垄上双行插装式排种器性能试验研究初报

为提高大豆育种试验的准确性,降低劳动强度,针对垄三栽培小区试验农艺技术要求,设计了一种与之配套的垄上双行插装式排种器,并以作业速度和株距为影响因素对其工作性能进行了测试。结果表明:当作业速度分别为3.6、4.5、5.4 km.h-1,双行株距为5 cm时,其粒距合格指数≥85.17%、重播指数≤11.11%、漏播指数≤4.24%、变异系数≤20.69%;当双行株距为7.5 cm时,其粒距合格指数≥85.26%、重播指数≤9.47%、漏播指数≤5.26%、变异系数≤18.17%。两种工况下,排种器均达到JB/T51017-1999《中耕作物精密播种机产品质量分等》优等品标准的要求。该排种器为垄三栽培模式配套大豆小区精密播种机的开发奠定了基础。     

2BMFJ-3型麦茬地免耕精密播种机排种器选型试验研究

为保证2BMFJ-3型麦茬地免耕大豆精密播种机播种大豆的性能,确定一种适合于该播种机的机械式精密排种器,参照GB6973-2005《单粒(精密)播种机试验方法》,以窝眼轮式、倾斜勺式和勺轮式排种器为研究对象,在JPS-12计算机视觉精密排种器性能检测试验台上实施了对比试验研究.结果表明:在作业速度3 ～6 km·h-1、粒距8 cm条件下,勺轮式排种器的排种性能最优,其合格指数87.8％～98.9％,重播指数0.5％ ～1.1％,漏播指数低于12％,变异系数小于16％,各项指标均达到国家标准优等品水平.     

基于响应面法的气吸式大豆高速精密排种器试验研究

以设计的气吸式大豆高速精密排种器为研究对象,采用响应面法试验设计方法,以吸孔直径、真空度、作业速度和吸孔数为影响因素,以合格指数、漏播指数、重播指数、变异系数为目标函数,运用Design Expert 7.0试验设计软件进行处理,建立排种器主要性能指标与试验因素之间的数学模型,分析试验诸因素对排种器性能指标影响规律及交互效应关系。优化得出最佳参数组合吸孔直径4.5~5.0 mm、吸孔数75~85个、真空度5 k Pa、作业速度9 km·h-1时,此时合格指数大于96,漏播指数小于1.5,重播指数小于2.5和变异系数小于20。     

2BMFJ-3(B)型茬地大豆免耕覆秸精播机性能试验研究

按照国标标准《GB/T6973-2005单粒(精密)播种机试验方法》,设定理论株距8cm和6cm,理论播深3～5cm,对2BMFJ-3(B)型茬地大豆免耕覆秸精播机进行田间性能测试,进而对其作业质量进行等级评定。结果表明:当理论株距为8cm和6cm时,粒距合格指数、重播指数、漏播指数及株距变异系数均达到了国家部颁标注优等品要求水平;当理论播深为3～5cm时,播深合格率达到一等品的要求水平。     

小麦茬地免耕大豆精密播种机性能试验研究

从大豆种子的株距、播深和施肥位置三个方面测试小麦茬地免耕大豆精密播种机的工作性能,并做了田间试验,结果表明:该机株距合格指数可达68.4%,重播指数为13.4%,漏播指数为18.1,变异系数为26.3,播深合格率为87.7%,达到了<中耕作物精密播种机产品质量分等>标准中关于一等品的要求.同时,施肥位置也满足农艺要求.     

脱毒微型马铃薯气力倾斜圆盘排种器试验

为提高脱毒微型马铃薯机械化播种水平,保证播种质量,针对脱毒微型马铃薯,设计了一种气力式倾斜圆盘排种器,并对其进行了单因素试验及正交试验。分析了该排种器合格指数、重播指数、漏播指数和变异系数等性能指标与排种轴转速、排种盘倾斜角度、排种盘型孔形式3个要素之间的关系。单因素试验结果表明,上述3个试验因素对排种器性能指标均有显著影响;正交试验结果表明,排种轴转速为10 r/min、排种盘倾斜角度为45°、排种盘型孔形式为9×Φ12 mm圆柱孔时,排种器合格指数达97.62%,漏播指数为0.67%,变异系数为8.94%;研究结果表明,气力倾斜圆盘排种器能满足大粒径且外形个体差异性大的脱毒微型马铃薯的精密播种要求,为大粒径种子的播种提供一个新的方法。     

