Effect of abamectin on root-knot nematodes and tomato yield

BACKGROUND: Tomato growers in Shandong Province, China, commonly face heavy root‐knot nematode infestations. Current methods of control include cadusafos and methyl bromide (MeBr), but alternative methods are required because of the high toxicity of these pesticides and the ecological risk of their use. Therefore, abamectin soil applications were evaluated for their potential to control soil nematodes in a series of laboratory tests, greenhouse pot experiments and field trials. RESULTS: Laboratory tests showed that abamectin exhibited rapid knockdown of Meloidogyne incognita, with LC₅₀ and LC₉₀ values that were superior to those of cadusafos and averaged 7.06 and 21.81 mg L^?1. In the greenhouse pot experiment, soil applications of abamectin provided significant M. incognita control similar to that provided by cadusafos while maintaining excellent plant height and vigour. In the field trials, abamectin exhibited excellent control effects to nematodes while giving a higher tomato yield. There was a 19.3–39.0% yield increase from the various treatments compared with the control, and the best results were obtained from the highest dose of abamectin. CONCLUSION: The results of this study demonstrated that abamectin has the potential to be used as an effective alternative to MeBr and cadusafos for nematode control in tomato production in Shandong Province. Copyright © 2012 Society of Chemical Industry     

阿维菌素和硫线磷对南方根结线虫的毒力

利用阿维菌素和硫线磷处理南方根结线虫离体卵与幼虫,测试其对线虫卵和卵块孵化以及对2龄幼虫的致死作用、活动能力、侵入能力的影响。结果表明阿维菌素和硫线磷均对线虫卵和卵块的孵化表现很强的抑制作用,阿维菌素5 μg/mL处理24 h对卵孵化抑制率高达82.57%,而硫线磷40 μg/mL处理24 h对卵孵化抑制率为73.05%;阿维菌素和硫线磷处理48 h对2龄幼虫的LD50分别为7.346 1、13.345 6 μg/mL;在阿维菌素2 μg/mL和硫线磷3 μg/mL处理中,2龄幼虫在沙柱中的平均移动距离仅为0.04 cm和0.05 cm,而对照处理的线虫平均移动距离为1.04 cm;在阿维菌素2 μg/mL和硫线磷50 μg/mL处理2龄幼虫48 h后,对番茄根部的侵入率为0.12%和0.45%,而空白对照处理线虫的侵入率达21.85%。     

土壤熏蒸结合机械化深耕处理防治连作土壤西瓜根结线虫效果评价

为筛选防治西瓜根结线虫(Meloidogyne incognita)的安全、高效防治技术,本研究对浅耕、深耕、浅耕+棉隆、深耕+棉隆4种土壤连作障碍处理耕作机械化技术防治西瓜根结线虫的效果及对土壤微量元素的影响等进行了评价。结果表明,与对照普通耕作模式相比,4种处理均能显著降低土壤中西瓜根结线虫的数量,提高对根结线虫的防治效果,增加西瓜的产量。其中,以深耕+棉隆处理的防治效果和增产效果最好。深耕+棉隆处理可以增加交换性镁和有效硒的含量,对交换性钙和有效铜的含量没有显著影响。综合评价认为深耕+棉隆处理适于在西瓜根结线虫发生非常严重的地区推广应用,而对于根结线虫发生特别轻的地区,仅以浅耕处理就能有效控制其危害。本研究提供了一种耕作措施与化学农药熏蒸相结合防治根结线虫的新方法,对于减少化肥农药用量,保护农业生态环境安全具有重要意义。     

