大豆根潜蝇发生危害与防治

大豆根潜蝇发生危害与防治顾成玉（黑龙江省农科院嫩江农科所）大豆根潜蝇是大豆主产区重要害虫之一，从７０年代以来危害有逐年加重的趋势。１９９３年全省普遍发病，被害株率７０～１００％，给大豆生产带来很大损失。因此，掌握大豆根潜蝇的发生规律，明确影响发生危害...     

大豆根潜蝇的发生与药剂防治

大豆根潜蝇的发生与药剂防治任柏栋（黑龙江省绥化市种子公司１５２０００）大豆根潜蝇又名大豆根蝇、豆根蛇潜蝇等，它是一种大型蝇子。黑龙江省发生比较普遍。据１９９６年在绥化地区５个市县２８个点调查，发生地块１００％，危害株率８０％～１００％。目前防治大豆根...     

包衣种子在重茬大豆田中的应用效果试验

由于大豆孢囊线虫病、根腐病、根潜蝇等三种病虫害的危害，造成土壤中养分缺乏和肥力下降，这是重茬大豆减产的主要原因。针对以上原因，我们连续三年在重茬大豆地块进行包衣大豆种子应用的试验、示范。结果包衣种子比不包衣种子保苗率提高9．6％，大豆孢囊线虫病指数少5．2％，相对防效较其它药剂处理提高10．2％；根潜蝇危害株率减少39．7％；地下害虫危害株率减少7．2％，平均增主10．5％，经方差分析，差异均达显著水平。     

盐碱地区大豆重迎茬对产量的影响及其解决的途径

地处黑龙江省西部的安达市，是大豆孢囊线虫病的重病区，也是大豆重迎茬播种禁区。不仅重迎茬减产严重，相隔3－4年减产幅度也很大。大豆重迎茬大幅度减产的主要原因：首先是孢囊线虫危害，其次是根蛆和根腐病危害，再次是某些元素缺乏。解决的措施：一是选用抗线大豆良种，二是感线大豆品种要执行相隔五年以上轮作，三是采用大豆种衣剂拌种，四是叶喷内吸杀菌剂。     

辽宁省新宾地区大豆根蛇潜蝇危害及药防效果

辽宁省新宾地区大豆根蛇潜蝇危害及药防效果郭德忱张廷杰郎丰太（新宾县植保站）（新宾县农业局）（旺清门农业站）新宾县地处辽宁省东部山区，常年大豆种植面积约１０万亩，占旱田作物面积的３３．３％。多年来，大豆经常遭受“哑叭灾”危害，造成减产，却不知缘由。１９...     

大豆疫病的发生及防治技术

危害大豆的一种重要病害大豆疫病 ,由真菌ｐｈｙｔｏ ｐｈｔｈｒａｍｅｇａｓｐｅｒｍａｆ·ｓｐ .ｇｌｙｃｉｎｅａｋｕａｎｅｔｅｒｗｉｎ所致 ,是大豆生产的毁灭性病害。该病原菌除危害大豆外 ,还可危害菜豆、豌豆等豆类作物。一、危害程度50年代大豆疫病在美国已大面积发生 ,并造成大幅度减产 ,曾对美国的大豆生产造成极大危害。黑龙江省近年来发现了大豆疫病 ,发生面积逐年增加 ,危害程度逐年加重。该病可造成种子、根、茎腐烂 ,在大豆整个生育期均可侵染危害 ,使植株逐渐枯萎死亡 ,在感病品种上可造成 2 5%～ 50 %的损失 ,个别感病品…     

大豆根潜蝇发生程度与前茬作物关系初步调查

大豆根潜蝇在我国主要分布在东北三省、内蒙古、河北、山东及山西等地,其中以黑龙江省等地尤为普遍。主要在大豆苗期进行危害,幼虫在大豆苗根部皮层和木质部钻蛀危害,造成根皮层腐烂,形成条状伤痕,导致大豆根系受损伤而不能正常生长和吸收土壤中的各种营养成分。2015年黑龙江省克山县大豆根潜蝇普遍发生,为了探求该虫害发生程度与前茬作物关系,同时初步统计该虫害发生程度。本研究在黑龙江省克山县大豆育种示范田进行,前茬作物分别为大豆、马铃薯、小麦,采用棋盘式取样法进行调查。结果显示:前茬为大豆的地块大豆根潜蝇发生程度最重,其次是前茬为马铃薯茬的田块,侵入率最低的是前茬为小麦茬地块。在调查所有的大豆株系中平均根潜蝇侵染率为66%,调查地块每平方米蛹的数量为21头,基本属于大发生。     

