不同施氮方式对强筋小麦群体及产量和品质的影响

以优质专用强筋小麦品种豫麦34为材料,在豫南地区生态条件下研究了不同氮肥基追比例及追氮时期对小麦群体及产量和品质的影响。结果表明,在总施纯氮量为165kg／hm^2的条件下,与氮肥全部基施相比,基追比6：4与4：6的施肥方式有利于小麦分蘖成穗,增加有效穗数,促进基部节间缩短,从而降低株高和提高抗倒伏性能。另外,追肥比不追肥提高了产量,改善了籽粒和面粉品质。两个基追比相比,基追比4：6更有利于小麦群体动态的合理发展,以及产量的提高和品质的改善．尤其在拔节期追肥效果最佳,既可获得小麦籽粒最高产量,面粉品质也相对较高。     

水稻土施用不同氮、硫水平对油菜产量的影响

浙东平原水稻土油菜田间试验施用不同氮、硫水平的结果显示：（1）油菜籽产量随氮肥用量的增大而增加，施N（50－200kg/hm^)不施硫肥条件下，增产幅度为2．0％－11．8％，施N和施S（30kg/hm^2)条件下，增产幅度为2．4％－12．7％。（2）不同施氮水平下，施硫增产油菜籽5．4％－6．9％。（3）油菜氮吸收量随施氮量的增加而呈增加趋势，低氮水平下施用硫肥促进油菜氮吸收量加大。（4）不同施氮水平的产投比为1．5－4．3，施用硫肥的产投比达5．2－6．7，氮硫配施可提高施用氮肥的产投比。     

钾肥对花生生育影响及适宜钾用量研究

两年花生钾肥试验结果表明,在氮、磷一定水平上,增施钾肥可促进地上部干物质积累和生殖器官的发育,改善花生的经济性状,提高荚果产量和经济效益。当施钾量为180kg／hm^2时,花生荚果产量最高达4260.5kg／hm^2,利润最大为9482．0元／hm^2,产投比达到9．1：1。当施钾量增加到270kg／hm^2以上,花生产量和效益呈明显下降趋势。     

施氮方式对强筋小麦济南17产量和品质的影响

以优质强筋小麦济南17为材料，研究氮肥不同施用量、基追比和追氮时期对小麦籽粒产量和品质的影响，分析了产量与品质的关系。结果表明：适当地增加施氮量和拔节期追氮比例可显著地提高产量，籽粒蛋白质含量和干、湿面筋含量与产量同步增加；施氮量和拔节期追氮比例超过一定值时再增加施氮量和拔节期追氮比例，籽粒蛋白质含量和干、湿面筋含量继续增加，而产量则显著下降；延迟追氮时期可使籽粒蛋白质含量和干、湿面筋含量有较大幅度地提高，但对产量形成不利。以施氮量为262．5～328．1kg／hm^2且基追比为4：6或5：5，拔节和始花两次追肥的施氮方式，强筋小麦济南17能较好地实现优质与高产的统一。     

施氮量对花生养分吸收及产量品质的影响

田间试验研究不同氮用量对花生生长、养分吸收、产量和品质的影响。结果表明：在O～120kg／hm^2范围内,随着施氮量增加,花生荚果数增加,产量提高。120kg／hm^2用量下,花生产量最高3639．88kg／hm^2,比不施氮肥增产18．61％。0～150kg／hm^2范围内,施氮量提高促进氮磷钾吸收和植株生长及粗蛋白...     

移栽密度和施肥量对烟叶产质量的影响

在湘南浓香型烟区,以K326为对象,研究了在不同密度和施氮量水平下烟株的长势和产质量.结果表明,低施氮量时,密度不同对烟株生长和产质量影响较小,施氮量增加时密度影响开始显现,尤其施纯氮180kg/hm^2时表现明显;施纯氮135kg/hm^2 时烟株落黄情况好,但产值并不高,上等烟比例也较低;施纯氮157.5kg/hm^2,行株距1.2m×0.4m和1.1m×0.5m时产量和产值较高,其中行株距1.1m×0.5m时上等烟比例较高,值得推广.     

重迎茬大豆栽培施氮技术试验

由于重迎茬大豆根部易受病虫危害，吸收氮素营养和固氮能力减弱。通过施氮肥试验，研究出一整套重迎茬条件下施氮技术。重迎茬大豆施氮有增产作用，迎茬施氮增产1．9％－9．71％。适宜施氮量54kg/hm^2其中1／2作追肥；重茬大豆施氮增产7．22％－12．6％，适宜施氮量54kg/hm^2，其中1／3作追肥。在大豆出复叶时2次追肥施尿素可增产9．4％－12．5％。出现“黄萎”症状时喷施增产为12．7％－16．8％。建议生产上采用此技术。     

寒地水稻不同基蘖穗肥比例对产量的影响

通过对水稻不同基蘖穗肥比例及施氮量的研究,探讨了施用氮肥对水稻产量的影响。试验结果表明:在施氮量为120 kg/hm2,基蘖穗肥比例为6∶4时,产量高达8 589.0 kg/hm2,说明在该施肥量和施肥比例下比较合理。     

沿淮晚稻区优化施肥对粳糯生长和产量的影响

研究结果表明,农民习惯施肥方式导致肥料对水稻产量贡献率低的原因在于氮磷钾配比不合理,施氮肥集中在水稻生育前期,与水稻对养分的生理需要不一致。从本试验看,粳糯皖稻68在肥力水平中等的水稻田,以施氮量300kg／hm^2（基肥：蘖肥：穗肥为35：20：45）,N、P、K比例为1：0．30：0．40时产量最高,达9586．5kg／hm^2,比不施肥对照增产35．91％,比习惯施肥增产11．82％,肥料贡献率达到26．42％,对土壤的依存率明显下降。     

豫南稻区不同施钾水平对作物产量效应影响

对豫南稻区不同施钾处理在水稻、小麦和油菜三种作物上的产量效应进行了田间试验研究。结果表明，施钾处理增加效果明显，其中稻田和麦田施钾124．5kg／hm^2处理，油菜田施钾186．75kg／hm^2处理与对照相比增产效果最明显。水稻、小麦、油菜分别在施钾146．6kg／hm^2、145．6kg／hm^2、183、6kg／hm^2时的产量最高，单位面积产量分别为6869．3kg／hm^2、3517．1kg／hm^2、2424．2kg／hm^2。     

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.     

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.     

Recent Modifications of Chitosan for Adsorption Applications: A Critical and Systematic Review

Chitosan is considered to be one of the most promising and applicable materials in adsorption applications. The existence of amino and hydroxyl groups in its molecules contributes to many possible adsorption interactions between chitosan and pollutants (dyes, metals, ions, phenols, pharmaceuticals/drugs, pesticides, herbicides, etc.). These functional groups can help in establishing positions for modification. Based on the learning from previously published works in literature, researchers have achieved a modification of chitosan with a number of different functional groups. This work summarizes the published works of the last three years (2012–2014) regarding the modification reactions of chitosans (grafting, cross-linking, etc.) and their application to adsorption of different environmental pollutants (in liquid-phase).