Meloidogyne Incognita Populations Research Articles

Efficacy of organic soil amendments on the population of meloidne incognita on Okra in South Western Nigeria

The efficacy of organic soil amendments on the populations of Meloidogyne incognita on okra were investigated in two field trials. Organic wastes comprising fresh poultry mature, crowding, fruits peelings and sawdust were each ploughed 15cm into the soil at the rates of 0,4, 8 and 16th/ha, respectively, most significant suppressive effect on soil and root nematode populations. The populations observed in sawdust-amended soil was the lowest. An inverse relationship was observed between nematode populations and rates of each manure type and decomposition period. Similar trends of results were observed in the effects of manure type x manure type x decomposition period interactions on the tested parameters. However, 8 t/ha of poultry in manure (PM) with 6 weeks decomposition period (PM x 8t/ha x 6 wk) interaction recorded the most outstanding effect other interactions.Keywords: organic soil amendments, Meloidogyne incognita, okraNigerian Journal of Horticultural Science Vol. 9 2005: 89-95

Incidence of Meloidogyne incognita and Development of Resistant Soybean Germplasm in Illinois

In 2002-2003, a nematode survey was conducted in the southernmost counties of Illinois. Species in eight nematode genera were detected in the survey with four genera having species considered to be important soybean pathogens. Populations of Meloidogyne incognita were detected in 6% of all fields surveyed in southern Illinois. Elite breeding lines and cultivars were evaluated for resistance to gall formation and reproduction by the nematode. Resistance was identified in several soybean genotypes. Accepted for publication 27 April 2005. Published 6 June 2005.

Regional variation in pathogenicity of Meloidogyne incognitapopulations on sweetpotato in Kyushu Okinawa, Japan

Regional variation in pathogenicity of Meloidogyne incognitapopulations on sweetpotato in Kyushu Okinawa, Japan

Manejo do solo e da irrigação como nova tática de controle de Meloidogyne incognita em feijoeiro

A população de Meloidogyne incognita e sua infetividade foram estudadas em parcelas amostradas a zero, dois e 14 dias após o revolvimento do solo com ou sem irrigação, irrigadas sem revolvimento e testemunha. Na amostragem aos dois dias após a instalação do ensaio, ocorreu maior redução (P<0,01) de juvenis do segundo estádio ( J2) no solo apenas revolvido seguido pelo revolvido e irrigado. A infetividade do inóculo do solo, contudo, foi menor (P<0,01) quando se revolveu e irrigou o solo comparado com aquele apenas revolvido. Aos 14 dias, a menor (P<0,01) população de J2 foi observada no solo revolvido e irrigado, seguido do revolvido, e elevada naquele apenas irrigado e na testemunha. A infetividade do inóculo do solo aos 14 dias continuou mais baixa no solo revolvido e irrigado. Aos 45 dias após a semeadura, a população de J2 continuou mais baixa (P<0,01) onde o solo foi revolvido e irrigado. O número de ovos por feijoeiro (Phaseolus vulgaris) no campo aos 90 dias também foi mais baixo (P<0,01) no solo revolvido e irrigado. Maior (P<0,01) peso das raízes e da parte aérea dos feijoeiros no campo foi observado em plantas crescidas em solo apenas revolvido, e no revolvido e irrigado A produção de feijão no solo revolvido e irrigado posteriormente foi quatro vezes maior que a testemunha, porém todos os tratamentos diferiram-se entre si. A irrigação como prática agrícola para aumentar a eficácia do alqueive no controle de fitonematóides tem sido postulada por alguns pesquisadores, mas nunca provada experimentalmente, o que agora foi realizada.

Host Reactions of Sweetpotato Genotypes to Root-knot Nematodes and Variation in Virulence of Meloidogyne incognita Populations

Sweetpotato [Ipomoea batatas (L.) Lam.] genotypes were evaluated for resistance to North Carolina root-knot nematode populations: Meloidogyne arenaria (Neal) Chitwood races 1 and 2; M. incognita (Kofoid & White) Chitwood races 1, 2, 3, and 4; and M. javanica (Treub) Chitwood. Resistance screening was conducted using 150-cm3 Conetainers containing 3 sand: 1 soil mix. Nematode infection and reproduction were assessed as the number of egg masses produced by root-knot nematodes per root system. Host suitability for the root-knot nematode populations differed among the 27 sweetpotato genotypes studied. Five genotypes (`Beauregard', L86-33, PDM P6, `Porto Rico', and `Pelican Processor') were selected for further study based on their differential reaction to the different root-knot nematodes tested. Two African landraces (`Tanzania' and `Wagabolige') were also selected because they were resistant to all the nematode species tested. The host status was tested against the four original M. incognita races, and an additional eight populations belonging to four host races, but collected from different geographical regions. The virulence of root-knot nematode populations of the same host race varied among and within sweetpotato genotypes. `Beauregard', L86-33, and PDM P6 were hosts for all 12 M. incognita populations, but differences in the aggressiveness of the isolates were observed. `Porto Rico' and `Pelican Processor' had different reactions to the M. incognita populations, regardless of the host race. Several clones showed resistance to all M. incognita populations tested. These responses suggest that different genes could be involved in the resistance of sweetpotato to root-knot nematodes. The results also suggest that testing Meloidogyne populations against several different sweetpotato hosts may be useful in determining the pathotypes affecting sweetpotato.

