bluuebunny/crossref_metadata_2025 huggingface dataset:
Widespread and accelerating glacier retreat on the Lyngen Peninsula, northern Norway, since their ‘Little Ice Age’ maximum
Authors: STOKES CHRIS R. , ANDREASSEN LISS M. , CHAMPION MATTHEW R. , CORNER GEOFFREY D.
Published: March 2018

The recession of mountain glaciers worldwide is increasing global sea level and, in many regions, human activities will have to adapt to changes in surface hydrology. Thus, it is important to provide up-to-date analyses of glacier change and the factors modulating their response to climate warming. Here we report changes in the extent of >120 glaciers on the Lyngen Peninsula, northern Norway, where glacier runoff is utilised for hydropower and where glacial lake outburst floods have occurred. Glaciers covered at least 114 km2 in 1953 and we compare this inventory with those from 1988, 2001 and a new one from 2014, and previously-dated Little Ice Age (LIA) limits. Results show a steady reduction in area (~0.3% a−1) between their LIA maximum (~1915) and 1988, consistent with increasing summer air temperatures, but recession paused between 1988 and 2001, coinciding with increased winter precipitation. Air temperatures increased 0.5°C per decade from the 1990s and the rate of recession accelerated to ~1% a−1 between 2001 and 2014 when glacier area totalled ~95.7 km2. Small glaciers (<0.05 km2) with low maximum elevations (<1400 m) experienced the largest percentage losses and, if warming continues, several glaciers may disappear within the next two decades.
FRACTIONAL FOCK–SOBOLEV SPACES
Authors: CHO HONG RAE , PARK SOOHYUN
Published: March 2018

Let $s\in \mathbb{R}$ and $0<p\leqslant \infty$. The fractional Fock–Sobolev spaces $F_{\mathscr{R}}^{s,p}$ are introduced through the fractional radial derivatives $\mathscr{R}^{s/2}$. We describe explicitly the reproducing kernels for the fractional Fock–Sobolev spaces $F_{\mathscr{R}}^{s,2}$ and then get the pointwise size estimate of the reproducing kernels. By using the estimate, we prove that the fractional Fock–Sobolev spaces $F_{\mathscr{R}}^{s,p}$ are identified with the weighted Fock spaces $F_{s}^{p}$ that do not involve derivatives. So, the study on the Fock–Sobolev spaces is reduced to that on the weighted Fock spaces.
Easter Island, Polynesia
Authors: Lavachery Henri
Published: March 2018

Few places in the world have given rise to more fantastic speculation than this volcanic island, 70 square miles in area, lying in the Pacific Ocean, lat. 27° 10′ s., long. 109° 20′ w. Actually the so-called ‘mysteries of Easter Island’, or rather the explanations which have been offered, are not the work of trained men of science. It is natural that the huge statues, standing erect as they do in a naked landscape against a background of black and yellow, should have appealed to the poetical imagination. But those who wish to face with candour the problems presented by certain parts of the world may well be annoyed when the poets’ lyrical love of mystery becomes the starting-point of speculation. The best students of Easter Island have always told us that it was Polynesian and could only be explained by Polynesia. The evidence that we have now obtained is merely an addition to what was already a formidable pile. Nevertheless we expect that before long others will come forward again with tales of a lost continent of Lemuria, submerged beneath the waters of the Pacific; and that Easter Island is one of its peaks, peopled with Lemurian idols!
The Story of Uruk
Authors: Andrae Walter
Published: March 2018

Uruk is the ancient name of the great ruin-field of Warka, which is situated near the station of El Khidr on the Irak railway, about 20 kilometres north of the Euphrates. It is now in the heart of a desert region almost exactly in the middle of the land of Sumer (the Shinar of the Old Testament).
Some Welsh Houses
Authors: Peate Iorwerth C.
Published: March 2018

The interaction between man and his environment, which is the basic principle of the science of Geography, is well-illustrated in a study of house-types in Wales. A detailed survey of Welsh house-types is being carried out by the Department of Folk Culture of the National Museum of Wales. It is felt that a study of the traditional types will not only throw much light on the history of culture but will also clarify some issues in the anthropological and archaeological field. This paper may be considered as a brief interim report of part of the survey, supplemented by some material already recorded.
Intermittentv. continuous energy restriction: differential effects on postprandial glucose and lipid metabolism following matched weight loss in overweight/obese participants
Authors: Antoni Rona , Johnston Kelly L. , Collins Adam L. , Robertson M. Denise
Published: March 2018

The intermittent energy restriction (IER) approach to weight loss involves short periods of substantial (>70 %) energy restriction (ER) interspersed with normal eating. Studies to date comparing IER to continuous energy restriction (CER) have predominantly measured fasting indices of cardiometabolic risk. This study aimed to compare the effects of IER and CER on postprandial glucose and lipid metabolism following matched weight loss. In all, twenty-seven (thirteen male) overweight/obese participants (46 (sem3) years, 30·1 (sem1·0) kg/m2) who were randomised to either an IER intervention (2638 kJ for 2 d/week with an overall ER of 22 (sem0·3) %,n15) or a CER intervention (2510 kJ below requirements with overall ER of 23 (sem0·8) %) completed the study. Postprandial responses to a test meal (over 360 min) and changes in anthropometry (fat mass, fat-free mass, circumferences) were assessed at baseline and upon attainment of 5 % weight loss, following a 7-d period of weight stabilisation. The study found no statistically significant difference in the time to attain a 5 % weight loss between groups (median 59 d (interquartile range (IQR) 41–80) and 73 d (IQR 48–128), respectively,P=0·246), or in body composition (P≥0·437). For postprandial measures, neither diet significantly altered glycaemia (P=0·266), whereas insulinaemia was reduced comparatively (P=0·903). The reduction in C-peptide tended (P=0·057) to be greater following IER (309 128 (sem23 268) to 247781 (sem20 709) pmol×360 min/l)v. CER (297 204 (sem25 112) to 301 655 (sem32 714) pmol×360 min/l). The relative reduction in TAG responses was greater (P=0·045) following IER (106 (sem30) to 68 (sem15) mmol×360 min/l) compared with CER (117 (sem43) to 130 (sem31) mmol×360 min/l). In conclusion, these preliminary findings highlight underlying differences between IER and CER, including a superiority of IER in reducing postprandial lipaemia, which now warrant targeted mechanistic evaluation within larger study cohorts.
A remark on Béjar & Kahnemuyipour 2017: Specificational subjects do have phi-features
Authors: HARTMANN JUTTA M. , HEYCOCK CAROLINE
Published: March 2018