安徽省潜山县栝蒌根结线虫发生危害及大田药效试验

为了有效防治栝蒌根结线虫，调查了安徽省潜山县栝蒌根结线虫及其发生，并分析了栝蒌根围土壤线虫的组成。通过线虫形态学鉴定，认为潜山栝蒌上的根结线虫为Meloidogyne incognita。栝萎根围土壤中有口针线虫占调查总量的50．7％，根结线虫2龄幼虫（J2）占31．8％。对当年栝萎J2在土壤表、中、下层的分布和年发生调查结果表明，J2在各层的分布量因月份不同而不同，并分别于3月初到9月中旬问出现2次虫口高峰；防治试验结果表明，除有机肥外，各试验小区在施药后49天J2虫口相对减退率在89．6％以上；施药后124天，克线丹和1．8％阿维菌素处理的小区增果率为250％～480％，收到很好的防效。     

内蒙古赤峰市保护地蔬菜根结线虫种类鉴定

正根结线虫(Meloidogyne spp.)广泛分布于世界各地,是影响我国农业生产最大的一类植物病原线虫,寄主植物有3 000多种,可侵染几乎所有的蔬菜作物,其中,茄科(Solanaceae)、葫芦科(Cucurbitaceae)和十字花科(Brassicaceae)等蔬菜受害最重~([1])。常见的根结线虫种类有南方根结线虫     

土壤药剂处理结合阳光消毒防治番茄根结线虫技术评价

为了筛选安全、高效、实用的化学防治技术,对国内外生产的5种杀线虫剂(棉隆、1,3 二氯丙烯·氯化苦、威百亩、噻唑磷、溴甲烷)土壤处理结合阳光消毒防治番茄根结线虫的效果进行了评价。结果表明,使用98%棉隆微粒剂450 kg/hm2或10%噻唑磷颗粒剂30 kg/hm2防治番茄根结线虫(Meloidogyne incognita),结合夏季高温进行阳光消毒,能有效地降低番茄根结线虫的数量,减轻根结线虫的危害程度,节省农户的生产成本,提高番茄的产量和农户的经济效益,是夏季防治番茄根结线虫的有效措施。     

酸黄瓜南方根结线虫病抗性的解剖学及其细胞学研究

为探明酸黄瓜南方根结线虫病抗性的内在机理,以抗病材料酸黄瓜与感病材料北京截头为试材,对南方根结线虫侵入与幼虫发育、根的解剖学及线虫侵入诱导形成的取食位点的细胞学结构进行了比较研究。结果表明,抗病材料酸黄瓜根系中线虫侵入率极显著低于感病材料北京截头(P0.01),酸黄瓜能够有效抵抗南方根结线虫的侵入;抗、感材料根系中雌雄虫个体比例分别为1∶12和1∶5(P0.01),抗性反应能够抑制线虫取食和幼虫发育;酸黄瓜根的解剖结构与普通栽培黄瓜相似,酸黄瓜的根不具有结构抗性;抗病反应中细胞发生过敏性坏死,感病反应中无此类现象发生。抗侵入、抑制取食和坏死反应是抗病材料酸黄瓜抗性反应的主要特征。     

静电自组装法制备阿维菌素纳米囊悬浮剂及其对黄瓜根结线虫病的防治效果

为提高阿维菌素在土壤中的移动扩散能力,改善其对作物根结线虫病的防治效果,采用静电自组装法制备了3%阿维菌素纳米囊悬浮剂,测定了其贮存稳定性和释放性能,并通过土壤淋溶试验与土壤薄层层析试验评价了其在土壤中的移动性,验证了其对南方根结线虫Meloidogyne incognita 2龄幼虫(J₂)的室内毒力和田间防治效果。结果显示：阿维菌素纳米囊为球形,平均粒径(D₅₀)为276.81 nm,在释放液中,60 min时纳米囊悬浮剂中阿维菌素的累积释放率为57.59%,而对照乳油制剂中阿维菌素的累积释放率为94.53%。阿维菌素纳米囊悬浮剂在土壤中横向和纵向的移动距离均明显大于阿维菌素乳油,二者对根结线虫J₂在24 h时的LC₅₀值分别为0.257与0.427 mg/L。田间试验中,相同用量下分别采用漫灌法与混土法两种方式施药,药后60 d,3%阿维菌素纳米囊悬浮剂处理比3%阿维菌素乳油处理的防治效果分别高21.82%与4.81%;而药后100 d,前者比后者分别高28.98%与19.79%。表明将阿维菌...     