Influences of organic and synthetic soil fertility amendments on nematode trophic groups and community dynamics under tomatoes

Research was conducted to examine the effects of organic and synthetic soil amendments and tillage on nematode communities in field soils planted to tomato ( Lycopersicon esculentum) at two locations. The experimental design was a replicated split plot with chisel-plow tillage and bare-soil or chisel-plow tillage and surface mulch with wheat straw as main plots, and soil amendments of synthetic fertilizer, composted cotton-gin trash, swine manure, or a rye-vetch green manure as subplots. Tillage did not affect free-living or plant-parasitic nematode community dynamics, but soil amendments had a large impact on nematode community structure and diversity. Populations of bacterivorous nematodes mainly in the Rhabditidae and Cephalobidae, and fungivorous nematodes were greater after planting in soils amended with swine manure, composted cotton-gin trash, or rye-vetch, than in soils amended with synthetic fertilizer at both locations. Populations of nematodes in these trophic groups decreased through time in each year. Populations of Meloidogyne incognita in soil were not affected by soil amendments, but increased through time at each location. Root-gall indices were lower in plots containing swine manure or cotton-gin trash than in those with synthetic fertilizer or rye-vetch during the second season. The combined nematode maturity index values were greater at planting in soils amended with rye-vetch or fertilizer than in soils with swine manure and composted cotton-gin trash. Shannon’s diversity index decreased over time for both years at one location, regardless of soil amendment. At the second location, the Shannon’s diversity index decreased only in the second year. Use of descriptive indices, including the Enrichment index, structure index, and channel index provided useful information about the effects of organic amendments on the structure of nematode communities in tomato field soils.

Root diseases, weeds, and nematodes with poultry litter and conservation tillage in a sweet corn–snap bean double crop

The effect of continuous applications of poultry litter on root diseases, nematodes, and weeds with different tillage practices in vegetable production in Georgia was investigated. Litter treatments (noncomposted and composted broiler or breeder litter) applied 3–5 weeks before planting were compared with no litter. In sweet corn and snap bean there were differences among years, and tillage and litter treatments had a variable effect on yield, post-emergence damping-off and plant stand. Crown and brace root rot in corn induced by Rhizoctonia solani AG 2-2 increased after 3 years conservation tillage, but there were no differences among litter treatments. Population densities of R. solani AG-4 were increased by conservation tillage before planting snap bean the first year but not in later years, while litter treatments had no effect. After 3 years, populations of Pythium spp., Fusarium solani, and Fusarium spp. did not differ among treatments, but noncomposted broiler litter increased populations of saprophytic fungi in soil compared with no litter. Population densities of stylet-bearing nematodes were low and usually not different among treatments. After 3 years of sweet corn populations of Meloidogyne incognita increased with conventional tillage compared with conservation tillage, populations of Paratrichodorus christiei were reduced by litter treatments and populations of Helicotylenchus dihystera were reduced by noncomposted broiler litter compared with no litter. Weed infestation increased in both tillage systems with time, but in snap bean there was a greater infestation in conservation tillage than in conventional tillage. Litter treatments had little effect on weed infestation.

The Relevance Of Poultry And Pig Droppings As Nematode Suppressants On Okra And Tomato In Ibadan, Southwestern Nigeria

The Efficacy Of Poultry And Pig Manure As Root-Knot Nematode Suppressants On Okra And Tomato Were Studied. The Organic Wastes Were Respectively Worked Into The Soil At The Rate Of 16tha-1 just before sowing Of Okra Seeds Or Transplanting Tomato Seedlings. Their Combination Was Applied Into The Plot In Equal Proportion Of 8tha-1. Mocap (Nematicide) Was Applied At The Rate Of 9kg A.I. Per Hectare. The Unamended Plots Served As The Control. The Field Layout Was A Randomized Complete Block Design In Four Replications. The Nematicide Effect On Meloidogyne Incognita Populations Was Not Different From The Corresponding Effect Of Poultry Manure. However The Suppressive Effect Of Mocap And Poultry On The Pest Populations Were Significantly Higher When Compare With Other Manure Types. Similarly, Plant Treated With Poultry Manure Recorded Significant Vegetative And Reproductive Growth When Compared With Other Tested Variables. Key Words: Organic Manure, Root-Knot, Meloidogyne Incognita; Lycopersicon, Lycopersicon, Abelmoschus Esculentus.