In a number of languages, agreement in specificational copular sentences can or must be with the second of the two nominals, even when it is the first that occupies the canonical subject position. Béjar & Kahnemuyipour (2017) show that Persian and Eastern Armenian are two such languages. They then argue that ‘NP2 agreement’ occurs because the nominal in subject position (NP1) is not accessible to an external probe. It follows that actual agreement with NP1 should never be possible: the alternative to NP2 agreement should be ‘default’ agreement. We show that this prediction is false. In addition to showing that English has NP1, not default, agreement, we present new data from Icelandic, a language with rich agreement morphology, including cases that involve ‘plurale tantum’ nominals as NP1. These allow us to control for any confound from the fact that typically in a specificational sentence with two nominals differing in number, it is NP2 that is plural. We show that even in this case, the alternative to agreement with NP2 is agreement with NP1, not a default. Hence, we conclude that whatever the correct analysis of specificational sentences turns out to be, it must not predict obligatory failure of NP1 agreement.
Diagnosis of schistosomiasis mansoni: an evaluation of existing methods and research towards single worm pair detection
Authors: Ogongo Paul , Kariuki Thomas M. , Wilson R. Alan
Published: March 2018

The inadequacy of current diagnostics for the detection of low worm burdens in humans means that schistosomiasis mansoni is more widespread than previously acknowledged. With the inception of mass drug treatment programmes aimed at disease elimination and the advent of human vaccine trials, the need for more sensitive diagnostics is evident. In this review, we evaluate the merits and limitations of the principal diagnostic methods, namely detection of eggs in faeces; anti-schistosome antibodies in serum; parasite-derived proteins and glycans in serum or urine; parasite DNA in blood, faeces or urine. Only in the baboon model, where actual worm burden is determined by portal perfusion, have faecal smear and circulating antigen methods been calibrated, and shown to have thresholds of detection of 10–19 worm pairs. There is scope for improvement in all the four methods of detection, e.g. the identification of single targets for host antibodies to improve the specificity of enzyme linked immunosorbent assay. Despite recent advances in the definition of the schistosome secretome, there have been no comprehensive biomarker investigations of parasite products in the urine of infected patients. Certainly, the admirable goal of eliminating schistosomiasis will not be achieved unless individuals with low worm burdens can be diagnosed.
Ethametsulfuron Interactions with Grass Herbicides on Canola (Brassica napus, B. rapa)
Authors: Harker K. Neil , Blackshaw Robert E. , Kirkland Ken J.
Published: March 2018

Field experiments were conducted from 1986 to 1988 at Lacombe and Lethbridge, Alberta and Scott, Saskatchewan to determine growth and yield response of canola to mixtures of ethametsulfuron with specific grass herbicides. Ethametsulfuron did not usually cause canola injury when mixed with sethoxydim. However, ethametsulfuron mixtures with the following grass herbicides listed in decreasing order of injury potential, often caused canola injury and yield loss: haloxyfop > fluazifop > fluazifop-P > quizalofop > quizalofop-P. Canola yield losses were severe in some experiments, ranging from 59% with quizalofop mixtures to 97% with haloxyfop mixtures; in other experiments, the same mixtures did not cause significant yield losses. ‘Tobin,’ aBrassica rapacultivar, tended to be more susceptible to injury than theB. napuscultivars ‘Pivot’ and ‘Westar.’ Canola injury symptoms were consistent with those expected from sulfonylurea herbicides. Therefore, we suggest that specific grass herbicides differentially impair the ability of canola to metabolize ethametsulfuron to inactive forms.
Comparison of Single and Multiple Applications of Propanil and Residual Herbicides in Dry-Seeded Rice (Oryza sativa)
Authors: Crawford Stephen H. , Jordan David L.
Published: March 2018

Experiments were conducted on Sharkey clay and Gigger silt loam soils in northeast Louisiana from 1990 through 1993 to compare season-long barnyardgrass control, rice yield, and estimated economic returns with single and multiple applications of propanil alone or with molinate or thiobencarb. Multiple herbicide applications were more effective than single applications in controlling barnyardgrass and provided the greatest rice yields and economic returns. Applying residual herbicides with propanil improved barnyardgrass control in five of six experiments and increased rice yield and economic returns in three of six experiments.
Effect of Soil Type and Liming Rates on Rotational Forage Crop Injury Following Metsulfuron Methyl
Authors: Holloway James C. , Cole A. Wayne , Shaw David R.
Published: March 2018

