Evaluation of Natural Chemical Compounds Against Root-lesion and Root-knot Nematodes and Side-effects on the Infectivity of Arbuscular Mycorrhizal Fungi

The survival of two species of plant parasitic nematodes: the root-lesion nematode Pratylenchus brachyurus, and the root-knot nematode Meloidogyne javanica, was evaluated in saturated atmospheres of 12 natural chemical compounds. The infectivity of two isolates of arbuscular mycorrhizal fungi: Glomus mosseae and Glomus intraradices, under identical experimental conditions, was also determined. All the compounds tested exerted a highly significant control against M. javanica and among them, benzaldehyde, salicilaldehyde, borneol, p-anisaldehyde and cinnamaldehyde caused a mortality rate above 50% over P. brachyurus. The infectivity of G. intraradices was inhibited by cinnamaldehyde, salicilaldehyde, thymol, carvacrol, p-anisaldehyde, and benzaldehyde, while only cinnamaldehyde and thymol significantly inhibited mycorrhizal colonization by G. mosseae.     

Population dynamics of the potato cyst nematode,Globodera pallida,in relation to temperature,potato cultivar and nematicide application

The impact of increasing temperatures on the population dynamics of the soil-dwelling nematode Globodera pallida, a persistent and economically important pest of potatoes, was investigated. The reproductive factor (final population⁄initial population) and length of life cycle were found to be temperature sensitive. Pot experiments performed over 4 months allowed comparison of the effect on development of G. pallida of two temperature regimes: an average temperature comparable to current field conditions (14.3 °C) and an average temperature above current field conditions (17.3 °C). A larger second generation of juveniles was observed at 17.3 °C compared to 14.3 °C. Multiplication of G. pallida at field sites in Shropshire and East Lothian (average soil temperatures of 15.5 and 14.1 °C, respectively, during potato cropping) was also examined. A quantitative PCR assay and visual examination of roots were used to monitor the dynamics of the G. pallida populations in both field sites at 4-weekly intervals. Four cultivars, Desirée, Cara, Maris Piper and Estima, were grown with and without nematicide treatments. Nematicide treatments suppressed population increases at both sites. Females were observed on the roots of cvs Cara and Desirée at the end of the growing season in Shropshire, but not at East Lothian, and are likely to represent a second generation.     

柑橘半穿刺线虫防治试验

[目的]筛选低毒高效的杀线剂,为半穿刺线虫的防治提供科学依据.[方法]进行10%噻唑膦颗粒剂、2.5亿个孢子/g厚孢轮枝菌微粒剂、0.5%阿维菌素颗粒剂、24.5%阿维菌素乳油、10%丙线磷颗粒剂、2亿/g盐生菌及2亿/g盐生菌+0.5%阿维菌素颗粒剂对柑橘半穿刺线虫田间防治效果试验,药后30 d统计不同药剂对柑橘半穿刺线虫的防治效果.[结果]供试的6种药剂对半穿刺线虫均有较好的防效,对土壤中和根上线虫的防效均在50%以上,其中10%噻唑膦颗粒剂的防效最好,对土壤中和根上线虫的防效达80%以上;其次为24.5%阿维菌素乳油和2.5亿个孢子/g厚孢轮枝菌微粒剂,两种药剂对土壤中和根上线虫的防效为70%~75%.[结论]10%噻唑膦颗粒剂、2.5亿个孢子/g厚孢轮枝菌微粒剂和24.5%阿维菌素乳油对柑橘半穿刺线虫有较好的防治效果,且对柑橘生长无不良影响,可作为柑橘半穿刺线虫的防治药剂在柑橘生产上推广应用.     

不同杀线剂对小麦孢囊线虫病的防治效果

小麦孢囊线虫病目前已在中国13个省(市区)的小麦种植区有发生与分布,其扩散与蔓延将直接威胁我国的粮食生产和经济安全,系统开展小麦孢囊线虫病的防治研究迫在眉睫.本文在大田条件下研究了5％涕灭威颗粒剂(aldicarb)、3％克百威颗粒剂(carbofuran)、5％硫线磷颗粒剂(cadusafos)、10％苯线磷颗粒剂(fenamiphos)和0.5％阿维菌素颗粒剂(abamectin)等5种杀线剂各3个不同剂量在小麦返青期使用对小麦孢囊线虫病的控制效果.结果表明,各药剂处理均对土壤中孢囊线虫的繁殖有明显的抑制作用,但各处理间的校正孢囊减退率差异并不显著;不同药剂处理后的小麦株高、单株根重和单株鲜重均优于对照,且小麦产量与对照相比均有增加.其中0.5％阿维菌素颗粒剂 30 kg/hm2处理后的校正孢囊减退率最大值为55.13％,且增产效果最好,增产率为18.54％;而0.5％阿维菌素颗粒剂60 kg/hm2处理后小麦株高平均值最大,为59.32 cm,促进植物生长的效果明显.由于0.5％阿维菌素颗粒剂能够明显抑制土壤中孢囊线虫的繁殖,同时促进植株生长并减少产量损失,因此,在小麦孢囊线虫重病田于小麦返青期施用0.5％阿维菌素颗粒剂30 kg/hm2进行土壤处理,可在一定程度上减轻小麦孢囊线虫造成的损失.     

