scholarly journals The root-knot nematode, Meloidogyne incognita, profoundly affects the production of popular biofortified cassava cultivars

Nematology ◽  
2020 ◽  
Vol 22 (6) ◽  
pp. 667-676 ◽  
Author(s):  
Aminat Korede Akinsanya ◽  
Steve Olaoluwa Afolami ◽  
Peter Kulakow ◽  
Danny Coyne
Keyword(s):  
Meloidogyne Incognita ◽  
Dry Weight ◽  
Sub Saharan Africa ◽  
Root Weight ◽  
Total Carotenoid ◽  
Storage Root ◽  
Root Knot Nematode ◽  
African Countries ◽  
Nematode Reproduction ◽  
Weight Percentage

Summary Despite being the single largest cassava-producing country, yields in Nigeria remain consistently poor and among the lowest. Regionally, yields are also particularly low across Africa. Pests and pathogens, including plant-parasitic nematodes, play an important role in this current yield deficit. African countries are not only faced with the problem of food security but also that of nutritional deficiency, due to limited micronutrients in the diet. In this study, six biofortified cultivars were evaluated for their response to inoculation with approximately 30 000 root-knot nematode (Meloidogyne incognita) eggs in 30 l pots in Nigeria. All cassava cultivars proved highly susceptible to M. incognita infection after 6 months, with nematode reproduction factor ranging from 7.0 to 44.8. Galling was common on feeder roots and gall index scores were recorded between 4 to 5 (on a scale of 1-5 where 5 ⩽ 100 galls). Meloidogyne incognita infection significantly reduced plant height, stem girth, fresh plant mass, fresh storage root number and storage root weight. Percentage yield loss of between 41.8-88.4% was recorded in M. incognita-infected plants compared with non-infected controls. Although M. incognita reduced storage root weight, it did not necessarily affect the nutritional quality (total carotenoid) or dry weight percentage of the biofortified cassava cultivars. Total carotenoid and dry weight contents of the control cultivar were similar to some of the biofortified cultivars. The high susceptibility of the biofortified cassava cultivars to M. incognita infection indicates that substantial yield losses are likely being experienced by farmers, as this nematode pest is prevalent across sub-Saharan Africa and the tropics.

scholarly journals Resistance screening of lentil cultivars against the root-knot nematode Meloidogyne incognita

2018 ◽  
Vol 11 (1) ◽  
pp. 9-18 ◽  
Author(s):  
T. Ansari ◽  
M. Asif ◽  
M.A. Siddiqui
Keyword(s):  
Plant Growth ◽  
Meloidogyne Incognita ◽  
Growth Parameters ◽  
Dry Weight ◽  
Fresh Weight ◽  
Root Knot Nematode ◽  
Nematode Reproduction ◽  
Egg Masses ◽  
Moderately Resistant ◽  
Reduction Percentage

SummaryThe root-knot nematodeMeloidogyne incognitais a major soil parasite of lentil crops. Increasing restrictions of chemical nematicides have triggered a growing attention and interest in alternate root-knot nematode management. The present study was conducted to examine the level of resistance and/or susceptibility of five lentil cultivars (PL-456, KLS-218, Desi, DPL-62, Malika), grown in pots, against the root-knot nematodeM. incognita. Root-knot nematode reproduction and host damage were assessed by recording the nematode infestation levels and reduction percentage of plant growth parameters. Nematode response and plant growth differentiated amongst the lentil cultivars. None of the cultivars was found immune or highly resistant. The cultivar Malika was found moderately resistant as it showed the lowest number of galls and egg masses/root as well as the lowest reduction of plant fresh weight (10.4%) and dry weight (6.9%). On the other hand, the cultivar Desi manifested the highest susceptibility exhibiting the highest number of galls and egg masses. There was a significantly negative correlation between the number of galls and plant growth parameters (plant fresh and dry weight and plant height).

scholarly journals Genotypic Diversity of Potato Germplasm against Root Knot Nematode (Meloidogyne incognita) Infection in Pakistan

