江苏里下河地区“一稻三虾”生态种养模式绿色生产关键技术(英文)

阐述了江苏里下河地区水稻+克氏原螯虾共(连)作绿色种养模式中"三大、二水、一网"的配套工程建设,稻前虾、稻中虾和稻后虾"一稻三虾"种养时空耦合技术,以及绿色施肥、绿色防控以及水位调控和投饵技术,为发展稻田综合种养,实现一水两用、一田四收绿色生产提供技术支撑。     

氟苯尼考及其代谢物在淡水小龙虾中残留消除规律的研究

本试验建立了小龙虾组织中氟苯尼考(FF)和氟苯尼考胺(FFA)残留的高效液相色谱检测方法,并采用连续6 d药浴(水温25℃)的方式,研究淡水小龙虾肌肉和肝胰脏中FF及其主要代谢物FFA代谢动力学和消除规律。检测方法是以PBS(pH 6.0)和乙酸乙酯-氨水(体积比为98∶2)作为提取溶剂,采用XTerra@RP18(5μm,4.6 mm×250 mm)反向色谱柱,利用乙腈-磷酸二氢钠缓冲液(体积比为3∶7)为流动相,流速0.8 mL.min-1,紫外检测波长224 nm。在添加20～500μg.kg-1标样时,该方法的回收率大于70%,变异系数低于7.92%。FF和FFA的检出限分别为20μg.kg-1和10μg.kg-1。残留消除试验结果表明:在药浴FF 6 d后,在组织中两种药物均检出,说明其代谢物也有出现。停药后168 h,肌肉中检测不到FFA;停药后336 h,肝胰脏中检测不到FFA残留,肌肉和肝胰脏中均检测不到FF残留。两种药物在肝胰脏的消除速率都慢于肌肉,FF的消除速率均略慢于FF和FFA总量在组织中的消除速率,肝胰脏中的FFA浓度远高于肌肉中的。FF和FFA两种药物残留总量在淡水小龙虾肌肉和肝胰脏的消除曲线方程分别是y=505.06e-0.012 9x和y=775.71e-0.010 0x、y=690.78e-0.013 5x和y=1 778.7e-0.011 1x,消除半衰期(t1/2)分别为51.33 h和62.43 h,在肌肉和肝胰脏中降至100μg.kg-1的理论时间分别为5.94 d和10.8 d。考虑到温度为影响药物代谢和残留的最主要环境因素,建议FF在小龙虾体内的休药期为270℃.d。     

冷冻龙虾仁辐照灭菌保鲜工艺技术研究

冷冻龙虾仁在我国水产品出口中占有较大的比例,由于高温加工,微生物很难控制到符合欧美标准。采用γ射线低剂量保温辐照工艺处理冷冻龙虾仁,结果表明:一般有效剂量控制在1.5 kGy即可使杂菌总数控制在1万个/g以下。在0~10 kGy处理剂量下,辐照对蛋白质无明显影响,并延长了保鲜期。研究还探讨了保温情况下的一整套灭菌工艺,使辐射剂量不均匀度控制在2以内,使被处理的产品保持原有的色、形,不回化。     

稻鳖鱼虾鳅生态种养关键技术

稻鳖鱼虾鳅生态种养关键在于选择优质水稻品种及优质水生动物品种.从水稻种植、稻田管理、水生动物养殖、病虫害防治等方面介绍了稻鳖鱼虾鳅生态种养技术.     

TENANCY ARRANGEMENTS USED BY LOUISIANA CRAWFISH PRODUCERS

Land tenancy arrangements vary widely in the U.S. crawfish industry, including full ownership by the crawfish producer, cash leases, share leases, and combination cash-share leases. This study examines the array of tenancy arrangements available and analyzes the types of farmers selecting each using a multinomial logit model. Choice of tenancy arrangement varies according to a number of traditional factors, such as farm size, experience, specialization, and production system. The influence of production system on land tenancy selection is of particular interest. Crawfish-rice double-crop producers tend to own all of their crawfish land, while those farming under rotational systems with crawfish and field crops tend to select combination cash-share leases. Shares, rental rates, and percentages of pumping cost paid by the landlord vary widely.     

