梨树开花前后要防梨茎蜂

梨茎蜂俗名折梢虫，属膜翅目茎蜂科，以成虫和幼虫为害梨树新梢，近年来招远市梨园受害严重。据笔者2007年4月下旬调查，梨树新梢被害率达90％以上，部分梨园新梢被害率达100％，严重影响树体成形和树冠扩大。部分幼虫还蛀人果台，影响果实发育。笔者对梨茎蜂的为害特点与发生规律进行了调查，总结出防治方法如下：     

库尔勒地区香梨茎蜂发生动态及黄板控害效果

为明确库尔勒市及其周边果园香梨茎蜂的发生规律和为害情况及黄色粘虫板的诱杀效果,于2020年香梨茎蜂成虫活动期,利用黄色粘虫板按五点取样法定期调查成虫诱捕数量,分析其当年发生动态;并于香梨茎蜂活动期之后采用五点取样法分别调查未悬挂黄板果园与悬挂黄板果园的香梨茎蜂为害率,对比分析黄色粘虫板对香梨茎蜂为害的防控效果。经调查,香梨茎蜂主要在梨树花期前后为害,在4月中旬达到发生高峰期,成虫活动时间为19天（4月6—24日）,主要通过雌成虫产卵行为为害新梢,在未挂黄板果园平均为害率为29.13%,悬挂黄板的香梨园平均为害率为13.60%,相较于未挂黄板的对照香梨园为害减少率为52.41%。香梨茎蜂成虫出枝活动期是防虫控害的关键时期,悬挂黄色粘虫板对香梨茎蜂的为害有明显的防控效果。建议当地4月在香梨园中大面积使用黄色粘虫板诱杀成虫,减少香梨茎蜂的为害。     

库尔勒地区梨木虱发生动态及黄板诱杀效果研究

为明确库尔勒市及其周边果园梨木虱的发生规律、为害情况及黄色粘虫板的诱杀效果,于2021年梨木虱成虫活动期,利用黄色粘虫板按五点取样法定期调查成虫诱捕数量,分析其当年发生动态;并于梨木虱活动期之后采用五点取样法分别调查对照区果园与悬挂黄板处理区果园的梨木虱为害率,对比分析黄色粘虫板对梨木虱为害的防控效果。经调查,在库尔勒地区,梨木虱主要在嫩梢期、花期前后、及果实成熟期前为害,全年有两次虫口发生高峰,分别在3月底和4月底。至8月初库尔勒地区梨木虱数量开始大幅减少,其为害几乎贯穿梨树的整个生长期。黄板诱杀试验结果表明,梨木虱成虫出枝活动期是防虫控害的关键时期,处理区梨木虱较对照区为害率减少43.76%。这说明悬挂黄色粘虫板对梨木虱为害有实质性的防控效果。     

梨树折梢“小坏蛋”——梨茎蜂及其防治

<正>每年梨树开花期,都会发生梨树嫩梢被截断梢头的现象,其实这是梨茎蜂危害所致。梨茎蜂截断梨树嫩梢所使用的工具是其身体后方的产卵器,其实梨茎蜂锯断嫩梢的目的不是为了取食,而是为了产卵,繁殖后代。所以,嫩梢截断处位置略靠下位置,一般都会有产卵孔,轻轻撕开茎秆,会发现1粒米粒形状的卵!同时,嫩梢截断位置靠下的叶片,     

梨瘤蛾发生规律及防治试验

梨瘤蛾又名梨枝瘿蛾,俗名糖葫芦、梨疙瘩,是为害新梢较严重的害虫。在我省各梨区均有发生。据1960年在晋县河头村调查,未经修剪及防治的梨园新梢被害率达56%。尤其是幼树,由于不加防治,几乎全部被害。被害严重者,新梢木瘿连接成串,多者可达10个左右,因此严重影响新梢发育、树冠形成和产量,是我省梨树前期主要     

目前登记防治梨树梨小食心虫的农药产品

正我国梨树开花期即将到来。截至2018年4月16日,在我国登记防治梨树梨小食心虫并在有效期内的农药产品共17个。现将防治梨树梨小食心虫农药产品有关信息整理见表1,具体防治对象用药量的大小、使用注意事项等信息以产品标签或使用说明书为准。截至目前,尚未有农药产品在梨实蜂、梨果象甲(梨实象虫)、茶翅蝽(臭大姐)、梨网蝽(梨花网蝽)、梨蝽(花壮异蝽)、梨茎蜂(梨梢茎蜂)、葛氏梨茎蜂     

