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1.
A survey of sheep dipping and spraying in Scotland during 1973 has shown that about 40 tonnes of organophosphorus, 8 tonnes of organochlorine and 2 tonnes of carbamate insecticides were used to control ectoparasites. Substances used to combat headfly (Hydrotaea irritans) and the main areas of Scotland affected by this pest are noted. Information about the pattern of dipping in relation to geographical area, season and flock size and about the disposal of surplus dip and empty containers is presented. Though a small potential for environmental damage still exists no evidence of such came to light.  相似文献   

2.
This is the third survey of control practices for ectoparasites on sheep farms in Northern Ireland, providing data comparative to those recorded in previous surveys in 1981 and 1988. Data relating to all aspects of ectoparasite control were collected from 210 farms representing 4% of the total sheep population. Quantitative data have been adjusted to provide accurate estimates of total pesticide usage. Since the previous survey in 1988, the number of sheep farms in Northern Ireland has increased by 10% to 11 692 with a consequent 39% increase in sheep population to 2.9 million. Despite this level of expansion, the total quantity of organophosphorus compounds used for ectoparasite control has remained approximately constant at 7–8 tonnes. The report considers that compulsory sheep‐dipping, prescribed since 1970 and revoked in 1993, impacted significantly on subsequent ectoparasite control practices and consequent pesticide usage. During 1997, approximately 20% of sheep farmers relied on alternative methods to control ectoparasites, including injectable formulations of avermectins and pour‐on formulations of insect growth regulators and pyrethroids. Dipping formulations containing pyrethroid compounds, which accounted for <1% of treatments in 1988, increased to 9% in 1997. Previously, regulatory sheep‐dipping periods were specified during the autumn months, which tended to increase dipping frequency. The majority of farmers dipping sheep during the summer strictly for blowfly maggot (Diptera: Calliphoridae) control were required to perform additional compulsory sheep‐dipping during the autumn. Withdrawal of compulsory sheep‐dipping has allowed farmers to synchronise dipping practices to control the major ectoparasites of sheep at a single dipping occasion. An estimated 7.5 × 106 litres of surplus dipwash required disposal and there were approximately equal numbers of farmers disposing dipwash immediately after sheep‐dipping or on occasions up to and including subsequent dipping. The decline in the number of farmers who allowed dipwash to run‐off into soakaways or surrounding soil observed in 1988 continued in 1997. The majority of farmers used tractor‐operated pumps to dispose of dipwash into slurry tanks for subsequent disposal onto permanent pasture. © Crown copyright 2000. Reproduced with the permission of Her Majesty's Stationery Office. Published for SCI by John Wiley & Sons, Ltd.  相似文献   

3.
本文报道在昆明、嵩明等地首次采到蚕豆主要害虫豌豆蚜的重要天敌阿尔蚜茧蜂,并对该蜂大量繁殖和利用进行了研究。1.阿尔蚜茧蜂在滇中、滇南地区均有分布是控制豌豆蚜的一种有利用前途的优势种蜂。2.昆明室内可周年繁殖,冬季发育周期为19～25天,夏秋季节10～17天,各代雌蜂数占62～75%,与田间自然寄生蜂群性比相近。3.冬季在田间搭一简易人工繁蜂棚,提早繁蜂,是大量繁蜂的一种好方法。4.僵蚜在低温(3～10℃)下保藏196、202天,羽化的成蜂仍具有生殖能力。5.田间初步实验结果表明,在豌豆蚜发生初期早春开始连续多次放蜂似比在发生中期一次释放寄生率要高。释放僵蚜比成蜂好,简便易行,不要特殊器皿盛放和饲喂成蜂以及运输工具等。  相似文献   