Solution pH from 6.0 to 8.0 did not affect the germination of Italian ryegrass, ‘Pensacola bahiagrass,’ or common bermudagrass grown in petri dishes in growth chambers. Seeding intervals following metsulfuron methyl application varied from species to species and between soil types. Greenhouse studies indicated that in an Okolona silty clay, common bermudagrass should not be planted until 12 wk after metsulfuron methyl application. Italian ryegrass showed no metsulfuron methyl injury at the 6-wk sampling date when no lime was added, indicating reseeding was feasible at this time; however, a 12-wk time interval was not sufficient when lime was applied. Pensacola bahiagrass was injured when reseeded at 12 wk, regardless of liming rate. In a Prentiss fine sandy loam soil, common bermudagrass could be reseeded 12 wk after application when no lime was added, but not when lime was added. Italian ryegrass and Pensacola bahiagrass should not be reseeded for at least 12 wk, regardless of lime rate. Field experiments, where metsulfuron methyl was applied to the field and seeding was carried out in the greenhouse, indicated on the Okolona silty clay that common bermudagrass reseeding could occur at all liming rates after 3 wk, and Italian ryegrass and Pensacola bahiagrass after 6 wk. In the Prentiss fine sandy loam, common bermudagrass reseeding could occur at 3 wk, regardless of lime rate. Italian ryegrass emergence was not affected when reseeded immediately after metsulfuron methyl application, but height was reduced for longer periods, and increased lime rate lengthened this interval. Pensacola bahiagrass reseeding was feasible at 3 wk.
Influence of Rainfree Period After Asulam Application on Johnsongrass (Sorghum halepense)Control
Authors: Bruff Stacey A. , Griffin James L. , Richard Edward P.
Published: March 2018

A rainfall simulator was used to deliver the equivalent of 1.3 cm of water in 0.25 h at 0, 3, 6, 12, 24, and 48 h after POST applications of asulam to johnsongrass in greenhouse and field studies. Johnsongrass control responses were similar when asulam was applied with either a crop oil concentrate or a commercially blended organosilicone/crop oil concentrate premix. Rainfall 24 h after asulam application reduced johnsongrass control in greenhouse studies. Maximum visual johnsongrass control of 80, 69, and 69% was obtained in field studies when rainfall occurred 20, 14, and 8 h after asulam application, respectively. Based on reductions in johnsongrass dry weight, rainfree periods needed to insure maximum performance with asulam in field studies ranged from 3 to 16 h. Variation in critical rainfree periods was related to plant growth stage when asulam was applied and environmental conditions and is indicative of the inconsistency in johnsongrass control commonly observed with asulam.
Littleseed Canarygrass (Phalaris minor) Resistance to Isoproturon in India
Authors: Malik Ram K. , Singh Samunder
Published: March 2018

The response of littleseed canarygrass biotypes to isoproturon, pendimethalin, and diclofop-methyl was evaluated in India, in pot studies and the field during the winters of 1991 to 1992 and 1992 to 1993. Some biotypes of littleseed canarygrass were resistant to isoproturon but cross-resistance to pendimethalin and diclofop-methyl was not confirmed. The resistant biotype required a higher dose of diclofop-methyl than the susceptible biotype. Variations in the response of littleseed canarygrass biotypes were not due to isoproturon formulation. Resistant biotypes required 2 to 8 times more isoproturon than a susceptible biotype for the same level of control. Diclofop-methyl at 1.0 kg ai/ha applied at the 2- to 3-leaf stage of littleseed canarygrass in pot experiments and PRE pendimethalin at 1.5 kg ai/ha in field trials controlled resistant biotypes. Field surveys of the affected areas revealed that resistance in littleseed canarygrass is more prevalent in rice-wheat rotations compared to other crop sequences. Control of littleseed canarygrass with isoproturon dropped from 78 to 21% from 1990 to 1993.
Interactions of Foliar Insecticides Applied with Pyrithiobac
Authors: Allen Ralph L. , Snipes Charles E.
Published: March 2018

Field and greenhouse experiments were conducted to determine the effect of selected insecticides on cotton when applied in combination with pyrithiobac. In the field, acephate, azinphos-methyl, bifenthrin, chlorpyrifos, dicrotophos, esfenvalerate, malathion, methomyl, or oxamyl was applied foliarly with the sodium salt of pyrithiobac at 70 g ae/ha. Pyrithiobac plus malathion resulted in greatest injury when compared with other treatments. There were no differences observed in fruiting characteristics of cotton. Cotton yield was lower with oxamyl, methomyl, and chlorpyrifos when applied in combination with pyrithiobac in one of three experiments. In greenhouse experiments, injury due to pyrithiobac was greater in a cool (21 C day, 13 C night) temperature than in a warm temperature (30 C day, 21 C night), but differences were less than 15%. Pyrithiobac plus malathion in the cool environment injured cotton more severely 7 DAT than either pesticide alone. Adding insecticides to pyrithiobac did not influence injury in the warm environment.
Winter Wheat (Triticum aestivum) Yield Response to Winter Annual Broadleaf Weed Control
Authors: Scott Robert C. , Peeper Thomas F. , Koscelny Jeffrey A.
Published: March 2018

Selected herbicide treatments from 25 winter annual broadleaf weed control experiments conducted across Oklahoma from 1979 to 1993 were examined for winter wheat yield response to weed control. All experiments contained one or two of the same three weeds (henbit, bushy wallflower, or cutleaf eveningprimrose) as the primary target(s). Herbicide treatments included chlorsulfuron at 8.8 or 17.6 g ai/ha, and/or 2,4-D at 420 g ae/ha, all broadcast POST to wheat. Most herbicide treatments controlled the weeds, but increased wheat grain yield at only one site, wherein bushy wallflower density was 830/m2. Correlation analysis found no relationship between weed densities and wheat yield when chlorsulfuron at 8.8 g/ha was applied for henbit or moderate levels of bushy wallflower or cutleaf eveningprimrose. There was a significant positive relationship favoring spraying of bushy wallflower when the correlation analysis included data from one site with a density of 830 plants/m2.
Sensitivity of Selected Field Corn Inbreds (Zea mays) to Nicosulfuron
Authors: Widstrom Neil W. , Dowler Clyde C.
Published: March 2018

