bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors Affecting Preemergence Bioactivity of Diclofop: Rainfall, Straw Retention, and Plant Growth Stage
Authors: Anderson R. L. 
Published: July 2010

AbstractDiclofop {(±)‐2‐[4‐(2,4‐dichlorophenoxy)phenoxy]propanoic acid} controls downy brome (Bromus tectorum L.) when mechanically incorporated after application, but preemergence surface applications result in erratic control of downy brome. To determine the physical factors that enhance diclofop bioactivity, laboratory and greenhouse studies were conducted with two soils: sand (Ustic Torripsamment) and sandy clay loam (Aridic Paleustoll). An oat (Avena sativa) root bioassay was used to measure bioactivity of diclofop. Movement of diclofop downward by simulated rainfall was affected by soil type and time of rainfall event. Oat root growth of seed planted 25 mm deep was reduced by >80% in the sand when 25 mm of rain was applied, but less than 30% in the sandy clay loam. Diclofop movement was reduced if the rainfall event was delayed by 4 d after application to the sand soil, indicating the need for precipitation within a few days after diclofop application. Surface straw interception and retention reduced diclofop activity by 20 to 30%, but simulated rainfall reduced this retention. Diclofop bioactivity was greatest when applied before oat seed germination. Diclofop applied to the soil surface after oat seedlings had emerged reduced plant growth 20 to 30%, while diclofop applied before oat germination reduced plant growth 75 to 85%. Preemergence surface applications of diclofop to the sand soil would be suitable for irrigated wheat (Triticum aestivum L.) production on the sand, provided that diclofop was applied before weed germination and an irrigation of 25 mm occurred within 2 to 4 d after application.
Winter Wheat Mainstem Leaf Appearance and Tiller Formation vs. Moisture Treatment
Authors: Krenzer E. G. , Nipp T. L. , McNew R. W. 
Published: July 2010

AbstractMainstem leaf (MSL) appearance and percent tiller formation (%TF) have been used to evaluate wheat (Triticum aestivum L.) development. The assumption is that MSL appearance is a linear relationship to accumulated heat or growing degree days (GDD) and is unaffected by other environmental factors. Young wheat plants were subjected to high (HM) and low (LM) moisture levels to study their effect on leaf appearance, %TF, and the timing of tiller appearance. Four winter wheat cultivars were raised in a growth chamber with a 12‐h photophase at 25 and 15 °C during dark. Leaf psychrometer thermocouple readings (at the end of the study) showed significant leaf water potential differences between LM (−0.61 MPa) and HM (−0.29 MPa) treatments. The final MSL stage of the LM plants (5.5) was lower than the HM plants (6.2). Moisture treatment also reduced %TF of the coleoptile tiller, 0% LM and 36% HM. Moisture treatment did not affect %TF of the first, second, or third tillers. Even though the number of GDD required for tiller appearance was increased under LM; moisture treatment did not influence the MSL stage at which each tiller appeared. The significant effect of moisture treatment on MSL appearance demonstrates that this measurement more accurately reflects the overall growth environment of the plants until the time observations are made, rather than measuring just the preemergent seedbed environment as has been previously suggested.
Corn Production in Relation to Water Inputs and Heat Units
Authors: Liang B. C. , MacKenzie A. F. , Kirby P. C. , Remillard M. 
Published: July 2010

AbstractIncreasing areas available for corn (Zea mays L.) production in eastern Canada have stimulated the search for improved management practices to obtain higher yields. These management practices include hybrid selection, plant density, and fertility optimization. Large year‐to‐year variations in corn yields due to weather, however may mask management effects. The objective of this study was to quantify corn grain yield, stover yield, and total dry‐matter production as functions of heat units (HU) and total seasonal water inputs. A field experiment was conducted on a Brookston sandy clay loam soil (fine‐loamy, frigid, mesic Typic Hapludalf) in Quebec from 1984 to 1989. Empirical equations for corn grain, stover, and total drymatter yield were developed for combinations of two plant populations (65 000 and 90 000 plants ha−1) and two fertilizer rates (170‐44‐141 and 400‐132‐332 kg ha−1 as N‐P‐K). Corn grain yield was a function of HU under conventional management practices with low and high HU reducing yields. Corn grain yield with the higher plant population and the higher fertilizer rate was proportional to the product of HU and water inputs received during the growing season. Interactions between management practices indicated that management practices must be devised for most probable climatic conditions. Optimization of climatic factors and management practices could increase grain corn yield.
Short‐ and Long‐Term Responses of Corn to a Pre‐Anthesis Soil Water Deficit
Authors: NeSmith D.S. , Ritchie J.T. 
Published: July 2010