大樱桃采收后主要虫害的防治

正1.梨小食心虫该虫又名折梢虫,简称梨小,主要以幼虫为害樱桃、桃、李、梨等果树嫩梢。为害时多从新梢顶端叶柄基部蛀入髓部,由上向下取食。幼虫蛀入新梢后,蛀孔外面有虫粪排出和树胶流出。蛀孔以上的叶片逐渐萎蔫,甚至干枯。每年在7月上旬至9月上旬,为害最为严重,尤其是苗圃受害较重。雨水多、湿度大的年份有利于成虫产卵,发生与为害加重。防治要点:一是果实采收后及时剪     

红香酥梨果面黑斑是咋回事

正近日,有果农反映红香酥梨树上果面出现黑点黑斑,并有不同程度的凹陷症状。农技专家通过实地调查和多方查阅,诊断为梨木虱若虫为害。梨木虱为梨树主要害虫之一,以幼、若虫刺吸芽、叶、嫩枝梢、幼果面汁液进行直接为害,梨木虱成虫不为害。梨木虱成虫在地面的杂草、落叶、,土缝、树皮缝中越冬,第二年春梨花器萌动时开始出蜇,成虫出蛰后在新梢上     

性诱剂测报梨小食心虫发生期与防治试验

为了掌握梨小食心虫的发生规律,找到适时有效的防治时间,采用梨小食心虫性诱剂测报梨小食心虫的发生情况,并进行诱杀防治。结果表明,性诱剂准确预报出梨小食心虫在库尔勒二十九团1年发生5代,成虫有5个羽化高峰期。通过诱杀防治,可有效地降低羽化的成虫数量,减少梨小食心虫的危害,同时,预测发生期能及时确定化学防治时间。     

苦瓜棉铃虫和瓜实蝇对选育种的为害及防治技术

正苦瓜又名凉瓜,是葫芦科植物,为一年生攀缘草本。苦瓜的病虫害是瓜农担心的问题,也是育种工作中常常遇到的问题。棉铃虫,鳞翅目,夜蛾科,属昆虫的一种,不仅为害棉花有时还为害苦瓜。瓜实蝇又名针蜂,主要祸害幼瓜。为害特点.生长期生长期苦瓜棉铃虫为害茎、叶、芽。苦瓜棉铃虫成虫交配和产卵多在夜间进行,交配后2~3d开始产卵,卵散产于嫩梢、嫩叶、茎上,孵出的幼虫啃食苦瓜的茎、叶、芽,真菌性病菌(如蔓枯病、枯萎病、病毒病     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Water Extraction Process of Chinese Herbal Compound Man Gan Ning

[Objectives]To optimize the water extraction process of Chinese Herbal Compound Man Gan Ning and establish a method for its extraction and content determination...     

Present status and future strategy in breeding faba beans (Vicia Faba L.) for resistance to biotic and abiotic stresses

Progress is being made, mainly by ICARDA but also elsewhere, in breeding for resistance to Botrytis, AScochyta, Uromyces, and Orobanche; and some lines have resistance to more than one pathogen. The strategy is to extend multiple resistance but also to seek new and durable forms of resistance. Internationally coordinated programs are needed to maintain the momentum of this work.Tolerance of abiotic stresses leads to types suited to dry or cold environments rather than broad adaptability, but in this cross-pollinated species, the more hybrid vigor expressed by a cultivar, the more it is likely to tolerate various stresses.     

Pollen and pollination experiments. III. The viability of apple and pear pollen as affected by irradiation and storage

Summary Apple and pear pollen was irradiated with doses of 0, 50, 100, 250 and 500 krad (gamma rays) and stored at 4°C and 0–10% r.h. From the in-vitro germination percentages an average LD 50 dose of about 220 krad was estimated. For both irradiated and untreated pollen a close and corresponding lineair relationship existed between germination percentage and pollen tube growth.Irradiated pollen was much more sensitive to dry storage conditions than untreated pollen, resulting in less germination and more bursting. Apparently, irradiation caused the pollen cell membrane to lose its flexibility faster than normal. Rehydration of dry-stored, irradiated pollen in water-saturated air restored germination percentages up to their initial levels. The importance of this procedure in germination trials is stressed.     

Optimization of Extraction Technology and Determination of Content of Total Phenols of Leaves in Acanthopanax giraldii Harms

[Objectives] To determine the optimum extraction technology for total phenols of leaves in Acanthopanax giraldii Harms.[Methods]The single factor test and ortho...     

