bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-nutritional uses of vitamin B6
Authors: Bender David A.
Published: May 2019

Vitamin B6is a water-soluble vitamin, and is readily metabolized and excreted, so it has generally been assumed to have negligible toxicity, although at very high levels of intake it can cause peripheral nerve damage. Nutritional deficiency disease is extremely rare, although a significant proportion of the population shows biochemical evidence of inadequate status, despite apparently adequate levels of intake. The vitamin has been used to treat a wide variety of conditions, which may or may not be related to inadequate intake. In some conditions use of vitamin B6supplements has been purely empirical; in other conditions there is a reasonable physiological or metabolic mechanism to explain why supplements of the vitamin many times greater than average requirements may have therapeutic uses. However, even in such conditions there is little evidence of efficacy from properly conducted controlled trials.
Physical exercise affects the lipid profile of mitochondrial membranes in rats fed with virgin olive oil or sunflower oil
Authors: Quiles José L. , Huertas Jesús R. , Mañas Mariano , Battino Maurizio , Mataix José
Published: May 2019

The effects of physical exercise on the lipid profile in mitochondrial membranes of liver and skeletal muscle were examined in rats fed with virgin olive oil or sunflower oil. Thirty male Wistar rats, 21 d old, were randomly assigned to four groups according to fat ingestion and physical activity over an 8-week period. For each type of oil, one group acted as a control group while rats from the other were trained to run for 40 min daily on a horizontal treadmill, at a speed of 35 m/min. The results show that diet affected the fatty acid profile of the mitochondrial membranes from skeletal muscle and liver. Physical exercise also modified the fatty acid profile of the mitochondrial membranes. Total monounsaturated fatty acids decreased (P< 0.001) in liver mitochondria of exercised animals. Total polyunsaturated fatty acids in mitochondrial membranes of liver increased (P< 0.005) after exercise but those in mitochondrial membranes of skeletal muscle decreased (P< 0.05). These changes due to the exercise may arise via several mechanisms, e.g. fluidity regulation; changes in the eicosanoid metabolism; differences in the availability or oxidation rate of the different fatty acids.
Influence of sodium fumarate addition on rumen fermentationin vitro
Authors: López S. , Valdés C. , Newbold C. J. , Wallace R. J.
Published: May 2019

The influence of sodium fumarate on rumen fermentation was investigatedin vitrousing batch and semi-continuous cultures of mixed rumen micro-organisms taken from three sheep receiving a basal diet of hay, barley, molasses, fish meal and a mineral–vitamin supplement (500, 299·5, 100, 91 and 9·5 g/kg DM respectively). Batch cultures consisted of 10 ml strained rumen fluid in 40 ml anaerobic buffer containing 200 mg of the same feed given to the sheep. Sodium fumarate was added to achieve a final concentration of 0, 5 or 10 mmol/l, as a result of the addition of 0, 250 or 500 μmol, equivalent to 0, 200 and 400 g/kg feed. CH4production at 24 h (360 μmol in the control cultures) fell (P< 0·05) by 18 and 22 μmol respectively (SED 7·5). Total gas production was increased by the addition of fumarate without significant accumulation of H2. Substantial increases in acetate production (92 and 194 μmol; SED 26·7,P< 0·01) were accompanied by increases in propionate formation (212 and 396 μmol; SED 13·0,P< 0·001). Longer-term effects of fumarate supplementation on ruminal fermentation and CH4production were investigated using the rumen simulation technique (Rusitec). Eight vessels were given 20 g basal diet/d, and half of them received a supplement of fumarate (disodium salt) over a period of 19 d. The response to the daily addition of 6·25 mmol sodium fumarate was a decrease in CH4production of 1·2 mmol (SED 0·39,P< 0·05), equivalent to the consumption of 4·8 mmol H2, and an increase in propionate production of 4·9 mmol (from 10·4 to 15·3 (SED 1·05) mmol/d,P< 0·01). The inhibition of CH4production did not decline during the period of time that fumarate was added to the vessels. Thus, the decrease in CH4corresponded well to the fraction of the fumarate that was converted to propionate. Fumarate had no significant (P> 0·05) effect on total bacterial numbers or on the number of methanogenic archaea, but numbers of cellulolytic bacteria were increased (8·8v. 23·9 (SED 2·49) × 105per ml,P< 0·01). Fumarate also increased DM digestibility of the basal diet after 48 h incubation (0·476v. 0·508 (SED 0·0123),P< 0·05). Thus, it was concluded that sodium fumarate may be a useful dietary additive for ruminants, because it diverts some H2from CH4production and because it is able to stimulate proliferation of cellulolytic bacteria and digestion of fibre.
The effect of malnutrition on the metabolic response to surgery
Authors: Emery Peter W. , Zadeh Ali R. Bosagh , Wasylyk Anna
Published: May 2019

The effect of previous malnutrition on the metabolic response to surgical hysterectomy was investigated in adult female rats. Malnutrition was achieved by feeding a 20 g protein/kg diet and restricting food intake to 50 % of normal. This dietary regimen was maintained for 3 weeks before surgery and for 4 d after surgery. Unoperated control rats were pair-fed with the hysterectomized rats after surgery. Energy balance was measured by the comparative carcass technique and, in a second experiment, urinary N excretion was measured. Surgery caused energy expenditure to increase by 37 % inad libitum-fed rats but in malnourished rats it increased by only 22 %. Urinary N excretion rose immediately after surgery. In thead libitum-fed rats it was on average 85 % greater in hysterectomized rats than controls for the first 3 d after surgery, whereas in the restricted rats it was 74 % greater on the first day and not significantly elevated thereafter. Thus, malnutrition attenuated the metabolic response to surgery but did not abolish it completely.
Hypovitaminosis D in an Italian population of healthy subjects and hospitalized patients
Authors: Romagnoli Elisabetta , Caravella Patrizia , Scarnecchia Liliana , Martinez Paolo , Minisola Salvatore
Published: May 2019

