"凤头姜"姜瘟病的发病规律与防治技术

"凤头姜"主产于恩施自治州来凤县,是全国著名的8大生姜品种之一,块茎大、肉质细嫩、纤维少、鲜脆、辛香,营养丰富.姜的根茎和姜芽中含有人体所必需的碳水化合物、蛋白质、纤维素、多种维生素、姜辣素(C17H26O4)、姜油酮(C11H14O3)、姜烯酚(C17H24O13)、姜醇(C17H26O)及无机盐.同时其产量高,一般667 m2产量800～1 000kg,高产栽培可达2 000～3 000 kg.但近年来由于姜瘟病的危害蔓延,每年造成大量减产,甚至是毁灭性的损失.针对上述原因,笔者对"凤头姜"姜瘟病的发病规律进行了一些调查,并对其防治措施进行了一些试验,现总结如下,供大家参考.     

防治山东省特色小宗作物姜炭疽病试验研究

为了明确450 g/L咪鲜胺水乳剂和25％嘧菌酯悬浮剂防治姜炭疽病的防治效果和安全性,本研究采用菌丝生长速率法、喷雾法分别测定了2种药剂对姜炭疽病菌的室内活性、田间防效以及对姜的安全性.室内活性试验结果表明,咪鲜胺和嘧菌酯对姜炭疽病均具有较高活性,EC50值(120h)分别为0.076mg/L和1.59mg/L.安全性...     

乳山市大姜主要病虫害防治技术

大姜是乳山市的主要经济作物之一,年种植面积为2 000 hm2左右.近几年来,随着大姜生产的迅速发展,大姜病虫害的发生也随之加重.     

定安县翰林镇林下姜叶斑病的调查

根据调查,定安县翰林镇林下姜叶斑病为害较严重,其中橡胶林下姜叶斑病的平均发病率为66.8％,病情指数为40.0;槟榔林下姜叶斑病的平均发病率为60.3％,病情指数为52.3.林下姜叶斑病发生严重的原因,还有待深入研究.     

大姜线虫病药效防治试验

大姜线虫病又称癞皮病,由南方根结线虫[Meloidogyne incognita(kofoid and white)chit wood]引起,是近年来大姜上发生的严重病害,对产量、品质影响很大,已成为制约大姜发展的重要障碍.为探讨大姜线虫病的有效防治方法,2003年4～10月,在安丘市白芬子镇刘家峪村进行了不同农药品种对比试验和不同时期防治试验,通过试验,筛选出了杀线虫的有效农药品种,确定了最佳防治适期和用药量,为彻底控制其危害提供了科学依据.     

姜瘟病生防菌幼套近明球囊霉N62的筛选鉴定

姜瘟病是一种细菌土传毁灭性病害,目前尚无特别有效的防治药剂.丛枝菌根(Arbuscular mycorrhizal,AM)真菌在作物促生及防治病害方面极具潜力,为充分发掘姜瘟病的生防菌资源,本研究采用盆栽试验方法评价4株AM真菌对生姜的促生作用和对姜瘟病的防治效果,利用形态学和分子生物学相结合的方法对优良菌株进行分类鉴...     

网隔栽培法对生姜姜瘟病防治及产量的影响

姜瘟病是由青枯雷尔氏菌(Ralstonia solanacearum)引起的一种细菌性病害,被称为生姜种植产业的"癌症".本试验设计了一种"网隔栽培法",并探索其对土传姜瘟病发病率和生姜产量的影响.结果表明,经过连续3年的田间验证,相比传统栽培法,"网隔栽培法"种植可显著降低姜瘟病的发病率,平均减少了6.08个百分点,...     

生姜主要病虫害的发生及防治措施

<正>在生姜生产中,常发生的病害有姜瘟病(又称姜腐烂病)、叶枯病、斑点病、炭疽病等,虫害主要有姜螟,对生姜生产影响大,造成减产。为了减少生姜损失,笔者现介绍乌沙镇生姜主要病虫害的防治措施。     

姜瘟病的综合防治技术

姜瘟病是生姜生产上的一种毁灭性细菌病害,又称姜腐烂病.始发期一般在6月初,7-8月份最为严重.发病初期叶片卷缩,略下垂;中期姜株茎基部和根尖病斑变黄,地下茎开始腐烂;后期根茎内部软化腐烂,产生带有恶臭的灰白色汁液,最后只剩表皮,植株全部枯死.对于该病害,应采取综合防治措施.     

