Non-chemical weed control on traffic islands: a comparison of the efficacy of five weed control techniques     

P KRISTOFFERSEN  A M RASK  & S U LARSEN† 《Weed Research》2008,48(2):124-130

The efficacy of five non‐chemical weed control methods for reducing weed cover on traffic islands was investigated in the growing season of 2004. Three trial sites were divided into six treatment areas which were treated with either flame, steam, hot air, hot water, brushes or left untreated. The treatments were carried out at regular intervals throughout the growing season. The percentage weed cover was measured every second week using a 75 × 75 cm quadratic frame with 100 squares. In the control areas, a rapid increase in weed cover was observed, whereas all treatments reduced weed cover. Hot water was the most effective method, although not significantly better than hot air or steam. Hot air treatment was more effective than brushing, whereas hot water was more effective than both flaming and brushing. The doses that were used were relatively high (150–355 kg ha^?1), partly because of the irregular shape of the traffic islands and the treatment intervals were quite short in comparison with those in similar studies. However, the treatments could keep down the weeds only to a certain extent. The present knowledge of the efficacy of various weed control methods, as well as an increase in our knowledge of adequate treatment intervals, supports an optimisation of hard‐surface weed control. Data and experience gained from these trials were used to develop further calibrated application studies.  相似文献   

Pyrethroid sensitivity monitoring in Germany of oilseed rape pest insects other than pollen beetle     

A. Müller  U. Heimbach  T. Thieme 《EPPO Bulletin》2008,38(1):85-90

Pyrethroid resistant pollen beetles ( Meligethes aeneus ) are widely distributed in Germany and other European countries. Other insect pests on oilseed rape are also exposed to pyrethroids which often have more than one application per season. In spite of this scarce information about the sensitivity of other oilseed rape pest insects is available. To address this monitoring of pyrethroid sensitivity of different oilseed rape pest insects has been carried out since 2005. Laboratory experiments were conducted using an adult-vial-test design with samples collected in different areas of Germany.
Most samples of Ceutorhynchus napi , C. assimilis , C. pallidactylus , Dasineura brassicae , Phyllotreta spp. and Psylliodes chrysocephala tested from 2005–2007 showed 100% mortality at 0.003 and 0.015 µg/cm² lambda-cyhalothrin used as reference test pyrethroid. Some samples especially of C. pallidactylus , C. napi and C. assimilis showed a lower mortality with alive and healthy beetles at 0.015 µg/cm² lambda-cyhalothrin. For all samples tested from 2005–2007 100% mortality was found only at higher rates of 0.0375 or 0.075 µg/cm² lambda-cyhalothrin.
To date, no clear pyrethroid resistance has been detected in other oil seed rape pest insect populations in Germany.  相似文献   

Thermographic assessment of scab disease on apple leaves   总被引：1，自引：0，他引：1  

E.-C. Oerke  P. Fröhling  U. Steiner 《Precision Agriculture》2011,12(5):699-715

Phytopathogenic fungi may affect both the cuticular and the stomatal conductance of plant tissue resulting in significant modifications of leaf temperature. Venturia inaequalis colonizes apple leaves below the cuticle (subcuticularly) causing scab disease. The suitability of digital infrared thermography for sensing and quantifying apple scab was assessed by investigating the effects of V. inaequalis on the water balance of apple leaves in relation to the disease stage and the severity of scab. Transpiration was measured by infrared thermo-imaging to evaluate spatial heterogeneity of the leaves in response to localized infections. Fungal development was assessed microscopically. Subcuticular growth of the pathogen caused localized decreases in leaf temperature before symptoms appeared that significantly increased the maximum temperature difference (MTD) of leaves. The MTD increased with scab development and was strongly correlated to the size of infection sites (r2_linear = 0.85) and overall disease severity (% diseased leaf area, r2_square = 0.71). In later stages of the disease, the MTD decreased because of leaf senescence. Thermographic measurements revealed differences in disease severity resulting from disease stage, resistance of host tissue and differences in the aggressiveness of V. inaequalis isolates. Subcuticular growth of the pathogen was beyond the area of conidia production, therefore, the area of leaf with increased transpiration was larger than the scab lesions; the proportion decreased from >70% in the early stages to <20% for mature lesions. Leaf transpiration was increased by all stages of scab development, therefore, MTD may be used not only for the differentiation between diseased and non-diseased leaves, but also for disease quantification, e.g. in screening systems and monitoring in precision agriculture.  相似文献   

Effect of humic acid on growth and crop nutrient status of wheat on two different soils     

R. U. Khan  M. Z. Khan  A. Khan  S. Saba  F. Hussain  I. U. Jan 《Journal of plant nutrition》2018,41(4):453-460

The effect of plant-derived humic acid (PDHA) and coal-derived humic acid (CDHA) on wheat growth was tested on two alkaline calcareous soils in pots. Humic acid derived from plant and coal materials was applied at the rate 0 (control), 50 and 100 kg/ha to wheat in pots carrying two soils viz. clayey loam soil and sandy loam soil separately. Data was collected on plant growth parameters such as spike weight, grain and straw weight, and plant nutrients (macronutrients and micronutrients). Results showed that spike weight increased by 19%, 15%, and 26%, and 11% with application of PDHA at the rate of 50 and 100 mg/kg in clayey loam and sandy loam soil, respectively. Grain yield show an increase of 21% and 11% over control with application of PDHA and CDHA at the rate of 50 mg/kg on both soils, respectively, and 10% and 22% with application of PDHA and CDHA at the rate of 100 mg/kg on both soils.  相似文献   