A small percentage (< 5%) of dent corn inbreds was sensitive to the herbicide nicosulfuron. Segregation within a backcross to inbred Ab18 demonstrated simple inheritance as a nuclear gene for corn sensitivity to this herbicide. Greenhouse tests indicated that cytoplasmic or maternal effects were not important in conditioning sensitivity. Tolerance in some crosses began to break down at application rates approaching twice that registered. Sensitivity was controlled by a single autosomal recessive gene in the inbred Ab18. Further testing will be required to determine whether this gene is common to other sensitive inbreds. Thorough screening continues to be necessary to identify sensitive elite inbreds in public and private breeding programs.
Common Lambsquarters (Chenopodium album) and Rotational Crop Response to Imazethapyr in Pea (Pisum sativum) and Snap Bean (Phaseolus vulgaris)
Authors: Vencill William K. , Wilson Henry P. , Hines Thomas E. , Hatzios Kriton K.
Published: March 2018

Field studies were conducted in 1987 and 1988 to investigate the control of common lambsquarters in pea and snap bean following preplant incorporated, preemergence, and postemergence applications of imazethapyr at 36 to 69 g ai/ha. The residual activity of imazethapyr on rotational crops of sweet corn, grain sorghum, and cucumber was evaluated. All rates of imazethapyr provided good (>80% initially) control of common lambsquarters. Although imazethapyr caused some injury to both pea and snap bean, yields were not reduced except for snap bean following postemergence applications. Imazethapyr residues resulting from the applications of 36 to 69 g/ha caused visible injury and fresh weight reductions to all three rotational crops.
Development of an Experimental Plot Sprayer
Authors: Chagnon Roger , Benoit Diane L. , Grunfeld Eva
Published: March 2018

An experimental plot sprayer, with a new mixing chamber and water measuring system, was developed to minimize operator exposure to pesticides during mixing and rinsing. Premeasured herbicide samples in 50-ml capped test tubes are emptied into the mixing chamber, and water is measured, rinses the test tube, and drains into the chamber to produce the spraying volume. This system eliminates operator contact with the chemicals and can be flushed quickly between plots to eliminate contamination. Rinsing efficiency with atrazine was greater for a suspension than a wettable powder formulation but less than 0.1% of the initial concentration was detected in water following the first or second rinsing.
Alfalfa (Medicago sativa) Seed Yield Response to Herbicides
Authors: Malik Najib , Waddington John
Published: March 2018

Seedling alfalfa was injured by chlorsulfuron and sethoxydim plus 2,4-DB but recovered the following year as alfalfa seed yields were comparable to the hand-weeded control. Fluazifopbutyl and flamprop-methyl (active isomer) at 0.5 kg/ha did not affect seedling alfalfa adversely; however, seed yields were lower the following year compared to those treated at the 0.25-kg/ha rate. In established alfalfa, sethoxydim alone or with 2,4-DB applied annually did not affect seed yields adversely. However, 2,4-DB alone reduced seed yields in 2 of 5 yr. Alfalfa tolerated chlorsulfuron at 0.015 kg/ha but was damaged at the 0.03-kg/ha rate. Initial injury and later recovery without adverse effects on seed yield also were observed following annual treatments with bromoxynil, MCPA plus 2,4-DB and bentazon plus 2,4-DB.
Yellow Nutsedge (Cyperus esculentus) Management in Transplanted Onions (Allium cepa)
Authors: Keeling J. Wayne , Bender David A. , Abernathy John R.
Published: March 2018

Studies were conducted to evaluate preplant incorporated (PPI), preemergence (PRE), and postemergence (POE) herbicide treatments on yellow nutsedge control and on growth and yield of transplanted onions. Most effective yellow nutsedge control (≥80%) was achieved with metolachlor applied PPI plus PRE. Metolachlor and SAN 582H were more effective applied PPI than PRE. Bentazon alone applied POE adequately controlled yellow nutsedge only 1 of 2 yr. Highest onion yields and percent jumbo bulbs were produced when treatments included metolachlor applied PPI.
Timing Effects on Johnsongrass (Sorghum halepense) Control with Asulam in Sugarcane (Saccharumsp.)
Authors: Richard Edward P.
Published: March 2018

Full-season johnsongrass competition reduced sugar yields by 53 and 44% in ‘CP 70–321’ and ‘CP 72–370’ sugarcane, respectively, primarily by reducing sugarcane stalk populations. Stalk population and height and sugar yields of both cultivars were optimized when asulam was applied at 3.7 kg ai/ha during April and early May. Asulam at 3.4 kg/ha, applied a second time 8 weeks later, generally increased johnsongrass control but did not increase sugar yields over one early application. By delaying the application, the potential for sugarcane injury from asulam applied once or twice increased in both cultivars. Injury appeared to be related to the stage of sugarcane growth and temperature and moisture stress at application time with asulam phytotoxicity being more pronounced in CP 72–370. Populations of johnsongrass stems in the year after treatment reflected the degree of johnsongrass control by asulam and the competitiveness of the crop in the previous year.
A Biotype of Goosegrass (Eleusine indica) With an Intermediate Level of Dinitroaniline Herbicide Resistance
Authors: Vaughn Kevin C. , Vaughan Martin A. , Gossett Billy J.
Published: March 2018

Two kinds of dinitroaniline-resistant biotypes of goosegrass have been found in counties in South Carolina where trifluralin is used for weed control. One biotype, termed the resistant (R) biotype, resists trifluralin about 1000- to 10 000-fold. The other biotype is intermediate (I) in resistance between the R and susceptible (S) biotypes, resisting trifluralin about 50-fold. Growth studies and root tip squashes were used to determine the level of resistance to other dinitroaniline herbicides. The R biotype is cross resistant to all dinitroaniline herbicides, and the I biotype is highly resistant to some and is resistant to others only at a low level. The cross resistance of the I biotype to other dinitroaniline herbicides does not correlate with structural or solubility characteristics of the herbicides. Electron microscopic investigations indicate that cell plate formation (controlled by phragmoplast microtubule arrays) is affected at lower herbicide concentrations than spindle microtubule formations. The level of herbicide resistance, the pattern of cross resistance, and the ultrastructural effects induced by the herbicide indicate that the I biotype has a unique mechanism of resistance from the R biotype.
Resistance of Kochia (Kochia scoparia) to Sulfonylurea and Imidazolinone Herbicides
Authors: Primiani Michael M. , Cotterman Josephine C. , Saari Leonard L.
Published: March 2018

