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31.
H.Mark Hanna Stephen J. Marley Donald C. Erbach Stewart W. Melvin 《Soil & Tillage Research》1994,28(3-4):315-328
A field experiment was conducted to measure surface soil velocity and to determine the relation between soil aggregate velocities at the tool surface and at the soil surface.
A technique incorporating use of both a video camcorder and wood blocks was developed to measure surface soil velocity. Soil velocity direction at the tool surface was measured from scratch marks on the tool. Velocity measurements were made for three sweeps with different rake angles operated at three speeds and two depths.
Surface soil moved in either of two modes: V-flow (upward and laterally in the shape of one leg of the letter V) or snowplow (initially moving upward and subsequently being buried in a wave of soil). Surface soil velocities were uncorrelated with velocities on the tool surface, indicating that soil flow paths over the sweep were not parallel. The ratio of vertical to lateral soil flow at the tool surface increased with larger rake angle and was greater than the ratio at the soil surface. At the soil surface, vertical velocity was greater near the nose than near the wing tip and velocity parallel to the travel direction increased with increased speed and rake angle. 相似文献
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Striga hermonthica is a major biotic constraint to sorghum production in Nigeria, sometimes causing total yield loss. Recommendations for Striga management often include the use of cultural and agronomic practices, herbicides and host plant resistance when available. The use of biological control has not been commercialized. Fusarium oxysporum (isolate PSM 197)‐based mycoherbicide was used in combination with selected sorghums (the Striga‐resistant cultivar Samsorg 40, and the Striga tolerant landrace Yar'ruruka) as an Integrated Striga Management strategy (ISM) in on‐farm trials in the Sudano‐Sahelian savanna of Nigeria. Crop stands were significantly (P = 0.05) higher in ISM compared with non‐ISM plots on which the mycoherbicide was not applied. Similarly, ISM plots had significantly (P = 0.05) lower Striga counts than non‐ISM plots. Striga emergence was reduced by ISM by around 95%. Sorghum yields were 49.6% higher where integrated management was used. Cost benefit analysis of the ISM package shows that use of the mycoherbicide increased the profitability of sorghum production on Striga‐infested soils. Farmers’ preferences monitored during and after the trials highlighted the need for careful selection and integration of control components into an ISM package. 相似文献
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Marley CL Cook R Barrett J Keatinge R Lampkin NH McBride SD 《Veterinary parasitology》2003,118(1-2):93-107
Studies in New Zealand and the UK have shown that lambs grazing birdsfoot trefoil (Lotus corniculatus) or chicory (Cichorium intybus) have reduced parasite intensities compared to lambs grazing ryegrass swards. However, data in the literature on the influence of forages on helminth parasites is equivocal and the underlying mechanisms by which different forage diets may affect these parasites have not been fully determined. The aim of the experiments reported here was to investigate the hypothesis that the consumption of these forages does not affect the hatching and development of helminth eggs in the faeces subsequently produced by the host animal. Lambs grazed monoculture swards of birdsfoot trefoil, chicory, Italian ryegrass (Lolium multiflorum)/red clover (Trifolium pratense) or perennial ryegrass (Lolium perenne)/white clover (Trifolium repens) for 5 weeks and faecal samples collected on days 14, 21, 28 and 35 directly from the rectum of each lamb were used to prepare replicate cultures for each forage type on each occasion. The experiment was repeated over two consecutive years but ryegrass/red clover was not included in Year 2. The dry matter of all faeces was made constant and the faeces were cultured at 27 degrees C for 7 days, before larvae were extracted, counted and identified according to genus or, where possible, species. Overall, the results showed that forage diet had no effect on egg hatchability but significantly affected the development/survival of infective helminth larvae in the faeces of the host animal. Furthermore, feeding birdsfoot trefoil to lambs was found to increase the percentage of helminth parasites that reached the infective stage in the subsequent faeces compared to other forages. Further work is needed to assess whether this would increase the number of larvae on birdsfoot trefoil swards overall under field conditions and to understand the implications of these findings in an applied farming system. 相似文献
35.