The present study aimed to investigate the prevalence and seasonal variation of hypovitaminosis D (defined as serum 25-hydroxyvitamin D level below 30 nmol/l) among healthy subjects and hospitalized patients living in central Italy. We studied 297 subjects, 131 in February 1997 and 166 in July 1997, subdivided into four groups: (a) young healthy blood donors; (b) healthy postmenopausal women; (c) inpatients with various medical diseases and (d) inpatients engaged in long-term rehabilitation programmes because of various neurological disorders. In all subjects and patients serum levels of 25-hydroxyvitamin D were measured by radioimmunoassay. We found a significant seasonal variation (P< 0·0001) of serum 25-hydroxyvitamin D levels, mean values being higher in summer in all groups, except in patients with a longer hospitalization time (group (d)). In each group, a significantly higher prevalence of hypovitaminosis D was found in winter compared with summer time (P< 0·001), being unexpectedly high in postmenopausal women (winter 32 % and summer 4·5 %); furthermore, in both seasons, inpatients were characterized by the highest incidences of hypovitaminosis, particularly those in group (d) (winter 82·3 % and summer 57·8 %). The results of the present study emphasize the importance of 25-hydroxyvitamin D measurement, and the need to increase vitamin D intake in Italy; foodstuff fortification and supplement use must be considered in order to prevent negative effects of vitamin D deficiency on skeletal integrity.
Plasma pyridoxal phosphate and pyridoxic acid and their relationship to plasma homocysteine in a representative sample of British men and women aged 65 years and over
Authors: Bates C. J. , Pentieva K. D. , Prentice A. , Mansoor M. A. , Finch S.
Published: May 2019

Concentrations of pyridoxal phosphate and pyridoxic acid were measured in fasting plasma samples from British men and women aged 65 years and over, participating in a National Diet and Nutrition Survey during 1994–5, selected to be representative of the population of mainland Britain. In this population, the concentration of pyridoxal phosphate declined, whereas pyridoxic acid rose, with increasing age and frailty; however, both status indicators were strongly and directly (with a positive coefficient) correlated with estimates of vitamin B6intake. This was little affected by the inclusion of food energy and protein intakes in the model. Forty-eight percent of the participants living in the community and 75% of those living in institutions had plasma pyridoxal phosphate concentrations below a range considered normal from other studies. In a univariate regression model, plasma pyridoxal phosphate concentrations were inversely correlated with plasma homocysteine concentrations, consistent with the hypothesis that vitamin B6status may influence plasma homocysteine levels, and hence vascular disease risk. However, this relationship was partly attenuated in a multiple regression model including age, sex, domicile and biochemical status indices, including those of folate and vitamin B12. There was evidence that plasma pyridoxal phosphate was sensitive to metabolic conditions associated with inflammation and the acute-phase reaction, and that plasma pyridoxic acid was sensitive to renal function. Thus, neither index is an ideal predictor of vitamin B6status in older people, unless these confounding factors are allowed for. Since poor vitamin B6status may have health implications, e.g. for immune function, cognition, and for essential intermediary metabolic pathways in older people, it needs to be investigated as a possible public health problem.
Assessment of net postprandial protein utilization of 15N-labelled milk nitrogen in human subjects
Authors: Bos Cécile , Mahé Sylvain , Gaudichon Claire , Benamouzig Robert , Gausserès Nicolas , Luengo Catherine , Ferrière Françoise , Rautureau Jacques , Tomé Daniel
Published: May 2019

The nutritional quality of milk proteins, evaluated both in terms of digestibility and postprandial oxidation and retention in human subjects, was investigated in this study. Five healthy adult volunteers were given 480 ml 15N-labelled milk (i.e. 190 mmol N). 15N was subsequently determined at the ileal level, using a naso-intestinal intubation technique, as well as at the faecal level. Plasma and urine were sampled for 8 h after meal ingestion. Dietary exogenous N recovered at the terminal ileum after 8 h reached 8·6 (se 0·8) mmol while the amount collected in the faeces was 6·5 (se 0·7) mmol after 5 d. The true ileal and faecal digestibilities were 95·5 (se 0·4)% and 96·6 (se 0·4)% respectively. The appearance of [15N]amino acids in the plasma was rapid and prolonged. The measurement of 15N in the body urea pool and in the N excreted in the urine allowed us to calculate the deamination occurring after [15N]milk protein absorption. The net postprandial protein utilization (i.e. NPPU = (Nabsorbed - Ndeaminated)/Ningested), calculated as an index of protein quality 8 h after milk ingestion, was 81·0 (se 1·9)%. Our data confirm that milk protein has a high oro-ileal digestibility in man and demonstrate that milk protein has a high NPPU, an index corresponding to a period in which the dietary protein retention is maximal.
Methane production and energy partition of cattle in the tropics
Authors: Kurihara M. , Magner T. , Hunter R. A. , McCrabb G. J.
Published: May 2019