A biotype of kochia resistant to chlorsulfuron has been isolated from a Kansas wheat field that had been treated with chlorsulfuron for five consecutive years. In greenhouse tests, the biotype also was resistant to both preemergence and postemergence herbicides with the same mode of action including imazapyr, CGA-131036, the methyl ester of metsulfuron, DPX-M6316, DPX-L5300, and the methyl ester of sulfometuron. The degree of cross resistance varied among the herbicides tested. Herbicides with different modes of action, including atrazine, bromoxynil, MCPA, and diuron, effectively controlled the resistant biotype in the greenhouse.
Herbicide-resistant Weeds in Australia
Authors: Powles Stephen B. , Howat Peter D.
Published: March 2018

This review considers the development of herbicide-resistant weed biotypes in Australia. Biotypes of the important annual weed species, capeweed, wall barley, and hare barley are resistant to the bipyridylium herbicides paraquat and diquat. These resistant biotypes developed on a small number of alfalfa fields that have a long history of paraquat and diquat use within a distinct geographical area in central western Victoria. The resistant biotypes are controlled by alternative herbicides and pose little practical concern. Some populations of wild oat are resistant to the methyl ester of diclofop. Of greatest concern is the development of cross resistance in biotypes of rigid ryegrass to aryloxyphenoxypropionate, cyclohexanedione, sulfonylurea, and dinitroaniline herbicides. The cross-resistant rigid ryegrass infests crops and pastures at widely divergent locales throughout the cropping zones of southern Australia. The options for control of cross-resistant rigid ryegrass by herbicides are limited. A biotype of rigid ryegrass on railway tracks treated for 10 yr with amitrole plus atrazine has resistance to amitrole and atrazine and other triazine, triazinone, and phenylurea herbicides. Management tactics for cross resistance are discussed.
Weed Potential of the Forage Legume Aeschynomene (Aeschynomene americana) in Rice (Oryza sativa) and Soybeans (Glycine max)
Authors: Thro Ann M. , Wier Alan T. , Barker F. Gilbert
Published: March 2018

Growth room and field studies were conducted to determine if increasing use of forage aeschynomene may lead to new weed problems in rice and soybeans and to identify possible control measures in these crops. In a growth room study, flooding of ‘Florida Common’ and ‘LSU 1147’ forage aeschynomene did not reduce yield. However, forage aeschynomene seedlings did not emerge from a flooded seedbed, and 1-week-old seedlings were killed by 2.5 or 7.5 cm of flooding. Competition from interseeded forage aeschynomene reduced ‘Centennial’ soybean yields by 81%. Acifluorfen, fomesafen, and lactofen, labeled for soybeans, control forage aeschynomene. Acifluorfen, labeled for rice, may control forage aeschynomene in that crop. Forage aeschynomene might become a weed problem in rice if plants are past the seedling stage when flood water is applied and could cause weed problems in soybeans; but, in most situations, cultural and chemical control practices should provide adequate control.
Effect of BAS-145-138 as an Antidote for Sulfonylurea Herbicides
Authors: Devlin Robert M. , Zbiec Irena I.
Published: March 2018

BAS-145-138 considerably muted the herbicidal effect of the sulfonylurea herbicides on corn. Decreases of 54 and 52% in shoot fresh and dry weight caused by 10 μM chlorsulfuron were countered almost completely by 1.5 mM BAS-145-138 with only a 10% loss in fresh weight and a 3% loss in dry weight. Similar strong antidotal influence by BAS-145-138 on chlorimuron was observed. BAS-145-138 partially protected corn against sulfometuron. Shoot fresh weight of corn treated with 0.2 μM sulfometuron was inhibited 88%, whereas adding 0.5 or 1.5 mM BAS-145-138 reduced inhibition to 52 and 24%, respectively.
Effect of Herbicides on Soybean Thrips (Sericothrips variabilis) in Soybeans (Glycine max)
Authors: Huckaba R. M. , Coble H. D.
Published: March 2018

Field studies were conducted to determine the effect of several herbicides on soybean thrips numbers in soybean. Adult soybean thrips numbers in the preplant-incorporated and preemergent herbicide treatments were observed to be either greater than or equal to, but never less than, numbers in the control plots. Larval soybean thrips numbers were not observed to be affected by the preplant-incorporated or preemergent treatments. The postemergence herbicide treatment of naptalam plus dinoseb consistently reduced both adult and larval soybean thrips numbers. The other postemergent treatments did not affect numbers consistently.
Loose Silky Bentgrass (Apera spica-venti) Control in Fall Rye (Secale cereale)
Authors: Zilkey Bryan F. , Capell Brent B.
Published: March 2018

Field experiments were conducted over a 3-yr period to evaluate the efficacy and crop yield response of selected herbicides to control loose silky bentgrass in fall rye. Loose silky bentgrass was controlled 18 to 100% with trifluralin preemergence incorporated at 0.4 to 0.6 kg ai ha-1, chlorsulfuron preemergence at 0.024 kg ha-1 and metsulfuron early postemergence at 0.006 to 0.024 kg ha-1. Rye yield was unaffected by these herbicides 2 of 3 yr. In a farm demonstration trial trifluralin preemergence incorporated at 0.4 kg/ha controlled loose silky bentgrass.
Fenoxaprop for Annual Foxtail (Setariasp.) Control in Seedling Perennial Forages
Authors: Linscott Dean L. , Vaughan Richard H.
Published: March 2018