基于EDEM的大豆窝眼轮式排种盘型孔参数优化与验证

对品种的适应性是大豆育种专用排种器技术研究的关键,主要取决于大豆种子与排种盘型孔间的关系,因此,如何精准构建排种盘型孔参数关于大豆种子物理参数的数学模型具有非常重要的意义。本研究基于东农52大豆种子的物理参数,理论分析并确定其各种型孔充填状态的型孔均径比范围(1.43~1.87)及对应状态概率。建立了大豆小区育种插装式排种器的EDEM仿真模型,并以型孔均径比及充种倒角为试验因素,漏播率及重播率为试验指标,进行了二因素五水平二次回归通用旋转组合设计试验,建立了试验指标的数学模型,以优化型孔的最佳结构参数。结果表明:对漏播率,型孔均径比极显著(P0.01),充种倒角显著(0.01P0.05);对重播率,型孔均径比极显著(P0.01),充种倒角有一定影响(0.05P0.1)。在试验范围内,随型孔均径比的增大,漏播率减小及重播率增大,随充种倒角的增大,漏播率先减小后增大,重播率无变化。型孔最佳参数为型孔均径比1.64,充种倒角1.54 mm,此时,漏播率4.95%,重播率6.49%。验证试验结果表明:优化型孔的排种盘具有相对最佳的作业性能。该研究为其它作物排种器型孔的设计研究提供了参考。     

山东烟台《气吸式花生精量播种机》通过专家鉴定

最近,由烟台市农机所承担的烟台市科技攻关项目《气吸式花生精量播种机的研究与开发》已顺利通过市级鉴定。烟台市农机所自主研发了垂直园盘排种器,在机械式花生播种机的基础上进行集成创新,研发出了2BHQ-2型气吸式花生精量播种机,申报了国家实用新型专利二项（201120314142．7,201120314143．1）。该机应用气吸式工作原理,可一次完成起垄、开沟、施肥、排种、喷药、覆膜、覆土压膜等作业功能,具有种子适应范围宽、损伤率低、播种精度高等优点,节约了种子,提高了出苗率和机具播种的适应性。     

2BMFJ-BL5型原茬地大豆免耕覆秸精量播种机性能试验研究

在北方垄作秸秆根茬残留量为0.994 kg·m~(-2)的人工收获后玉米原茬地上,测试分析2BMFJ-BL5型大豆原茬地免耕覆秸精量播种机田间作业性能。在作业速度5 km·h~(-1)条件下,按照中华人民共和国机械行业标准NY/T1768-2009《免耕播种机质量评价技术规范》实施了本次试验。结果表明:播种均匀性达到了国家标准优等品标准,播种深度合格率达到了国家一等品的标准。各行排肥量一致性变异系数达到了国家一等品的标准,总排肥量稳定性变异系数达到了国家优等品的标准。秸秆清秸率达97%以上,植被覆盖率达97%以上,田间出苗率达94%以上。试验结果为2BMFJ-BL5型大豆原茬地免耕覆秸精量播种机的产业化和推广应用提供了理论依据。     

内充种式大豆排种器仿真和试验研究

为了实现大豆单粒精密排种,从而节约种子用量,使用EDEM软件设计内充种式大豆排种器,针对5个黄淮海地区普遍种植的大豆品种,对内充种式大豆排种器的性能进行仿真试验,分析排种器工作转速对排种器的单粒率的影响,并进行台架试验验证.结果显示:仿真试验中排种器工作转速在30 r·min-1时单粒率为90.81％～95.42％.台...     

Comparative Assessment of the Efficacy of Various Nitrogen Fertilizers

Summary

The efficiency of N fertilizers is usually poor; often less than 50% of the applied N is taken up by the crop. This review focuses on various N fertilizers with respect to the significance of different N loss pathways, namely (i) ammonia volatilization, (ii) dinitrogen and nitrogen oxide emissions, and (iii) nitrate leaching. Further, the significance of biological N immobilization, ammonium fixation and, finally, the impact of nitrate vs. ammonium uptake on crop yield are also discussed. The reviewed literature shows that N fertilizers may differ markedly in their susceptibility to losses. There is, however, considerable scope to improve N efficiency of each N source by proper N management practices.     