4.
Hordeum spp. (barley grass) and Bromus spp. (brome grass) are annual weed species that achieve long-distance seed dispersal via attachment to sheep, but also lead to sheep carcass damage due to the penetration of seeds into animal tissues. Range expansion of invasive weed populations predicted as a consequence of climate change may be associated with an increase in seed contamination incidence globally. An examination of Australian abattoir data (2006–2012), along with recent weed distribution patterns, indicates carcass contamination was associated with rainfall and abundance of key annual grass weeds, primarily Bromus spp. and Hordeum spp., although other factors may play a contributing role. Significant differences in seed contamination in slaughtered sheep were noted between states and regions, with widespread contamination occurring throughout all agro-ecological zones. Abattoir, sheep age and sex significantly influenced incidence, with contamination highest in adult males. Incidence increased with mean monthly rainfall, but declined with mean elevation, and significant interactions were noted between mean monthly temperature and state, and between mean elevation and year. Results show the need for vigilant recording of seed injuries in sheep to enhance weed surveillance efforts and effective integrated weed management of contributing annual grass weeds.  相似文献   

5.
Tomato is one of the most important vegetable crops in Turkey, with national production of over 10 million tonnes in 2010. Tuta absoluta (Meyrick) is an important pest of tomato, and was first recorded in Urla District of Izmir Province in the Aegean region of Turkey in August 2009. It has since spread rapidly to the other regions of Turkey and become the main pest of tomato. Since its dispersal, chemical control has been the main method of control. Intensive use of insecticides has led to the development of resistance in T. absoluta. In this study, the baseline toxicity (LC50 values) of some insecticides was determined using a leaf‐dip bioassay method in Antalya and Ankara populations of T. absoluta.  相似文献   

6.
Since 1978, Trialeurodes vaporariorum has caused increasing problems in plastic houses in Crete, and chemical control is complicated by resistance. Effectiveness of biological control by the parasite Encarsia formosa has been tested in five untreated commercial houses in 1981–1983. Whitefly populations peaked in October, then persisted at a low level, to rise again as temperatures rose in spring. Autumn releases of E. formosa gave poor results, but spring releases were more promising, a parasitization rate of up to 75% being reached. Cultural measures and chemical treatments are liable to reduce effectiveness.  相似文献   

7.
This paper reports for the first time on farmers’ knowledge, perceptions and management practices of the fall armyworm (Spodoptera frugiperda) in Ethiopia and Kenya. A survey of 343 smallholder maize farmers was conducted. Most farmers in Ethiopia and Kenya had knowledge about fall armyworm; they could identify it mainly during its larval stage. Furthermore, most farmers in Ethiopia (93%) and Kenya (97%) encountered damage by fall armyworm in their farms. They estimated an average of 32% crop damage in Ethiopia and 47.3% of crop damage in Kenya, with an estimated yield reduction between 0.8 to 1 tonnes/ha. Nearly half of the farmers relied on chemical insecticides to control this pest. The majority (60%) of the farmers in Kenya perceived that insecticides were not effective in controlling fall armyworm as compared to most farmers (46%) in Ethiopia who perceived that chemical spray is effective for the control of fall armyworm. In Ethiopia, 26% of the farmers combined handpicking larvae with insecticide sprays, whilst 15% of the farmers practiced only handpicking. The present study highlights the need to develop management strategies for fall armyworm based on farmers’ needs and priorities.  相似文献   

8.
The study deals with the effect of common, annually-used pesticides on soil microorganisms, pesticide residues in soil, and carrot (Daucus carota) yields in Central Finland. Linuron residues in carrot roots were also analysed. Thiram+lindane and dimethoate were applied from 1973–1981 at the commercially recommended doses on experimental plots of carrots, linuron was applied at twice the recommended rate from 1973–1979 and at the normal rate thereafter and in addition TCA was applied in 1978. Maleic hydrazide was used in the years 1973–1976, and glyphosate after 1977. The numbers of different soil microorganisms, their activities and the pesticide residues were studied from autumn 1978 to 1981. The pesticide treatments reduced the growth of soil algae but increased the total number of microorganisms and the number of aerobic spore-forming bacteria. Linuron residues in the soil were 0.9–2.8 mg kg?1 in the growing season and 1.2–1.7 mg kg?1 in the autumn, 3 months after application. The residues of glyphosate in the soil were 0.7 mg kg?1 in the autumn, 41 days after the treatment, and had declined to a level of about 0.2 mg kg?1 by the following summer. In the pesticide-treated plots the carrot yield was only 20–60% of the yield in the hand-weeded plots. The herbicide programme controlled most of the annual weeds but not couchgrass Elymus repens and milk sow-thistle Sonchus arvensis.  相似文献   