Mapping of Aegilops umbellulata‐derived leaf rust and stripe rust resistance loci in wheat          下载免费PDF全文

M. Bansal  S. Kaur  H. S. Dhaliwal  N. S. Bains  H. S. Bariana  P. Chhuneja  U. K. Bansal 《Plant pathology》2017,66(1):38-44

Aegilops umbellulata, a non‐progenitor diploid species, is an excellent source of resistance to various wheat diseases. Leaf rust and stripe rust resistance genes from A. umbellulata were transferred to the susceptible wheat cultivar WL711 through induced homoeologous pairing. A doubly resistant introgression line IL 393‐4 was crossed with wheat cultivar PBW343 to develop a mapping population. Tests on BC₂F₇ RILs indicated monogenic inheritance of seedling leaf rust and stripe rust resistance in IL 393‐4 and the respective co‐segregating genes were tentatively named LrUmb and YrUmb. Bulked segregant analysis placed LrUmb and YrUmb in chromosome 5DS, 7.6 cM distal to gwm190. Aegilops geniculata‐derived and completely linked leaf rust and stripe rust resistance genes Lr57 and Yr40 were previously located in chromosome 5DS. STS marker Lr57/Yr40MAS‐CAPS16 (Lr57/Yr40‐CAPS16), linked with Lr57/Yr40 (T756) also co‐segregated with LrUmb/YrUmb. Seedling infection types differentiated LrUmb from Lr57. Absence of leaf rust‐susceptible segregants among F₃ families of the intercross (IL 393‐4/T756) indicated repulsion linkage between LrUmb and Lr57. YrUmb expressed a consistently low seedling response under greenhouse conditions, whereas Yr40 expressed a higher seedling response. Based on the origin of LrUmb/YrUmb from the U genome and Lr57/Yr40 from the M genome, as well as phenotypic differences, LrUmb and YrUmb were formally named Lr76 and Yr70, respectively. These genes have been transferred to Indian wheat cultivars PBW343 and PBW550, and advanced breeding lines are being tested in state and national trials.  相似文献   

Analysis of early events in barley (<Emphasis Type="Italic">Hordeum vulgare</Emphasis> L.) roots in response to <Emphasis Type="Italic">Fusarium culmorum</Emphasis> infection     

Feyza Tufan  Cüneyt Uçarlı  Berna Tunalı  Filiz Gürel 《European journal of plant pathology / European Foundation for Plant Pathology》2017,148(2):343-355

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Effect of prolonged photoperiod on ocular tissues of domestic turkeys          下载免费PDF全文

Marina L. Leis  Mary‐Magdalene U. Dodd  Gregory Starrak  Catherine J. Vermette  Susantha Gomis  Bianca S. Bauer  Lynne S. Sandmeyer  Karen Schwean‐Lardner  Henry L. Classen  Bruce H. Grahn 《Veterinary ophthalmology》2017,20(3):232-241

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The effect of repeated eye examinations and breeding advice on the prevalence and incidence of cataracts and progressive retinal atrophy in German dachshunds over a 13‐year period          下载免费PDF全文

Sarah Koll  Sven Reese  Ivica Medugorac  Carsten U. Rosenhagen  Rick F. Sanchez  Roberto Köstlin 《Veterinary ophthalmology》2017,20(2):114-122

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Anaesthesia in a Eurasian lynx with an intranasal zolazepam–tiletamine combination     

Latif Emrah Yanmaz  Elif Doğan  Uğur Ersöz  Zafer Okumuş  Veysel Doğan 《Veterinary anaesthesia and analgesia》2017,44(1):193-194

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Long‐term Treatment with Methylene Blue in a Dog with Hereditary Methemoglobinemia Caused by Cytochrome b5 Reductase Deficiency          下载免费PDF全文

J.A. Jaffey  M.R. Harmon  N.A. Villani  E.K. Creighton  G.S. Johnson  U. Giger  J.R. Dodam 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2017,31(6):1860-1865

A juvenile male mixed breed dog was presented for lethargy, exercise intolerance, and aggression when touched on the head. Cyanosis, tachycardia, and tachypnea were observed and persisted during oxygen supplementation. Arterial blood gas analysis by co‐oximetry identified an increased methemoglobin concentration (27%; normal, <2%) with normal arterial oxygen tension. The methemoglobinemia and associated clinical signs resolved after administration of methylene blue (1 mg/kg) IV, and the dog was discharged. The affected dog's whole‐genome sequence contained 2 potentially causal heterozygous CYB5R3 missense mutations suggesting that cytochrome b5 reductase deficiency was responsible for the methemoglobinemia. This hypothesis was confirmed by enzyme analysis that identified cytochrome b5 reductase activity in the affected dog's erythrocytes to only approximately 6% of that in a control sample. Clinical signs recurred 11 days after discharge but normalized and the methemoglobin concentration decreased with methylene blue administration PO (1.5 mg/kg, initially daily and then every other day).  相似文献