Utilization of plant materials for control of soybean cysts nematode

Field experiments were conducted in 2011 and repeated in 2012 to study the nematicidal potentials of acacia, brassica, neem, and seaweed as alternatives to chemical nematicide on population management of Heterodera glycines and growth and yield of soybean. Results obtained showed acacia at 200 g, neem at 450 g, brassica at 1000 g, and seaweed at 2000 g caused the maximum suppression of population of H. glycines and produced the highest yield and growth of soybean. Neem, brassica, acacia, and seaweed caused reduction in H. glycines population by 48.3%, 41.4%, 34.5%, and 28.3%, respectively. Also, neem, brassica, acacia, and seaweed produced increase in soybean pods number by 58.7%, 33.7%, 28%, and seaweed 37.9%, respectively. The results obtained showed the potentialities of these plant materials as alternative to synthetic chemical pesticides. The plant could be utilized in a sustainable farming system to save the environment, conserve the biodiversity, and protect man against harmful effects of chemical nematicides.     

Assessment of Non-chemical Alternatives for Controlling the Burrowing Nematode on Banana in Costa Rica

The objective of this study was to technically and economically assess the effect of biopesticides on the serious plant parasitic nematode Radopholus similis on banana in Costa Rica. The following treatments were evaluated： a mixture of nematode trapping fungi-Arthrobotrys oligospora, A. botryospora, Dactylella brochophaga and Drechmeria coniospora; DiTera DF which consist of a ＂dead＂ fungus Myrothecium spp. and its fermentation substrate; Savitan produced from desert plant extracts; QL Agri which contain Quillaja saponaria extracts; Japanese-style compost called Bokashi; two application of a chemical nematicide; and an absolute control. Results of root sampling on a six month basis showed that the biopesticides had lower nematode population densities than the control with the nematode trapping-fungi having statistically significant differences over the other treatments. Chemical control was highly effective and produced the lowest nematode density. However, there were no significant differences between the chemical treatment and the trapping-fungi treatment. The functional root weight and bunch weight showed no significant differences between treatments. Conversely, economic analyses indicated that using nematode trapping-fungi, chemical nematieide, or the QL Agri treatments gave a detectable profit. The land expectation value （LEV） of the banana plantation was higher than the price of banana land which indicated that under normal conditions in the banana sector, production is economically sustainable / profitable. Other results confirm that profit in banana production is affected by the price of a banana box, production and discount rate. The optimal production cycle was obtained in year ten after farm establishment, which refers to the year with the highest profit following plantation renewal. Finally, economical results highlighted the importance of nematodes control, since profitability indexes were sensitive to the efficiency and cost of nematode management technology adopted by the banana company.     

胡萝卜肾形肾状线虫病的发生及药剂控制试验

从广东省番禺市胡萝卜根系及根际土分离到１种线虫,经鉴定为肾形肾状线虫,该线虫在胡萝卜的生长期内,以１０￣１１月份虫口密度最大,主要分布于０￣１５ｃｍ土壤层。该线虫危害胡萝卜,是国内胡萝卜上的１种新病害。药剂试验表明供试的几种杀线剂均对肾形肾状线虫有较好的控制作用,其中益舒宝复方Ｂ和Ｅ是值得生产上推广应用的杀线剂。     

Systemic nematicidal activity of fluensulfone against the root-knot nematode Meloidogyne incognita on pepper

BACKGROUND: Fluensulfone, a new nematicide of the fluoroalkenyl group, has proved to be very effective in controlling root‐knot nematodes, Meloidogyne spp., by soil application. The systemic activity of this compound against M. incognita on peppers via soil drenching and foliar spray was evaluated. RESULTS: Root application of fluensulfone via soil drenching showed slight and no nematode control activity when applied 4 and 10 days, respectively, after inoculation. A single foliar spray of peppers with a fluensulfone solution at 3.0 g L^?1 prior to inoculation reduced the galling index by 80% and the number of nematode eggs by 73–82% of controls. The reduction in these parameters by fluensulfone was much higher than that obtained with oxamyl or fenamiphos at the same concentration. This activity was also observed when the plants were sprayed 21 days before inoculation. A series of experiments suggested that foliar spray with fluensulfone prior to inoculation reduces nematode invasion. However, foliar spray after inoculation did not inhibit nematode development inside roots. CONCLUSION: Fluensulfone showed relatively high nematode control activity when sprayed on the foliage before inoculation. Fluensulfone may be used as a foliar application, in addition to soil application, for root‐knot nematode control. Copyright © 2011 Society of Chemical Industry