The aim of this experiment was to determine CH4production and energy partition for a range of diets fed toBos indicuscattle. Six Brahman cattle were fed on three different diets in a replicated Latin square experiment over three periods. The diets were (1) long-chopped Angleton grass (Dicanthium aristatum) hayad libitum(DM digestibility (DMD) 41 (se 2)%; 4 g N/kg), (2) long-chopped Rhodes grass (Chloris gayana) hayad libitum(DMD 60 (se 1)%; 14 g N/kg) or (3) 2 kg long-chopped lucerne (Medicago sativa) hay/d plus a high-grain diet (ad libitum) (DMD 70 (se 1)%; 31 g N/kg). CH4production was measured using confinement-type respiration chambers. Metabolizable energy intake (MJ/d) of cattle fed on Angleton grass (18·4 (se 2·0)) was lower (P< 0·01) than that for Rhodes grass (54·9 (se 2·1)), which was lower (P< 0·01) than that for the high-grain diet (76·7 (se 5·8)). CH4production (g/d) for cattle fed on Rhodes grass (257 (se 14)) was higher (P< 0·01) than that for cattle fed on both the high-grain diet (160 (se 24)) and Angleton grass (113 (se 16)). CH4conversion rate (MJ CH4produced per 100 MJ gross energy intake) was not significantly different between cattle fed on Angleton (10·4 (se 1·1)) and Rhodes (11·4 (se 0·3)) grass, but was higher (P< 0·01) than for cattle fed on the high-grain diet (6·7 (se 0·7)). CH4production (g/kg live-weight gain) was associated (P< 0·001) with both live-weight gain and feed: gain ratio. We conclude that the relationships between CH4production, energy utilization and live-weight change of cattle fed on tropical forages differ from those of cattle fed on diets based on temperate forages.
Telestes and the ‘five-rodded joining of strings’
Authors: Barker Andrew
Published: May 2019

Athenaeus (637a) records these lines from the dithyrambHymenaios, along with a number of other snippets of poetry, in the course of an inconclusive discussion about the characteristics of the instrument (if it is an instrument) called the magadis. Athenaeus had good reasons for being puzzled; the wordfirst appeared in Greek, so far as we know, in the seventh centuryb.c., and its sense was already a matter of some doubt in the fourth. As to this particular fragment, even Telestes' original audience might be forgiven some bafflement in the face of the third line, on which I shall initially focus here. What can be meant by ‘the five-rodded joining of the strings’?
The Liturgical Argument in Apollinarius: Help and Hindrance on the Way to Orthodoxy
Authors: Spoerl Kelley McCarthy
Published: May 2019

In the essay “Creed or Chaos?” written in the midst of the turmoil of World War II, British mystery novelist Dorothy L. Sayers defended the relevance of the creeds produced during the doctrinal debates of the fourth and fifth centuries to the lives of modern Christians. The theological dogmas contained in such documents as the Nicene Creed (325) or the Chalcedonian Definition (451) are not, she notes wittily, “a set of arbitrary regulations inventeda prioriby a committee of theologians enjoying a bout of all-in dialectical wrestling,” but were “hammered out under pressure of urgent practical necessity” to resolve theological controversies that had real impact on the discipleship of ordinary Christians. To put matters at their simplest, the trinitarian controversies revolved around the question of whether Christ was divine, and so capable of saving humankind from sin and death. The christological controversies, at least in their earliest stage, debated whether Christ was really human, truly the God-made-man capable of healing wounded humanity and providing aviable role model for Christians to follow in the living of a redeemed life. At stake in both controversies was a convincing explanation of the central Christian tenet that “Jesus saves” for those who profess to be his followers.
SOUND AND DESIRE: RACE, GENDER, AND INSULT IN EGYPT'S FIRST TALKIE
Authors: Elsaket Ifdal
Published: May 2019

This article explores the coloniality of gender, sexuality, and desire, and the links between nationalist and commercial imperatives, in the making of Egypt's first sound film, or talkie, in 1932. Through an analysis of the politics, economy, and memory of Yusuf Wahbi's filmAwlad al-Dhawat(Sons of the Aristocrats), it shows how the interplay between new sound technologies, the global film trade, and nationalist and racialized narratives of gender and resistance shaped the contours of ideal femininity and masculinity during the interwar period in Egypt. The article also shows how the film's representations formed at the intersection between the filmmakers’ attempts to challenge colonial stereotyping and their efforts to capture an ever-expanding global film market. Often neglected in cinema scholarship, early filmmaking in Egypt, I argue, is critical to understanding wider processes of nation formation and gendered characterizations.
Whither India? 1919 and the Aftermath of the First World War
Authors: Ghosh Durba
Published: May 2019

As diplomats across the world gathered in Paris in spring 1919 to discuss the peace process, observers asked “Whither India?” Critics wondered how the British government could enact emergency laws such as the Rowlatt Acts at the same time as it introduced the Government of India Act of 1919, which was intended to expand Indian involvement in governing the British dominions on the Indian subcontinent. Because Britain presented itself as a liberal form of empire on the international stage, its willingness to suspend rule of law over its subjects appeared contradictory. India's support of the Allied powers allowed Indian moderates to represent India in Paris; during the war, Indian subjects had contributed over one million soldiers and suffered influenza, plague, and famine. The possibility of a new relationship between those governing and those being governed led many Indians to demand an adherence to the rule of law, a guarantee of civil liberties, and the foundations of a government that was for and by the Indian people. In a time of revolution in Russia, and assassinations by anarchists in Italy and France, it seemed foolhardy to repress radicals by censoring the press, preventing the right of individuals to assemble, or detaining suspects before they had committed any crimes. Lala Lajpat Rai, an Indian political activist who had been part of the progressive wing of the Indian National Congress, wrote from the United States, “India is a part of the world and revolution is in the air all the world over. The effort to kill it by repression and suppression is futile, unwise, and stupid.”
Asia in the Global 1919: Reimagining Territory, Identity, and Solidarity
Authors: Manela Erez
Published: May 2019