Seedling timothy tolerated fenoxaprop at 0.09 kg ai ha-1whereas seedling orchardgrass tolerated applications as high as 0.13 kg ai ha-1. Several fenoxaprop treatments increased perennial grass yields the year following establishment. Fenoxaprop appears to solve annual foxtail problems in new plantings of orchardgrass or timothy seeded alone. Over a 2-yr period, alfalfa yields in on alfalfa-grass mixture were maintained or increased from fenoxaprop applied the seedling year. In the mixtures, timothy yield declined in relation to fenoxaprop applied, but orchardgrass did not. Use of fenoxaprop on seedling alfalfa-timothy or alfalfa-orchardgrass mixtures is questionable.
Methodology for Establishing Witchweed (Striga asiatica) in Research Plots
Authors: Ransom Joel K. , Eplee Robert E. , Langston Marion A. , Norris Rebecca S.
Published: March 2018

Experiments were conducted in North Carolina and South Carolina, 1989, to evaluate methods of infesting research plots with witchweed. At both locations sowing witchweed (mixed with very fine sand) in or beneath the maize planting hole resulted in more rapid attachment of witchweed than other methods. Sowing witchweed only in the maize planting hole increased significantly witchweed attachment compared to the control late in the season at Evergreen, NC. At Dillon, SC, in fumigated soil, sowing witchweed seeds to the side of the maize row in a band or in planting holes or broadcasting and incorporating with a hoe increased witchweed attack. Broadcasting and raking was ineffective.
Wild Garlic (Allium vineale) Control with Thifensulfuron and DPX-L5300
Authors: Gast Roger E. , Liebl Rex A. , Slife Fred W.
Published: March 2018

Field studies were conducted over 2 yr and two locations per year in soft red winter wheat to determine the efficacy of thifensulfuron and thifensulfuron plus DPX-L5300 (2:1 ratio) on all wild garlic reproductive bulbs. The herbicide formulations controlled wild garlic equally. Aerial bulblet control was excellent (>90%) with either herbicide regardless of application timing (March 21, April 8, and April 29) and significantly better than the standard treatment of the butoxyethanol ester of 2,4-D. Control of developing underground offset bulbs was less complete compared to aerial bulblets, and was found to depend on application time. Offset bulbs were controlled better when herbicides were applied in late March or early April compared to the April 29 treatment date. The rate response (9 to 70 g ha-1) was positive for the control offset bulb production at the two earlier dates but not at April 29. These herbicides also adversely affected the germination and viability of the bulbs that were produced.
Weed Control During Establishment and Yield Response of Timothy (Phleum pratense)
Authors: Malik Najib
Published: March 2018

The effects of 14 herbicide treatments, tested in the establishment phase, were investigated on timothy productivity in two field experiments conducted at Melfort, Saskatchewan. Satisfactory weed control achieved with chlorsulfuron, metsulfuron, thifensulfuron, bentazon, diclofop plus bromoxynil, and MCPA/mecoprop/dicamba during the establishment year ensured good forage establishment which in turn caused a ‘residual effect’ for 1 to 3 yr increasing individual cut as well as cumulative forage dry matter yields significantly. In the stand established in 1985, when field pennycress (97 m-2) was the dominant weed in the seedling stage, these treatments increased yields 29 to 52% over a 3-yr period. In the stand established in 1986, when common lambsquarters (27 m-2) was the dominant weed, these treatments increased cumulative yields 24 to 44%. Sethoxydim and fenoxaprop, tested alone, caused significant crop injury in both experiments.
An Inexpensive Rhizotron for Teaching Weed Biology
Authors: Gallandt Eric R. , Raitt Gary G. , Fay Peter K.
Published: March 2018

A rhizotron containing 10 1.5-by 1.2-by 2.4-m chambers and two 1.5-by 1.2-by 1.2-m chambers for plant growth was constructed for teaching purposes at Montana State University. The rhizotron, constructed of pressure-treated plywood and redwood lumber, has a life expectancy of 40 yr and a prorated cost of approximately $100/yr.
Undergraduate Essay: St. Johnswort, A Potential Problem in Pasture Land in Nova Scotia
Authors: Robinson Darren K.
Published: March 2018

Recently, a problem has developed in Hants County, Nova Scotia, Canada. The weed species common St. Johnswort (Hypericum perforatum L.), has become established in areas of West Hants County. It had previously been found along roadsides and ditched embankments, but it has now made its way into established pastures. On June 13, 1987, a local beef producer reported a case of photosensitization from grazing common St. Johnswort in one of her nurse cows. No prior cases had been reported in the province, although a neighboring farmer had lost cattle in the previous two years. This sparked the concern of farmers and agriculture representatives in the area as to the potential problem from this weed.
Cheeseweed–The Common Mallows
Authors: Mitich Larry W.
Published: March 2018

Because of its dissipated appearance and enormous profusion on waysides and in vacant lots during northern California winters, mallow (Malva spp.) is one of the last uncultivated herbs I would have considered eating. My mistake. Several species of weedy Malva have been used interchangeably for food, tea, and medicine for thousands of years–among them little mallow (Malva parviflora L. ♯3 MALPA), common mallow (M. neglecta Wallr. ♯ MALNE), round-leaf mallow (M. rotundifolia L.), and high mallow (M. sylvestris L. ♯ MALSI).
Imazethapyr Efficacy with Adjuvants and Environments
Authors: Nalewaja John D. , Palczynski Jerzy , Manthey Frank A.
Published: March 2018

