Management of parthenium weed through competitive displacement with beneficial plants     

CHRIS O'DONNELL  STEVE W. ADKINS 《Weed Biology and Management》2005,5(2):77-79

  相似文献   

A Comparison of the Cutaneous Trunci Myocutaneous Flap and Latissimus Dorsi Myocutaneous Flap in the Dog     

MICHAEL M. PAVLETIC DVM  DiplomateACVs    MARILYN KOSTOLICH DVM    PHILIP KOBLIK DVM  PhD  STEVE ENGLER VMD 《Veterinary surgery : VS》1987,16(4):283-293

Latissimus dorsi and cutaneous trunci myocutaneous flaps of equal dimension and location were randomly elevated on opposite sides of the thorax in 10 dogs (group 1) and resutured to their respective bed. The procedure was repeated in four additional dogs (group 2); however, the short perforating branches of the thoracodorsal artery and vein were divided at the base of each cutaneous trunci myocutaneous flap, whereas the cutaneous pedicle and underlying cutaneous trunci muscle were divided in the latissimus dorsi myocutaneous flaps to determine subsequent skin survivability and the major source of circulation of each myocutaneous flap. There was little difference in the percentage of skin survival between the latissimus dorsi and cutaneous trunci myocutaneous flaps in group 1 dogs. Circulation to the "skin island" of group 2 latissimus dorsi myocutaneous flaps originated from intramuscular anastomotic connections between the major branch of the thoracodorsal artery entering the latissimus dorsi muscle and the proximal lateral intercostal arteries perforating the muscle. Ligation of the short perforating branches of the thoracodorsal artery resulted in partial skin necrosis in all group 2 cutaneous trunci myocutaneous flaps. Results from this study indicate that it is unnecessary to elevate the latissimus dorsi muscle for major skin flap elevation and survival. The thicker latissimus dorsi myocutaneous flap is more difficult to develop surgically and appears to have no clinical major advantage over the more mobile cutaneous trunci myocutaneous flap or the adjacent thoracodorsal axial pattern flap for closure of large skin defects within the radius of flap rotation.  相似文献   

Rhizomania disease of sugar beet in England   总被引：2，自引：3，他引：2  

S. A. HILL  L. TORRANCE 《Plant pathology》1989,38(1):114-122

Rhizomania disease was first detected in the UK in 1987, in a single crop in Suffolk. Affected plants had pale leaves, often upright, narrow and rolled; roots were small, often with constrictions, warty outgrowths, proliferation of fibrous roots, and vascular staining. Disease occurred in strips at right angles to one another, parallel with directions of cultivation, suggesting that the previous beet crop had also been infected. Beet necrotic yellow vein virus was detected by ELISA, by electron microscopy, and by transmission to indicator species. It was sometimes associated with beet soil-borne virus. The affected crop was destroyed with herbicide. No other outbreaks were detected in subsequent surveys of crops in 1987.  相似文献   

On difficulties with allelopathy methodology   总被引：1，自引：0，他引：1  

J. R. QASEM  T. A. HILL 《Weed Research》1989,29(5):345-347

Summary. The main techniques and the common experimental methods used in studying allelopathy are reviewed. Problems associated with both methodology and conclusions drawn based on certain techniques are discussed. The accuracy obtained using these techniques is evaluated and show that some of the techniques could be a misleading tool. Some changes are suggested.  相似文献   

Possible rôle of allelopathy in the competition between tomato, Senecio vulgaris L. and Chenopodium album L.     

J. R. Qasem  T. A. HILL 《Weed Research》1989,29(5):349-356

Summary. The allelopathic effect of Chenopodium album L. (fat-hen) and Senecio vulgaris L. (groundsel) on tomato ( Lycopersicon esculentum Mill cv. Ailsa Craig) plants was investigated under glasshouse conditions. A new technology was used to separate competitive from allelopathic effects. These experiments suggested that C. album had an effect on tomato through allelopathy. C. album leach-ates significantly reduced shoot fresh and dry weights and the accumulation of N, P, K, Ca and Mg of tomato shoots. No effect was found on the quantities of these elements in tomato roots. Leachate of five plants of C. album per pot was sufficient to reduce tomato growth. Addition of 10 or 20 g kg⁻¹ of C. album dried shoots to the soil mixture significantly decreased the fresh and dry weights of tomato plants. S. vulgaris leachates did not show significant effects on the growth or nutrient accumulation of tomato plants.  相似文献   

The influence of inoculum concentration, relative humidity, and temperature on infection of greenhouse tomatoes by Botrytis cinerea   总被引：1，自引：0，他引：1  