Perhaps the first thing to note about a forum on the subject of 1919 in Asia is how awkwardly the spatial frame of “Asia” maps onto the international history of that moment. To be sure, the postwar international conjuncture, which I have elsewhere called the “Wilsonian Moment,” had a revolutionary impact across Asia, perhaps more so than in any other world region outside of Europe. As the three preceding essays in this forum note, that year was a waypoint, and sometimes a launching pad, for a rush of novel or renewed revolutionary discourses, connections, and mobilizations in China, India, and Korea, as it was in other parts of Asia and of the world. These were all propelled by the accumulated material and ideological transformations of the years of war, transformation that imbued the moment with revolutionary potential and gave contemporaries a sense that the international order, its power structures and its norms of legitimacy, were uniquely malleable, amenable to concerted action. Indeed, 1919 was a moment in which the very idea of “Asia”—its spaces, the identities they attached to, and the solidarities that ran across and beyond it—was reimagined in ways that at once stitched it together and rent it apart.
Effect of picloram on resistant and susceptible yellow starthistle (Centaurea solstitialis): the role of ethylene
Authors: Sabba Robert P. , Sterling Tracy M. , Lownds Norm K.
Published: May 2019

The noxious weed yellow starthistle is commonly controlled by the auxinic herbicide picloram. Induction of ethylene synthesis, epinasty, and reduction in shoot growth are typical symptoms of picloram treatment. Picloram did not induce ethylene evolution in the resistant accession RDW-1, though it caused a 250% increase in ethylene evolution in the susceptible wildtype SCI-1. The ethylene synthesis inhibitor aminoethoxyvinylglycine reduced the amount of ethylene induced by picloram in SCI-1 to control levels, but only reduced epinasty by 20% after 6 d. Aminoethoxyvinylglycine did not affect the reduction in shoot weight caused by picloram. The ethylene-releasing compound ethephon induced only a small amount of epinasty and had little effect on shoot weight in either accession. These results suggest that ethylene induced by picloram in wildrype plants plays only a minor role in the herbicidal effects of picloram. Furthermore, the resistance of the RDW-1 accession is not due to the lack of ethylene biosynthesis following picloram application to this accession.
Role of seed coat in regulation of seed dormancy in houndstongue (Cynoglossum officinale)
Authors: Stabell Elisa , Upadhyaya Mahesh K. , Ellis Brian E.
Published: May 2019

To understand the role of the seed coat in regulation of houndstongue seed dormancy, the effects of manipulation of seed coat integrity on seed germination and O2uptake were studied. The results suggest that the seed coat of this weed regulates dormancy in part by interfering with the diffusion of O2to the embryo. Scanning electron microscopy showed a network of ridges on the seed coat surface that were partially dissolved following 1.5 min of sulphuric acid scarification. Mechanical scarification removed fragments of the seed coat surface. Both scarification treatments stimulated seed germination. Supply of an elevated level of O2also stimulated seed germination. O2uptake by seeds imbibed in O2-saturated water was 150% higher than that for seeds imbibed in air-saturated water. Although all treatments that stimulated seed germination also stimulated O2uptake, there was a lack of a consistent, quantitative relationship between increases in O2uptake and seed germination in various experiments. This suggests that limitation of O2availability to the embryo is not the only factor involved in regulation of houndstongue seed dormancy by the seed coat. Mechanical restriction of embryo expansion by the seed coat may also be important. Methanol-insoluble phenolics constituted < 1% of the total phenolic pool in the embryo. Their potential oxidation could not account for more than a small fraction of the previously reported massive stimulation of O2uptake by the embryo upon decoating. The present O2uptake and seed germination studies indicate that not all of the large increase in O2uptake following decoating is essential for houndstongue seed germination.
Influence of purple nutsedge(Cyperus rotundus)density and nitrogen rate on radish(Raphanus sativus)yield
Authors: Santos Bielinski M. , Morales-Payan Jose P. , Stall William M. , Bewick Thomas A.
Published: May 2019

Greenhouse and field experiments were conducted to determine the effects of nitrogen (N) supply and purple nutsedge population densities on the yield of radish. In the greenhouse studies, additive series with purple nutsedge densities of 0, 50, 100, 200 or 350 plants m−2were established. Nitrogen rates of 0, 110, 220, or 330 kg ha−1were provided to the potting medium. A significant density by N interaction was found for radish fresh weight. Within a given nutsedge density, radish yield decreased as N rate increased. In field studies, additive series of 0, 50, 100, 150, or 200 nutsedge plants m−2were established the same day radish was sown. Nitrogen rates were 100 or 200 kg ha−1. Marketable radish yield losses and nutsedge shoot dry weight and height were determined 30 d after seeding the crop. Nutsedge densities and N rates interactively influenced radish root yield. Radish yield loss reached 100% at nutsedge densities of 75 and 125 plants m−2at 200 and 100 kg N ha−1, respectively. Purple nutsedge produced larger shoot biomass as N increased from 100 to 200 kg ha−1. Results of both greenhouse and field studies showed that as N increased, the negative effect of the weed on the crop was enhanced.
Rapid evaluation ofFusariumspp. as a potential biocontrol agent for weeds
Authors: Pleban S. , Strobel G. A.
Published: May 2019