Adjuvant effectiveness with imazethapyr for kochia control was generally methylated seed oil ≥ nonionic surfactant ≥ petroleum oil in the greenhouse experiments, and methylated seed oil ≥ petroleum oil nonionic surfactant in the field. Oil adjuvants were applied at 2.3 L ha-1and nonionic surfactants were applied at 0.25% (v/v) of spray volume. None of the adjuvants overcame imazethapyr reduced phytotoxicity caused by simulated rain soon after treatment, posttreatment cold (10 C), low soil moisture, or low soil nitrogen. However, kochia fresh weight reductions usually were the greatest when imazethapyr was applied with methylated seed oil, except in the case when soil had 80 ppm or less soil nitrogen. Kochia control with imazethapyr was enhanced the most by methylated seed oil followed by nonionic surfactant and petroleum oil regardless of relative humidity. High compared to low relative humidity tended to increase control for imazethapyr alone or with nonionic surfactant and decrease control for imazethapyr with oils. Kochia fresh weight reduction following imazethapyr treatment was greatest at 20 C, intermediate at 30 C and least at 10 C posttreatment when used with any of the adjuvants.
Shattercane (Sorghum bicolor) Control in Soybeans (Glycine max) with Preplant and Postemergence Herbicides
Authors: Defelice Michael S.
Published: March 2018

Field studies were established to evaluate several new herbicides for preplant incorporated and postemergence shattercane control in soybeans. Imazethapyr applied postemergence controlled shattercane most consistently. The type of adjuvant tank mixed with sethoxydim did not influence shattercane control, panicle production, or soybean yields. Preplant incorporated applications of imazethapyr, imazaquin, or clomazone either alone or tank mixed with trifluralin or pendimethalin gave inconsistent shattercane control and soybean yields compared to handweeded plots.
Horseweed (Conyza canadensis) Control in Full-Season No-Till Soybeans (Glycine max)
Authors: Moseley Carroll M. , Hagood Edward S.
Published: March 2018

Cyanazine and 2,4-D were the most effective herbicides for horseweed control before establishing full-season no-till soybeans. Paraquat plus 2,4-D was less effective than 2,4-D alone but superior to paraquat alone. Chlorimuron plus metribuzin or chlorimuron plus linuron was less effective than cyanazine but controlled horseweed better than metribuzin, linuron, or imazaquin. Herbicides were generally more effective when applied early. These studies indicate paraquat was antagonistic to 2,4-D for horseweed control when these herbicides were combined.
Interference and Critical Time of Removal of Hemp Sesbania (Sesbania exaltata) in Cotton (Gossypium hirsutum)
Authors: Bryson Charles T.
Published: March 2018

Hemp sesbania interference in cotton was investigated in the greenhouse and in a 2-yr field experiment at Stoneville, MS. In greenhouse experiments, cotton and hemp sesbania heights and plant dry weights (PDW) were not different in ratios of cotton to hemp sesbania of 4:0, 2:2, 1:3, and 0:4 at 3 and 5 wk after emergence (WAE). Hemp sesbania PDW were less for ratios of cotton to hemp sesbania of 3:1 when compared to hemp sesbania PDW of other ratios. Early season cotton seedling vigor and growth (0 to 28 DAP) were not affected by 32 000 hemp sesbania plants ha-1(3 plants m of row-1). Hemp sesbania plants were hand removed 28, 42, 56, 70, and 84 d after planting (DAP). White cotton blooms and yields were reduced when hemp sesbania plants were not removed by 70 DAP. Seed cotton yields were 2590, 2570, 2460, 2030, 1610, and 1070 kg ha-1for hemp sesbania removed at 28, 42, 46, 70 and 84 DAP or not removed, respectively. The critical period of weed control or removal of hemp sesbania in cotton is ≤62 DAP.
Growth and Development of Bulbous Oatgrass (Arrhenatherum elatiusvar.bulbosum)
Authors: Tanphiphat Karin , Appleby Arnold P.
Published: March 2018

Bulbous oatgrass, a weed in parts of the United States and Europe, is an unusual grass, which forms corms at the stem base. Growth and development of this creeping perennial grass was investigated in the field and in pots outdoors. Under the mild climate of the Willamette Valley, Oregon, shoots emerged in early autumn. Plants grew vegetatively and formed corms during the winter and spring. Aboveground portions of the plant stopped growing and senesced in the summer. The absolute growth rate of the plants was highest in early May, shortly before the onset of flowering. In early May, the growth rate of corms was higher than that of the shoot.
Woolly Croton (Croton capitatus) and Bitter Sneezeweed (Helenium amarum) Control in the Blackland Prairie of Texas
Authors: Bovey Rodney W. , Meyer Robert E.
Published: March 2018

Field studies were conducted in 1984 and 1986 to identify herbicides that would control woolly croton and bitter sneezeweed on grazing land in the Blackland prairies of Texas. Herbicides included chlorsulfuron, clopyralid, dalapon, dicamba, 2,4-D, glyphosate, metsulfuron, picloram, tebuthiuron, 2,4,5-T, and triclopyr. Chlorsulfuron and metsulfuron applied at 0.018 kg ha-1and 2,4-D, picloram, 2,4,5-T, and triclopyr at 0.28 kg ha-1controlled >80% of the woolly croton. Metsulfuron controlled more than 90% of the bitter sneezeweed at 0.018 kg ha-1. Similar control was obtained with clopyralid, glyphosate, and picloram each at 0.28 kg ha-1. Bermudagrass cover increased with all herbicide treatments except dalapon at one of three sites.
Italian Ryegrass (Lolium multiflorum) Control in Small Grains with Flurtamone
Authors: Bridges David C.
Published: March 2018

Research was conducted on a sandy clay loam in Georgia during 1987–88 and 1988–89 to determine winter wheat, oats, barley, and Italian ryegrass tolerance to flurtamone. Flurtamone was applied PPI, PRE, and early POST at 0.28, 0.56, and 1.1 kg ai ha-1. Order of tolerance of the four species was barley > wheat > oat > Italian ryegrass. Flurtamone potentially can be used to control Italian ryegrass in winter wheat and barley, but not in oats. In general, wheat and oat injury with flurtamone was PPI > PRE ≥ early POST, particularly at 1.1 kg ha-1.
Effects of CO2, N2, Air, and Nitrogen Salts on Spray Solution pH
Authors: McCormick Ronald W.
Published: March 2018

