专用玉米品种类型及其栽培技术要点

<正>专用玉米是根据不同需要培育出的适合特殊用途的玉米品种,具有专用性、优质性、高效性等特点,在国内外具有广阔的市场前景。1专用玉米品种类型目前,国内推广的专用玉米品种,主要分为以下八大类型,分别为甜玉米、糯玉米、高油玉米、高蛋白玉米(高赖氨酸玉米)、高淀粉玉米、笋用玉米、饲用玉米和爆裂玉米。     

从塔城近年玉米种子销售看玉米种子发展趋势

<正>塔城盆地目前已经成为新疆第二大玉米种植区,面积仅次于伊犁河谷,2013年盆地玉米种植面积超过13.3万hm2;盆地农民已具备规模种植玉米技术、管理能力;玉米烘干厂遍布盆地,烘干能力已能够满足13.3万hm2以上玉米需求;玉米产业初步完善。种子在盆地玉米产业形成及发展中起到了至关重要的作用,回顾盆地玉米种子演变、更新史可以发现:我区现代玉米种子产     

万亩杂交玉米高产栽培技术分析

1986年黔西南州农技站在兴义、安龙两县连片示范推广杂交玉米10275亩。其中:单作杂交玉米4051亩,平均亩产352公斤;杂交玉米与花生间作4994亩平均亩产玉米197公斤,花生53.4公斤;杂交玉米与大豆间作957亩,平均亩产玉米338公斤,大豆30.5公斤;杂交玉米与芭蕉芋间作273亩,     

玉米主产省生产效率测度及影响因素分析——基于DEA-Tobit模型的实证研究

本文通过利用2004—2018年中国20省（直辖市、自治区）玉米投入产出面板数据,运用DEA-Malmquist方法,分析研究阶段内中国玉米生产效率的变化、空间差异及玉米生产过程中投入产出冗余情况,同时使用Tobit模型分析影响中国玉米生产效率的主要因素。研究结果表明:技术进步是促进中国玉米全要素生产率增长的主要关键因素,综合技术效率提升较小,其主要依赖于规模效率的增加;中国玉米生产综合技术效率总体呈现北方春播玉米区>西北灌溉玉米区>黄淮海夏播玉米区>西南山地玉米区;其中山西省、辽宁省、山东省、湖北省、云南省、陕西省、甘肃省均存在产出不足或投入冗余现象;农业机械总动力、受灾面积及地区差异对玉米生产技术效率影响显著。基于研究结论,提出3点建议,第一培育新型技术人才,加强玉米发展动力;第二改善基础设施建设,减缓自然灾害冲击;第三落实结构调整政策,开展规模适度经营。     

鲜食玉米产业现状与发展对策

鲜食玉米已在浦口区区域产业优势逐渐显现,目前,全区鲜食糯玉米生产已形成一定规模,鲜食玉米种植面积已发展到2000hm2;不断引进示范推广优质新品种;糯（甜）玉米生产取得了较好的效益;配套技术日趋完善;特色玉米产业化有了良好的开端。分析了鲜食玉米发展中存在的问题,提出了发展与对策：一是大力宣传,扩大南京市浦口区鲜食玉米的知名度;二是巩固和提高生产基地建设;三是优化结构,提高鲜食玉米综合生产水平;四是加快产业化开发,延长产业链。     

玉米螟虫防治试验与宏观效益分析

哈尔滨市呼兰区是黑龙江省农业大区,玉米种植面积9.33万hm2,占总耕地面积的80%以上。玉米种植面积不断扩大,重茬玉米面积剧增;秸秆处理不当;灭茬不及时;玉米秸秆垛不能及时药物封存;虫源基数增加。     

菲律宾转基因玉米的发展及对玉米产业的影响

菲律宾自2003年批准种植转基因玉米以来,发展迅速,2011年种植转基因玉米68.5万 hm2,已占到玉米总面积的26.9%;而双抗转基因玉米占到转基因玉米的94%,成为未来发展的主导趋势。分析表明,菲律宾玉米总产的提高得益于单产的提升,两者的相关系数达到0.98;玉米单产的提高与转基因玉米的大力推广关系密切,单产与转基因玉米普及率的相关系数为0.86,说明转基因玉米的推广对菲律宾玉米单产的提高和总产的增加有显著的积极作用。     

本玉系列玉米自交系及杂交种选育与应用

育种家王树功先生组建的玉米育种课题组用美国玉米杂交种Ci7&#215;L289选育二环系78-6;再用H84作抗原,改良78-6,育成高产、抗病、高配合力自交系7884-7;用国外02玉米转育高赖氨酸玉米自交系;用当地硬粒玉米作修饰基因改良02玉米选育（Q．P．M）优质蛋白玉米自交系。其中育成国审品种本玉9号、本玉15、本玉18;省审品种本玉11、本玉12、本玉13等本玉系列玉米杂交种,成为我国中熟、中晚熟玉米品种的重要组成部分;育成本高4号是辽宁省第1个、全国第2个高赖氨酸玉米杂交种;育成本优1号是东北地区第一个优质蛋白玉米杂交种。同时,育成了一批中熟、高产、优质、抗病和高配合力的本玉系列玉米自交系群体。     