2012 ◽  
Vol 1 (1) ◽  
pp. 27-38 ◽  
Author(s):  
Amjad S. Gondal ◽  
Nazir Javed ◽  
Sajid A. Khan ◽  
Sajjad Hyder
Keyword(s):  
Meloidogyne Incognita ◽  
Negative Control ◽  
Fruit Weight ◽  
Egg Mass ◽  
Root Weight ◽  
Female Reproduction ◽  
Root Knot Nematode ◽  
Nematode Reproduction ◽  
Potato Germplasm ◽  
Final Population

Potato (Solanum tuberosum), an important vegetable crop of Pakistan endures significant yield losses due to root knot nematode (Meloidogyne incognita).. Research wok was designed to identify resistant potato germplasm against RKN (Meloidogyne incognita) infection. A field trial was conducted in the research area of Department of Plant Pathology, University of Agriculture Faisalabad. Thirty six (36) potato verities/ cultivars relocated five times were sown in four years sick plot containing root knot nematode (Meloidogyne incognita) in RCBD layout. Root knot nematode reproduction and host damage was accessed by recording nematode root galls and egg mass indices, root weight, shoot weight, , number of leaves, fruit weight, rate of reproduction and final population of nematodes. Experiment revealed a considerable variation in response against Meloidogyne incognita infection among the genotype tested but none of the single cultivar was immune. FD-8-1 was used as negative control. The cultivar FD-19-2 was highly susceptible followed by SH-692 and SH-5. All other cultivars had less galling index with low fecundity rate indicating their ability to suppress the adult female reproduction. The cultivar FD-1-3 scored least number of galls and egg mass indices followed by FD-49-62, SH-339 and SH-332.

Assessment of the most suitable nematode inoculum density and plant growth period to screen coffee genotypes for their reaction to Meloidogyne incognita

Nematology ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 373-380
Author(s):  
Santino A. Silva ◽  
Anderson C.G. Bicalho ◽  
Débora C. Santiago ◽  
Lucas S. Cunha ◽  
Andressa C.Z. Machado
Keyword(s):  
Meloidogyne Incognita ◽  
Genetic Screening ◽  
Coffea Arabica ◽  
Growth Period ◽  
Root Knot Nematode ◽  
Population Densities ◽  
Nematode Reproduction ◽  
Rf Values ◽  
Reproduction Factor ◽  
The Ideal

Summary One of the concerns for nematological research is the absence of information on standard nematode population densities to be used when screening to assess resistance/susceptibility levels of a genotype. In addition, the length of the growth period, especially for perennial crops such as coffee, must also be known. The objective of this work was to evaluate the ideal evaluation periods and population densities of the root-knot nematode, Meloidogyne incognita, for phenotyping Coffea arabica genotypes. Seedlings of coffee ‘Mundo Novo’ with five leaf pairs cropped in 700 cm3 plastic pots were inoculated with population densities of 700, 1400, 2800, 5600 and 11 200 eggs of M. incognita per plant and evaluated at 90, 120, 150 and 180 days after inoculation (DAI) to determine the nematode reproduction factor (RF). The use of population densities of M. incognita from 700-2000 nematodes with evaluations between 90 and 180 DAI was the most suitable to obtain higher RF values and allows earlier and more accurate evaluations, which reduces the time for phenotyping in genetic screening programmes.

scholarly journals Age of Plant Material Influences Resistance of Some Prunus Rootstocks to Meloidogyne incognita

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 582-585 ◽  
Author(s):  
Carolina Fernández ◽  
Jorge Pinochet ◽  
Daniel Esmenjaud ◽  
Maria Joao Gravato-Nobre ◽  
Antonio Felipe
Keyword(s):  
Meloidogyne Incognita ◽  
Prunus Persica ◽  
Saline Soil ◽  
Soil Condition ◽  
Plant Age ◽  
Root Knot Nematode ◽  
Maturation Period ◽  
Nematode Reproduction ◽  
Loss Of Resistance ◽  
High Level