AbstractIrrigation should be scheduled in order to minimize water application while maximizing crop yield, and such judicious watering requires better understanding of how crops respond to water supply. This field study was initiated to determine the influence of water deficits prior to anthesis on growth and yield of corn (Zea mays L.) grown in a sandy soil. A rain shelter was employed to provide periods without water of 21 d in 1988 and 18 d in 1989. Water deficit treatments were begun as the eighth or ninth leaf emerged from the whorl of plants for two corn hybrids. Control plots were irrigated to maintain plant available water (PAW) at 80% or greater throughout the growing season. A correlation between leaf extension and PAW revealed relative growth of deficit plants declined linearly beginning at 85% PAW, and approached zero at 25% PAW. Short‐term effects of the water deficits were delayed leaf tip emergence and decreased production of leaf area. Long‐term consequences were manifested in the form of reduced final sizes of certain leaves and internodes; delays of tassel emergence, silk emergence, the onset of grain filling by 2 to 3 d; and yield losses of 15 to 25%. Decreased yield of deficit plants was attributed to a reduction in the number of well‐developed kernels.
Evaluation of the Nitrogen Fertilizer Value of Plant Materials to Spring Wheat Production
Authors: Mahler R. L. , Hermamda H. 
Published: July 2010

AbstractUse of green manure crops has become a preferred alternative source of N. The objectives of this 3‐yr field study were to evaluate the N supplying power of 1, 2, and 3 Mg ha−1 of Austrian winter pea (Pisum sativum ssp. arvense (L.) Poir), alfalfa (Medicago sativa L.), and wheat (Triticum aestivum L.) residue. Residues were incorporated in September and the N contribution of each amendment to a subsequent spring wheat crop was calculated. We measured inorganic soil N levels and wheat yields in northern Idaho on Latahco silt loam (fine‐silty, mixed, mesic Pachic Ultic Haploxeroll) soils. Soil samples were taken during July of each year to determine residual inorganic N. Plant material addition and incorporation affected spring wheat yield and soil inorganic N level in each study. Pea and alfalfa material applied at 3 Mg ha−1 resulted in the highest spring wheat yields. Austrian winter pea residue at 3 Mg ha−1 provided a N credit of 51 to 63 kg ha−1 to spring wheat, compared to 1 to 36 kg ha−1 for alfalfa applied at the same rate. Based on inorganic soil N in July, application of 3 Mg ha−1 of Austrian winter pea, alfalfa, and wheat residue provided an N credit of 16 to 24, 21 to 26, and –1 to –25 kg ha−1, respectively. Average total N credits (soil + plant uptake) for the 3 Mg ha−1 application of Austrian winter pea, alfalfa, and wheat materials were 76, 47, and –35 kg ha−1, respectively. Estimated N recovery of Austrian winter pea material after 10 mo of incorporation was 77% (58% in wheat and 19% in soil).
A Simple Conductimetric CO2 Analyzer with Automatic Recalibration: II. Factors Affecting Calibration
Authors: Wall Gerard W. , Acock Basil , Milliken G. A. 
Published: July 2010