"十一·五"期间我国粮油 果蔬加工业发展重点

1."十一·五"期间我国粮油加工业发展重点 (1)玉米加工 加强高油玉米、蜡质玉米、高直链玉米等加工专用玉米品种的选育,建设优质原料示范基地;发展专用变性淀粉、玉米淀粉糖、多元醇、乳酸和聚乳酸、淀粉基生物材料等精深加工产品,以及玉米胚芽、蛋白粉和玉米纤维等副产物综合利用新技术、新工艺研究与产业化开发;开展玉米主食食品、休闲食品、方便食品和功能食品的产业化开发;研制年产10万t以上玉米变性淀粉生产专用设备,主要包括脱胚磨、针磨、分离机、浓缩机等;开发竞争力强和技术含量高的品牌产品,使玉米的加工转化率(不包括饲料)由12%提高到20%.     

腐植酸钾浸种对干旱胁迫下玉米幼苗保护酶活性及MDA含量的影响

探索腐植酸钾浸种对玉米抗旱性的影响及其在作物生长化学调控中的作用。采用不同浓度（0、300、400、500 μg/mL）的腐植酸钾浸种玉米,研究了在16%的PEG-6000模拟干旱胁迫环境下,三叶期玉米幼苗叶保护酶活性及丙二醛含量的变化。与对照相比,浸种玉米的超氧化物歧化酶活性增高,但无显著差异;浸种玉米的过氧化物酶活性增高,在500 μg/mL时达极显著水平;浸种玉米的过氧化氢酶活性增高,在400、500 μg/mL时分别达极显著水平和显著水平;浸种玉米的丙二醛含量降低,在300~400 μg/mL时达显著水平,在500 μg/mL时达极显著水平。腐植酸钾浸种玉米,可减轻玉米在干旱胁迫下的膜脂过氧化程度,提高玉米抗旱性。     

Growth and dynamics in populations of echinocardium cordatum living in the North Sea off the Dutch North coast

Numerical densities and size distributions in populations of the spatangoid Echinocardium cordatum were followed at 19 fixed sampling stations with sandy sediments at depths of 6 to 18 m off the west-Frisian islands of Texel and Terschelling.Recruitment was irregular with some recruitment occurring during half of the years and successful year classes developing during only 3 of the years in the 10 year period of observation (1972–1982). Annual mortality of the strong year class born in 1972 was rather regular in the ages of 1 to 7 years, averaging ∼27% in the 2 areas, but was followed by catastrophic mortality at most stations during the severe winter 1979.Growth was rapid. A mean length of 2 to 2.5 cm was reached after 2 growing seasons and 4 cm after 4 or 5 growing seasons.     

西北地区蝴蝶兰反季节栽培技术

近几年，随着花卉产业的发展，使前几年还是价格不菲的高档兰花走进了越来越多的平常家庭，纵观国内，由于受气候条件的约束，绝大部分的蝴蝶兰生产商都把目光集中在年宵花上，所以出现了年宵蝴蝶兰竞争激烈、价格偏低的现象，通过对市场的考察，不难发现每年的9-11月份是蝴蝶兰的缺货期，但市场需求量却仍然很大，价格也不低。南方的夏季日温高、降温难，     

华北地区冬小麦生产中磷素利用特征研究

目前,中国农业集约化过程中普遍存在着化肥,特别是磷肥利用效率不高、土壤残留磷量较大的问题,这造成了磷肥资源的浪费以及由淋溶和径流造成的面源污染。笔者通过文献查阅,收集和筛选了自1980年以来中国公开发表的小麦田间试验论文,对华北平原及山西和陕西等地区小麦田间试验数据进行分析,对小麦生产和磷肥利用特征进行统计分析。本研究获得了冬小麦籽粒与秸秆产量的回归方程,以及施磷量与籽粒和秸秆含磷量的回归方程。在施磷为61 kg P₂O₅/hm ²时,冬小麦-土壤系统表现为磷素表观平衡;随着磷肥数量增加,磷素表观盈亏量呈线性增加。在当前华北地区常规磷肥(102 kg P₂O₅/hm ²)水平下,冬小麦一季在土壤中磷肥累积量约为25.7 kg P₂O₅/hm ²。华北地区冬小麦磷肥平均利用效率为(14.7±7.6)%,氮肥增加有利于提高磷肥利用效率。整体上,冬小麦对磷酸二铵的利用效率高于过磷酸钙,有机肥和化肥配施有利于提高磷肥利用效率,‘郑麦9023’的磷肥利用效率较高。所以选择合适的磷肥品种,通过合理的氮肥水平以及有机肥与化肥配施,能够提高华北地区的冬小麦磷肥利用效率。这对于该地区提高磷肥利用效率、降低磷肥损失和土壤污染风险,具有重要参考价值。     

Determinants of Local Highway Spending in North Carolina

Public spending, because it is influenced by elected officials, can be swayed by political considerations as well as socio‐economic factors. Previous studies have confirmed the importance of political measures in the allocation of general public spending as well as in spending for infrastructure and highway projects at the state level. This study examines the determinants of the allocation of state highway funds within one state—in North Carolina to counties during the period 1990–2005—and assesses the relative importance of socio‐economic and political factors in these decisions. Determinants were derived from three conceptual approaches to public spending: the median voter model, the special interest model, and the political model. Persistence was found in both highway construction spending and highway maintenance spending. In addition, employment market conditions were a strong determinant of highway construction spending, as was one political factor—the county's relative vote in the most recent election for the state's dominant political party. Highway maintenance spending was found to be dominated by median voter factors with no finding of political influence.     