乳山大姜健康栽培中存在的问题及改进措施

大姜是我国重要的经济栽培作物,也是我国的重要蔬菜品种.近年来,大姜种植已成为乳山地区农民增收致富的一大支柱产业,并已实现了产业化经营.然而随着种植规模的逐渐增加,栽培措施不当、常年连作、肥料与农药使用不科学、病虫害发生普遍等问题也逐渐成为影响乳山地区大姜生产发展的关键.针对近年来该地区大姜生产中的问题,笔者进行了较系统的分析,并提出相应的解决措施.     

重视有害蚜虫研究,确保作物安全

<正>蚜虫隶属半翅目蚜虫总科,是世界上分布最广的微小昆虫之一。世界已知4 700余种,中国分布约1 100种[1-2]。蚜虫种类多、繁殖快、世代重叠,还存在孤雌生殖与两性生殖世代交替等独特生物学现象。许多蚜虫种类是非常重要的农作物害虫,其刺吸式口器可吸食植物汁液,造成植物生长不良,其唾液也对植物有毒害作用[3-4]。受蚜虫为害的植物具有多种不同症状,如生长率降低、产生叶斑、泛黄、发     

高原人体生理适应学理论在进藏旅游中的应用

青藏铁路的贯通运行,带来了国内外进藏旅游热.然而,青藏高原毕竟是世界屋脊,高海拔带来的低氧及其引发的高原疾病依然威胁着游客的身体健康.健康高原旅行是当前游客进藏旅游的基本前提,通过综合国内外高原医学工作者对高原医学生理学的研究成果,提出阶梯进藏旅游的方法.旨在对越来越多的短期赴西藏高原旅行的人群以正确的健康指导,从而减...     

白刺花(Sophoraviciifolia)适应土壤干旱的生理学机制

用盆栽的方法人工控制土壤干旱条件,研究白刺花天然实生幼苗适应土壤干旱的生理学机制。结果表明:随土壤含水量的减少,白刺花叶水势在胁迫前期下降缓慢,随胁迫时间的延长,水势大幅度下降。白刺花通过在叶片内积累大量渗透保护性物质可溶性糖和K ,增加细胞的保水力,维持细胞生长所需膨压。白刺花游离脯氨酸含量变化与水分关系不大,可溶性蛋白质含量随土壤含水量减少而下降,可能是水分胁迫下受伤害的表现。随土壤水分含量的减少,白刺花SOD的活性明显升高,POD活性不高但随胁迫时间延长其活性较稳定,CAT活性下降但幅度不大,且CAT活性变化趋势与POD活性相反,说明三个保护酶能够相互配合协同作用,降低膜脂过氧化程度,减少水分胁迫造成的伤害,提高质膜稳定性,维持细胞膜的完整性,表现出很强的抗旱适应性。     

稻瘟病菌对三环唑抗药性测定方法的建立

研究了稻瘟病菌对三环唑抗药性的测定方法,确定了保绿培养基的成分,建立了抗药性测定的标准化模型。4叶I心期将稻苗在三环唑系列浓度药液中浸根处理36 h,剪取稻苗叶段插于100 μg/mL苯并咪唑+0.5％水琼脂保绿培养基上,用孢子含量为10⁵个/mL的稻瘟病菌孢子悬浮液喷雾接种,保湿培养8 d后调查结果,计算EC₅₀值。该测定方法与小苗测定相比较结果更加稳定且灵敏度高,重复性好。     

Heritability of Ulmus minor resistance to Dutch elm disease and its relationship to vessel size,but not to xylem vulnerability to drought

Dutch elm disease (DED) is a vascular wilt disease that causes the occlusion and cavitation of xylem vessels. Therefore, it is hypothesized that those elms that are less vulnerable to cavitation by drought might be more resistant to DED. To test this hypothesis, the relationship between xylem vulnerability to cavitation and susceptibility to DED was examined in progenies of crosses between susceptible and resistant individuals of Ulmus minor. Hydraulic conductivity and xylem vulnerability curves were evaluated and anatomical features such as vessel size, length and grouping were measured. Next, elms were inoculated with Ophiostoma novo‐ulmi, the cause of DED, and pre‐dawn and midday water potentials, stomatal conductance and wilting percentages were assessed. Progenies of R × R crosses showed significantly lower mean wilting percentages (30–50%) than the progeny of S × S crosses (75%). Fifty percent conductivity loss was reached at c. ?1 MPa, pointing out a high vulnerability of this species to drought‐induced cavitation. Crown wilting percentage as a result of inoculation and xylem vulnerability to cavitation by water stress did not show any significant correlation. Nevertheless, significant differences in theoretical hydraulic conductivity and vessel size parameters (diameter, length and size distributions) were found among the tested progenies. Susceptible trees had significantly wider and longer vessels. Xylem structure of resistant elms seems to restrict pathogen spread rather than prevent cavitation.     

