宜宾市胡萝卜主要害虫及其防治

胡萝卜属伞形科蔬菜,其营养丰富,近年来栽培面积较大,胡萝卜虫害对胡萝卜产量和品质的影响较大,现介绍宜宾一带胡萝卜主要虫害及防治方法.     

胡萝卜地化学除草试验

胡萝卜苗期生长缓慢,从播种到5—6叶,需要1个多月时间,这段时间必须防除杂草,否则,在严重的杂草竞争下,将减产30—60％。Blanco,H. G.认为胡萝卜全生育期中前三分之一段时间是杂草竞争的临界期。北京地区7月中下旬播种胡萝卜,正值高温多雨季节,杂草生长迅速。再加上许多胡萝卜采用密植方式栽培,除草就更加困难。针对这些问题,我们自1977年来断续地     

韭菜迟眼蕈蚊在胡萝卜上的发生为害情况初报

2017年3月,韭菜迟眼蕈蚊在山东省寿光市化龙镇胡萝卜上大面积发生,造成部分田块严重缺苗。这是关于该害虫为害胡萝卜的首次报道。2017年秋季,对不同品种胡萝卜上韭菜迟眼蕈蚊发生量进行了调查。结果表明,韭菜迟眼蕈蚊秋季发生高峰期为11月中旬,平均幼虫量为40头/株;不同品种的胡萝卜上发生数量无显著差异。     

辣椒胡萝卜脯的制作

辣味胡萝卜脯呈金黄色半透明状 ,营养丰富、酸甜适口 ,有姜辣味 ,含有大量的胡萝卜素及钙、铁、磷等物质。现将辣椒胡萝卜脯的制作技术介绍如下 :1　选料切条选取橙黄或黄色 ,大个、无虫病的新鲜胡萝卜 ,用清水洗去胡萝卜表面的泥土及污垢 ,用刨皮刀去掉胡萝卜的表皮 ,接着切成长 5ｃｍ、宽 1ｃｍ、厚约 0 5ｃｍ的条状。2　灰浸处理将切好的胡萝卜条用 0 5 %～ 1%的石灰水浸泡 8～ 12ｈ ,捞出装在竹萝内 ,沥去石灰水 ,然后用流动的清水冲净粘附在胡萝卜条表面的石灰液。3　沸水烫煮把胡萝卜条倒入沸水中烫煮 2 0ｍｉｎ ,然后捞出放入流动…     

胡萝卜田苗后杂草化学防除药剂筛选

为探究安全、高效的胡萝卜田苗后杂草化学防除技术,采用盆钵法研究了13种苗后茎叶处理除草剂对胡萝卜的室内安全性,并对筛选得到的苗后除草剂进行了初步的田间药效及安全性试验。结果表明：供试13种除草剂中扑草净对胡萝卜的安全性较好,在225 g（a.i.）/hm²剂量下,胡萝卜苗的鲜重为53.61 g,与对照无显著差异,未出现药害反应;在450、750 g（a.i.）/hm²剂量下分别出现了1级和2级的低级别药害反应;而噁草酮、氰草津、嘧啶肟草醚、双草醚、辛酰溴苯腈、乙氧氟草醚、乙羧氟草醚、咪唑乙烟酸、灭草松、噻吩磺隆、双氟磺草胺和氯吡嘧磺隆在推荐剂量下,对胡萝卜鲜重抑制率为19.30%~100.00%,出现了3~5级的药害反应。扑草净对胡萝卜田杂草有较好的防效,在剂量为450~600 g（a.i.）/hm²时对胡萝卜田杂草总体的株防效和鲜重防效均达到80.56%以上,且对胡萝卜安全,无药害反应。胡萝卜田苗后杂草化学防除建议使用450~600 g（a.i.）/hm²扑草净进行茎叶喷雾处理,可达到对禾本科和阔叶杂草的有效防除,且对胡萝卜安全。     

胡萝卜田杂草化学防除技术

济南市长清区胡萝卜田杂草有10科18种,双子叶杂草占55.6%,单子叶杂草占44.4%,相对多度达30以上的杂草有马唐、牛筋草、马齿苋、狗尾草4种,是防除的主要对象。胡萝卜田人工除草困难,笔者将近几年进行化学除草的一些经验介绍供参考。1)苗前一次性除草。每亩用48%氟乐灵EC130ml或33%二甲戊乐灵EC(商品名施田补,下称)125ml对水40kg,于胡萝卜播种前5～7d均匀喷施,然后浅混土。施田补也可于胡萝卜播后苗前每亩用药150ml对水40kg喷雾。1999年试验,这两种除草剂对胡萝卜田一年生单、双子叶优势杂草的防效均达90%以上。2)苗期茎叶处理防除禾本科杂…     