Denitrification and nitrous oxide in the North Sea

In situ sediment denitrification rates were determined in the major areas of deposition of the North Sea, using the acetylene block technique. In addition, nitrous oxide profiles of the water column were determined. Nitrous oxide production generally occurred in the photic zone possibly due to nitrification; and throughout the water column in the German Bight region. Consumption at depth was possibly due to reduction in the anoxic microzones of faecal pellets, concentrated at the thermocline. Saturation of surface waters was 102.2% compared to 130.3% in the German Bight region. Calculated flux of nitrous oxide to the atmosphere was 9.5 × 10⁶ kg yr⁻¹, over half of which was produced in the German Bight.Sediment denitrification rates varied through three orders of magnitude; the highest value of 150 μmol m⁻² d⁻¹ was recorded in the Norwegian Trench. Nitrous oxide production by the sediments was low (1.1 μmol m⁻² d⁻¹ max.), and was undetectable at half of the sites. Sediment nutrient profiles exhibited porewater nitrate concentrations exceeding that of the overlying water suggesting that denitrification was fuelled by nitrification, which, in turn was related to other environmental variables. A significant positive relationship existed between in situ denitrification rate and the nitrate content of the upper sediment. Extrapolation of the rate to the total area of deposition in the North Sea suggests that denitrification is responsible for a minimum loss of 7.5–12% of the total annual nitrogen contaminant input.     

Nutrient depletion studies in offshore North Sea areas

Nanomolar nitrate and nitrite concentrations are reported for offshore areas of the North Sea during a research cruise in July 1987. The detection system employed was a sea-going chemiluminescence analyser. Surface concentrations during a period of nutrient depletion are reported, not previously described for this sea area.Very low values for the N/P ratio are reported (<0.1), which suggested that phytoplankton primary production was potentially nitrogen limited during the study period for large areas of the North Sea. Some coastal and river influenced regions exhibited a N/P Redfield ratio of >16, suggesting potential phosphate limitation. As well as the horizontal structure for nitrate and nitrite, vertical profiles are reported showing some structure in the nitrate profile above the thermocline. Nitrate levels generally increased towards the surface, from a minimum at the thermocline, and this may represent an important source of nitrogen to the system during nutrient depletion. A nitrite maximum was observed at the base of the thermocline at the deep water sites, this is attributed to either nitrification or nitrate reduction, and indicates that the thermocline region was a site of active nitrogen regeneration. A significant correlation between primary production and the nitrate concentrations below 100 nmoles.dm⁻³ was found, showing that the nitrate pool, as well as the recycling rate, remains an important influence during periods of nutrient depletion.     

北冬虫夏草饮料的研制

以人工培育的北冬虫夏草为原料,采用水浸提方法,利用L(934)正交实验,确定多糖浸提的最佳工艺。再以浸提液含量、酸味剂、甜味剂和稳定剂的添加量为正交因素配制饮料。实验得到了北冬虫夏草浸提最佳工艺条件为:料液比1∶6,浸提时间3h,浸提温度75℃;北冬虫夏草饮料的配制最佳配方为:浸提液53.8%,甜味剂30.8%,酸味剂7.7%,稳定剂7.7%。     

北青龙衣褐变机制的研究

北青龙衣在由鲜品到干品的贮藏期间会出现失水、颜色变深等褐变现象。研究该褐变过程发生的机制,为控制褐变、提高药材的稳定性提供试验依据。采用北青龙衣鲜果果皮,4℃低温贮藏,研究其褐变度(browning degree,BD)、多酚氧化酶(polyphenol oxidase,PPO)、苯丙氨酸解氨酶(phenylalanine ammonialyase,PAL)、过氧化物酶(peroxidase,POD)活性变化、丙二醛(malondialdehyde,MDA)、总多酚(total polyphenols,TP)、还原糖含量及维生素C(Vitamin C,VC)含量变化。试验数据显示果皮颜色变深、TP含量下降、PPO活性降低、PAL活性上升、SOD和POD活性先上升后下降、MDA含量升高、还原糖和VC含量下降。BD与PPO、SOD、POD活性和TP含量呈显著负相关,与PAL活性呈显著正相关,与VC和还原糖无显著相关性。北青龙衣贮藏过程中发生了酶促褐变和非酶褐变,且以酶促褐变为主,PPO在酶促褐变中可能起主要作用。