Studies on natural repellents against potato tuber moth (Phthorimaea operculella Zeller) in country stores

Summary The effects of the leaves of five plant species, one from each of the generaAmbrosia, Anemone, Eupatorium, Eucalyptus andLantana, on potato tuber moth were investigated under indigenous storage conditions at the Central Potato Research Station, Shillong (1800 m above sea level). Their action was compared with that of a biological insecticide (spores ofBacillus thuringiensis), a chemical insecticide (carbaryl), and an untreated control. The data collected after six months storage on tuber damage, sprout damage and the rotting indicated that the leaves ofLantana aculeata provided most protection to the tubers, reducing damage from over 70% in the check to below 5%, and sprout damage from over 45% to below 3%. Next best wasEucalyptus globulus followed byB. thuringiensis. They may be used on tubers stored for table use or for seed as they had no adverse effect on germination or on the yield of a subsequent crop.     

Mineral composition of some traditional Mexican teas

Teas of plant origin traditionally consumed by the Mountain Pima of Chihuahua, Mexico, were analyzed for mineral nutritional content. Fe, Cu, Zn, Ca, and Mg composition was determined for native teas made from shoots ofTagetes lucida, T. filifolia, Elytraria imbricata, andHolodiscus dumosus, and from root xylem ofCeanothus depressus andPhaseolus ritensis. Native uses of these teas are also described.     

Novel food and non-food uses for sorghum and millets

Sorghum and millets have considerable potential in foods and beverages. As they are gluten-free they are suitable for coeliacs. Sorghum is also a potentially important source of nutraceuticals such antioxidant phenolics and cholesterol-lowering waxes. Cakes, cookies, pasta, a parboiled rice-like product and snack foods have been successfully produced from sorghum and, in some cases, millets. Wheat-free sorghum or millet bread remains the main challenge. Additives such as native and pre-gelatinised starches, hydrocolloids, fat, egg and rye pentosans improve bread quality. However, specific volumes are lower than those for wheat bread or gluten-free breads based on pure starches, and in many cases, breads tend to stale faster. Lager and stout beers with sorghum are brewed commercially. Sorghum's high-starch gelatinisation temperature and low beta-amylase activity remain problems with regard to complete substitution of barley malt with sorghum malt . The role of the sorghum endosperm matrix protein and cell wall components in limiting extract is a research focus. Brewing with millets is still at an experimental stage. Sorghum could be important for bioethanol and other bio-industrial products. Bioethanol research has focused on improving the economics of the process through cultivar selection, method development for low-quality grain and pre-processing to recover valuable by-products. Potential by-products such as the kafirin prolamin proteins and the pericarp wax have potential as bioplastic films and coatings for foods, primarily due to their hydrophobicity.     

In vitro antimicrobial activity of different accessions ofSolanum commersonii Dun. from Uruguay

Summary The in vitro antimicrobial activity of extracts from accessions ofSolanum commersonii Dun. collected in the south of Uruguay was investigated against five microorganisms including the pathogenRalstonia solanacearum. A total of 30 extracts corresponding to organic and aqueous extracts were studied. Interestingly, most of the positive results for growth inhibition were againstR. solanacearum. The extracts were also analyzed for the presence of glycoalkaloids and lectins. Six of the ten aqueous extracts showed lectin presence and a wide variation in the type and amounts of glycoalkaloids, was found. Results indicate that there is no clear relationship between the antimicrobial activity against the five microorganisms screened and the presence or amounts of lectins and glycoalkaloids, traditionally regarded as possible antimicrobial metabolites in theSolanum genus, which indicates the presence of as yet unidentified antimicrobial compounds.     

Extreme resistance to infection by potato virus X in genotypes of wild tuber-bearingSolanum species

Summary Clones derived from thirty-one different accessions (nineteen of Argentine origin) belonging to eightSolanum species were screened for resistance to infection by potato virus X strain cp (PVX cp) by mechanical inoculation of plantlets that had been micropropagated in vitro. Estimates of PVX multiplication obtained by enzyme linked immunosorbent assay and slot blot nucleic acid hybridization allowed the identification of resistant clones derived from five accessions belonging toS. commersonii S. oplocense, S. sparsipilum andS. tuberosum andigena. Resistant genotypes supported PVX concentrations 5 to 15 times smaller than did the susceptible control cultivar Spunta. Graft inoculation test confirmed the presence of extreme resistance similar to that conferred by the ‘immunity’ gene X¹ (also called RX_act).     