An accurate method is described for evaluating the relative effectiveness of isolates ofFusarium avenaceumas potential biological control agents for weeds such as spotted knapweed and wild oat. The method uses seeds that have been disinfected, placed in tubes containing water agar, and challenged with various isolates ofF. avenaceum.Evaluatory data on the pathogenicity of the fungi are obtained after 14 d, when plants and fungi both are grown on water agar in the lab. Commonly, potential biocontrol agents are tested on seeds placed in the soil, but up to 60 d may be required for results. However, comparative studies using the soil test vs. the water agar test indicated that the water agar tests are giving comparable results to those from greenhouse tests but in a shorter time (14 vs. 60 d). Also, both water agar and soil tests were done with a number of crop plants including wheat, barley, alfalfa, and wild oat with comparable results. Thus, this method has the potential to screen many pathogens that may have potential biocontrol activities in a short time.
Integrating crop management and crop rotation effects into models of weed population dynamics: a review
Authors: Colbach Nathalie , Debaeke Philippe
Published: May 2019

Current weed demography models were reviewed to evaluate how the effects of cultural practices on weed dynamics were integrated into the models and to suggest possible ways to improve the simulation of cropping system effects. Several models were chosen to illustrate the interactions between cropping systems and weed dynamics. The first one described the structure of the weed life cycle. The second model integrated the effects of a wide set of cultural practices; the comparison of this example with other models suggested how the integration of cropping system effects could be improved. The last two models introduced the interactions of cultural practices with intraplot weed variability, either spatial variability of weed densities or genetic and phenotypic variability within weed populations. This review indicates some ways to make weed population models more comprehensive, robust, and accurate in order to improve their contribution to the evaluation and management of cropping systems.
PALWEED: WHEAT II: revision of a weed management decision model in response to field testing
Authors: Kwon Tae-Jin , Young Douglas L. , Young Frank L. , Boerboom Chris M.
Published: May 2019

PALWEED:WHEAT is a bioeconomic decision model for determining profit-maximizing postemergence herbicide treatments for winter wheat in the Washington–Idaho Palouse region. PALWEED:WHEAT performed relatively well economically in 2 yr of on-farm field tests. However, the model was less sensitive than desired in prescribing postemergence broadleaved herbicides in the presence of high densities of broadleaved weed seedlings. Therefore, PALWEED:WHEAT was revised in response to the field testing. This paper compares the revised model's agronomic and economic performance to the original model in computer simulations. The revised model, PALWEED:WHEAT II, differs from the original model in several respects: (1) exponential functions replace linear functions in predicting weed survival, (2) preplant application of a nonselective herbicide is entered as an exogenous binary variable, (3) separate indices of broadleaved and grass competition are substituted for an aggregate weed competition index in the wheat yield function, (4) hyperbolic replaces logistic functional representation of weed damage to wheat yield, and (5) separate models are estimated for winter wheat after spring dry pea and for winter wheat in all examined crop rotation positions. In simulations including a variety of agronomic and economic conditions, PALWEED:WHEAT II recommended postemergence herbicide types and rates that consistently complied with agronomic and economic theory. Furthermore, the revised model, especially when estimated from the relevant wheat after pea data set, was markedly more balanced in recommending both broadleaved and grass herbicides in response to observed densities of both weed groups. The substantial change in herbicide recommendations in response to changes in model functional specifications following field testing confirms the importance of field testing and revision of bioeconomic decision models.
The effect of light environment during tillage on the recruitment of various summer annuals
Authors: Gallagher Robert S. , Cardina John
Published: May 2019

Weed seeds can require an exposure to light for induction of germination. Conducting tillage operations at night and thus preventing the photoinduction of germination has been proposed as a means to reduce weed emergence in agricultural systems. This research was conducted to evaluate night tillage as a weed management option and to determine which tillage operations have the greatest effect on light-mediated recruitment. Weed emergence was evaluated after conducting factorial combinations of day and night moldboard plowing and disking in the springtime from 1992 through 1995. The light environment during disking generally had a slightly greater effect on emergence than the light environment during plowing. Emergence of pigweed species and giant foxtail was, at most, 30 to 55% higher following day vs. night disking. Emergence of other weeds was not affected by the light environment during tillage. We conclude that night tillage may not be a viable approach to weed management due to insufficient reductions in weed emergence associated with night tillage and the high degree of variability in the recruitment response to light conditions during tillage.
Effects of soil moisture and yellow nutsedge (Cyperus esculentus) density on cotton (Gossypium hirsutum)
Authors: Moffett Jody E. , McCloskey William B.
Published: May 2019

