyperthermic, coated Typic Quartzipsamments) at Gainesville, FL (29°38′N), in 1985 and 1986 to assess the interrelationships among maize canopy structure, light interception, and vegetative growth over 15 PPD (0.8 to 15.4 plants m−2). Fractional light transmission (by canopy levels at different times up to noon), leaf area index (LAI), total dry matter (TDM) yield, plant height, and tiller number were recorded. Light interception was similar at 5 and 3 h before and at solar noon for each PPD measured at ground, ear, and below‐tassel levels. Leaf area and light interception were highly concentrated at ear level, but level of light interception shifted upward with increasing PPD. Maxima LAI were 1.7, 2.6, and 4.0 at tasseling for the 1.7, 2.6, and 6.3 plants m−2 respectively. Light interception by tassels was approximately 2, 30, and 40% for 1.9, 3.5, and 6.3 plants m−2, respectively, while that for whole canopy was 75, 90, and 97%, respectively. As early as 35 d after planting (DAP) canopy interception was 40, 60, and 75% for 1.9, 3.5, and 6.3 plants m−2, respectively. Leaf area index, TDM, crop growth rate, and plant height were significantly influenced by PPD. Tiller number decreased linearly with increasing PPD to no tillers at 3.5 plants m−2. We conclude that increasing PPD of maize increases LAI and vegetative DM yield but alters light distribution within the canopy by shifting it from lower to upper canopy strata and increasing fraction intercepted by tassels.
Transpirations Efficiency of Oat
Authors: Ehlers W.
Published: July 2010

Dry matter production, water use, and their ratio (ie., the water use efficiency [WUE] of crops) vary among species and with climatic conditions. This study was undertaken to determine the WUE of oat (Avena sativa L.) because recent field evaluations for this crop are not available. Oat was grown on loess‐derived silt loam (finesilty, mixed, mesic Typic Hapludalf) near Goettingen, West Germany, during 4 yr. Periodically, shoot and root dry matter were determined. Water use within five consecutive growth stages was evaluated by the soil water budget approach. Balanced evapotranspiration (ET), including evaporation from soil (E), water intercepted by leaves (I), and transpiration from plants (T), was divided into its components, E, I, and T by calculation procedures. The term E was approximated from meteorological factors, leaf area index (LAI), and soil water tension, and I from daily precipitation and LAI. Shoot and total oat dry matter including roots were linearly related to cumulative T, IT, and ET. The x‐intercept of the regression line was nearest to zero, when ✕ was IT. Therefore, I was regarded to be part of “productive“ water use. Including I and considering only shoot dry matter, WUEIT was 4.1 kg m−3. When considering shoots and roots, WUEIT increased to 4.5 kg m−3. The relation between dry matter production and IT was improved by relating IT to the potential evapotranspiration rate or the saturation deficit (Δe) of the air. As compared with other crops, WUEIT of oat appeared to be lower. This study provided evidence that normalization of IT by Δe requires the appropriate evaluation of Δe for the daylight period when transpiration occurs.
Wheat and Maize Yields in Response to Straw Management and Nitrogen under a Bed Planting System
Authors: Limon‐Ortega Agustin , Sayre Kenneth D. , Francis Charles A.
Published: July 2010

In the Yaqui Valley, northwest Mexico, the crop sequence that is becoming more common consists of planting wheat (Triticum aestivum L.) as a winter crop on a raised bed followed by maize (Zea mays L.) as a summer crop. In this area, straw of both winter and summer crops is commonly burned. The consequences of burning crop residues on crop yields in the Yaqui Valley have not previously been documented, and alternative practices have not been proposed. A 5‐yr study was conducted at the CIANO (Centro de Investigaciones Agrı́colas del Noroeste) experiment station in Sonora, Mexico, to compare the effects of burning with other straw management strategies on wheat and maize yields. We tested two tillage systems (conventional‐tilled bed, CTB, and permanent bed, PB), five straw management treatments (incorporated with CTB and straw as stubble, partly removed, removed, or burned with PB), and seven N treatments, five applied preplant (0, 75, 150, 225, and 300 kg N ha−1) and two at the 1st node stage (150 and 300 kg N ha−1) of wheat. Maize following wheat received a uniform application of 150 kg N ha−1. The combination of PB and straw as stubble produced superior maize and wheat grain yields in high‐yielding environments; in low‐yielding environments, PB–straw burned produced greater wheat grain yields. Nitrogen fertilizer application of 150 and 300 kg N ha−1 at the 1st node stage of wheat increased grain yields compared with preplant N fertilizer applications. Permanent beds combined with retaining all crop residues in the soil as stubble have the potential to increase both wheat and maize yields in the Yaqui Valley.
Grazing Pressure on Beef and Grain Production of Dual‐Purpose Wheat in Argentina
Authors: Arzadun Martín J. , Arroquy José I. , Laborde Hugo E. , Brevedan Roberto E.
Published: July 2010