Cyanobacteria Secondary Metabolites as Biotechnological Ingredients in Natural Anti-Aging Cosmetics: Potential to Overcome Hyperpigmentation,Loss of Skin Density and UV Radiation-Deleterious Effects

The loss of density and elasticity, the appearance of wrinkles and hyperpigmentation are among the first noticeable signs of skin aging. Beyond UV radiation and oxidative stress, matrix metalloproteinases (MMPs) assume a preponderant role in the process, since their deregulation results in the degradation of most extracellular matrix components. In this survey, four cyanobacteria strains were explored for their capacity to produce secondary metabolites with biotechnological potential for use in anti-aging formulations. Leptolyngbya boryana LEGE 15486 and Cephalothrix lacustris LEGE 15493 from freshwater ecosystems, and Leptolyngbya cf. ectocarpi LEGE 11479 and Nodosilinea nodulosa LEGE 06104 from marine habitats were sequentially extracted with acetone and water, and extracts were analyzed for their toxicity in cell lines with key roles in the skin context (HaCAT, 3T3L1, and hCMEC). The non-toxic extracts were chemically characterized in terms of proteins, carotenoids, phenols, and chlorophyll a, and their anti-aging potential was explored through their ability to scavenge the physiological free radical superoxide anion radical (O₂^•−), to reduce the activity of the MMPs elastase and hyaluronidase, to inhibit tyrosinase and thus avoid melanin production, and to block UV-B radiation (sun protection factor, SPF). Leptolyngbya species stood out for anti-aging purposes: L. boryana LEGE 15486 presented a remarkable SPF of 19 (at 200 µg/mL), being among the best species regarding O₂^•− scavenging, (IC₅₀ = 99.50 µg/mL) and also being able to inhibit tyrosinase (IC₂₅ = 784 µg/mL), proving to be promising against UV-induced skin-aging; L. ectocarpi LEGE 11479 was more efficient in inhibiting MMPs (hyaluronidase, IC₅₀ = 863 µg/mL; elastase, IC₅₀ = 391 µg/mL), thus being the choice to retard dermal density loss. Principal component analysis (PCA) of the data allowed the grouping of extracts into three groups, according to their chemical composition; the correlation of carotenoids and chlorophyll a with MMPs activity (p < 0.01), O₂^•− scavenging with phenolic compounds (p < 0.01), and phycocyanin and allophycocyanin with SPF, pointing to these compounds in particular as responsible for UV-B blockage. This original survey explores, for the first time, the biotechnological potential of these cyanobacteria strains in the field of skin aging, demonstrating the promising, innovative, and multifactorial nature of these microorganisms.     

Marine Pharmacology in 2009–2011: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis,and Antiviral Activities; Affecting the Immune and Nervous Systems,and other Miscellaneous Mechanisms of Action ?

The peer-reviewed marine pharmacology literature from 2009 to 2011 is presented in this review, following the format used in the 1998–2008 reviews of this series. The pharmacology of structurally-characterized compounds isolated from marine animals, algae, fungi and bacteria is discussed in a comprehensive manner. Antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral pharmacological activities were reported for 102 marine natural products. Additionally, 60 marine compounds were observed to affect the immune and nervous system as well as possess antidiabetic and anti-inflammatory effects. Finally, 68 marine metabolites were shown to interact with a variety of receptors and molecular targets, and thus will probably contribute to multiple pharmacological classes upon further mechanism of action studies. Marine pharmacology during 2009–2011 remained a global enterprise, with researchers from 35 countries, and the United States, contributing to the preclinical pharmacology of 262 marine compounds which are part of the preclinical pharmaceutical pipeline. Continued pharmacological research with marine natural products will contribute to enhance the marine pharmaceutical clinical pipeline, which in 2013 consisted of 17 marine natural products, analogs or derivatives targeting a limited number of disease categories.