Water samples from eight locations, ranging in pH from 7.1 to 8.5, were tested to determine the effect of carbon dioxide (CO2) pressurization on pH. After pressurization with CO2the pH of the water decreased 1.8 to 4.1 pH units. An increase of 0.4 to 1.2 pH units occurred after the CO2pressurized water exited a spray nozzle. The use of N2or air as a pressurizing gas had very little effect on pH. The addition of diammonium phosphate, urea-ammonium nitrate (UAN)3, or ammonium sulfate had only minor effects on water pH. The addition of monoammonium phosphate reduced water pH to 4.6 to 5.5. The physical/chemical properties and activity of a herbicide may be altered with the change in spray solution pH by using CO2to pressurize the spray solution.
Spray Deposition of Clopyralid on Honey Mesquite (Prosopis glandulosa)
Authors: Bovey Rodney W. , Stermer Raymond A. , Bouse Louis F.
Published: March 2018

Greenhouse and laboratory experiments were conducted to evaluate the influence of clopyralid formulation, spray droplet size, and spray volume on deposit of clopyralid on greenhouse-grown honey mesquite. The addition of surfactant WK at 0.5% (v/v) of the spray solution caused a twofold increase in deposition of spray of the monoethanolamine salt (MEA) of clopyralid but not the oleylamine salt (OLA). There were no differences in spray deposit between spray droplet size spectrums of 160 or 330 μm Dv.5or spray solution applications of 47 or 187 L ha-1. Dye and gas chromatography measurements of spray deposit of clopyralid compared favorably except where surfactant WK was used with the OLA formulation.
BAY SMY 1500 for Selective Control of Black Nightshade (Solanum nigrum) and Other Weeds in Tomato (Lycopersicon esculentum) Fields
Authors: Kleifeld Yeshaiahu , Blumenfeld Titi , Herzlinger Geza
Published: March 2018

Black nightshade was selectively controlled along with other annual weeds in direct-seeded tomatoes by BAY SMY 1500 applied preemergence. BAY SMY 1500 was also found selective for transplanted tomatoes when applied prior to transplanting or soon after planting prior to black nightshade emergence. Black nightshade control and crop selectivity were obtained with BAY SMY 1500 at 0.75 and 1.25 kg ai ha-1applied on sandy loam and clay loam soils, respectively.
Response of Quackgrass (Elytrigia repens) Biotypes to Primisulfuron
Authors: Gillespie Greg R. , Vitolo David B.
Published: March 2018

Quackgrass biotypes collected from 15 locations exhibited differential response to primisulfuron at 20 g ha−1in field experiments at Hudson, NY during 1990 and 1991. Quackgrass control ranged from 23 to 100% 77 days after application (DAA) in 1990 and from 38 to 100% 88 DAA in 1991. The biotype from Montpelier, OH was the most tolerant both years. Differential response of quackgrass biotypes from five locations was confirmed in greenhouse experiments. The primisulfuron rate required to reduce shoot regrowth by 50% in the greenhouse was estimated at 15, 15, 17, 17, and 37 g ha−1for biotypes from Amherst, MA; Mahnomen MN; Fargo, ND; State College, PA; and Montpelier, OH, respectively. Quackgrass shoot regrowth was reduced more when primisulfuron was applied with the linear alcohol ethoxylate additive 1412-70 compared with Scoil, Sylgard 309, Agridex, or X-77.
Cover Crop Management and Weed Control in Corn (Zea mays)
Authors: Johnson Gregg A. , Defelice Michael S. , Helsel Zane R.
Published: March 2018

Field experiments were conducted in central Missouri in 1989 and 1990 to evaluate weed control practices in conjunction with cover crops and cover management systems in reduced tillage corn. There was no difference in weed control among soybean stubble, hairy vetch, and rye soil cover when averaged over cover management systems and herbicide treatments. However, mowed hairy vetch and rye covers provided greater weed control in the no-till plots than soybean stubble when no herbicide was used. Differences in weed control among cover management systems were reduced or eliminated when a PRE herbicide was applied. corn population and height were reduced by hairy vetch and rye soil cover. Corn grain yield was reduced in rye plots both years. There was no difference in grain yield between tilled and no-till plots.
Weed Science—The Step Child
Authors: Burnside Orvin C.
Published: March 2018

A brief evolutionary description is given of the development of the discipline of weed science in the United States. Topics discussed include public recognition of weed science, losses from weeds, allocation of resources, herbicide usage, and future predictions of the development of the discipline. Weed scientists have had a major impact during the past four decades in increasing crop yields and reducing labor requirements for controlling weeds in crop production systems. Weed scientists have been so effective that recognition of their contributions and impact have often been overlooked in academic institutions but not in private industries that have staffed for herbicide development.
Effects of Weed Control and Irrigation on Pecan (Carya illinoinensis) Growth and Yield
Authors: Patterson Michael G. , Goff William D.
Published: March 2018

Pecan trees subjected to different weed control and irrigation regimes from planting in 1986 through 1993 produced similar yields when irrigated (400 kg/ha, 3-yr avg) and not irrigated (320 kg/ha, 3-yr avg). Trees receiving total chemical weed control produced over five times more pecans (735 kg/ha, 3-yr avg) than weedy trees (131 kg/ha, 3-yr avg). Trees receiving disking produced more pecans when irrigated (677 kg/ha, 3-yr avg) than when not irrigated (339 kg/ha, 3-yr avg). Growth rate, expressed as increase in tree stem diameter, decreased for trees in all treatments once trees began bearing.