药剂拌种与温汤浸种对胡萝卜斑枯病防效研究

采用60℃温汤浸种10 min和0.3%三唑酮药剂拌种,可使胡萝卜斑枯病发病率比对照分别降低30.6%和46.0%;胡萝卜产量比对照分别增加0.2 kg/m2和0.4 kg/m2。     

胡萝卜常见病害的发生与防治

胡萝卜为伞形科蔬菜,因其营养十分丰富,近年来种植面积迅速扩大,但由于对病害预防措施不力,防治病害方法单一等,胡萝卜病害逐渐加重,成为当前生产上亟待解决的问题.现将胡萝卜常见病害的发生与防治情况介绍如下:     

异色瓢虫对胡萝卜微管蚜防治潜能评价

为明确异色瓢虫对胡萝卜微管蚜的防治效果潜能,本试验以芹菜为寄主植物,研究了异色瓢虫4龄幼虫对胡萝卜微管蚜捕食功能反应和不同益害比的控害效果.结果表明胡萝卜微管蚜密度为40、80、120(头)时,异色瓢虫的捕食量成增大趋势且各组之间有显著性差异,当胡萝卜微管蚜的密度为160、200、240(头)时瓢虫的捕食量各组间无显著性差异.4龄异色瓢虫幼虫的取食量受胡萝卜微管蚜密度影响显著,且捕食功能反应符合Holling-Ⅱ型反应模型.4龄异色瓢虫幼虫的瞬时攻击率a'为1.1862,取食1头胡萝卜微管蚜所需时间(即处置时间Th)为0.004,4龄异色瓢虫幼虫对胡萝卜微管蚜的最大捕食量为210.9头,瓢虫对蚜虫的搜索效应S=1+0.00474 N.益害比试验中得出4龄异色瓢虫幼虫对胡萝卜微管蚜捕食量符合二次回归方程,二次回归方程显示当胡萝卜微管蚜密度均为500时,随着异色瓢虫数量的增加,其捕食量成先增大后减少趋势,根据公式其最大捕食量为186.26,最佳益害比例为1∶83.本试验对利用异色瓢虫防治胡萝卜微管蚜具有一定的指导意义,以期为无公害芹菜种植提供有效的生物防治对策.     

臭氧水防治胡萝卜根蛆试验

用不同次数臭氧水滴灌处理防治胡萝卜根蛆的试验结果表明,臭氧水对胡萝卜根蛆有一定的防治效果,在胡萝卜整个生育期用臭氧水滴灌4次,对胡萝卜安全。     

The disease

In order to inoculate roots of tomato seedlings with tobacco mosaic virus, seeds were germinated singly in perforated plastic tubing obtained from ladies' hair curlers filled with sieved soil. The time which elapsed between inoculation of the roots and observation of first leaf symptoms varied with individual plants between one and ten weeks and was on average three to five weeks. As plant raising requires about six to eight weeks in winter, mosaic symptoms appearing in a tomato crop after planting out may well be the result of a root infection sustained during pricking off of the seedlings in the nursery.Samenvatting Om bij kiemplanten van tomaat wortelinoculaties met TMV uit te voeren werden geperforeerde plastiek hulzen, afkomstig van haarkrullers, met aarde gevuld en gebruikt voor het afzonderlijk laten kiemen van tomatezaden. Na inoculatie van de wortels, welke door de perforatie van de huls waren heengegroeid (Fig. 1), werden de desbetreffende kiemplanten tegelijk met de huls in potten overgeplant. Vervolgens werd het verschijnen van bladsymptomen afgewacht, terwijl van tijd tot tijd van uiterlijk nietgeïnfecteerde planten zowel bladeren als wortels afzonderlijk werden getoetst opNicotinana glutinosa. Uit de resultaten (Tabel 1) is gebleken, dat een aantal planten niet of slechts in de wortels werd geïnfecteerd. Bij de meeste planten had inoculatie van de wortels een systemische infectie tot gevolg. De periode tuseen wortelinoculatie en waarneming van de eerste bladsymptomen varieerde voor de individuele planten van één tot tien weken met een, ruw geschat, gemiddelde van drie tot vijf weken. Aangezien met de opkweek van planten in de winter zes tot acht weken gemoeid zijn, inhet niet uitgesloten, dat het verschijnen van mozaïeksymptomen kort na het uitplanten nog het gevolg is van een wortelinfectie in het kiemplantstadium.     

青海省栽培秦艽新病害——锈病

秦艽,别名牛尾艽,为龙胆科,龙胆属高山药用植物,自然分布于海拔2 400～3 500m,气候冷凉、日照充足地区,青海适应其生长,分布较广.随着农业产业结构的调整和退耕还林(草)政策的实施,青海省中、藏药种植面积逐年扩大,已成为青海省的优势产业.秦艽因其主治风湿脾痛、筋脉拘挛、骨节酸痛、小儿疳积和发热疾病,种植和开发前景较好.     