The effects of three different grazing pressures on beef (Bos taurus) and wheat (Triticum aestivum L.) grain production were studied at Pasman (Argentina) during a 3‐yr study. Thirty hectares of the variety ‘Pincen’ wheat were grazed with Angus heifers during 3 yr (1995–1997) until apex differentiation. The different grazing pressures were obtained through different stocking rates, adjusted every 21 d according to forage mass, predicted forage production rate, and an estimated forage allowance of 10, 15 and 20 kg dry matter (DM) heifer−1 d−1 for high, medium, and low pressures, respectively. The three treatments were randomly allocated within a complete block design with two replications. Every 21 d forage samples were clipped and forage mass and plant composition were recorded and in vitro dry matter digestibility (IVDMD), crude protein (CP), and neutral detergent fiber (NDF) were determined. Spike density and grain production were measured at harvest. Average daily gain (ADG) was obtained from 10 heifers per plot, present throughout the entire grazing period. Gain per hectare (GH) was obtained in each plot from the mean ADG and animal days per hectare computed during stocking rate adjustments. During grazing period the levels of CP and IVDMD decreased and NDF content increased, and these trends were more pronounced in 1996 and 1997 because of rust infection. Increased grazing pressure caused increased GH and reduced ADG, forage mass at the end of the grazing period, and grain production. Means of treatments over the years for GH were 283, 225, and 176 kg ha−1, and for grain production were 955, 1150, and 1351 kg ha−1 for high, medium, and low pressures, respectively. The increase in grazing pressure (from low to high treatment) produced an increase of 107 kg ha−1 in beef production and a 396 kg ha−1 reduction in grain production. Taking into account the traditional price of beef with respect to grain in Argentina, this beef gain over grain relation at increased grazing pressure is economically profitable for farmers.
A WEB‐BASED DATA EXCHANGE SYSTEM FOR CROP MODEL APPLICATIONS
Authors: Bostick W. McNair , Koo Jawoo , Walen Valerie K. , Jones James W. , Hoogenboom Gerrit
Published: July 2010

Development, evaluation and, application of cropping system models (CSMs) require multiple types of data. Cropping system data sets can often be used multiple times by different groups of modelers and experimentalists around the globe. However, for various reasons, data sets are often underutilized while at the same time, lack of data creates a bottleneck for many modeling efforts. In an effort to increase utilization of cropping system data, the International Consortium for Agricultural Systems Applications (ICASA) has developed an internet‐based system, the ICASA Data Exchange (ICASA DE; www.icasa.net; verified 15 Feb. 2004), that provides a convenient forum for documenting, archiving, and exchanging cropping system experiment and/or weather data sets. Users of the ICASA DE can enter metadata that describe their data sets, upload their data set files, edit their entries, search for data using specific criteria, browse metadata of data sets in the system, and download data sets from the system. The purpose of this paper is to present the functional design and implementation of this system.
Dry Matter Intake and Digestibility of ‘Coastal’, ‘Tifton 44’, and ‘Tifton 85’ Bermudagrass Hays Grown in the U.S. Upper South
Authors: Burns J. C. , Fisher D. S.
Published: July 2010

