Biological control of botrytis leaf blight of onion byGliocladium roseum applied as sprays and with fabric applicators     

T. D. W. James  J. C. Sutton 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(3):265-275

Gliocladium roseum (5×10⁶ conidia ml^–1) and chlorothalonil (Bravo 500) were compared in two field tests for effectiveness in suppressing leaf blight caused byBotrytis squamosa in cooking onions. The biological control agent and fungicide were applied with sprayers and with specially designed fabric applicators that were mounted interchangeably on an aluminium carriage with bicycle wheels. In the applicators, inoculum and fungicide gravitated from a reservoir down curtains of denim strips and onto portions of onion leaves contacted by the strips. Initial applications were timed using a leaf blight forecasting system (BOTCAST) and three or four subsequent applications were made at weekly intervals. When compared to water checks,G. roseum applied as sprays or by applicators reduced density of leaf spots by about 50–58% during middle and late stages of epidemics. The antagonist was about half as effective as chlorothalonil in suppressing density of spots, regardless of application method. The applicators delivered inoculum in similar densities to proximal and distal halves of leaves, and used at least 35% less volume of inoculum compared to the sprayers. Density of inoculum on leaves treated by applicators was about the same as in spray-treated leaves when canopies were sparse, but less when canopies were dense. It is concluded thatG. roseum has good potential for controlling leaf blight sufficiently to avoid economic yield losses.  相似文献   

Synthesis and herbicidal activity of some potent bicyclic ether herbicides     

Wendy S. Taylor  James E. Powell  Eileen L. Marsilii  Kathryn J. Leep 《Pest management science》1995,44(1):85-87

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Analysis,sorption and residues of a homologous series of isothiocyanates on wheat     

Eli Shaaya  James M. Desmarchelier 《Pest management science》1995,44(3):249-253

A series of isothiocyanates (R-NCS, R, 1–6 carbon atoms) was applied in the vapour phase to wheat in sealed containers. The speed of sorption, as measured by the rate of loss from the intergranular air space, was inversely proportional to molecular weight; e.g. the time for 50% sorption of hexyl isothiocyanate was over 100 times longer than for the methyl analogue. Despite extensive sorption, most of the applied chemicals was recovered from the fumigated wheat seven days after dosing, indicating that sorption did not lead to extensive degradation. Purge and trap techniques proved suitable for recovery of low-boiling, but not high-boiling chemicals.  相似文献   

Biocontrol of soil-borne plant pathogens: Concepts and their application     

James W. Deacon  Lorraine A. Berry 《Pest management science》1993,37(4):417-426

A few soil-borne plant pathogens have been controlled successfully by commercial formulations of biocontrol agents, but many attempts to develop biocontrol inoculants, although promising under experimental conditions, have met with difficulties in practice. The reasons for this are discussed in this review, which outlines some of the major findings on the behaviour of microbial inoculants in soil. It is emphasized that biocontrol also occurs naturally in current agricultural practice and can be exploited purposely, but it is vulnerable to disruption by agrochemicals or mismanagement. The future of biocontrol of soilborne plant pathogens probably lies in integrated (biorational) control systems that combine the use of commercial inoculants, where appropriate, with management practices that maintain and enhance the natural biocontrol systems.  相似文献   

Economic Analysis of Japanese Household Demand for Salmon     

Cathy Roheim  Wessells  James E.  Wilen 《Journal of the World Aquaculture Society》1993,24(3):361-378