Contribution of Fimbrial and Afimbrial Adhesins of Xylella fastidiosa to Attachment to Surfaces and Virulence to Grape

ABSTRACT The role of fimbrial and afimbrial adhesins of Xylella fastidiosa in biofilm formation was assessed by visualization of cell aggregates of mutant strains after incubation on glass surfaces. FimA- or FimF- fimbrial mutants adhered as solitary cells at a slightly lesser frequency to glass surfaces than the parental strain; however, cell aggregates were not formed, unlike the wild-type strain. Conversely, whereas the XadA- and HxfB- nonfimbrial mutants also exhibited a much lower frequency of adherence to glass surfaces than the wild-type strain, most of the cells retained on the surfaces were in cell aggregates of different sizes, much like that of the parental strain. Neither fimbrial or afimbrial mutants formed a mature biofilm on the sides of flasks of broth cultures, unlike the dense biofilm formed by the wild-type strain. Although FimA- and FimF- mutants did not form cell aggregates on glass surfaces when incubated as individual strains, aggregates of a FimA- or FimF- mutant were observed when co-incubated with either a XadA- mutant or HxfB- mutant, respectively. These results are consistent with a model in which the fimbrial adhesins FimA and FimF are involved preferentially in cell-to-cell aggregate formation whereas the afimbrial adhesions XadA and HxfB preferentially contribute to initial cell binding to surfaces, whereupon further cell aggregation can occur. In each of five separate experiments, FimA, FimF, XadA, and HxfB mutants of X. fastidiosa all were less virulent to grape than the corresponding wild-type strain. Fimbrial and afimbrial mutants might produce a reduced biofilm within vessels of grape and, hence, be deficient in various cell-density-dependent traits required for movement through the plant and, thus, virulence.     

Note to chew on: insect damage to musical instruments

Insects have a diverse range of ecologies that leaves many pre‐adapted to exploiting manufactured products as food sources, including musical instruments. To review what is known and to make recommendations for preventing and managing insect damage to musical instruments, we conducted a systematic search and a narrative review of the area. Of 339 papers, only eight peer‐reviewed publications met the inclusion criteria, and all were on xylophagous insects causing damage to wooden instruments. To supplement this material, we report a case of damage to the key pads (composed of felt enclosed in fish buoyancy bladder skin) of a clarinet by carpet beetles (Anthrenus verbasci (Dermestidae)), the first reported case of non‐woody damage and the first instance of insect damage rendering an instrument unplayable. To avoid such damage, regular inspection of instruments is recommended, and rapid treatment of any insect infestations in the immediate environment that could extend to affecting stored instruments. Instruments themselves can be extremely expensive, and if insects are still present these should only be treated by an expert; instrument cases can be more easily dealt with by heat treatment (black plastic bag in the sun) or application of a residual insecticide. © 2020 Society of Chemical Industry     

A grower-friendly method to transfer predacious mites to commercial orchards

The establishment of predacious mites in commercial orchards may be accelerated by the transfer of pruned wood in winter and summer from donor orchards to release orchards. Following winter pruning, 3-year-old and older wood is collected and transported as soon as possible in bundles to a release orchard for distribution. If the release orchard is composed of dwarf trees, then one or two bundles of 5 kg each are placed vertically at the base of the trunk of every tree in the block (0.5 to 1 ha); if the trees are of standard size, then four or five bundles used. Following summer pruning, annual shoots and suckers are distributed immediately in a release orchard composed of dwarf trees by placing 12–15 branches on the foliage of fruit-bearing branches; if the release orchard is composed of standard trees, then 50 branches are used. The pruned wood should have 20–25 leaves and not less than one predator per leaf. The release orchard should have a light infestation (two or three mites per leaf) of pest tetranychids. These phytophagous mites would serve as food and help establish the predators. The release orchard grower should develop a pest management program based on the same groups of pesticides used in the donor orchard. http://www.phytoparasitica.org posting Aug. 31, 2005.