AbstractConductimetric CO2 analyzers provide an economical means of monitoring and controlling carbon dioxide concentration ([CO2]) in enclosed plant growth cabinets. They rely on dissolving CO2 from an air sample in demineralized water and measuring the resulting change in electrical conductivity. Regressing the analog output from the conductivity meter against [CO2] values over the range 200 to 1000 μL L−1 yields a quadratic response. Calibration curves for conductimetric CO2 analyzers are affected primarily by temperature and air and water flow rates. Air and water flow rates are relatively fixed, whereas temperature varies over time in normal operation. A covariate analysis for a three‐way treatment structure in a randomized complete block design determined how the intercept (B0) and the linear and quadratic parameter estimates (B1 and B2) varied with temperatures of 10, 20, 30, and 40°C, air flow rates of 540, 1880, and 3700 mm3 s−1, and water flow rates of 1.0, 0.66, and 0.33 mL s−1. Temperature effects were greatest, with air flow rate causing minor changes, while water flow rate had no effect. Temperature and air flow rate significantly altered B0, with only minor changes in B1 and B2. Variations in B0 were sufficient enough to alter the [CO2] around the desired set point by 70 μL L−1 for all treatments evaluated. Deviations in [CO2] control due to variation in B1 and B2 were within 10 to 15 μL L−1; only the adjustment in B0 must be made every sampling period (every 900 s) to maintain [CO2] control within 10 to 15 μL L−1 of the set point.
Separation and Dispersion of Conditionally Sampled Eddies through an Intake Tube
Authors: McInnes Kevin J. , Campbell C. S. , Heilman James L. 
Published: July 2010

AbstractWith conditional sampling, atmospheric fluxes are estimated from the difference in mean concentration of a gas between upward and downward moving eddies and a measure of the standard deviation of the vertical wind velocity. Two basic components of a conditional sampling system are a sonic anemometer to measure the direction and standard deviation of the vertical wind velocity, and a valve to separate air sampled from updrafts and downdrafts. Use of the Campbell Scientific CSAT3 three‐axis sonic anemometer to measure the vertical direction of the eddies and to trigger a splitter valve requires building a physical delay into the air sampling line to counter the electronic delay that is built into the anemometer. This physical delay in the form of an intake tube creates a source of dispersion that may reduce concentration differences and affect estimates of fluxes. Our objectives were to determine the proper match of electronic and physical delays to separate eddies, and then to measure the amount of dispersion from the combined mixing in the tube and the splitter valve. A conditional sampling system to measure CO2 fluxes was constructed using a CSAT3 anemometer and a three‐way valve. A physical delay was created by adding tubing on the upstream side of the valve. A simple timing circuit was used to control a highspeed valve that pulsed CO2 in front of the intake tube to mark the locations of eddy transitions. Differences in concentrations between updraft and downdraft lines were measured as flow rates and electronic delays were varied. Tube length based on electronic delay, flow rate, and intake tube geometry was found to be adequate for separation of updrafts and downdrafts. Dispersion in the intake tube was significant and predictable. The effect of the splitter valve on dispersion was minimal. A correction factor to adjust concentration differences in the lines for dispersion may be warranted, but only for eddy reversal frequencies > 2 Hz.
Inheritance and Utilization of Five Dwarfs in Pearl Millet (Pennisetum typhoides) Breeding1
Authors: Burton Glenn W. , Forston James C. 
Published: July 2010

Height measurements were made on over 39,000 parent, F1, F2, and backcross plants of hybrids involving five dwarf and four normal inbreds of pearl millet, grown in replicated randomized blocks. F1 hybrids between four of the dwarfs were as tall as normal × dwarf hybrids, proving that these dwarfs carried different recessive genes for dwarfness. One dwarf × dwarf hybrid was little taller than its taller dwarf parent, suggesting that both carried similar dwarf genes. Most dwarf × normal F1 hybrids were significantly taller (up to 37%) than their normal parents. Inheritance of dwarfness in D1 and D2 appeared to be conditioned largely by one or two recessive genes. Near‐normal F2 distribution curves and minimum‐gene‐number estimates indicated that dwarfness in D3, D4, and D5 was controlled by more than two recessive genes. When transferred to a near‐isogenic background, dwarfness in D1 and D2 was controlled by single but different recessive genes, named d1 and d2, respectivel.Gahi‐2 seed, produced by harvesting all seed from a field planted to a mixture of equal numbers of seeds of D1, D2, D3, and D4, contains about 75% of tall hybrids and yields nearly as much as Gahi‐1. Cytoplasmic malesterile dwarfs can be used as females to facilitate singlecross seed production. They will give tall hybrids if tall or different dwarf males are used. By using males carrying the same dwarf genes, short, extra‐leafy, high‐quality forage hybrids can be produced.
Effects of Defoliation and Stem Bruising on Soybeans1
Authors: Weber C. R. , Caldwell B. E. 
Published: July 2010