‘Coastal’ bermudagrass [Cynodon dactylon (Pers.) L.] is the major warm‐season grass grown across the U.S. upper south. More recent hybrids of ‘Tifton 44’ (T44) and ‘Tifton 85’ (T85) (Cynodon sp.) offer improved nutritive value. Compared are dry matter (DM) intake and digestion of Coastal bermudagrass (CB), T44, and T85 hays grown under different soil and climate conditions and harvested at either the same or different maturities. In the comparison of CB and T44 with steers (Bos taurus L.), DM intake was greater for CB in one of three experiments, whereas intakes did not differ in the other two. Greater intake for CB was associated with greater DM digestion. In the other two experiments, T44 had greater DM digestion than did CB in one trial but did not differ in the other. Hays of CB, T44, and T85, harvested in 2 yr, were compared by means of sheep (Ovis aries L.). In Year 1, sheep consumed more CB than either T44 or T85, whereas in Year 2, no differences in intake were detected. Coastal was digested least in both experiments compared with T44 and T85, and T85 had greatest DM digestion in one of the two years. Samples of masticate of CB had the least in vitro true dry matter disappearance (IVTDMD) with T44 intermediate and T85 generally greatest. In general, animal response data showed little advantage of T44 in comparison with CB; however, Tifton 85 appears to have greater digestible fiber and offers potentially greater DM digestion and digestible intake compared with CB.
Mapping and Confirmation of the ‘Hyuuga’ Red‐Brown Lesion Resistance Gene for Asian Soybean Rust
Authors: Monteros Maria J. , Missaoui Ali M. , Phillips Daniel V. , Walker David R. , Boerma H. Roger
Published: July 2010

Asian soybean rust (ASR), caused by Phakopsora pachyrhizi Syd., is a widespread disease of soybean [Glycine max (L.) Merr.] with the potential to cause serious economic losses. The objective of this study was to genetically map red‐brown lesion type resistance from the cultivar Hyuuga. A population of 117 recombinant inbred lines (RILs) from the cross of Dillon (tan lesion) × Hyuuga (red‐brown [RB] lesion) was rated for ASR lesion type in the field and inoculated with P. pachyrhizi in the greenhouse. The RB resistance gene mapped between Satt460 and Satt307 on linkage group (LG)‐C2. When field severity and lesion density in the greenhouse were mapped, the Rpp?(Hyuuga) locus explained 22 and 15% of the variation, respectively (P < 0.0001). The RB lesion type was associated with lower severity, fewer lesions, and reduced sporulation when compared to the tan lesion type. A population from the cross of Benning × Hyuuga was screened with simple sequence repeat (SSR) markers in the region on LG‐C2 flanked by Satt134 and Satt460. Genotype at these markers was used to predict lesion type when the plants were exposed to P. pachyrhizi All the lines selected for the Hyuuga markers in this interval had the RB lesion type and they averaged approximately 50% fewer lesions compared to lines with tan lesions. Sporulation was only detected in 6% of the RB lines compared with 100% of the tan lines. Marker‐assisted selection can be used to develop soybean cultivars with the Rpp?(Hyuuga) gene for resistance to ASR.
Heteroic Responses in Oats1
Authors: Murphy Charles F.
Published: July 2010

Yield, yield components, and subcomponents were measured in spaced, F1 plants of 72 oat crosses. Heterosis was studied as a percent of the mid‐parent, as a percent of the high‐parent, and by the number of crosses in which the F1 average was greater than the high parent average or less than the low parent average. Comparisons, between characters, of mid‐parent heterosis percentages were found to be invalid because they were masked by differences in the variability of the characters. High‐parent heterosis was exhibited for yield but not for the components, i.e., panicles per plant, seeds per panicle, and weight per seed. Seeds per panicle, although the most variable character, exhibited the least heterotic response. Heterotic responses for yield were positively associated with those for panicles per plant and seeds per panicle, and negatively associated with weight per seed responses. Panicles per plant responded independently from seeds per panicle and weight per seed, and a negative relationship was found between seeds per panicle and weight per seed responses. Weight per groat responses were positively associated with those of the sub‐components, groat length and width, and length and width responded independently.
Effect of Seed Moisture Content, Field Weathering, and Combine Cylinder Speed on Soybean Seed Quality1
Authors: Green D. E. , Cavanah L. E. , Pinnell E. L.
Published: July 2010

Two varieties of soybeans were harvested at varying dates and at varying seed moisture contents in 1959, 1960, and 1961. Two harvest methods, hand shelling and machine harvesting, were used at each date of harvest. With the machine harvest method combine cylinder speeds of 500, 700, and 900 rpm were used.

In all 3 years there was a general trend for the whole seed from later dates of harvest to have a lower percentage of normal seedlings in laboratory germination and field emergence tests, a higher percentage of splits and cracked seedcoats, and smaller average seed size as measured in grams per 100 seed and by a screening method. Exceptions to this general rule occurred in 1961 when the initial quality of the seed was very high.