The influence of soil moisture on the competitive relationship between yellow nutsedge and cotton was determined in an additive competition experiment where main plots were irrigation regimes and subplots were nutsedge densities. Increasing nutsedge density caused a significant linear decrease in seed cotton yield. Regression analysis indicated that approximately 9 (1993), 12 (1994), or 37 (1995) kg ha−1of seed cotton yield was lost for each additional initial nutsedge tuber per meter of crop row. Both postharvest stem biomass, an indicator of total aboveground biomass, and seed cotton yield increased with increasing soil moisture in all 3 yr of the study. Increasing yellow nutsedge density reduced midseason cotton height in both wet and dry soil moisture regimes but only slightly reduced postharvest stem biomass in the wet treatment in 1995. There was an interaction between soil moisture regime and yellow nutsedge density only with respect to midseason cotton leaf water potentials. Soil moisture availability did not interact with the effect of yellow nutsedge density with respect to end of the season stem biomass or seed cotton yield.
Response of soybean cyst nematodes and soybeans (Glycine max) to herbicides
Authors: Levene Brian C. , Owen Micheal D.K. , Tylka Gregory L.
Published: May 2019

The effect of herbicides applied to V3 soybeans on race 3 soybean cyst nematode (SCN) reproduction and glyceollin production in roots was measured. Soybeans were treated postemergence with 1 × and 2 × rates of herbicides plus adjuvants or with adjuvants alone, and SCN development was measured. Acifluorfen, bentazon, lactofen, crop oil concentrate (COC), and nonionic surfactant (NIS) applications reduced SCN egg population densities 50 to 60% compared with the untreated control 4 and 8 wk after application. The SCN reproduction on plants treated with fluazifop-P, sethoxydim, and imazethapyr was similar to the untreated control. Crop oil concentrate or NIS applications alone were as effective as acifluorfen, bentazon, or lactofen applications for reducing SCN reproduction. However, no additive effect of adjuvant-herbicide combinations was observed, nor did herbicide rate affect SCN reproduction. Treatments reduced SCN reproduction only when applied to soybeans and had no effect on SCN reproduction when applied directly to the soil. No treatment stimulated SCN reproduction relative to the untreated control. Soybeans treated with COC, NIS, acifluorfen, and bentazon also had more glyceollin detected than the untreated control. Herbicide-induced glyceollin production may have increased the resistance of soybean to SCN.
Evaluation of soybean injury from sulfentrazone and inheritance of tolerance
Authors: Swantek Jason M. , Sneller Clay H. , Oliver Lawrence R.
Published: May 2019

Experiments were conducted in the field and greenhouse to evaluate the effects of cultivar and sulfentrazone rate on soybean injury and yield from soil-applied sulfentrazone and to determine soybean inheritance of sulfentrazone tolerance. Excessive rainfall and cool growing conditions in 1996 enhanced sulfentrazone injury and caused yield reduction in the susceptible cultivars ‘KS4895’ and ‘Hutcheson’ at 0.56 kg ai ha−1and KS4895 at 0.42 kg ha−1. Yields of tolerant cultivars ‘Deltapine 3478’ and ‘Manokin’ were not reduced. Sulfentrazone at 0.42 kg ha−1reduced soybean stand 17 and 35% for tolerant and susceptible cultivars, respectively. Field and greenhouse inheritance studies were conducted on plant families developed from two crosses: Manokin (tolerant) by ‘Asgrow A4715’ (susceptible) and ‘Northrup King S59–60’ (tolerant) by KS4895 (susceptible). The sulfentrazone tolerance of Manokin and Northrup King S59–60 appeared to be controlled by a single gene, with tolerance being dominant to susceptibility. The allelic relationship of tolerance from these two sources needs to be determined.
A kochia (Kochia scoparia) biotype resistant to triazine and ALS-inhibiting herbicides
Authors: Foes Matthew J. , Liu Lixin , Vigue Gerald , Stoller Edward W. , Wax Loyd M. , Tranel Patrick J.
Published: May 2019

A kochia biotype from McDonough County, Illinois, was suspected to be resistant to both triazine and acetolactate synthase (ALS)-inhibiting herbicides. We performed greenhouse and laboratory experiments to confirm, quantify, and determine the molecular basis of multiple herbicide resistance in this biotype. Whole-plant phytotoxicity assays confirmed that the biotype was resistant to triazine (atrazine), imidazolinone (imazethapyr), and sulfonylurea (thifensulfuron and chlorsulfuron) herbicides. Relative to a susceptible kochia biotype, resistance to these herbicides ranged from 500- to > 28,000-fold. The kochia biotype from McDonough County also displayed high levels of resistance (2,000- to 9,000-fold) to ALS-inhibiting herbicides in in vivo ALS enzyme assays, indicating that resistance to these herbicides was site-of-action mediated. Results from chlorophyll fluorescence assays indicated that triazine resistance was also site-of-action mediated. Foliar applications of atrazine had little or no effect on photosynthesis in the resistant biotype, even when atrazine concentrations were 108-fold higher than needed to inhibit photosynthesis in the susceptible biotype. A region of the gene encoding the D1 protein of photosystem II and all of the open reading frame of the gene encoding ALS were sequenced and compared between the resistant and susceptible biotypes. Resistance to triazine and ALS-inhibiting herbicides in the kochia biotype from McDonough County was conferred by, respectively, a glycine for serine substitution at residue 264 of the D1 protein and a leucine for tryptophan substitution at residue 570 of ALS.
Competition between wheat and canarygrass biotypes and their response to herbicides
Authors: Afentouli Catherine G. , Eleftherohorinos Ilias G.
Published: May 2019