The influence of salinity and plant age on nematode reproduction was determined on two susceptible and six root-knot-nematode-resistant Prunus rootstocks inoculated with Meloidogyne incognita (Kofoid and White). Experiments were conducted under greenhouse conditions over 120 (plant age study) and 75 (salinity study) days. Following inoculation with 4000 nematodes per plant, susceptible 2-month-old GF-677 (Prunus persica L. Batsch. × P. dulcis Mill. Webb) and Montclar (P. persica) were affected significantly more than 1-year-old plants. Barrier (P. persica × P. davidiana Carr. Franch.) plantlets showed a partial loss of resistance in relation to older plants, suggesting that a root tissue maturation period is required for expression of full resistance. Nemared (P. persica); G × N No 22 (P. persica × P. dulcis); and the plums GF 8-1 (P. cerasifera Ehrh. × P. munsoniana Wight and Hedrick), PSM 101 (P. insititia L.), and P 2980 (P. cerasifera) maintained their high level of resistance or immunity, regardless of plant age. Nematode reproduction was higher in GF-677 rootstock in saline soil. Nemared and Barrier showed similar low galling and nematode reproduction in nonsaline and saline soil. PSM 101 immunity to M. incognita was not affected by soil condition.

scholarly journals Pathogenicity of Meloidogyne Incognita on Sesamum Indicum and the Efficacy of Yield-Based Scheme in Resistance Designation

2008 ◽  
Vol 48 (1) ◽  
pp. 73-80
Author(s):  
Jonathan Atungwu ◽  
Steve Afolami ◽  
Olufunke Egunjobi ◽  
Opeyemi Kadri
Keyword(s):  
Meloidogyne Incognita ◽  
Host Response ◽  
Sesamum Indicum ◽  
Additional Parameter ◽  
Grain Production ◽  
Harvest Time ◽  
Root Knot Nematode ◽  
Population Densities ◽  
Nematode Reproduction ◽  
Two Phases

Pathogenicity ofMeloidogyne IncognitaonSesamum Indicumand the Efficacy of Yield-Based Scheme in Resistance DesignationTwo screenhouse experiments were conducted in 2004 and 2005 rainy season to investigate the reaction of three selectedSesamum indicumcultivars against three population densities of a root knot nematode,Meloidogyne incognita.Seedlings ofS. indicumwere raised in pots arranged in completely randomised design and inoculated with 0, 5 000, and 10 000 eggs ofM. incognita, replicated six times. Root knot disease was evaluated at mid-season and harvest. A new method for evaluating and reporting resistance toMeloidogynespp. that divides the screening procedure into two phases in the same experiment was adapted. The first phase investigated the host response through the traditional standard method that utilises only gall and nematode reproduction indices, while the second considered the effect of root knot disease on grain production of the crop. There was consistency in host designation of E8 and NICRIBEN-01M (syn: 530-1-6) which were classified under the traditional and improved rating schemes as tolerant and resistant, respectively. However,S. indicumbreeding line Pbtil (No. 1) which was considered susceptible under the old system was found to be tolerant using the integrated and improved system. Root galls incited by the nematode degenerated significantly from mid-season to harvest time. Utilising yield as additional parameter for assessing resistance to root knot nematode provides a complete picture ofSesamum-Meloidogyneinteraction, and therefore a more meaningful system for determining host response.

scholarly journals (70) Hydroponic Sunflower Production as Influenced by Cultivar, Nitrogen Fertilization, and Root-knot Nematode Infestation

HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1013D-1013
Author(s):  
Yan Chen ◽  
Donald Merhaut ◽  
J. Ole Becker
Keyword(s):  
Plant Growth ◽  
Meloidogyne Incognita ◽  
Dry Weight ◽  
N Fertilization ◽  
Harvest Time ◽  
Cut Flowers ◽  
Root Knot Nematode ◽  
Hydroponic System ◽  
Flower Quality ◽  
N Rates

Nitrogen (N) fertilization is critical for successful production of cut flowers in a hydroponic system. In this study, two sunflower cultivars: single-stand `Mezzulah' and multi-stand `Golden Cheer' were grown under two N fertilization rates: 50 mg·L-1 and 100 mg·L-1 in a recirculating hydroponic system. At the same time, `Mezzulah' sunflowers were biologically stressed by exposing each plant to 2000 second-stage juveniles of the plant parasitic nematode Meloidogyne incognita, race 1. The experiment was conducted in May and repeated in Sept. 2004, and plant growth and flower quality between control and nematode-infested plants were compared at the two N rates. The two cultivars responded differently to fertilization treatments. With increasing N rate, the dry weight of `Mezzulah' increased, while that of `Golden Cheer' decreased. Flower size and harvest time were significantly different between the two cultivars. However, N had no effect on flower quality and harvest time. Flower quality rating suggests that quality cut stems can be obtained with 50 mg·L-1 N nutrient solution. Nematode egg count suggests that plants in the nematode treatment were successfully infested with Meloidogyne incognita, however, no significant root galling was observed, and plant growth and flower quality were not affected by nematode infestation.