Cytoplasmic male sterility,resistance to gall mite and mildew,and season of leafing out in black currants

Summary Cytoplasmic male sterility (cms) is described in the F₁ hybrids Ribes × carrierei (R. glutinosum albidum × R. nigrum) and R. sanguineum × R. nigrum. In backcrosses to R. nigrum, progenies with R. glutinosum cytoplasm were either all male sterile, or segregated for full male fertility (F) and complete (S) and partial (I) male sterility. Ratios of F:I+S suggested that two linked genes controlled cms, F plants being dominant for one (Rf ₁) and recessive for the other (Rf ₂).Segregation for cms in relation to three linded genes, Ce (resistance to the gall mite, Cecidophyopsis ribes), Sph ₃(resistance to American gooseberry mildew, Sphaerotheca mors-uvae) and Lf ₁(one of two dominant additive genes controlling early season leafing out) indicated that Rf ₁and Rf ₂were in this linkage group. The gene order and approximate crossover values appeared to be: % MathType!MTEF!2!1!+-% feaafiart1ev1aaatCvAUfeBSjuyZL2yd9gzLbvyNv2CaerbuLwBLn% hiov2DGi1BTfMBaeXafv3ySLgzGmvETj2BSbqef0uAJj3BZ9Mz0bYu% H52CGmvzYLMzaerbd9wDYLwzYbItLDharqqr1ngBPrgifHhDYfgasa% acOqpw0xe9v8qqaqFD0xXdHaVhbbf9v8qqaqFr0xc9pk0xbba9q8Wq% Ffea0-yr0RYxir-Jbba9q8aq0-yq-He9q8qqQ8frFve9Fve9Ff0dme% aabaqaciGacaGaamqadaabaeaafaaakeaacaWGdbGaamyzamaamaaa% baGaaiiiaiaacccacaGGWaGaaiOlaiaacgdacaGG0aGaaiiiaiaacc% caaaGaaiiiaiaacccacaGGGaGaamOuaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaaccdacaGGUaGaaiOmaiaacs% dacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaaaacaWGsbGaamOzaSGa% aGOmaOWaaWaaaeaacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccaaaGaamitaiaadAgaliaaigdakmaamaaa% baGaaiiiaiaacccacaGGGaGaaiiiaiaacccacaGGGaGaaiiiaiaacc% cacaGGGaGaaiiiaiaacccacaGGGaaaaiaadofacaWGWbGaamiAaSGa% aG4maaaa!6E4D!\[Ce\underline { 0.14 } Rf1\underline { 0.24 } Rf2\underline { } Lf1\underline { } Sph3\]. Crossover values of 0.36 for Ce-Lf ₁, and 0.15 for Lf ₁-Sph ₃were estimated from the relative mean differences in season of leafing out between seedlings dominant and recessive for Ce and Sph ₃.It is suggested that competitive disadvantage of lf ₁-carrying gametes and/or zygotes at low temperatures may be implicated in the almost invariable deficit of plants dominant for the closely linked mildew resistance allele Sph ₃. Poor performance of lf ₁- (and possibly lf ₂-) carrying gametes and young zygotes during periods of low temperature at flowering might also account for the liability of some late season cultivars and selections to premature fruit drop (running off).     

Screening techniques and sources of resistance to parasitic angiosperms

Parasitic angiosperms cause great losses in many important crops under different climatic conditions and soil types. The most widespread and important parasitic angiosperms belong to the genera Orobanche, Striga, and Cuscuta. The most important economical hosts belong to the Poaceae, Asteraceae, Solanaceae, Cucurbitaceae, and Fabaceae. Although some resistant cultivars have been identified in several crops, great gaps exist in our knowledge of the parasites and the genetic basis of the resistance, as well as the availability of in vitro screening techniques. Screening techniques are based on reactions of the host root or foliage. In vitro or greenhouse screening methods based on the reaction of root and/or foliar tissues are usually superior to field screenings and can be used with many species. To utilize them in plant breeding, it is necessary to demonstrate a strong correlation between in vitro and field data. The correlation should be calculated for every environment in which selection is practiced. Using biochemical analysis as a screening technique has had limited success. The reason seems to be the complex host-parasite interactions which lead to germination, rhizotropism, infection, and growth of the parasite. Germination results from chemicals produced by the host. Resistance is only available in a small group of crops. Resistance has been found in cultivated, primitive and wild forms, depending on the specific host-parasite system. An additional problem is the existence of pathotypes in the parasites. Inheritance of host resistance is usually polygenic and its transfer is slow and tedious. Molecular techniques have yet to be used to locate resistance to parasitic angiosperms. While intensifying the search for genes that control resistance to specific parasitic angiosperms, the best strategy to screen for resistance is to improve the already existing in vitro or greenhouse screening techniques.