海南岛南药根结线虫种类鉴定

运用比较形态学、同工酶和mtDNA-PCR对采自海南岛9个市县的南药根结线虫进行种类鉴定,结果发现有南方根结线虫、象耳豆根结线虫、爪哇根结线虫、花生根结线虫和西班牙根结线虫等5种根结线虫危害海南岛南药。5种根结线虫均能在海巴戟上寄生与危害,而南方根结线虫寄主非常广泛,可危害大多数调查的药用植物。     

北京地区保护地蔬菜根结线虫种类鉴定

从北京市9个区、县大型蔬菜生产基地的温室中采集蔬菜根结线虫样本21份,采用会阴花纹形态特征及分子生物学的方法对其进行了鉴定,结果表明北京地区温室中蔬菜根结线虫为南方根结线虫(Meloidogyne incogni-ta)。     

玫瑰黄链霉菌片剂对根结线虫病的防治作用及对土壤微生物区系的影响

玫瑰黄链霉菌Men-myco-93-63是从马铃薯疮痂病自然衰退土壤中筛选到的对多种重要植物病原菌具有较强抑制作用的拮抗链霉菌,其发酵液对根结线虫具有较好的防治作用。为明确Men-myco-93-63活菌片剂在蔬菜根结线虫防治中的应用前景,采用温室盆栽法和稀释平板法研究了Men-myco-93-63活菌片剂对黄瓜根结线虫病的防治效果及对土壤微生物区系的影响。结果表明:Men-myco-93-63片剂对黄瓜根结线虫病具有较好的防效,1.0和1.5 g/株用量下防效分别为51.85%和55.56%,而对照药剂淡紫拟青霉颗粒剂1.5 g/株及M en-myco-93-63固体发酵物(发酵物与病土体积比为1∶200)的防效分别为54.17%和50.00%;施药60d后,该片剂对植株根际土壤中微生物区系影响较大,1.0 g/株用量下,细菌和放线菌数量分别比空白对照增加了225.45%和75.45%,真菌数量降低了66.43%,3种可培养微生物的总量比空白对照增加了195.35%,表明M en-myco-93-63片剂的施用可明显改善根际土壤中的微生物结构。     

根结线虫食道腺细胞表达的基因及其应用潜力

根结线虫是国际公认的最为重要的植物病原线虫,研究其食道腺细胞表达的基因是了解其寄生性和致病性的基础。近年来国际上已从根结线虫食道腺细胞分离基因22个,其基因产物主要包括β 1,4内切葡聚糖酶、果胶酸裂解酶、分支酸变位酶、钙网蛋白、类毒液过敏蛋白等。本文对上述工作的研究进展作简要评述,并对今后的应用潜力进行了讨论。     

甘肃省白银市保护地蔬菜根结线虫病病原鉴定

2012年5月-7月在甘肃省白银市采集了番茄、黄瓜、豇豆等几种保护地蔬菜的25个根结线虫群体.直接解剖获得雌虫,通过雌虫会阴花纹观察,结合酯酶和苹果酸脱氢酶(MDH-EST)测定,鉴定出所收集的25个群体中有16个为南方根结线虫[Meloidogyne incognita (Kofoid&White)],9个为爪哇根结线虫[M.javanica (Treub)].南方根结线虫为优势种群,本次试验也是首次在甘肃省发现爪哇根结线虫.     