Field experiments were conducted in Thessaloniki, Greece, from 1991 to 1994 to study the competition of littleseed canarygrass and short-spiked canarygrass biotypes in wheat and to evaluate their response to diclofop, fenoxaprop, tralkoxydim, and CGA-184927. Competitive ability of all canarygrass biotypes was similar, though species differed in panicle numbers. All littleseed canarygrass biotypes showed faster growth rate than the short-spiked canarygrass biotypes. Wheat grain yield decreased as canarygrass density increased. For example, 152 and 304 canarygrass plants m–2reduced wheat yield 32 and 42%, respectively. None of the canarygrass biotypes at any density had any effect on grain yield of wheat when cold and dry weather prevailed during the early stages of growth. CGA-184927 and tralkoxydim were more effective herbicides against all short-spiked canarygrass biotypes than fenoxaprop and diclofop. CGA-184927 and fenoxaprop provided > 98% control of all littleseed canarygrass biotypes; control with tralkoxydim was < 80%; and diclofop gave 82 to 96% control of this weed species. Herbicide control of canarygrass increased wheat yield relative to the weedy control, and only diclofop was phytotoxic to wheat.
Weed seedbank response to crop rotation and tillage in semiarid agroecosystems
Authors: Dorado J. , Monte J. P. Del , López-Fando C.
Published: May 2019

In a semiarid Mediterranean site in central Spain, field experiments were conducted on a Calcic Haploxeralf (noncalcic brown soil), which had been managed with three crop rotations and two tillage systems (no-tillage and conventional tillage) since 1987. The crop rotations consisted of barley→vetch, barley→sunflower, and a barley monoculture. The study took place in two growing seasons (1992–1994) to assess the effects of management practices on the weed seedbank. During this period, spring weed control was not carried out in winter crops. In the no-tillage system, there was a significant increase in the number of seeds of different weed species: anacyclus, common purslane, corn poppy, knotted hedge-parsley, mouse-ear cress, spring whitlowgrass, tumble pigweed, venus-comb, andVeronica triphyllos.Conversely, the presence of prostrate knotweed and wild radish was highest in plots under conventional tillage. These results suggest large differences in the weed seedbank as a consequence of different soil conditions among tillage systems, but also the necessity of spring weed control when a no-tillage system is used. With regard to crop rotations, the number of seeds of knotted hedge-parsley, mouse-ear cress, and spring whitlowgrass was greater in the plots under the barley→vetch rotation. Common lambsquarters dominated in the plots under the barley→sunflower rotation, whereas venus-comb was the most frequent weed in the barley monoculture. Larger and more diverse weed populations developed in the barley→vetch rotation rather than in the barley→sunflower rotation or the barley monoculture.
Isozyme and RAPD variation among and within hemp dogbane (Apocynum cannabinum) populations
Authors: Ransom Corey V. , Douches David S. , Kells James J.
Published: May 2019

Clonal individuals from 16 hemp dogbane populations with phenotypic variation were analyzed using isozyme and randomly amplified polymorphic DNA (RAPD) analysis. Plants originated from populations in Michigan and Illinois. Three knownApocynumspecies, spreading dogbane, hemp dogbane, and prairie dogbane, were evaluated. Genetic distance among populations was more pronounced with isozyme analysis compared to RAPD analysis. The combined isozyme and RAPD analysis data separated spreading dogbane from all other plants analyzed. Genetic variation was present among the 16 hemp dogbane populations, but was less than expected based on the phenotypic variation present among the collections. The short genetic distance between the 16 hemp dogbane collections and the threeApocynumspecies suggests that variation among populations of hemp dogbane may be from outcrossing with other closely relatedApocynumspecies. Isozyme and RAPD analyses were also conducted on plants from two populations in Michigan to determine the level of genetic variation among plants within the same population. Genetic analysis revealed that one population was entirely clonal, while the other population was a mixture of clonal and segregating plants.
Temporal and spatial distributions of velvetleaf seedlings after 1 year's seeding
Authors: Zhang Jianhua , Hamill Allan S.
Published: May 2019

Two separate experiments were conducted from 1974 through 1980 and from 1976 through 1982 at an experimental farm in southwestern Ontario, Canada, to determine the pattern of temporal and spatial distributions of velvetleaf seedlings from seed produced by uncontrolled plants. For each experiment, a soybean field with no previous record of velvetleaf infestation was selected and planted with four patches of 10 velvetleaf plants. The plants were allowed to grow to reproductive maturity for 1 yr, and the density and spatial distribution of velvetleaf seedlings within the field were mapped over the next 6 yr. Although velvetleaf seedlings emerged each year after seeding, the highest percentage emerged the second year after seeding. Velvetleaf seedlings emerged at locations with or without a seeding plant, but a high density of emerged seedlings was often observed at locations some distance away from the seeding plants. The results suggest that under conventional harvesting methods there may not always be a close spatial relationship between the distribution of parent plants and their offspring, depending on the scale of the land and biotic and abiotic environmental conditions.
Competition of noogoora burr (Xanthium occidentale) and fierce thornapple (Datura ferox) with cotton (Gossypium hirsutum)
Authors: Charles Graham W. , Murison Robert D. , Harden Steven
Published: May 2019

Competitiveness of noogoora burr and fierce thornapple in irrigated cotton was assessed using area-of-influence methodology. Lint yields were regressed against distances from the weeds using spline regression. The resulting regression curves were used to estimate areas of influence and yield losses, which were further modeled as functions of weed size to understand weed competitiveness. Cotton lint yield reductions averaged 36 and 12%, with maximum distances of influence of 1.71 and 1.65 m for noogoora burr and fierce thornapple, respectively. Economic thresholds for control using hand hoeing were related to weed size. Thresholds for average-size weeds were one cocklebur in 195 m and one fierce thornapple in 73 m of cotton row.
Control of parasitic witchweeds (Striga spp.) on corn (Zea mays) resistant to acetolactate synthase inhibitors
Authors: Abayo Gordon O. , English Terry , Eplee Robert E. , Kanampiu Fred K. , Ransom Joel K. , Gressel Jonathan
Published: May 2019