“Resistance-breaking” nematodes identified in California tomatoes

Resistance to root-knot nematodes in tomato is conferred by the gene Mi. We have identified two field populations of Meloidogyne incognita that parasitize tomato plants containing the Mi gene. This necessitates the use of planned crop rotation practices and the incorporation of other resistance genes into cultivated tomato.

南九州のサトイモおよびサツマイモ栽培圃場における数種対抗植物の線虫密度回復抑制効果の検討

南九州のサトイモおよびサツマイモ栽培圃場における数種対抗植物の線虫密度回復抑制効果の検討

Identification of Four MajorMeloidogynespp. by Random Amplified Polymorphic DNA (RAPD-PCR)

The random amplified polymorphic DNA (RAPD) assay is a variant of the polymerase chain reaction (PCR) in which a single primer of random sequence is used at a low-annealing temperature. Twenty-two primers were evaluated for their usefulness in identifying 18 populations of Meloidogyne incognita, M. arenaria. M. javanica, and M. hapla collected worldwide. Reactions with primer OPA-01 produced amplified DNA bands whose size allowed the separation of the four species. Reactions with another group of 11 primers made possible the separation of one, two, or three species []

Organic Amendments for Control of Root-Knot Nematode (Meloidogyne Incognita) on Ginger.

Poultry manure and sawdust (24, 36 or 48 tlha) were incorporated into soil with urea (0–1800 kg nitrogenlha) and their effects on yield of ginger and populations of Meloidogyne incognita were compared with those of nematicide programmes involving ethylene dibromide andlor fenamiphos. The pre-plant nematicide treatments proved inadequate but improved nematode control was achieved when these treatments were followed by postplant applications of fenamiphos. Total yields in soil amended with poultry manure or sawdust plus urea were greater than in non-amended soil and equal to or greater than those in the best nematicide treatments. The yield increase for poultry manure appeared to be due in part to its beneficial effects on soil fertility. Both amendments provided good control of root-knot nematodes, with significantly fewer rhizomes being discarded at late harvest from the amendment treatments than from the untreated and some nematicide-treated plots. Addition of the highest rates of urea to soil produced ammonium-nitrogen concentrations of more than 1000 μ/g soil, but no measurable effect on root-knot nematode populations or the degree of nematode damage.

各種作物の栽培によるサツマイモネコブセンチュウの密度変化

各種作物の栽培によるサツマイモネコブセンチュウの密度変化

Título en español.

Formulaciones granuladas de phenamiphos (Nemacur), oxamyl (Vydate) y fensulfothion (Dasanit) aplicadas al suelo y emulsiones concentradas al follaje mantuvieron bajas las densidades poblacionales de Meloidogyne incognita y Pratylenchus coffeae, incrementando significativamente (P:0.05) en el invernadero el desarrollo y crecimiento de plántulas de café, cultivar Puerto Rico selecto. Los mejores resultados se obtuvieron con los siguientes tratamientos: phenamiphos a razón de 11.20 kg ia/ha aplicado al suelo 15 días antes del transplante, combinado con una aspersión al follaje de 1.12 kg ia/ha 15 días después del transplante o con dos aspersiones de 0.56 kg ia/ha al follaje 30 y 60 días después del transplante; dos aspersiones de oxamyl (0.56 kg ia/ha) a intervalos de 30 días y fensulfothion granulado a razón de 300 mg del material comercial por planta en cuatro aplicaciones a intervalos de 30 días, comenzando un mes y terminando 7 meses después del transplante. La inmersión de las raíces de café durante 10 minutos en una solución de 400 ppm de phenamiphos y 600 ppm de oxamyl, respectivamente, redujeron los niveles poblacionales de los nematodes noduladores y lesionadores en el suelo y en las raíces. Aunque se encontraron diferencias significativas (P:0.05) en el índice de nodulación entre estos tratamientos y el testigo, el incremento en el desarrollo y crecimiento de las plantas no fue significativo. Dosificaciones altas de phenamiphos y fensulfothion (2.24 kg ia/ha) asperjadas más de una vez al follaje después del transplante causaron fitotoxicidad y defoliación parcial durante los primeros meses del crecimiento, pero sin ocasionar la muerte de las plantas.