Nonparametric tests in plant disease epidemiology: characterizing disease associations

ABSTRACT Nonparametric tests are suited to many statistical applications, including experimental design, regression, and time series analysis, for example. Often these tests are thought of as alternatives to their parametric counterparts when certain assumptions about the underlying population are questionable. Although suited for this scenario, there are a number of nonparametric tests that fill unique niches in the analysis of data, for example, characterizing interspecific associations. Quantifying the degree of association between two or more pathogens or diseases at a defined spatial scale is essential to gain a thorough understanding of disease dynamics, generate testable hypothesis behind the mechanisms that cause association, and is often necessary in modeling applications. In this paper, nonparametric approaches to characterizing interspecific associations will be covered. Specifically, I will address the use of rank correlation coefficients and the development of a randomization procedure for testing the Jaccard index of association against a null model.     

北美森林新病害——山毛榉叶线虫病

2012年,北美地区发生了一种由山毛榉李氏垫刃线虫麦肯恩亚种(Litylenchus crenatae mccannii)引起的森林新病害——山毛榉叶线虫病,病情蔓延迅速,已扩散至美国和加拿大30个县。病原为害山毛榉属植物,可造成病树成片死亡。由于山毛榉是北美温带阔叶林的主要构成树种和重要用材树种,新病害已引起美国农业部的高度重视并采取积极的应对措施。我国分布5种山毛榉属植物(均为特有种),是我国南方森林的主要组成树种。鉴于我国每年从北美进口大量山毛榉木材,病原线虫存在随进境木材传入国内的巨大风险。因此,检疫部门应开展风险评估,口岸应针对性开展山毛榉叶线虫病的检测。本文主要介绍了山毛榉叶线虫病的发生历史、分布范围、为害症状、病原线虫形态学特征、生活史、传播途径、分子检测方法等方面的信息,以期为口岸检疫工作提供参考。     

果蔗脱毒种苗甘蔗花叶病、黄叶病和宿根矮化病分子检测

为监测2016-2017年种植的果蔗脱毒种苗脱毒效果,分别采集广州市南沙区和增城区、湛江市麻章区及华南农业大学甘蔗育种基地共83份果蔗脱毒种苗样本,进行甘蔗花叶病毒(SCMV)、高粱花叶病毒(SrMV)和甘蔗黄叶病毒(SCYLV)RT-PCR检测。结果表明SCMV的阳性样本数为3个,阳性检出率3.61%;SrMV的阳性样本数为0;SCYLV的阳性样本数为78个,阳性检出率93.98%。采用常规PCR和巢式PCR技术对采集于广州市增城区和华南农业大学甘蔗育种基地的30份果蔗脱毒种苗样本进行宿根矮化病菌(Lxx)检测,常规PCR检测阳性样本数为0,巢式PCR检测疑似阳性样本数为8,疑似阳性检出率26.67%。本研究采用茎尖组织培养脱毒技术培育的果蔗脱毒种苗能有效脱除果蔗种苗内的SCMV、SrMV和Lxx,但SCYLV的脱除效果有待进一步研究。     

Cassava brown streak disease in Rwanda,the associated viruses and disease phenotypes

Cassava brown streak disease (CBSD) was first observed on cassava (Manihot esculenta) in Rwanda in 2009. In 2014 eight major cassava‐growing districts in the country were surveyed to determine the distribution and variability of symptom phenotypes associated with CBSD, and the genetic diversity of cassava brown streak viruses. Distribution of the CBSD symptom phenotypes and their combinations varied greatly between districts, cultivars and their associated viruses. The symptoms on leaf alone recorded the highest (32.2%) incidence, followed by roots (25.7%), leaf + stem (20.3%), leaf + root (10.4%), leaf + stem + root (5.2%), stem + root (3.7%), and stem (2.5%) symptoms. Analysis by RT‐PCR showed that single infections of Ugandan cassava brown streak virus (UCBSV) were most common (74.2% of total infections) and associated with all the seven phenotypes studied. Single infections of Cassava brown streak virus (CBSV) were predominant (15.3% of total infections) in CBSD‐affected plants showing symptoms on stems alone. Mixed infections (CBSV + UCBSV) comprised 10.5% of total infections and predominated in the combinations of leaf + stem + root phenotypes. Phylogenetic analysis and the estimates of evolutionary divergence, using partial sequences (210 nt) of the coat protein gene, revealed that in Rwanda there is one type of CBSV and an indication of diverse UCBSV. This study is the first to report the occurrence and distribution of both CBSV and UCBSV based on molecular techniques in Rwanda.