Parasitic witchweeds inflict most of their damage while still underground and attached to crop roots. Most selective translocated herbicides are detoxified by crops such as corn and thus cannot reach the attached parasites. Corn with target site resistance to acetolactate synthase (ALS)-inhibiting herbicides was tested to ascertain whether these herbicides could control witchweeds, assuming that witchweeds do not obtain amino acids from the crop. Postemergence directed sprays of 27 g ae ha−1 imazapyr 54 d after planting (DAP) delayed Striga asiatica emergence on corn in South Carolina from 3 wk (control) to 7 wk and to 11 wk when mixed with 45 g ae ha−1 AC 263 222. Treatments with up to 71 g ae ha−1 imazamox, and up to 71 g ae ha−1 AC 263 222 only delayed Striga emergence by 1 wk, and 71 g ae ha−1 imazethapyr was ineffective. ALS-inhibiting herbicides were far more effective when applied in 1-ml drenches above the seed at planting. Chlorsulfuron (10 g ai ha−1) and sulfometuron (50 g ai ha−1) were somewhat phytotoxic to Pioneer 3245IR. Rimsulfuron (30 g ai ha−1), metsulfuron (10 g ai ha−1), halosulfuron (120 g ai ha−1), and imazethapyr (140 g ae ha−1) were marginally active in Kenya, with some mature Striga hermonthica seed-bearing capsules appearing at harvest (12 wk). Imazapyr at 15 g ae ha−1 gave 70 to 95% suppression of capsule formation, whereas no capsules appeared at 30 g ae ha−1. The use of imazapyr in Kenya increased the harvest index by 17% when corn plants in Striga-infested soils were kept insect and disease free by using insecticides and fungicides. Thus, complete control can be achieved at affordable cost by farmers in subsistence conditions.
Ecology in the management of Indian jujube (Ziziphus mauritiana)
Authors: Grice Anthony C.
Published: May 2019

Strategies for controlling invasive plants in northern Australian ecosystems must be designed to use limited resources. This paper examines the potential contribution of ecology to develop management strategies for Indian jujube, an invasive shrub in northern Australian tropical woodlands. Its fleshy fruits are dispersed by a variety of birds and mammals. Domestic cattle are the major dispersal vector, whose movements can be controlled at critical times to minimize the risk of new infestations. Containment of Indian jujube must include avoiding cattle movement from infested to weed-free paddocks and from infested to weed-free areas. The species has a capacity to sprout following topkill due to fire or mechanical treatment. This means that current options for effectively treating established plants are limited to the application of herbicides and the more expensive mechanical techniques. In single paddocks, concentrating limited resources on large reproductive plants may be more effective than concentrating on plants spatially peripheral to an infestation. At the property level, the first priority should be to prevent weed-free paddocks from becoming infested, the second should be to minimize increases in lightly infested paddocks, and the third to treat heavily infested paddocks that are major potential sources of new infestations. At the regional level, distributional outliers become important; their control may significantly reduce the length of the front from which local range expansion will occur.
Formulation of mycoherbicidal strains ofFusarium oxysporum
Authors: Hebbar K. P. , Lumsden R. D. , Lewis J. A. , Poch S. M. , Bailey B. A.
Published: May 2019

Biomass abundant in chlamydospores obtained by liquid fermentation of mycoherbicidal strains ofFusarium oxysporumwas incorporated into alginate prills with various food substrates and granular formulations such as corn flour : starch, wheat flour : kaolin, rice : wheat flour, and rice : wheat gluten formulations. These fungal strains cause vascular wilts in coca (Erythroxylum cocavar.coca) and in poppy (Papavar somniferum). Fungal strain, formulation method, and interaction of these two parameters significantly affected the shelf life of the formulations at room temperature as well as the ability to form secondary propagules on 1% water agar. In bioassays, there were no significant differences amongF. oxysporumstrain EN4-S formulations in their ability to colonize root tissue or the rhizosphere ofE. cocaseedlings. The study indicates that most of the formulations meet at least three of the four criteria important for biological control agents to be effective: low losses in viability during the formulation process, satisfactory shelf life at room temperature, abundant secondary chlamydospore formation, and rhizosphere colonization.
Inbreeding coefficients of field populations ofKochia scopariausing chlorsulfuron resistance as a phenotypic marker
Authors: Guttieri Mary J. , Eberlein Charlotte V. , Souza Edward J.
Published: May 2019

Inbreeding coefficients were determined for nine southeastern Idaho kochia populations using chlorsulfuron resistance as a phenotypic marker. Inbreeding coefficients in six of the populations approximated 0, indicating that these field populations were random mating. One population had an inbreeding coefficient of 0.32, indicating partial selfing. No susceptible genotypes were identified in one population, which suggested recent selection and skewed the inbreeding coefficient. One population had an inbreeding coefficient of −0.19, suggesting either heterozygote advantage or some recent selection in the population. Our results suggest that kochia populations generally approximate random mating. Therefore, unlinked alleles will be independently assorted in field populations of kochia.