Investigations were conducted to determine the effects of (a) early defoliation on soybeans from emergence through stage 1 and (b) various degrees of stem bruising and defoliation individually and combined.Data from early defoliation indicated that at least one cotyledon was essential for maximum yield after emergence and, in the absence of the unifoliolate leaves the cotyledons were of value 12 days after emergence. Cut‐off below the unifoliolates and complete defoliation at stage 1 treatments indicated the great recuperative ability of soybean plants.The bruising and defoliation experiment indicated that bruising and defoliation were interrelated in producing yield loss in soybeans. Stem breakage resulted from the severity and location of the stem bruise, and to the amount of defoliation. Bruising was more important than breakage in causing yield loss.
Inheritance of a Variegated Leaf Pattern in Hexaploid Wheat1
Authors: Briggle L. W. 
Published: July 2010

Eight mutant wheat seedlings exhibiting a distinct leaf pattern were observed in an F3 progeny involving a powdery mildew‐resistant line crossed with one which was susceptible. Other F3 plants and all I1, F2, and parent plants were normal green.Test crosses were made among specific progenies from seven of the original plants and observations made on chlorophyll mutant characteristics. When normal green plants were self‐pollinated or used as female parents with variegated plants, only normal green progeny were produced. Variegated or albino plants (or both) appeared in the progeny only if variegated plants were selfpollinated or used as female parents in a cross. The variegated leaf pattern was maternally inherited.Variegation could be the result of a sorting out process involving two distinct kinds of plastids (yellow or green), as had been proposed in a similar instance by Pao and Li (6). White and green regions on the variegated leaves were clearly defined; no areas of intermediate tissue were observed. Sorting out of the plastids resulted in some leaves being entirely green, some all white, and some variegated. True‐breeding variegated lines could not be established.
Response of Birdsfoot Trefoil and Alfalfa to Various Levels of Shade1
Authors: Cooper Clee S. 
Published: July 2010

In 1963 and 1964, birdsfoot trefiol (Lotus corniculatus L.) and alfalfa (Medicago sativa L.) were grown in the field under full sunlight, and under 51, 76, and 92% shade. Growth of the two species was evaluated in terms of relative growth rate and other attibutes of classical growth analyses.Relative growth rate (RGR, g/g/week) of birdsfoot trefoil was greater than that of alfalfa under all shading intensities due to a greater leaf area ratio (LAR, dm2/g plant weight). Net assimilation rate (NAR, g/dm2/week) of alfalfa was greater than that of birdsfoot trefoil at high light intensities, but similar at low light intensities. The greater NAR of alfalfa at high light intensities was more than offset by the greater LAR of trefoil. The greater RGR of birdsfoot trefoil did not overcome the initial advantage of alfalfa for greater seed size and initial advantage of alfalfa for greater seed size and initial amount of phgotosynthetic tissue. This adavantage was directly responsible for the final greater yields of alfalfa.Formulas were derived expressing LAR as the product of leafiness by weight of a plant (leaf weight/plant weight, LWR) and the leaf area per unit of leaf weight (leaf area/ leaf weight, LALW)., Dirrerences iin LAR between species were due to differences in LWR, and those between shading intensities were due to differences in LALW.Shading reduced yield and plant height proportionately more for alfalfa than for birdsfoot trefoil. It reduced mean area of individual leaves of both species in 1 year, but only slightly affected it in the other. Shading did not affect stands of legumes.
Evaluation of Eight Inbred Lines of Maize (Zea mays L.)1
Authors: Nanda Devender K. 
Published: July 2010

The general combining ability of eight maize inbred lines was determinedb y meanso f testcrosses with an openpollinated variety and two single crosses. The inbred lines also were grown to observe their usefulness in predicting the perfor~nance of hybrid combinations. Twenty eight possible single crosses amongth e eight inbred lines, excluding the reciprocals, were grown to predict the performance of double crosses. Of the possible 210 double crosses, 28 were randomlys elected and grownt o compare their performance with that predicted from the single crosses by Jenkins' method (b).The lines were rated similarly by the three testers for mosta gronomictr aits studied. Anyo ne of the three testers could be used for evaluating the lines for general combining ability. The correlations between the testcrosses and the inbred lines were low for grain yield and shelling percentage but they were of sufficiently high magnitude for maturity characters, plant and ear height, and ear length to have predictive value in hybrid development. Positive significant correlations were obtained between the observed performance of double crosses and that predicted from single crosses by Jenkins' method (b) for all characters studied.
Seedling Vigor and the Early Nonphotosynthetic Stage of Seedling Growth in Grasses1
Authors: Whalley R. Derwyn B. , McKell Cyrus M. , Green Lisle R. 
Published: July 2010