With only a few exceptions, hand harvested seed‐lots had higher viability and a lower incidence of splits and cracked seedcoats than machine harvested seed‐lots. Within the machine harvested seed‐lots, harvesting at lower cylinder speeds produced seed with a higher percentage of normal seedlings in laboratory germination and field emergence tests, a lower percentage of abnormal seedlings in laboratory tests, a lower percentage of splits and cracked seedcoats, and larger average seed size. There was some indication that the threshing effect split a larger percentage of the larger soybean seed within each seed‐lot.
Influence of Temperature, Light Intensity, and Photoperiod on the o‐Hydroxycinnamic Acid Content in Plant Parts of Sweetclover1
Authors: Whited D. A. , Gorz H. J. , Haskins F. A.
Published: July 2010

The influences of telnperature, light intensity, and photoperiod on content of o‐hydroxycinnamic acid in various parts of sweetclover plants were studied. Increases in temperature, light intensity, and light duration to which the plants were exposed were generally followed by increases in the amounts of o‐hydroxycinnamic acid produced in each of the plant parts. Contents of o‐hydroxycinnalnic acid in leaves and stems increased most rapidly and, in plants 25 days or more in age, these parts contributed the overwhelmingp ortion of the total plant content. Percentages of o‐hydroxycinnamic acid calculated on a dry‐matter basis were highest in leaves, intermediate in stems, and lowest in roots; values generally decreased as the plants grew. Data obtained will be of value in growing and sampling plants in future experiments.
Partitioned Genetic Variances for Several Characters in a Cotton Population of Interspecific Origin1
Authors: Ramey H. H. , Miller P. A.
Published: July 2010

Estimates of additive and dominance gentic variances were obtained for 11 agronomic and fiber traits in a cotton population of interspecific origin (Gossypium thurberi Tod., Gossypium arboreum L., Gossypium hirsutum L.). Substantial amounts of additive genetic variation were found for the traits lint percentage, lint index, seed index, weight per boll, fiber length (U.H.M.), fiber strength (T1), fiber elongation (El), fiber fineness (A), and fiber shape (D). Additive genetic variations were also found for seed cotton yield and lint yield but were small in magnitude. Positive estimates of dominance genetic variance were obtained for seven of the traits. Magnitudes of these estimates were generally small and only three (those for lint percentage, weight per boll, and fiber length) exceeded their standard errors. Negative estimates of dominance genetic variance were obtained for seed cotton yield, lint yield, seed index, and fiber shape. Estimates of average degree of dominance, where obtained, were less than unity indicating only partial dominance for genes controlling these traits.
Estimates of Variety ✕ Environmental Interactions in Yield Tests of Three Small Grains and Their Significance on the Breeding Programs1
Authors: Liang George H. L. , Heyne E. G. , Walter T. L.
Published: July 2010

The purpose of this study was to obtain estimates of the relative magnitudes of the various types of variety ✕ environment interactions in variety tests, and to consider the significance of these interactions on variety evaluation procedures. Ten varieties of winter wheat at 13 locations, 4 varities of winter barley at 10 locations, and 5 spring oat varieties at 5 locations were evaluated in Kansas for a 3‐year period. The variety ✕ year interactions were small and nonsignificant, but the second‐order interactions of variety ✕ location ✕ year were of considerable magnitude and highly significant. The significant three‐factor interaction was not accounted for by grouping locations, and in general, must be regarded as an error variance to be controlled by the number of locations used and number of years of testing. Significant variety ✕ location interactions were obtained for wheat and barley, indicating the state could be divided into subareas. By grouping appropriate locations together, a reduction of the magnitude of variety ✕ location mean square was generally observed. However, it is suggested that each subarea should be considered as an independent unit in testing the significance of variety ✕ location interaction because the decrease or increase in the magnitude of variety ✕ location mean squares of subareas compared to that of the state as a whole does not always provide the true picture of its significance.
Relationships Among Malt Quality Characteristics of Spring Barley Grown in Pennsylvania1
Authors: Streeter John G. , Pfeifer Robert P.
Published: July 2010

Two 2‐row and four 6‐row spring malt barley varieties were grown at 5 locations in Pennsylvania in 1963. From these 5 experiments, 22 samples of the two‐row varieties and 34 samples of the 6‐row varieties were subjected to complete malt quality analysis. Dealing with the data in 2 groups (2‐ and 6‐row), all possible combinations of correlation coefficients were computed among 20 of the quality variables available. The correlation matrices were then used in multiple regression analysis in which one independent variable is elminated at a time. The elminination was based on its relative lack of contribution to an explanation of the variation in the dependent variable. All statistical analyses were done with the aid of an electronic computer.

