The effect of sowing date, stale seedbed, row width and mechanical weed control on weeds and yields of organic winter wheat   总被引：1，自引：0，他引：1  

I A Rasmussen 《Weed Research》2004,44(1):12-20

Three field experiments were carried out in organically grown winter wheat in Denmark. The treatments were sowing time (normal or late sowing) and false seedbed, row width (12 and 24 cm) and weed control method [untreated; mechanical weed control (weed harrowing at 12 cm supplemented with inter‐row hoeing at 24 cm); and herbicide weed control]. Weed biomass in midsummer was greatest on plots sown at the normal sowing time (compared with delayed sowing) and was reduced by mechanical or chemical weed control (compared with untreated plots). Row width alone had no influence on weed biomass, but in the experiment with high weed pressure, the more intensive mechanical weed control used at a row width of 24 cm reduced weed biomass. Normal sowing time tended to give higher yields, but this was only statistically significant in one of the three experiments. Wide rows gave a yield decrease in the experiment with low weed pressure. The effect of weed control on yield was dependent on the weed pressure. At low weed pressure, mechanical weed control caused a yield decrease compared with untreated or herbicide treated. At intermediate weed levels there were no differences, whereas at high weed pressure, mechanical weed control and herbicide treatment caused a yield increase compared with untreated. False seedbeds were shown to contribute to a decrease in the soil seed reserve.  相似文献   

Skin lesions in Aubrac cows strongly associated with fly bites (Haematobia irritans)          下载免费PDF全文

Marion Mosca  Murielle Vabret  Pia Randleff‐Rasmussen  Didier Pin 《Veterinary dermatology》2018,29(3):254-e94

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The development of the normal Schirmer tear test results during the dog's first year of life     

Manuella Oliveira Borges de Sampaio  Bret A. Moore  Nathália Mendonça de Seabra  Mariza Bortolini  Thayane Cristina Vieira  Camilla Bolmann Martins  Ana Leticia Groszewicz de Souza  Camila Marinelli Martins  Fabiano Montiani-Ferreira 《Veterinary ophthalmology》2023,26(3):184-190

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An investigation into an outbreak of pancytopenia in cats in the United Kingdom     

Barbara Glanemann  Karen Humm  Camilla Pegram  Daniel L. Chan 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2023,37(1):117-125

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Effects of cultural methods and physical weed control on intrarow weed numbers, manual weeding and marketable yield in direct-sown leek and bulb onion     

B Melander  & G Rasmussen 《Weed Research》2001,41(6):491-508

Manual weeding of intrarow weeds in direct-sown leek and bulb onion crops grown organically can be very labour-intensive. Four field experiments, two in direct-sown leek and two in direct-sown bulb onion were made in this investigation to study the effects of physical and cultural methods on intrarow weed numbers, time consumption for hand-weeding and marketable yield parameters. The physical methods considered were: pre-emergence flaming and harrowing, and post-emergence hoeing close to the row (only leek) and vertical brush weeding. The cultural methods were: seed priming, slurry placement and cultivar choice (only leek). Generally, flaming plus brush weeding gave the highest intrarow weed control at 92% and 87%, respectively, in the two leek experiments and 39% (only brush weeding was effective) and 74%, respectively, in the two onion experiments. Time consumption for hand-weeding after the different treatments was linearly related to the remaining numbers of intrarow weeds, with no significant influences of the experimental factors on the general relationship. Generally, the cultural methods had no significant influence on the effects of physical weeding in terms of their effect against intrarow weeds. They did not affect the tolerance or robustness of the crop plants against negative impact from the physical control methods. However, generally, seed priming and cultivar choice did improve yield in the leek experiments and seed priming also did so in the one experiment with onion.  相似文献   

Concentrations of trimethoprim and sulphadoxine in tissues from goats and a cow.     

P Nielsen  F Rasmussen 《Acta veterinaria Scandinavica》1975,16(3):405-410

The concentration of trimethoprim and sulphadoxine in plasma and tissue from goats and a cow have been determined after a single intravenous injection. Furthermore, the concentration of the two drugs and their metabolites in plasma and tissues have been determined after continuous intravenous infusion for 2½–3 hrs. Trimethoprim was present in all tissues but brain at higher concentrations than in plasma while the concentration of sulphadoxine in the different tissues were lower than in plasma. The highest concentration of the 2 drugs and their metabolites was found in the kidney. The distribution pattern of trimethoprim and sulphadoxine was similar in cow and goats.  相似文献   

Active mammary excretion of N4-acetylated p-aminohippuric acid     

F Rasmussen 《Acta veterinaria Scandinavica》1969,10(2):193-194

Different excretion patterns were observed for p-amino- hippuric acid and its acetylated metabolite in mammary excretion experiments in goats and cows. The excretion of p-aminohippuric acid conformed to passive diffusion of the non-protein bound and un-ionized fraction (Rasmussen 1958, 1966) as described by Miller et al. (1967). Thus, the p-aminohippuric acid (pK_a 3.8) appeared in ultrafiltrates of milk in concentrations 1/4—1/10 of the concentrations in ultrafiltrates of blood plasma. The concentrations of acetylated p-aminohippuric acid (pK_a 3.9) in ultrafiltrates of milk were on the other hand equal to or higher than in ultrafiltrates of blood plasma.  相似文献   

Svend Dalgaard-Mikkelsen     

Rasmussen F 《Historia medicinae veterinariae》2002,27(5-6):329-332

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Reaction of Ptr ToxA-Insensitive Wheat Mutants to Pyrenophora tritici-repentis Race 1     

Friesen TL  Rasmussen JB  Kwon CY  Francl LJ  Meinhardt SW 《Phytopathology》2002,92(1):38-42

ABSTRACT The host-selective toxin Ptr ToxA is produced by races 1 and 2 of Pyrenophora tritici-repentis, causal agent of tan spot of wheat. Ptr ToxA has been causally associated with pathogenicity by the race 2 phenotype in this system. However, the role of toxin in disease caused by race 1, the most prevalent form of the fungus in the central and northern Great Plains of North America, has not been rigorously investigated. Three independent wheat lines harboring mutations for insensitivity to Ptr ToxA were derived from ethylmethane sulfonate treatment of the hard red spring wheat cv. Kulm, possessing the single dominant gene for toxin sensitivity. Each of the three mutants was insensitive to Ptr ToxA in bioassays based on necrosis development and electrolyte leakage. Each mutant was crossed to each of the other mutants and to the wild-type Kulm. Segregation data indicate that each mutant line harbors a single recessive mutation for toxin insensitivity that maps to or near the same locus, possibly the toxin-sensitivity gene. Each toxin-insensitive mutant line was susceptible to two isolates of race 1 of P. tritici-repentis. F(2) and F(3) generations derived from crosses between Kulm and each mutant segregated for toxin reaction. However, segregation for fungal reaction was not evident, and all F(3) families were tan spot susceptible regardless of toxin reaction. Host insensitivity to Ptr ToxA is not necessarily equivalent to resistance to race 1. Ptr ToxA should not be used alone as a proxy for fungal inoculations by breeding programs aimed at developing tan spot-resistant wheat.  相似文献   

Believes veterinarians should help shelters     

Rasmussen LM 《Journal of the American Veterinary Medical Association》2000,216(1):21

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