9.
Endozoochory is known as an important mechanism for the spread of weeds. We carried out experiments to assess the fate of seeds of several weed species (Convolvulus arvensis, Cuscuta campestris, Rumex crispus, Hordeum spontaneum and Sorghum halepense) after passing through the gut of sheep and goat. Eighteen animals of both sheep and goat received diet mixed with seeds of the weed species or control with only wheat bran (five weed species + control × three replications). Results showed that a higher proportion of seeds were missing after passage through the sheep gut than in goats. In goats, a greater proportion of seeds were dead after passage, but the number of seeds collected from dung was also greater. Weed species differed, with the highest seed recovery and viability in Cuscuta campestris. Based on time of seed passages through the animal gut estimated for the different weed species, we recommend that sheep should be kept in a corral for 96 hr to minimise seed transportation via their faeces. For goats, if R. crispus and C. arvensis seeds could be excluded from the diet, then maintaining them for 96 hr in an animal stall would ensure little seed transportation via dung, but we found R. crispus and C. arvensis seeds to be present and viable in goat dung even 120 hr after feeding. Very large numbers of viable seeds can be found in goat and sheep dung, so the use of rotted manure is highly recommended to avoid transportation of viable seeds via manure fertilisers.  相似文献   

10.
7-Hydroxy-5-oxo-5H-thieno[3,2-b]pyran-6-carboxanilides and -6-thio-carboxanilides represent a novel series of anthelmintic compounds, with broad-spectrum activity against important parasitic nematodes in sheep and dogs. In particular, an improved efficacy against Trichostrongylus colubriformis in sheep over the related 3-carbamoyl-4-hydroxycoumarins has been noted. New synthetic routes to the key intermediate, 7-hydroxythieno[3,2-b]pyran-5-one, have been developed.  相似文献   

11.
Diamphenethide is the result of a search for a fasciolicide effective against immature parasites. The history of its development is followed from the active but toxic 4-tert-butoxyacetanilide ( II ) through the progressively more active and less toxic 4-allyloxyacetanilides to di-[2-(4-acetamidophenoxy)ethyl] ether, diamphenethide ( VII ). Evidence is presented that the activity and good therapeutic index of VII depend on deacylation to (probably) the di-amino analogue ( VIII ) by liver de-acylases, which occurs in the liver parenchyma infected by the immature fluke. Structure-activity relationships against immature Fasciola gigantica in mice show that the acetyl group is about the correct size for maximum effectiveness, that ring-substitution is generally very unfavourable, and that central polymethylene bridges longer than ethylene lead to lower activity or greater toxicity. The effects of functionalised central chains are shown, and a selection of activities against F. hepatica in sheep is given.  相似文献   

12.
Diamphenethide, di-[2-(4-acetamidophenoxy)ethyl] ether, is the active ingredient of a new fasciolicide for oral administration to sheep at a dose rate of 80 to 120 mg/kg liveweight. This drug possesses an exceptionally high activity against the youngest of immature stages of the liver fluke Fasciola hepatica present in the liver parenchyma. Activity is high against flukes of all ages and adequate control is achieved against mature infestations. Strategic administration of this fasciolicide could in time lead to the prophylaxis of liver fluke disease in sheep.  相似文献   