Seven of the most meaningful multiple regressions with high predictive power were reported. Three of these were associated with R2 values of about .90. Three of the expressions developed showed potential as prediction equations for diastatic power (2‐row varieties) and for fine grind extract and fine minus coarse extract (6‐row varieties). Many close relationships between barley and malt kernel size and other quality characteristics were found. It was emphasized that multiple regression analysis, made feasible with electronic computers, was a potentially valuable tool in understanding and defining malt quality.
Relationship Among Seedling Height, Greenhouse Regrowth, Fall Height, and Spring Height in Medicago sativa L.1
Authors: Davis R. L. , Buker R. J.
Published: July 2010

Crosses of early fall dormant ✕ early fall dormant,early dormant ✕ late dormant, and late dormant ✕ late dormant clones of Medicago sativa L. were planted in greenhouse flats and subsequently transplanted into the field. Seedling height, greenhouse regrowth, fall height (regrowth), spring height (regrowth), and percent winterkill were recorded. Correlation coefficients indicated that 25 to 36% of the variation in greenhouse regrowth could be associated with seedling height. Less than 5% of the variation in fall height and spring height could be associated with seedling height. A similar relationship was noted between fall height and spring height. This relationship, along with the range of types found in any seedling class, suggested that plants with good seedling vigor and good spring recovery could be selected from the early dormant ✕ early dormant group even though the tallest plants for fall height were only about half as tall as those in the early ✕ early or late ✕ late group. The segregation in the early ✕ late and late ✕ late group suggested that winterhardy plants with good seedling vigor, good regrowth, having tall fall and spring height could be selected.
A Hexaploid Pangolagrass Clone1
Authors: Rotar Peter P. , Urata Ukio
Published: July 2010

Colchicine treatment of single‐node pangolagrass cuttings resulted in the production of a hexaploid clone (2n=54) which is partially pollen fertile and produced some filled seeds not all of which were viable.
Variation and Covariation in Agronomic and Malting Quality Characters in Barley I. Heritability Estimates1
Authors: Rutger J. N. , Schaller C. W. , Dickson A. D. , Williams J. C.
Published: July 2010

‘Atlas’, a coast‐type barley that possesses desirable agronomic characteristics, was crossed with ‘Kindred’, a Manchurian‐type barley characterized by superior malting quality but which shatters severely in arid climates. Fourteen agronomic and 13 malting quality traits were studied in a population of 102 random F4 lines grown at 2 planting dates in 1962. Four of the agronomic traits were studied again in 1963.

Genotype ✕ environment interaction variances generally were small relative to genotypic variances. Significant (5% level) genotype ✕ planting date interactions were present for only 4 of the 27 traits evaluated in 1962 and for only 1 of the 4 traits studied in both years. Five of the 6 significant genotype interactions in the 2‐year data involved year terms.

Higher estimates of heritability generally were obtained for malting quality traits than for agronomic traits, although heritability estimates for a majority of the latter were 0.7 or greater. One notable exception was yield, for which heritability was estimated to be 0.48.

Predicted selection advances indicated that it should be possible to make substantial gains in most individual characters. However, predicted advances from one cycle of selection for yield, malt extract, wort nitrogen, diastatic power, and beta amylase were less than the amounts needed to achieve preferred levels.
Breeding of Nonflowering Orchardgrass, Dactylis glomerata L.1
Authors: Hovin A. W. , Rincker C. M. , Wood G. M.
Published: July 2010