大豆应用埃姆泌(MB-97)生物菌肥试验效果

应用埃姆泌(MB-97)生物菌肥能促进大豆根瘤形成，增强固氮能力，增强抗逆性，降低根庸痛、根蛆、孢囊线虫的发生危害率，增加大豆株高、荚数、粒数等，具有抗重茬增产作用，效果比较明显；本试验示范以常规施肥 MB菌肥45kg／hm^2效果较好。     

黑龙江省大豆根腐病的危害与防治

黑龙江省大豆根腐病的危害与防治黑龙江省农科院大豆所张玉华大豆根腐病是世界各大豆产区的重要病害之一，一般减产１０％，如果和其他根部病害混合侵染，则危害更重。一、大豆根腐病的发生与危害大豆根腐病分布广、危害严重，是我省目前应引起高度重视的主要病害之一。据...     

大豆根际真菌类群对大豆幼苗生长的影响

利用稀释平板法分离连作大豆根际真菌类群，结果表明：大豆根际真菌类群主要有１０种，以青霉菌、根霉菌和丝核菌占优势。根际真菌类群接种大豆的土培盆栽试验结果表明，青霉菌对大豆幼苗生长具有明显的促进作用，镰刀菌和丝核菌对大豆幼苗根部有寄生作用，是大豆极腐病的主要致病菌，且丝核菌致病力强于镰刀菌。     

Modelling root and stem lodging in sunflower

Stem and root lodging constitute significant adversities to sunflower (Helianthus annuus L.) cropping in Argentina. We have adapted previously developed models of the lodging process in cereals to the particularities of sunflower by using functions, developed using data obtained by mechanical lodging, for the [root failure moment/plant anchorage] and [stem failure moment/thickness of stem wall] relationships, and estimates of plant area loaded by wind gusts. The model uses this information to estimate wind failure speed (i.e., the wind speed at which lodging [stem or root, as appropriate] is expected to occur). The model was tested against information (plant and soil characteristics, measured wind gust velocity immediately preceding rainfall) obtained in 26 naturally lodged plots (6 stem-lodged, 20 root-lodged) which occurred across a network of trials (2 seasons, 4 sites, 3 hybrids, 4 crop population densities, all experiments fitted with automatic meteorological stations). Lodging events took place over a range of crop developmental stages between visible capitulum and harvest maturity. Lodging index (proportion of plants lodged) against the difference between observed and model-estimated wind failure speeds showed that the model had good predictive skill across the range of conditions explored in these experiments and was able to distinguish between hybrids of differential susceptibility to lodging within the same experiment. Sensitivity analyses showed that the principal determinants of lodging susceptibility were root plate diameter, stem wall thickness, and the area of the plant loaded by wind gusts. Within the observed ranges (almost twofold) of stem height and stem natural frequency, these two variables had little influence on lodging susceptibility. We conclude that the model, despite the simplifications incorporated into its structure, provides an effective and useful tool for the integration of the complex factors that determine lodging susceptibility in this species.     

大豆根系在土层中分布特点的研究

采用框架剖面法测定了大豆根系干重在草甸黑土和白浆土中的分布特点。大豆根系干重 85 %分布在水平方向的 0～ 12 .7cm ,获得高产的最适宜株行距为 12 .7× 12 .7cm ;大豆根系干重 85 %分布在垂直方向的 0～ 10cm ,呈现T型分布。根系在草甸黑土中水平分布与白浆土相似 ;但垂直方向的 0～ 10cm土层中 ,草甸黑土的根系干重高于白浆土     

大豆根腐病的识别与防治

介绍了大豆根腐病的主要种类与症状识别,分析了大豆根腐病的发生规律,提出了大豆根腐病的综合控制措施。     

Precision tillage effects on potato root and tuber production

American Journal of Potato Research - Impedance to the extension of potato roots in a high-strength soil was reduced by chiseling with a subsoil shank directly in the center of the potato bed...     

