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1.
为探讨紫花苜蓿春季返青前不同药剂处理对田间杂草的防除效果,以促进高质量苜蓿生产。本研究通过布设480 g/L氟乐灵、10%咪唑乙烟酸和20%乙氧氟草醚3种药剂在紫花苜蓿春季返青前开展杂草防除效果的试验。结果表明:效果最好的为2.70L/hm^(2)的480 g/L氟乐灵及2.70 L/hm^(2)的480 g/L氟乐灵与0.90 L/hm^(2)10%咪唑乙烟酸混合使用,可有效抑制苜蓿田间杂草的发生频率,显著提升苜蓿草产品产量。  相似文献   

2.
采用大田试验方法,研究了芽前除草剂氨氟乐灵和氮肥尿素对纯雌野牛草(Buchloe dactyloides)草坪建植的影响。第一次杂草调查结果表明氨氟乐灵处理显著降低野牛草分株的移苗死亡率、对草坪建植初期杂草封杀显著有效,虽然第二次杂草调查结果欠佳,但氨氟乐灵对杂草仍有一定的控制效果,推荐使用浓度在600 ~ 1 200 g·hm-2。其次,氨氟乐灵和尿素的结合处理提高了纯雌野牛草草坪的生物量、盖度以及降低了杂草总数量和杂草物种数,双因素方差分析结果表明氨氟乐灵相较于尿素对纯雌野牛草草坪建植的影响更大。最后,通过聚类分析发现氨氟乐灵和尿素结合处理中A3B2和A2B3的效果相近且最优。  相似文献   

3.
化学除草剂对越冬之星苜蓿杂草防除效果的试验   总被引:2,自引:0,他引:2  
为探讨研究除草剂对越冬之星苜蓿苗期的杂草防除效果,以期筛选出适宜的除草剂品种,笔者进行了化学除草剂对越冬之星苜蓿的杂草防除试验,并对苜蓿株高、产量及杂草量作了综合调查与分析。结果表明,高效盖草能、精禾草克、精稳杀得、拿捕净对禾本科杂草的防效为100%,5%苜草净在杂草株龄较大的情况下综合表现较好。苜蓿无药害的除草剂品种推荐5%苜草净在杂草株龄较大的情况下喷雾。  相似文献   

4.
苜蓿田间杂草综合防除的研究   总被引:3,自引:0,他引:3  
根据苜蓿的生长规律以及田间杂草的危害特点,提出了苜蓿田间杂草综合防除的基本措施。播前精细整地、早秋适时播种、窄行条播、间播多年生禾本科牧草以及刈割期及时清除杂草,能有效地防除苜蓿田间杂草。  相似文献   

5.
种植苜蓿时防除杂草很重要,因为杂草与苜蓿竞争阳光、水分和养分。苜蓿最容易受到杂草危害的时期主要在幼苗期和夏季收割后。在苗期,由于苜蓿幼苗地上部生长缓慢,而杂草的生长速度较快,因此会大量消耗苜蓿生长所需的水分和养分,造成苜蓿生长受阻。在夏季收割后,由于水热同步,杂草生长迅速,同苜蓿争夺养分,影响刈割后苜蓿  相似文献   

6.
苜蓿草地杂草防除技术探讨   总被引:1,自引:0,他引:1  
本文在研究苜蓿的生长规律以及田间杂草的植物学与生物学特点的基础上,提出了苜蓿草地田间杂草综合防除的基本措施。结果表明,播前精细整地,早秋适时播种,窄行条播,间播多年生禾草以及刈割期及时清除杂草,能有效地防除苜蓿田间杂草。  相似文献   

7.
苜蓿田杂草对苜蓿的生长具有很大的危害,需要采取有效措施防除杂草。笔者介绍了多种苜蓿田杂草的防除措施,希望对苜蓿种植者有所帮助。  相似文献   

8.
着重探讨苯达松,草甘膦在苜蓿种子地的化学除莠作用。通过对两种农药的适用浓度和喷施期的研究表明,苯达松对防除苜蓿种子地杂草-田旋花,灰绿藜,匾蓄,地肤等有较好效果,在杂草幼苗期,0.5%浓度即可达到防除目的,且对苜蓿影响不大,值得推广;草城膦是灭生性农药,不宜在芷蓿地中喷施,但在苜蓿地头田边喷施有较好效果,0.2%浓度的杂草死亡率可达95%以上。  相似文献   

9.
十四种化学除草剂对沧州地区苜蓿地杂草防效试验   总被引:2,自引:0,他引:2  
选用14种除草剂对沧州地区苜蓿(Medicago sativa)地苗期的杂草进行了防除试验。对苜蓿株高,产量及杂草量的综合调查分析结果表明,高效盖草能、精禾草克、精稳杀得、拿捕净对禾本科杂草的防效为100%,苜蓿保系列各剂型在杂草株龄较大的情况下综合表现较好,其中苜蓿保2%EC将杂草率从80.6%(CK)降到了36.5%,苜蓿增产40.6%。沧州地区春播苜蓿幼苗期单独使用禾本科除草剂或阔叶草除草剂效果不理想。  相似文献   

10.
苜蓿幼苗细嫩、不耐杂草,杂草较多会导致减产甚至绝收,所以在苜蓿生长过程中,要做好杂草防除工作。本文从农业防治和化学防治两方面总结了苜蓿田间杂草的防除措施,以供参考。  相似文献   

11.
试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。  相似文献   

12.
Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.  相似文献   

13.
14.
1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.  相似文献   

15.
Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.  相似文献   

16.
Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.  相似文献   

17.
Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.  相似文献   

18.
The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.  相似文献   

19.
<正>1.INTRODUCTION Ensuring transportation network security is one Of the most daunting challenges confronting homeland security agencies today.Significant research has been dedicated.To model and analyze the vulnerability of transportation systems,while notably fewer studies propose specific strategies for deploying defensive technologies to safeguard these systems.  相似文献   

20.
The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.  相似文献   

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