Chemical alternatives to methyl bromide for the control of root-knot nematodes in greenhouses

The complete phase-out of methyl bromide from use in developed countries by 1 January 2005 will cause many problems in agricultural industries that are now heavily reliant on its use. Three field experiments were established to compare management tactics on tomato and cucumber in commercial greenhouses naturally infested with root-knot nematodes (Meloidogyne spp). Reduction of nematode juveniles in soil and roots to nil detection levels was observed in all plots following soil fumigation with methyl bromide. A significant reduction of nematode juveniles and root-galling index was observed in plots treated with metham-sodium, dazomet and 1,3-dichloropropene compared with the control and plots treated with non-fumigant nematicides. Reduction of the nematode population led to an increase in fruit yield. However, data collected from the second cultivation season indicated that single control methods such as fumigant or contact nematicides alone cannot drastically decrease initial nematode population and those nematodes which escape control lead to population increase by the end of the cropping season.     

宁波地区蔬菜主要病原线虫的分离和种类鉴定

对宁波14个主要蔬菜基地进行土壤和植株取样,通过形态学和分子生物学鉴定明确了宁波地区蔬菜主要病原线虫为南方根结线虫［Meloidogyne incognita (Kofoid & White)］和咖啡短体线虫［Pratylenchus coffeae (Zimmer mann)］。南方根结线虫主要分布在江北费市、宁海冠庄、宁波梅墟和镇海九龙湖,咖啡短体线虫分布在江北费市。南方根结线虫的寄主为番茄、黄瓜、豇豆和白菜,咖啡短体线虫的寄主为萝卜和大豆。     

不同技术措施对蔬菜根结线虫种群的影响

采用土壤熏蒸结合水旱轮作、清除病残植株结合翻耕晒垡进行蔬菜根结线虫的田间防治。结果表明,两种措施均对蔬菜根结线虫2龄幼虫(J2)具有较好的防控效果。用化学杀线虫剂10%噻唑磷颗粒剂、10%硫线磷颗粒剂、5%丁硫克百威颗粒剂和3%氯唑磷颗粒剂实施了大田应用技术试验,结果表明,10%噻唑磷颗粒剂对根结线虫种群数量的控制作用最好,其制剂用量15kg/hm2处理后30d和60d对土壤中J2的相对防效分别为75.12%和95.18%。     

Effects of pyrrolizidine alkaloids on the performance of plant‐parasitic and free‐living nematodes

BACKGROUND: Chemical nematicides such as methyl bromide have for decades played a significant role in the management of plant‐parasitic nematodes. Their application is problematic because of negative environmental impacts, and therefore methyl bromide was phased out in Europe in 2005. A possible alternative to synthetically derived nematicides is seen in the use of plants and/or their secondary metabolites. These plants could either be used as nematicidal green manure or as a source for nematicidal extracts. This study aimed to evaluate the effects of 1,2‐dehydropyrrolizidine alkaloids (PAs), a group of secondary plant metabolites found in hundreds of plant species throughout the world, on the performance of plant‐parasitic and free‐living nematodes. RESULTS: PAs induced nematicidal, ovicidal and repellent effects on different plant‐parasitic and free‐living nematodes. There was no conclusive ranking in toxicity for the different structural types of PAs tested. However, the effects were often more pronounced for the tertiary than for the oxidised form of PAs. Further, large differences were observed in the susceptibility of different nematode species to PAs. CONCLUSIONS: PAs do affect several performance parameters and developmental stages of nematodes. Therefore, PA‐producing plants such as species of Crotalaria, Ageratum or Senecio might be promising candidates for nematode management strategies. [Correction made here after initial online publication] Copyright © 2009 Society of Chemical Industry     

土壤湿度对三氮苯类除草剂药效的影响及优化方案

以稗草为生物测定材料,运用二次正交旋转组合设计,以土壤湿度和除草剂用量二因子为决策变量,对稗草的抑制率为目标函数,研究土壤湿度对三氮苯类除草剂药效的影响。结果表明,适当的土壤水分是三氮苯类除草剂发挥药效的重要因素,药效随土壤湿度的提高而提高。不同的土壤湿度对不同除草剂药效影响各异,高湿条件下,湿度差异对药效影响大小依次为嗪草酮、西草净、扑草净、莠去津,低湿条件下则相反。除草剂用量与土壤湿度存在最佳发挥药效的组合。