Identification of cassava root protein genes

The protein population of cassava root layers was characterized bySDS-PAGE and bidimensional polyacrylamide gel electrophoresis. SDS-Pagerevealed the presence of a protein population in the molecular weight rangebetween 94 and 20 kDa. The expression pattern of these proteins was welldefined within the different layers. Partial protein sequence analyses andpreliminary results on the layer-specific expression pattern obtained withNorthern analyses are presented.     

Effects of root exudates and pH on Plasmodiophora brassicae resting spore germination and infection of canola (Brassica napus L.) root hairs

Clubroot, caused by Plasmodiophora brassicae, is emerging as a serious threat to canola production on the Canadian Prairies. Germination of soil-borne resting spores (RSs) and their subsequent infection of canola root hairs are important requirements for the establishment of the clubroot pathogen in canola. Stimulation of RS germination by certain non-host plant species and elevation of soil pH by application of calcium-rich compost may provide some level of clubroot control in the field. Experiments were conducted under controlled conditions to determine the effects of (i) host and non-host root exudates (REs) and different pH values on the germination of RSs, and (ii) different pH values either alone or in conjunction with a Ca-containing nutrient solution (NS) on root hair infection of a susceptible canola cultivar. The percentage of RS germination was significantly enhanced when incubated with REs prepared in NS from three plant species compared to a NS alone or sterile dH₂O. Non-host REs from perennial ryegrass (Lolium perenne L.) produced higher spore germination than exudate preparations from canola (Brassica napus L.) and Chinese cabbage (Brassica rapa var. pekinensis, cv. Granaat) roots. The percentages of RS germination were higher at pH values ranging from 5.0 to <7.0, and lower at pH values >7.0 in both the presence and absence of REs. The effects of various pH values on the percent of root hair infection varied. Root hair infection was higher at relatively lower pH values (6.0–7.0) compared to either lower or higher pH values when a NS was added. It was however lower at pH values below 6.5 compared to those above 6.5 when the experiment was conducted in the absence of a NS. The possible impacts of REs, different pH values, and calcium levels in the soil on the severity of clubroot on canola are discussed.     

Population studies and successful control of the potato root eelworm

Summary Field methods for the control of potato root eelwormHeterodera rostochiensis bring fairly predictable percentage decreases in the population available to attack potato roots, but are only economically successful when applied to the lower soil populations. Successful treatment must be capable of lowering the population to the equivalent of 0.3 cysts with contents per gram of soil when a reasonably large increase in yeild and a substantially diminished production of new, persisting cysts could both be expected. A graph giving the upper limits of population which can be reduced to the equivalent of 0.3 viable cysts per gram of soil by different percentage degrees of control is given (Fig. 3). Populations too high for direct treatment can be reduced to controllable levels by natural wastage of the persisting cyst population in the absence of potatoes. The annual decrement of natural wastage is a uniform percentage which in Britain varies from 18 to 60 according to temperature (Fig. 5). A forecast chart of the persistence of eelworm populations in a viable state is also given (Fig. 6, lower diagram) and practical implications are considered. Consecutive annual treatments have given such high degrees of control, particularly with a new, inexpensive method of mixing mercury dust (Grainger, 1958), that complete control of the potato root eelworm can be envisaged.