Among nearly 4,000 spaced plants in a breeding nursery of orchardgrass, Dactylis glomerata, 9 remained nonflowering near University Park, Pa., during the growing seasons of 1959, 1960, and 1961. Experiments with floral inductive treatments of 8, 10, 13, and 16 weeks of short days at 10 C or below subdivided selected clones from this nursery into three groups. Three 4‐clone synthetics with different cold inductive floral requirements were formulated. First‐generation (Syn 1) seed produced in 1963 at Prosser, Wash., of Syn A, Syn B, and Syn C, averaged, respectively, 50 g, 21 g, and 32 g per clone. The Syn 1 generation was compared with ‘Pennlate’ in solid‐seeded field plots for production of panicles and forage in the Northeast. In June 1965 Pennlate, Syn A, Syn B, and Syn C produced, respectively, 12.6, 13.1, 4.1, and 1.7 panicles per square foot in Pennsylvania and 37.2, 4.3, 1.8, and 0.6 in Vermont These data indicated a genetic basis for the nonflowering characteristic.
A Rapid Method of Fatty Acid Analysis of Oil from Individual Corn (Zea mays L.) Kernels1
Authors: Jellum M. D. , Worthington R. E.
Published: July 2010

Five chromatograms of the fatty acid composition of oil of 2 kernels from each of 8 entries were used in comparing 3 gas‐liquid chromatographic procedures. Procedures 1 and 2 had a column temperature of 235 C and recorder chart speed of 2 and 3 inches per minute, respectively. Procedure 3 had a column temperature of 200 C and chart speed of 1 inch per minute. Differences in entries, procedures, and kernels in entries were highly significant. However, variance components estimates showed that procedures and kernels in entries contributed little to the total variance. Standard errors and coefficients of variation were similar for all procedures. Accurate fatty acid analyses were obtained in less than 3 minutes by procedures 1 and 2.
Genotypic Correlations, Dominance, and Heritability of Quantitative Characters in Oats1
Authors: Petr F. C. , Frey K. J.
Published: July 2010

Three methods of estimating dominance were applied to F1 data on plant height, panicle number, heading date, number of spikelets per panicle, number of panicles per plant, and grain yield from the 15 diallel crosses among 6 oat varieties. Genotypic correlations and heritability percentages, in the broad sense, were calculated for the F2.

In general, the dominance values from the 3 methods of estimation were in good agreement with one another and with the observed effects. Overdominance was indicated for number of panicles per plant in the F1 whereas estimates for yield ranged from partial to overdominance. Partial dominance was indicated for short panicles and plant height. Earliness of heading was partially dominant in both the F1 and F2 and few spikelets per panicle were partially dominant.

The heritability percentages were 33, 53, 54, 61, 74, and 87 for number of panicles per plant, grain yield, panicle length, plant height, number of spikelets per panicle, and heading date, respectively. The genetic correlations between plant height, panicle length, number of spikelets, heading date, and grain yield were positive, and most of them were relatively high.

The heritability percentages and high levels of dominance for yield and panicles per plant observed in the F1 indicate that selection for these attributes should be delayed until later generations. Selection for plant height, panicle length, number of spikelets and heading date should be feasible in early generations.
Transgressive Segregation for Increased Winter Survival in Oats (Avena sativa L.)1
Authors: Finkner Verne C.
Published: July 2010

Transgressive segregation for increased winter hardiness was found in a cross between the winter oat cultivars ‘C.I. 4897’ ✕ ‘Dubois.’ C.I. 4897 is an introduction from Wales and Dubois was developed at Purdue University. Transgressive segregation was expressed both as greater resistance to leaf kill resulting from fall freezes and higher percent winter survival. In a replicated evaluation 44 F7 lines selected for winter hardiness and other characteristics averaged 66% survival, Dubois 9% and C.I. 4897 3%.
A Breeding Procedure for the Utilization of Heterosis in Tobacco‐Related Species Hybrids1
Authors: Wernsman E. A. , Matzinger D. F.
Published: July 2010

A technique is described in which the heterosis observed in interspecific hybrids of Nicoriana tabacum L. ✕ N. sylvestris Speg. and Comes and N. tabacum ✕ N.otophora Griesbach could be utilized in flue‐cured tobacco breeding programs. The method facilitates the partial substitution of the S genome of N. sylvestris and the T genome of N. otophora for the S and T genomes of N. tabacum independently. This is accomplished by selfing, or selfing and testcrossing to N. tabacum, pentaploid F1 interspecific hybrids of 8x N. tabacum ✕ 2x N. sylvestris and 8x N. tabacum ✕ 2x N. otophora. High yielding species‐derived varieties or F1 hybrids between two species derived lines are suggested as a means of utilizing the heterosis from these interspecific hybrids, depending on the type of gene action involved.
Coumestrol Differences in Medicago sativa L. Free of Foliar Disease Symptoms1
Authors: Stuthman D. D. , Bickoff E. M. , Davis R. L. , Stob Martin
Published: July 2010