M. A. EDEN  R. A. HILL  R. BERESFORD  & A. STEWART 《Plant pathology》1996,45(4):795-806

Botrytis cinerea causes serious crop losses in greenhouse tomato crops through infection of flowers and stem wounds. Experiments were carried out to determine the effects of inoculum concentration, relative humidity (RH), and temperature at these two infection sites. Infection of permanent flower parts increased as a function of inoculum concentration and both length of exposure to high RH (approximately 100% for 0–36 h) and specified continuous RH (56–100%). A low level of infection was still evident under continuous 56% RH. Interruption of periods of high RH with breaks of low RH did not reduce infection. Infection of stem wounds was less dependent on inoculum concentration or RH. Factorial combinations of inoculum concentration, RH, and temperature produced significant interactions. Higher temperature increased infection of flowers but reduced infection of stem wounds. The main implications for control in commercial crops are as follows. Lowering the aerial spore concentration by maintaining the disease at a low level will reduce flower infection. Lowering RH will reduce but not eliminate flower infection but will have only a small effect on stem infection. Raising the temperature (from 15 to 25°C) will reduce stem infection, and whilst flower infection increases, this is counteracted by increased flower production and a decrease in the proportion of infections reaching the peduncle and stem.  相似文献   

营养在保证禽产品质量中的作用     

STEVE LEESON  田玮  赵改名 《中国畜牧兽医》2000,27(4):38-42

1　禽产品的组成肉和蛋都是蛋白质和氨基酸的极好来源 ,是消费者日常饮食的重要组成部分。从营养上讲 ,禽肉和禽蛋都是必需氨基酸的丰富来源 ,1 0 0 g禽肉或 1个鸡蛋就可以满足成年人的氨基酸需要 (表1 )。禽肉和禽蛋在大部分矿物质和维生素方面都是缺乏的。禽产品中的脂肪酸组成有回报饲料脂肪酸的趋势 ,可以利用这一特点来调控禽蛋和禽肉中的脂肪酸组成。表 1　禽肉和禽蛋中几种营养物质的含量与人的日常需要量营养物质 成年人日需要量能供给量10 0 g熟肉 1个鸡蛋蛋白质 ( g) 5 2 2 7 8能量 ( kcal) 2 3 5 0 2 3 910 0钙 ( mg) 75 0 15 3 …  相似文献   

Vegetation and Environment in Afforested Sand Dunes at Newborough, Anglesey     

HILL  M. O.; WALLACE  H. L. 《Forestry》1989,62(3):249-267

Newborough Forest was planted with pines, chiefly Corsican pine,during the period 1947–65. In 1986, its soils and vegetationwere surveyed and related to the preplanting condition of thedunes, inferred from air photographs. The youngest dunes contained4 per cent calcium carbonate in the top 30cm; the oldest wereacid, with no free calcium carbonate. There was little acidificationof the soil and no extra leaching of calcium carbonate due tothe pines. Vegetation under trees varied according to the ageand pH of the dunes. Young dunes were almost bare except formoss; older dunes had been colonized by ferns and brambles.All plant species of the original open dune system had apparentlysurvived in unplanted slacks or on road verges; some had increased.Many new species had invaded, including woodland mosses, ferns,orchids and two species of Pyrola.  相似文献   

Inactivation of infectious pancreatic necrosis virus for vaccine use   总被引：1，自引：0，他引：1  

P. F. DIXON  B. J. HILL 《Journal of fish diseases》1983,6(5):399-409

Abstract. Formalin and β-propiolactone (BPL) were compared for efficacy in inactivating infectious pancreatic necrosis virus (IPNV) for vaccine use. Incubation with a 1:200 dilution of formalin at 20°C for four days or longer, or a 1:200 dilution of BPL at 4°C for six days or longer, completely inactivated the virus infectivity. However, whereas treatment with formalin caused only a slight reduction in anti-genicity as titrated by in vitro tests, treatment with BPL destroyed over 50% of the antigenicity of the virus. Virus inactivated with formalin also proved highly effective at inducing high titres of neutralizing antibody in trout.  相似文献   

A NEW TECHNIQUE FOR THE ACCURATE AERIAL APPLICATION OF HERBICIDES TO DRAINAGE CHANNELS WITH NEGLIGIBLE SPRAY DRIFT     

T. O. ROBSON  E. C. S. LITTLE  D. R. JOHNSTONE  R. F. HILL 《Weed Research》1966,6(3):254-266

Summary. Difficulties of access met with in Britain when applying dalapon to emergent water weeds in drainage channels led to work starting in 1964 on the development of a method of accurate aerial application of aqueous solutions of herbicide. The narrow, sinuous nature of the targets and the proximity of susceptible crops made it necessary to minimize spray drift and maintain a constant height and a slow speed. Nozzles designed to give large droplets were tested for droplet size and distribution. Selected nozzles were then tested from a helicopter in the field and the effect of their spray characteristics on the biological performance of dalapon was assessed. No daman occurred as a result of spray drift and satisfactory control of Phragmites communis, Typha angustifolia and T. latifolia was achieved with a lower dose of dalapon in a lower volume of spray than previously considered necessary for ground applications.
Une nouvelle technique pour l'application précise d'herbicides par voie aérienne sur les canaux de drainage, avec des risques négligeables d'entrainement  相似文献