The recent glut of both wild and farmed salmon in world markets has forced producers to become aware of the need to expand their marketing efforts to ensure that demand is not outpaced by supply resulting in a further decline in prices. Japan has been a major market for wild salmon, particularly sockeye salmon from North America, since the introduction of the 200 mile Exclusive Economic Zone. As farmed supplies have continued to increase, exporters such as Norway and Chile have turned their attention to this market as well. Up until now, most of the farmed salmon exported to Japan has been targeted to the restaurant market. If exporters wish to expand their market in Japan, they may focus also on the retail market. Prior to any assessment of the potential of the retail market for fresh farmed salmon, it is useful to understand the role that salmon plays in Japanese household seafood consumption.
This paper examines household consumption patterns of salmon in Japan. An econometric model is presented which estimates household demand for fresh and salted salmon focusing specifically on the effects of seasonality, regional location, and prices of other seafood products. Two systems of demand equations, one for each of two regions of Japan, are specified and estimated using monthly data on prices and expenditures to capture the effects on household demand for 12 seafood products. Results indicate that seasonality plays a significant role in the demand for many seafood products, particularly fresh and salted salmon. In addition, these seasonal effects are not necessarily the same between regions of Japan. Salmon competes with different seafood products during different times of the year. A rich variety of factors should be considered when marketing fresh aquacultured salmon in the Japanese retail market.  相似文献   

Clinical trial of parvaquone for the treatment of East Coast fever in Kenya   总被引：1，自引：0，他引：1  

S Chema  S Waghela  A D James  T T Dolan  A S Young  W N Masiga  A D Irvin  G H Mulela  L S Wekesa 《The Veterinary record》1986,118(21):588-589

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Antibiotic persistence and tolerance in the lactating sheep following a course of intramammary therapy     

J F Buswell  D M Barber 《The British veterinary journal》1989,145(6):552-557

The commercial use of sheep for the production of milk and milk products is attractive to farmers actively diversifying their dairy interests due to the impact of the quota system. As intensification of milking increases, flock sizes will enlarge and the incidence of ovine mastitis will inevitably increase. The pharmaceutical industry and the veterinary practitioner will be required to provide advice and data upon the performance of currently available bovine intramammary preparations for the sheep. This study produces evidence to confirm that one available bovine intramammary preparation, when infused into milking sheep, produced a withholding time approximately three times as long as that defined for the cow. Following a course of three infusions over a period of 24 hours after consecutive milkings, milk was not acceptable for human consumption or for the production of cheese and yoghurts until 136 hours following the final infusion. This situation is likely to be representative of that which will occur with other intramammary products used in the ovine species following infusion with bovine intramammary preparations.  相似文献   

Organophosphate degradation by insecticide-resistant and susceptible populations of mosquitofish (Gambusia affinis)     

Janice E. Chambers  James D. Yarbrough 《Pesticide biochemistry and physiology》1973,3(3):312-316

Phosphorothionate and phosphate degradation was investigated as a factor which could influence the tolerance of organochlorine compound-resistant and susceptible mosquitofish (Gambusia affinis) to parathion and methyl parathion. The greater toxicity of methyl parathion than parathion can be attributed in part to a higher rate of degradation of methyl paraoxon than paraoxon (7-fold), but not to any difference in phosphorothionate dearylation. Resistant fish possess higher levels of microsomal mixed-function oxidases which can degrade methyl parathion (1.3-fold); these higher levels could contribute to the increased methyl parathion tolerance by this population over the susceptible population. Environmentally induced tolerance to parathion in the resistant population may be the result of increased levels of parathion degradation by induced mixed-function oxidases which can dearylate parathion. The increased tolerance of either insecticide by the resistant population is not caused by degradation of the phosphates by phosphotriesterases.  相似文献   

Early embryonic death in ewes given Veratrum californicum     

K R Van Kampen  W Binns  L F James  L D Balls 《American journal of veterinary research》1969,30(4):517-519

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TRANSITIONAL CELL CARCINOMA OF THE URETHRA IN FOUR FEMALE DOGS: ITS URETHROGRAPHIC APPEARANCE     

James W.  Ticer  Crispin P.  Spencer  Norman  Ackerman 《Veterinary radiology & ultrasound》1980,21(1):12-17

ansitional cell urethral carcinoma in four female dogs is reported. Lesion distribution in the proximal two thirds of the urethra and the radiographic appearance with retrograde positive contrast urethrography were similar in each dog. The normally smooth longitudinal urethral striations were replaced by multiple small, poorly marginated intraluminal masses that resulted in a generalized moth-eaten appearance. Extension of contrast medium into the periurethral tissues also occurred. Retrograde urethrography, a simple diagnostic technic, aided in establishing a differential diagnosis in dogs that had urine retention and stranguria.  相似文献