The coumestrol content of 4 clones of alfalfa free of foliar pathogens ranged from 6 to 25 ppm. Expressed as percent of control, uterotrophic activity ranged from 105 to 182. These data indicated that differences for coumestrol content and uterotrophic activity could be demonstrated in Medicago sativa clones in the absence of foliar disease symptoms.
Clipping and Regrowth of Barnyardgrass1
Authors: Vengris Jonas , Hill E. R. , Field D. L.
Published: July 2010

Three field experiments were conducted to study the regrowth of barnyardgrass (Echinochloa crusgalli (L.) Beauv.) after clipping. Yields were decreased by cutting at more frequent intervals and less mature stages of top growth. The lowest yields were obtained by continuous clipping at vegetative stage of growth before internods elongation. At the vegetative stage of growth, higher clipped plants had faster regrowth and resulted in the production of more clippings and slightly higher total yields. Plants intensively clipped and liberally fertilized with nitrogen produced higher yields at first cuttings only. Fertilization with nitrogen decreased fructosan content in the stubble. After clippings, barnyardgrass regrew until killing frost.
Morphological Expression of Genetic Male Sterility in Maize (Zea mays L.)1
Authors: Datuk Sjofjan , Madjolelo Paduko , Grogan C. O. , Sarvella P. A.
Published: July 2010

Morphological variations between sterile and normal segregates were found in the three genetic male‐sterile stocks of maize under study. The degree and plant part(s) affected varied with the strain and with the time of plant development when the measurements were made. Pollen breakdown took place between 5 and 10 days after meiosis in the 3 stocks.
Inheritance of a Strain‐Specific Ineffective Nodulation in Soybeans1
Authors: Caldwell B. E.
Published: July 2010

Certain strains of Rhizobium japonicum fail to produce effective nodules on the soybean variety ‘Hardee,’ Glycine max L. Merr.). F1, F2, and F3 generations of Hardee ✕ normal nodulating varieties were used to study the inheritance of the strain‐specific ineffective nodulation of Hardee. Ineffective nodulation was found to be conditioned by a single dominant gene, which was given the symbol Rj2. Investigation of the parentage of Hardee indicated that the source of this gene was the parent ‘CNS.’
Effect of the Yellow‐Green (yg) Character on Certain Characteristics of Cigar‐Wrapper Tobacco1
Authors: Dean C. E.
Published: July 2010

An investigation was conducted into the effects of the yellow‐green (yg) gene on certain characteristics of cigar‐wrapper tobacco. The recessive monogenic virescent character was transferred into the varieties ‘Florida 15,’ ‘Dixie Shade,’ ‘Rg,’ and ‘No. 63,’ through four generations of backcrossing and self‐pollination. The four virescent selections, together with normally pigmented sister selections, were compared with their respective recurrent parent varieties.

Virescent segregates, even though shorter during the period of measurements, grew at a rate comparable to their parental varieties. Virescent selections had longer leaves at the tenth node position, more leaves exceeding 16 inches in length, and a higher total leaf count. A pleiotropic action for the yg gene or the effect of linked or modifying genes was postulated to be responsible for the differences observed.

Virescent segregates, as a group, had a lower yield than green varieties; however, variation between families existed. Virescent selections had a higher percentage of tobacco in the light wrapper, off‐color, and first three grades, and a lower percentage in the dark and number 2 off‐color grades. Grade and crop indices substantiated the superiority of virescent segregates over their respective normally pigmented parental varieties. These data indicate that the yellow‐green color inherent in virescent plants will result in a lighter and more uniform colored cured leaf, which could be of value to the cigar‐wrapper trade.