13.
Sheep can be vectors for the long‐distance dispersal of weeds when seed becomes attached and retained in wool or survives the gastrointestinal tract. This study aimed to determine an appropriate quarantine period for sheep that minimized the risk of the long‐distance dispersal of the seeds of branched broomrape (Orobanche ramosa L. subsp. mutelii [F.W. Shultz] Cout.), a parasitic weed. Experiments with penned sheep found that the seeds that were placed on the soil surface adhered to the wool on the thigh and belly of the sheep, with most of the seeds attaching to the feet. Most of the seeds that were applied to the belly and thigh wool detached within 2 days, although a small proportion was present after 7 days. The seeds that were introduced to the digestive tract via drenching had a peak voidance 2 days later and no seed was detected on Day 8. It is suggested that a 7 day quarantine period for sheep would be sufficient in order to reduce the risk of the internal transport of seed to acceptable levels, but a small risk of the external transport of seed on the fleece remains.  相似文献   

14.
1976～1978年从长春、白城市郊田间病株分离到 Verticillium 共64株,其中产生黑色菌落的60株,白色菌落的4株,经过致病性、形态、梅干培养基上特性、温度、pH 值范围、营养和同功酶等测定。确定是 V.dahliae Klek.,并且有黑色和白色二种不同的类群或小种。1975～1982年用8种化学农药和4种生物农药筛选、小区试验和较大面积示范试验表明多菌灵和甲基托布津在苗期施药(每平方米药5克拌30斤土)或在移植期、定植期灌药防效都较好,前者小区平均防效为71.78%、较大面积示范平均为74.29%,并可增产一倍以上,后者小区平均防效71.33%,较大面积示范为61.16%。生物农药中公主岭霉素较好。多菌灵对 V.dahliae 敏感 5ppm 即有抑菌效果,施药后40天的幼苗体内多菌灵含量较多每株达44ppm。示范田中播期施药土移植期又灌根,在20天后即定值时仍测得幼苗内含有10ppm 以上的多菌灵。  相似文献   

15.
Abstract

Village weaverbirds (Ploceus cucullatus Muller) normally feed on early maize in the morning (0800 to 1100 h) and evening (1600 to 1800 h) in southwestern Nigeria. However, when disturbed the birds feed during all the hours of daylight, and to be effective bird scaring would have to persist throughout the day. Developing grains are eaten, but rarely dry grains. The period of active bird scaring can therefore be reduced to about two weeks. In 1977 the mean percentage damage varied from 2.2 ± 0.3% in plots with dry ears to 34.1 ± 12.7% in plots with fresh ears, but in 1978 the situation was reversed with 17.7 ± 3.1% damage in plots with dry ears to 1.1 ± 0.2% in plots with fresh ears. The pattern of damage to early maize is associated with the annual rainfall, which determines the occurrence of lepidopterous larvae and wild sorghum (Sorghum arundicearum Stapf) which form alternative food items for the birds. Less than 2% of late maize ears was damaged since alternative food resources were abundant. Only early maize may need protecting from bird damage, but there was no definite relationship between time of planting and amount of damage caused.  相似文献   

16.
Notices     
Abstract

Seed‐bed types, fertilizers, cassava stem portions, planting time and yam cultivars were studied for the incidence of termites in cassava and yam fields. Planting cassava on ridges reduced the incidence of termites and significantly (P<0.05) increased tuber yield. The bottom stem portion of cassava stick was the least attacked by termites. Planting cuttings when rains became steady reduced termite incidence. NPKMg (12:12:17:2) suppressed termites in yam and improved yield significantly. Delay in harvesting yam tubers increased termite infestation. Yield loss was highest for Dioscorea rotundata cv. Nwopoko, with losses of more than 5 metric tonnes/ha when harvest was done after December in termite infested soil. Chinese yam showed the greatest resistance to termites.  相似文献   

17.
In the years 1969–1985, the population density of Microtus arvalis in Poland varied depending on the area, the largest populations and the most frequent mass occurrence being noted in the southern part of the country. Mass occurrences of rodents were observed in 1971, 1978, 1981, 1983 and 1984. Differentiation in the occurrence of M. arvalis was caused by the sculpture of the landscape, soil structure and by the length of the growing season.  相似文献   