克氏螯虾累枝虫病防治

通过药物浸泡试验和Karber法研究了福尔马林、硫酸锌粉、双效硫酸铜、杀毒先锋和虫茵双杀对克氏螯虾累枝虫病的防治效果.结果表明:治疗克氏螯虾累枝虫病的最佳治疗药物为福尔马林,且其安全浓度为22.5 mg·L-1.     

Engineering considerations for water circulation in crawfish ponds with paddlewheel aerators

Engineering considerations for paddlewheel aeration in vegetated shallow water ponds for the production of procambarid crawfish is necessary to ensure cost-effective application. Three experimental ponds (approximately 2 ha each) were planted with rice in August as forage for the resident pond population of red swamp crawfish, Procambarus clarkii, and flooded in October. Two 2.2 kW (3 hp), single-phase electric motor (110 V_ac) paddlewheel aerators were placed in each pond. The aerator rotors were 160-cm long and 95-cm in diameter. The aerator rotor had 36 paddles with half the paddles 27.3-cm long and half 34.9-cm long. Rotor speed was set at 83 rpm and operated at three paddle submergence settings: 7.6, 12.7, and 17.8 cm below the water surface. Over a 20-week period between November and April, channel velocity, head difference, and aerator amperage was measured for both one and two aerators in operation in each pond. Results indicated that circulation of oxygenated water from the aerators can be accomplished as efficiently with a single aerator set at a lower paddle depth (7.6-cm) compared to operating two aerators set at a greater paddle depth (12.7 or 17.8-cm). However, based on the apparent efficiency of the aerators and the calculated channel roughness coefficients values obtained from the channel velocities, paddlewheel aerators are an inefficient option for circulating the pond water especially when rice foliage dominants the total vegetative biomass of the pond.     

Comparative acute toxicity of neonicotinoid and pyrethroid insecticides to non‐target crayfish (Procambarus clarkii) associated with rice–crayfish crop rotations

BACKGROUND: Most insecticides used to control rice water weevil (Lissorhoptrus oryzophilus Kuscel) infestations are pyrethroids. However, pyrethroids are highly toxic to non‐target crayfish associated with rice–crayfish crop rotations. One solution to the near‐exclusive reliance on pyrethroids in a rice–crayfish pest management program is to incorporate neonicotinoid insecticides, which are insect specific and effective against weevils but not extremely toxic to crayfish. This study aimed to take the first step to assess neonicotinoids as alternatives to pyrethroids in rice–crayfish crop rotations by measuring the acute toxicities of three candidate neonicotinoid insecticides, clothianidin, dinotefuran and thiamethoxam, to juvenile Procambarus clarkii (Girard) crayfish and comparing them with the acute toxicities of two currently used pyrethroid insecticides, lambda‐cyhalothrin and etofenprox. RESULTS: Neonicotinoid insecticides are at least 2–3 orders of magnitude less acutely toxic (96 h LC₅₀) than pyrethroids to juvenile Procambarid crayfish: lambda‐cyhalothrin (0.16 µg AI L^?1) = etofenprox (0.29 µg AI L^?1) ? clothianidin (59 µg AI L^?1) > thiamethoxam (967 µg AI L^?1) > dinotefuran (2032 µg AI L^?1). CONCLUSION: Neonicotinoid insecticides appear to be much less hazardous alternatives to pyrethroids in rice–crayfish crop rotations. Further field‐level neonicotinoid acute and chronic toxicity testing with crayfish is needed. Copyright © 2009 Society of Chemical Industry     

湖北省出口小龙虾质量安全管理研究

作为为数稀少的自然资源性虾类产品———淡水小龙虾,是我国重点出口水产品之一,也是备受关注的高风险出口商品。目前乃至今后一段时期,出口淡水龙虾行业存在着若干内“忧”外“患”的困难和问题。文章将对湖北省出口小龙虾质量安全管理问题进行研究。