Usage of green manure plants as cover-crops in controlling root-knot nematode, Meloidogyne incognita (Kofoid and White) on tomato, Lyco-persicon esculentum (Mill.)

2016 ◽  
Vol 6 (1) ◽  
pp. 23-33
Author(s):  
L. D. Amarasinghe ◽  
N. W. Premachandra
Keyword(s):  
Cover Crops ◽  
Meloidogyne Incognita ◽  
Lower Number ◽  
Root Weight ◽  
Root Knot Nematode ◽  
Plant Materials ◽  
Tomato Plants ◽  
Soil P ◽  
Juvenile Mortality ◽  
Plant Parts

This study was conducted to determine the nematicidal effect of aqueous extractions of dry plant materials, Tithonia diversifolia, Gliricidia sepium and Tagetes erecta on juveniles of Meloidogyne incognita (Kofoid and White) and to determine the effect of dry leaves of wild sunflower, dry leaves of Gliri-cidia, and dry plant parts of marigold as cover crops on the growth of potted tomato, Lycopersicon esculentum (Mill.) infested with M. incognita. Nemati-cidal effect of aqueous extracts of T. diversifolia, G. sepium and T. erecta (20 g/ 100 mL w/v) were evaluated at 0.05 g/mL, 0.1 g/mL and 0.2 g/mL concentrations in the laboratory bioassay. Results revealed that 0.1 g/ mL and 0.2 g/ mL concentration of T. erecta and 0.2 g/mL concentration of T. diversifolia were very effective in juvenile mortality by over 50% within 48 hours com-pared to other treatments. T. erecta plant parts were the most effective causing above 70% juvenile mortality in 48 hours. M. incognita infested potted tomato plants supplement with dry plant parts of Marigold (2% w/w) showed; significantly higher number of green leaves (P=0.000, F=10.95); significantly lower number of yellow leaves (P=0.001, F=6.78); significantly high-er plant height (P=0.000, F=8.90), stem diameter (P=0.000, F=11.83), root length (P=0.000, F=14.71) and root weight (P=0.000, F=15.08); significantly lower number of root galls (P=0.000, F=116.74), gall index (P=0.000, F=95.80) and significantly lower population of M. incognita in soil (P=0.000, F=24.78) compared to other treatments. This study concludes that addition of botani-cals as cover crops enhanced plant growth and significantly reduced root-knot infestation in tomato plants.

Integrated approach for the management of the root-knot nematode, Meloidogyne incognita, on eggplant under field conditions

Nematology ◽  
2013 ◽  
Vol 15 (6) ◽  
pp. 747-757 ◽  
Author(s):  
Satyandra Singh
Keyword(s):  
Meloidogyne Incognita ◽  
Biological Control Agent ◽  
Solanum Melongena ◽  
Dry Weight ◽  
Integrated Approach ◽  
Control Agent ◽  
Field Application ◽  
Root Knot Nematode ◽  
Neem Cake ◽  
Natural Infestation

A 2-year field study was conducted to develop an eco-friendly field application method for controlling root-knot disease of eggplant (Solanum melongena). The test sites were heavily infested with the root-knot nematode, Meloidogyne incognita. The efficacy of neem cake (1.5 t ha−1), talc-based preparations of Pseudomonas fluorescens (10 kg ha−1) and Trichoderma harzianum (10 kg ha−1) as soil application and seed treatment (10 g (kg seed)−1) were tested to develop an integrated nematode management module against M. incognita infecting eggplant. Neem cake, P. fluorescens and T. harzianum alone and in combinations significantly reduced the incidence of root-knot disease of eggplant. Fresh and dry weight of shoots were higher in the plant where neem cake, P. fluorescens and T. harzianum had been applied, than in both M. incognita-infected plants and other treatments. The best protection of disease, in terms of reduction in number of galls (81%) and reproductive factor (Pf∕Pi < 0.5) of the nematode, was achieved through this treatment. It also enhanced yield of eggplant by up to 70%. It is suggested that integrated approach using organic amendment with bio-control agents to manage root-knot disease of eggplant under natural infestation is not only environmentally friendly but also more beneficial to growers. This approach also has potential for overcoming some of the efficacy problems that occur with application of individual biological control agent.