18.
A few years ago, a new invasive weed was found in Spanish maize fields grazed by sheep after harvest and identified as a subform of teosinte (Zea mays ssp. mexicana ad int). If teosinte seeds survive digestion, then the weed could spread via sheep manure. The aim of this study was to assess the effect of this process on the emergence and viability of teosinte seeds. In an in sacco study, seeds were introduced into the rumen of fistulised wethers and extracted after 24, 48, 72 and 96 h. Then, seed emergence was recorded and the viability of non‐germinated seeds was analysed. In an ‘intake and in vivo’ study, lambs were kept in metabolic cages and fed for 6 days with 200 g teosinte seeds and ears. The daily faecal production was individually collected, seeds were recovered and viability was tested (15 days). In the in sacco trials, a decrease in teosinte viability was observed after remaining for 48 h or more in the rumen. In the ‘intake and in vivo’ trial, between 0.1% and 3% of the ingested seeds that were excreted were viable. Uncoated seeds that lost their exocarp during the mastication and digestion processes were less viable (18%) than intact excreted seeds (74%). The last viable and intact seeds appeared 4 and 6 days after intake respectively. In areas with teosinte infestation, sheep grazing on maize stubble should be avoided and, in case of ingestion, sheep should be kept isolated for 4–6 days to avoid the spread of this invasive weed.  相似文献   

19.
Abstract

The common myna Acridotheres tristis Linn., the jungle crow Corvus macrorhynchus Wagner and the house crow Corvus splendens Viellot are the major pests of oil palm in India. Other birds like crow pheasant Centropus sinensis Stresmann, parrot Loriculus sp. and pariah kite Milvus migrans Sykes also feed on oil palm fruits. These birds feed on the fleshy mesocarp of the ripe fruits resulting in heavy fruit loss, significantly reducing oil yield. Gizzard and intestinal content analysis indicated that oil palm fruits are the major source of food for these birds. Observations on 1657 oil palm fruit bunches during 1985–86 revealed that 76% of the ripe bunches and 5.6% of the unripe bunches were damaged by birds. The damage by birds was either ‘partial’ or ‘complete’, where 40–50% and 80–100% respectively, of the individual fruit weight was lost. The partial fruit damage was more common in 130–160 day‐old bunches and the complete fruit damage increased after 150 days of fruit set. Fruit loss due to bird damage was higher in palms in the border area of the plantation (2.3 kg/bunch) than in the interior (1.3 kg/bunch). It is estimated that around 2.8 tonnes of fresh fruits/ha/yr, equivalent to 420 kg of palm oil, are lost due to bird damage.  相似文献   

20.
Analysis of the economics of managing Cirsium arvense in grazed pastures worldwide has been hampered by a lack of data on the within‐year seasonal dynamics of the weed and its impact on the yield of palatable herbage. To redress this, the seasonal pattern in within‐patch percentage ground cover of the weed was determined from measurements on 39 dairy and 66 sheep and/or beef cattle farms in New Zealand during 2009–2010 and 2010–2011. This pattern was then scaled using farmer estimates of peak whole‐farm cover to derive mean monthly covers for dairy, beef, sheep/beef, sheep and deer farms. These monthly covers corresponded, respectively, to mean annual percentage covers of 2.7, 1.7, 3.0, 5.9 and 2.9% and to mean annual percentage losses in pasture growth (palatable herbage yield) of 3.6, 2.3, 4.0, 7.8 and 3.9%. The latter, in combination with 2011–2012 farm statistics, revealed that C. arvense caused a national loss in pastoral farm gross revenue in New Zealand in 2011–2012 of $685 million ($446 m dairy, $233 m sheep/beef, $6 m deer). Beyond the scope of this paper, the monthly covers and their corresponding monthly losses in pasture growth provide a basis for modelling the economic impacts of C. arvense and its management at a farm scale. More generally, the analytical method that we have developed is appropriate for evaluating the economic impact of any weed in a grazed pasture, particularly those exhibiting pronounced seasonal patterns in occupancy, such as annuals and deciduous perennials.  相似文献   

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