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Zusammenfassung Feldmethoden für die Bek?mpfung des KartoffelnematodenHeterodera rostochiensis ergeben ziemlich gut voraussagbare prozentuale Verminderungen der Population, die die Kartoffelwurzeln angreifen kann. Aber diese Behandlungen sind im wirtschaftlichen Sinne nur erfolgreich wenn sie gegen die weniger zahlreichen Populationen angewandt werden. Erfolgreiche Behandlung muss die Population auf das ?quivalent von 0,3 Zysten mit Inhalt pro Gramm Boden vermindern k?nnen, wenn sowohl eine angemessene Ertragszunahme wie eine wesentliche Verminderung neuer überlebender Zysten zu erwarten sind. Es wird graphisch dargestellt wie die oberen Populationsgrenzen durch verschiedene prozentuale Abt?tungsgrade bis zum ?quivalent von 0,3 lebensf?higen Zysten herabgesetzt werden k?nnen. (Abb. 3). Populationen, die für direkte Behandlung zu zahlreich sind, lassen sich durch natürliches Absterben bei Abwesenheit von Kartoffeln auf ein Niveau, auf dem effektive Bek?mpfungsmassnahmen durchgeführt werden k?nnen, herabsetzen. Diese natürliche Verminderung betr?gt einen ziemlich einheitlichen j?hrlichen Prozentsatz, der in Grossbritannien in Abh?ngigkeit von der Temperatur zwischen 18% und 60% liegt (Abb. 5). Prognosekurven der überlebung der Nematodenpopulationen werden ebenfalls gezeigt (Abb. 6, unten) und die praktischen Folgerungen werden er?rtert. Aufeinanderfolgende j?hrliche Behandlungen haben solche gute Bek?mpfungserfolge ergeben, besonders mit einer neuen billigen Methode, wobei Quecksilberoxyd-Staub im Boden gemischt wird (Grainger, 1958), dass damit die Aussicht auf v?llige Kontrolle des Kartoffelnematoden er?ffnet wird.

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Résumé Les méthodes de plein champ pour la lutte contre le nématode doré de la pomme de terre,Heterodera rostochiensis, réduisent en une proportion assez aisée à prédire la population de nématodes qui peut attaquer les racines de la pomme de terre. Cependant, ces traitements n'ont de valeur économique que lorsqu'ils sont appliqués contre une population peu dense. Un traitement efficace doit pouvoir réduire la population jusqu'à l'équivalent de 0,3 kyste avec contenu par gramme de sol, pour que l'on puisse s'attendre à une assez forte augmentation de la récolte et à une diminution considérable de la production de nouveaux kystes persistants. Un diagramme indique les limites supérieures de populations pouvant être réduites à l'équivalent de 0,3 kyste viable par gramme de sol pour différentes proportions de destruction (Fig. 3). Les populations trop nombreuses pour un traitement direct peuvent être réduites à un niveau traitable par le recul naturel du niveau de population de kystes persistants en l'absence de la pomme de terre. La diminution naturelle se produit en une proportion annuelle assez uniforme qui, en Grande-Bretagne, varie de 18 à 60% selon la température (Fig. 5). Un autre diagramme (Fig. 6, en bas) indique les prévisions de persistance de populations de nématodes viables et les conséquences pratiques sont considérées. Par des traitements annuels consécutifs, on a obtenu de si hauts degrés de destruction, en particulier par une nouvelle méthode économique de mélange au sol du poudrage d'oxyde jaune de mercure (Grainger, 1958), que l'on peut envisager la destruction entière du nématode doré de la pomme de terre.

     

移栽与直播对油菜根系建成及籽粒产量的影响

为深入理解根系调控在轻简化栽培技术中的作用,以甘蓝型油菜品种中双11号和中油杂12号为材料,通过设置直播（4.5万株/公顷）和移栽（12万株/公顷）两种栽培方式,高氮和低氮两种施肥方式的田间试验,从群体的角度研究了油菜的根系分布特征。结果表明,直播油菜根系比移栽油菜分布更深,直播油菜在0～10cm土层的根系分布显著低于移栽油菜,但在10～20cm和20～30cm土层的根系显著高于移栽油菜;初花期根干重是决定油菜群体籽粒产量的主要因素,根干重越大,籽粒产量越高;粗壮的根系是油菜获得高产的关键,移栽油菜的根系比直播油菜更为粗壮,增施氮肥有助于根系的粗壮型生长。     

大豆疫霉根腐病研究进展

从大豆疫霉根腐病病害的起源、生理小种的分化、病害的流行、抗源筛选、抗性机制等方面,综述了国内外该病的研究进展。