The effect of sandy soil, bacterium dose and time on the efficacy of Pasteuria penetrans to control Meloidogyne incognita race 1 on coffee

Nematology ◽  
2007 ◽  
Vol 9 (6) ◽  
pp. 845-851 ◽  
Author(s):  
Maria Célia Cordeiro ◽  
Regina Carneiro ◽  
Pedro Cirotto ◽  
Luiz de Mesquita ◽  
Maria Ritta Almeida ◽  
...  
Keyword(s):  
Biological Control ◽  
Sandy Soil ◽  
Meloidogyne Incognita ◽  
Pasteuria Penetrans ◽  
Root Knot Nematode ◽  
Nematode Reproduction ◽  
Second Stage ◽  
Race 1 ◽  
Coffee Plants ◽  
Reproduction Factor

AbstractAn obligate parasite bacterium of the root-knot nematode, Pasteuria penetrans strain P10, isolated from Meloidogyne incognita females on banana roots in Imperatriz Maranhão State, Brazil, was evaluated in glasshouse conditions, using two doses of a dry root bionematicide (107 endospores (5.0 g/seedling) and 106 endospores (0.5 g/seedling)) on seedlings of cv. Mundo Novo coffee. The soil in which coffee seedlings were raised was inoculated previously with these two doses of P. penetrans and after 2 months the plants were transferred to soils of different textures: clay-sandy soil (38% clay, 2% silt and 60% sand) and sandy soil (17% clay, 0% silt and 83% sand). When the coffee plants were 30 cm high, they were inoculated with 20 000 eggs/plant of M. incognita race 1. The coffee plants were examined 8, 16 and 24 months after nematode plant infestation. The effectiveness of the biological control was determined by the reduction of nematode reproduction factor, which ranged from 62 to 67% in clay-sandy soil and 80 to 85% in sandy soil. The mechanism of suppression caused by the bacterium was evaluated by the percentage of infected second-stage juveniles (J2), number of endospores attached/J2 and number of infected females. The high levels of suppression were related to time, increasing from 8 to 24 months, and to the percentage of sand in the soil.

scholarly journals Influence of Meloidogyne incognita and Thielaviopsis basicola Populations on Early-Season Disease Development and Cotton Growth

Plant Disease ◽  
2000 ◽  
Vol 84 (4) ◽  
pp. 449-453 ◽  
Author(s):  
N. R. Walker ◽  
T. L. Kirkpatrick ◽  
C. S. Rothrock
Keyword(s):  
Meloidogyne Incognita ◽  
Population Level ◽  
Dry Weight ◽  
High Rate ◽  
Thielaviopsis Basicola ◽  
Cotton Production ◽  
Treatment Rate ◽  
Nematode Reproduction ◽  
Severity Of Disease ◽  
Root Necrosis

Microplot studies were used to examine the effect of various population densities of Meloidogyne incognita and Thielaviopsis basicola on cotton-plant development and disease severity. Plots were infested with 0, 20, or 100 T. basicola chlamydospores/g and 0, 5, or 10 M. incognita eggs and juveniles/cm3 of soil in a factorial arrangement in 1997 and 1998. Combinations of M. incognita and T. basicola reduced plant survival in both years compared to the noninfested control, except in 1998 for the high rate of T. basicola over all nematode rates. Plant height-to-node ratios were reduced by pathogen combinations compared to the noninfested control or to either pathogen alone. Plant dry weight was reduced by M. incognita in 1998 and the high rate of T. basicola in 1997. Root necrosis was increased by increasing rates of T. basicola in 1997 and by M. incognita over all rates of T. basicola in both years. Colonization of root tissue by T. basicola was increased by the low inoculum density of the nematode at 20 CFU/g soil in 1997 and 100 CFU/g in 1998. Nematode reproduction with the high M. incognita treatment rate was reduced in both years of the study by the high T. basicola rate. This study suggests the importance of population level of each pathogen to the severity of disease and confirms the potential of this disease interaction to impact cotton production.

Sign in / Sign up

Export Citation Format

Share Document