The degree of reconstitution of the recurrent parent genotype was estimated. Four backcrosses were considered to be a minimum number required in a gene transfer program of this nature.
Designs to Estimate Effects of Clone Substitution in Alfalfa Synthetics1
Authors: Hill R. R.
Published: July 2010

Variations of a 4‐factor factorial experiment were developed for estimation of components of variance due to general, 2‐, 3‐, and 4‐line combining ability effects in populations of 4‐clone alfalfa synthetics. Applications of the double cross and 4‐stage nested mating designs were also discussed. Knowledge of the relative importance of the components would be an aid in planning a breeding program.
Inheritance and Control of Obligate Apomixis in Breeding Buffelgrass, Pennisetum ciliare1
Authors: Taliaferro C. M. , Bashaw E. C.
Published: July 2010

We studied the inheritance of obligate apomixis, using both selfed and F1 progenies. In both cases, the female parent was a completely sexual plant heterozygous for genes controlling method of reproduction, and the male parents in the crosses were obligate apomicts. Classification of S1 and F1 plants for mode of reproduction was achieved by embryo‐sac analyses, or study of progeny variability, or both. Four hundred and sixty‐nine S1 progeny, involving two populations grown in the years 1962 and 1965, respectively, segregated for sexual to apomictic types at ratios not significantly different from a 13:3. One hundred and forty‐five S1 progeny grown in 1963 gave a sexual to apomictic ratio of 8.66:l. Pooled data for these 614 S1 progeny of the sexual plant fit the 13:3 ratio. Seven hundred and sixty‐six F1 hybrids between the sexual plant and two obligate apomictic ecotypes, blue and common, gave sexual to apomictic ratios not significantly different from a 5:3. Interpretation of the 13:3 S1 and 5:3 F1 sexual to apomictic ratios is as follows. The genetic constitution of the sexual plant is hypothesized to be AaBb, where gene B conditions sexuality, and it is epistatic to gene A, which controls apomixis. The genetic constitution of the apomictic male parents is hypothesized to be Aabb. Results obtained support the hypothesis and suggest that the sexual plant originated by mutation at the b locus. The manipulation and use of obligate apomixis in a buffelgrass breeding program is discussed.
Genetic Variability in Flue‐Cured Varieties of Nicotiana tabacum. II. Dixie Bright 244 ✕ Coker 1391
Authors: Matzinger D. F. , Mann T. J. , Cockerham C. Clark
Published: July 2010

In the F2 generation of a cross between two flue‐cured tobacco varieties, additive genetic variance was the predominant genetic variance for percent total alkaloids, yield, flower, leaves, and suckers. For value per acre and plant height, there was evidence of nonadditivity, which could not be resolved between dominance and epistasis. Most additive genetic correlations among yield, height, flower, and leaves were positive and significant. Number of suckers was negatively correlated with all traits except value. Yield and percent total alkaloids were negatively correlated. The gain predicted from one cycle of selection by intercrossing the top 12.5% of the full‐sib families for total alkaloids was 21% above the mean of the full‐sib families. An expected correlated response was a decrease of 87 pounds yield per acre.
Effects of Shade on the Survival of Crested Wheatgrass Seedlings1
Authors: McGinnies William J.
Published: July 2010

A 3‐year study at Fort Collins, Colorado, evaluated the effects of several levels of shading on the survival of crested wheatgrass (Agropyron desertorum (Fish. ex Link) Schult.) seedlings. In general, shade did not increase the number of seedlings surviving. Seedling height was greater under shade, but much of the increase appeared to be etiolation, because dry matter production was not necessarily related to the shade‐induced plant height. The effects of shade on herbage production varied greatly between months within years and also between years. Shade had little effect on air temperatures and minimum soil temperatures, but substantially reduced maximum soil temperatures. Under the conditions of this study, shading provided no significant benefit toward seedling survival. Furthermore, shade was not detrimental to the seedlings.
Predicting Yields from Associated Characters in Medicago sativa L.1
Authors: Davis R. L. , Buker R. J.
Published: July 2010

The F1 progenies of eight clones of Medicago sativa crosed in all combinations and the polycross progenies of the eight clones were seeded in 10‐foot rows. Coefficients of determination for multiple regression of dry weight of plants on July 21 and September 6 with characters associated with dry weight (height, width, stand, % leaves, and Leptosphaerulina leafspot) varied from 0.61 to 0.68 when calculated on an individual plot basis. Predictive equations were generated for both dates using F1 and polycross data. Correlation coefficients calculated on means between F1 observed and predicted yield were 0.89 and 0.90, respectively, for July 21 and September 6 harvest, using the predictive equation generated from F1 data. The correlations between F1 observed and predicted yields were 0.89 and 0.92, respectively, for the July 21 and September 6 harvest, using the predictive equation generated from the polycross data. Selection based on the variables associated with dry weight would be 96% and 109% as effective as selection based on actual dry weight for the July 21 and September 6 harvest respectively.