Several species of grasses which have different ratings for seedling vigor were examined for rapidity of germination, seedling growth rates in the dark, and the ultimate length of dark grown seedlings. These are attributes which could be of importance in seedling vigor during the early, nonphotosynthetic stage of seedling growth.Extreme rapidity of germination largely accounts for the high seedling vigor of Schismus arabicus. In three species and strains of Phalaris, there were indications that rapidity of germination and mean seedling growth rates paralleled their rating for seedling vigor. No relation appeared to exist between total seedling length adjusted to a common seed weight and rating for seedling vigor.
Inheritance of Partial Male Fertility in Maize in the Presence of Texas Sterile Cytoplasm1
Authors: Beckett J. B. 
Published: July 2010

In tests involving 4 partial pollen fertility restoring maize inbreds, 13 chromosome marker lines, and Texas sterile cytoplasm, chi‐square tests for association of male fertility and marker genes were run on 30 families, and significant or highly significant association was found for 2 of the inbreds. When M14 was used, genes affecting partial restoration were indicated on chromosomes 2 (2 loci), 3, 7, and 9. For K64, similar genes were indicated on chromosome 2 (2 loci), 3 (2 loci), 4, 7, and 10.These tests indicate that partial restoration of cytoplasmically male‐sterile maize depends on the action of genes located on several chromosomes.
Variation in Oil Content and Its Relation to Other Characters in Oats (Avena sativa L.)1
Authors: Brown C. M. , Alexander D. E. , Carmer S. G. 
Published: July 2010

Wide‐line nuclear magnetic resonance (NMR) was used to determine the oil content from groats of 129 spring and 40 winter oat strains. Groats from spring oats varied from 3.8 to 8.5% with a mean of 5.6% oil, while the winter oats varied from 6.8 to 9.8% with a mean of 8.2%. Protein content of the spring oats varied from 15.2 to 20.8% with a mean of 18.4%, while winter oats varied from 16.8 to 20.6% with a mean of 17.1%.Significant negative correlations were observed between oil content and protein content in spring and winter oats. Yields were not recorded for winter oats but there was a significant negative correlation between yield and protein content of the spring oats. There also appeared to be a slight negative association between kernel weight and oil content, especially in the winter oats.
Inheritance of Seedling and Adult Reaction of Wheat to Stripe Rust1
Authors: Allan R. E. , Purdy Laurence H. , Vogel O. A. 
Published: July 2010

The inheritance of adult plant reaction of 8 wheat crosses to a stripe rust collection was determined under Pullman, Washington field conditions; an interpretation of the inheritance of seedling reaction of 4 of these crosses was also made under greenhouse conditions. Sources of resistance studied included ‘Nord Desprez’, ‘Dickson 114’, ‘C. I. 13431’, and ‘Spinkcota’. Three loci controlled field adult reaction to stripe rust of two crosses involving Dickson 114, whereas simple monogenic inheritance occurred in crosses C.I. 13431 ✕ ‘Golden’, C.I. 13431 ✕ ‘Itana’, and Spinkcota ✕ Itana. Two complementary loci or epistatis between 2 loci regulated greenhouse seedling reaction of crosses ‘Norin 10‐Brevor 14 ’ Nord Desprez, Spiukcota ✕ Golden, Itana ✕ Spinkcota, and Dickson 114 ✕ Itana.Greenhouse seedling and field adult reactions were related in all crosses studied in both environments. In the Norin 10‐Brevor 14 ✕ Nord Desprez cross, the same or closely related genetic mechanisms seem to govern field adult and seedling greenhouse reaction.Resistance typical of crosses involving Dickson 114 and Spinkcota is particularly valuable since some loci controlling seedling and adult reaction are dissimilar, The need to incorporate multi‐factor genetic systems into Pacific Northwest wheat varieties was emphasized.