Antiparasitic activity of an ivermectin and praziquantel combination paste in horses 总被引：2，自引：0，他引：2
Marley SE Hutchens DE Reinemeyer CR Holste JE Paul AJ Rehbein S 《Veterinary therapeutics : research in applied veterinary medicine》2004,5(2):105-119
Modern anthelmintic use in horses has decreased the prevalence of the large strongyles, which has in turn shifted the focus of parasitologists to the pathogenic importance of the small strongyles, tapeworms, and other parasites. These studies show that a combination product containing ivermectin and praziquantel allowed efficacious treatment of horses for nematode, cestode, and bot infections. The use of this combination product may be of special benefit to horses that are mainly kept outdoors and on grazing pastures. 相似文献
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First documented pest outbreak of the herbivorous springtail Sminthurus viridis (Collembola) in Europe 
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下载免费PDF全文 F. V. Crotty R. Fychan C. M. Benefer D. Allen P. Shaw C. L. Marley 《Grass and Forage Science》2016,71(4):699-704
Sminthurus viridis (Collembola: Sminthuridae) is a native of grasslands across Europe and feeds preferentially on clover (Trifolium spp.) and lucerne (Medicago sativa), although its abundance does not normally reach damaging pest levels (as occurs in Australasia). This research note describes the first quantitative assessment of a pest outbreak of this springtail in Europe, which occurred within an existing experiment investigating the effects of cultivation practices on forage establishment. Using sticky traps to assess the incidence of S. viridis, we found a significant outbreak consisting of catches that were 10‐fold greater than background levels in nearby undamaged fields. Within the experimental area, lucerne established by direct drilling with herbicide had the highest incidence (105 (± 4·9) individuals per trap) compared to other treatments [79 (± 3·9)]. Results are discussed in terms of how cultivation practice may have imbalanced the ecosystem; for example, herbicide use may have diminished potential refugia for predators during forage establishment. This paper highlights the potential of a currently innocuous, widely established invertebrate to become present at damaging levels in agricultural crops. 相似文献
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S E Marley E F Illyes D S Keller T R Meinert N B Logan M O Hendrickx G A Conder 《American journal of veterinary research》1999,60(6):665-668
OBJECTIVE: To evaluate efficacy of topically administered doramectin against eyeworms, lungworms, and gastrointestinal nematodes of cattle. ANIMALS: 400 cattle (20 cattle in each of 20 trials). PROCEDURE: Trials were conducted in North America; natural and experimentally induced infections were used. In each trial, cattle were allocated randomly to control (placebo [saline [0.9% NaCl] solution at 1 ml/10 kg of body weight] or untreated; n = 10) or doramectin-treated (500 microg/kg of body weight; 10) groups. Treatments were applied in a single passage along the midline of the back, from the withers to the tailhead. Cattle were euthanatized > or =14 days after treatment, and worm burdens were determined by use of standard techniques. RESULTS: Efficacy of doramectin was > or =95.3% against adults of Thelazia gulosa, T skrjabini, Dictyocaulus viviparus, Haemonchus contortus, H placei, Ostertagia lyrata, O ostertagi, Trichostrongylus axei, Bunostomum phlebotomum, Capillaria spp, Cooperia oncophora, C pectinata, C punctata, C spatulata, C surnabada, Nematodirus spathiger, Strongyloides papillosus, T colubriformis, Oesophagostomum radiatum, and Trichuris spp. Efficacy was 95.1% against fourth-stage larvae of D viviparus, H placei, O lyrata, O ostertagi, T axei, C oncophora, C punctata, C spatulata, C surnabada, N helvetianus, T colubriformis, O radiatum, and Trichuris spp. In addition, efficacy against inhibited fourth-stage larvae of O ostertagi and Ostertagia spp was > or =98.1%. CONCLUSIONS AND CLINICAL RELEVANCE: A single topical application of doramectin pour-on was efficacious against a broad range of nematode species in cattle. 相似文献
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B E Stromberg B W Woodward C H Courtney W E Kunkle E G Johnson G L Zimmerman L A Zimmerman S E Marley D S Keller G A Conder 《Veterinary parasitology》1999,83(1):49-54
Three studies were conducted to evaluate the persistent efficacy of doramectin injectable solution against experimental challenges with infective larvae of Cooperia punctata and Dictyocaulus viviparus. In each study, four groups of ten randomly-assigned calves, negative for trichostrongyle-type eggs on fecal examination, were treated subcutaneously in the midline of the neck with saline (1 ml/50 kg) on Day 0 or doramectin (200 microg/kg = 1 ml/50 kg) on Day 0, 7, or 14. Two additional calves from the same pool of animals were randomly assigned as larval-viability monitors and received no treatment. On Days 14-28, approximately 1000 and 50 infective larvae of Cooperia spp. and D. viviparus, respectively, were administered daily by gavage to each animal in Groups T1-T4. On Day 28, the two larval-viability monitor calves were inoculated in a similar manner with a single dose of approximately 30000 and 2000 larvae of Cooperia spp. and D. viviparus, respectively. Equal numbers of calves from each treatment group were killed on Days 42-45, as well as the two viability monitor animals to enumerate worm numbers. A 2% or 5% aliquot of small intestinal contents and washings were examined for worm quantification and identification, while 100% of the lung recoveries were quantified and identified. For each study and across the three studies, geometric mean worm recoveries for each treatment group were calculated from the natural log transformed data (worm count + 1) and were used to estimate percentage reduction. In the three studies, doramectin injectable solution was 97.5% efficacious against lungworms for up to 28 days and was 99.8% efficacious in reducing infection resulting from challenge with infective larvae of C. punctata for at least 28 days post-treatment. 相似文献
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Benjamin W. Newcomer M. Shonda Marley Patricia K. Galik Yijing Zhang Kay P. Riddell David W. Boykin Arvind Kumar Leah A. Kuhnt Julie A. Gard M. Daniel Givens 《Canadian journal of veterinary research》2013,77(3):170-176
Bovine viral diarrhea virus (BVDV) is a widespread bovine pathogen capable of causing disease affecting multiple body systems. Previous studies have shown 2-(2-benzimidazolyl)-5-[4-(2-imidazolino)phenyl]furan dihydrochloride (DB772) effectively prevents BVDV infection in cell culture. The aim of this project was to assess the efficacy of DB772 for the prevention of acute BVDV infection. Four calves seronegative to BVDV were treated with DB772 and another 4 calves were treated with diluent only on the same dosing schedule. Each calf was subsequently challenged intranasally with BVDV. Virus was isolated consistently from untreated calves on days 4 to 8, while treated calves remained negative by virus isolation during this period. Azotemia was exhibited by all treated calves on day 4 resulting in the euthanasia of 1 calf on day 10 and the death of another on day 13. Virus was isolated from the 2 remaining treated calves on day 14 or 21. On day 21, both remaining treated calves and all 4 untreated calves had anti-BVDV antibody titers > 1:2048. This pilot study indicates that DB772 temporarily prevented acute disease due to BVDV, but carries a significant concern of renal toxicity. 相似文献