scholarly journals Effects of Meloidogyne incognita and Thielaviopsis basicola on Cotton Growth and Root Morphology

2014 ◽  
Vol 104 (5) ◽  
pp. 507-512 ◽  
Author(s):  
Jianbing Ma ◽  
Juan Jaraba ◽  
Terrence L. Kirkpatrick ◽  
Craig S. Rothrock
Keyword(s):  
Meloidogyne Incognita ◽  
Root Morphology ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Thielaviopsis Basicola ◽  
Root Knot Nematode ◽  
Root Parameters ◽  
Topological Parameters ◽  
Top Dry Weight ◽  
Additional Approach

Effects of the root-knot nematode Meloidogyne incognita and the fungal pathogen Thielaviopsis basicola on cotton seedling growth and root morphology were evaluated in controlled environmental experiments. Four pathogen treatments, including noninfested soil, soil infested with M. incognita, soil infested with T. basicola, and soil infested with both pathogens were evaluated at soil bulk densities (BDs) of 1.25 and 1.50 g/cm3. Plant growth and the morphology of the root systems were evaluated 44 days after planting. Infestation with M. incognita and T. basicola together significantly reduced seedling emergence, number of stem nodes, and root system volume compared with either pathogen alone. Either M. incognita or T. basicola reduced plant height, root fresh weight, top dry weight; root parameters total root length, surface area, and links; and root topological parameters magnitude, altitude, and exterior path length. M. incognita infection increased root radius. Root colonization by T. basicola increased with the presence of M. incognita at the lower soil BD. In contrast to previous research with Pythium spp., root topological indices (TIs) were similar with all of the treatments. Root TIs were near 1.92, indicating a herringbone (less branching) root architectural structure. Studying root architecture using a topological model offers an additional approach to evaluating fungi and nematodes and their interactions for soilborne-pathogen systems.

scholarly journals Effect of Temperature on and Histopathology of the Interaction Between Meloidogyne incognita and Thielaviopsis basicola on Cotton

1999 ◽  
Vol 89 (8) ◽  
pp. 613-617 ◽  
Author(s):  
N. R. Walker ◽  
T. L. Kirkpatrick ◽  
C. S. Rothrock
Keyword(s):  
Meloidogyne Incognita ◽  
Vascular Tissue ◽  
Root Surface ◽  
Effect Of Temperature ◽  
Infested Soil ◽  
Thielaviopsis Basicola ◽  
Root Knot Nematode ◽  
Cortical Cells ◽  
Node Ratio ◽  
Cotton Seeds

Controlled environments were used to study the relationship between the root-knot nematode (Meloidogyne incognita) and Thielaviopsis basicola on cotton. Temperature treatments were continuous 20, 24, and 28°C or two cyclic linear regimes with ranges of 14 to 32 or 18 to 28°C over 24 h. Cotton seeds were planted in fumigated soil infested with T. basicola, M. incognita, or both. After 42 days, pathogen effects on plant growth and pathogen development were evaluated. Histology was conducted on roots collected 14, 28, and 42 days after planting in the continuous 24°C treatment. Reductions in plant height-to-node ratio and total fresh weight were observed for soils infested with both pathogens compared with the control or with soils infested with either pathogen, except for M. incognita-infested soil at 28°C. T. basicola reduced root galling and reproduction of the nematode at all temperatures. Vascular discoloration caused by T. basicola was greater in the presence of M. incognita compared with that by T. basicola alone. At 2 and 4 weeks, histological studies showed that plants grown in all T. basicola-infested soils contained chlamydospore chains on the root surface and in cortical cells. The fungus was not observed inside the vascular cylinder. Roots from 4-week-old plants from soils infested with T. basicola and M. incognita showed fungal sporulation in vascular tissue and localized necrosis of vascular tissue adjacent to the nematodes. At 6 weeks, plants grown in soil infested with T. basicola alone exhibited no remaining cortical tissue and no evidence of vascular colonization by the fungus. Six-week-old plants grown in T. basicola + M. incognita-infested soils exhibited extensive vascular necrosis and sporulation within vascular tissue. These studies suggest that coinfection expands the temperature ranges at which the pathogens are able to cause plant damage. Further, M. incognita greatly increases the access of T. basicola to vascular tissue.

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.

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.

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.

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 Bioefficacy of Bacillus subtilis against root knot nematode Meloidogyne incognita (Kofoid and White) Chitwood in tomato

2015 ◽  
Vol 7 (2) ◽  
pp. 1012-1015
Author(s):  
Subhalaxmi Roy ◽  
Arun Rathod ◽  
Aniruddha Pramanik
Keyword(s):  
Bacillus Subtilis ◽  
Trichoderma Harzianum ◽  
Meloidogyne Incognita ◽  
Dry Weight ◽  
Control Agent ◽  
Seedling Height ◽  
Root Knot Nematode ◽  
Tomato Fruits ◽  
Highest Weight ◽  
Gall Index

An investigation was conducted for the management of root knot nematode Meloidogyne incognita (Kofoid and White) Chitwood infesting tomato through the application of bio-control agent like Bacillus subtilis, Trichoderma harzianum and Pseudomonas fluorescens. Experiment result revealed that minimum no. of galls/25seedlings (17.50) and maximum seedling height (27.6cm) were observed in Bacillus subtilis @50g/m2 in nursery bed + B. subtilis @ 5kg along with 2.5 tons of FYM/ ha. The highest weight/25seedlings (69.50g) was noticed in the B. subtilis @50g/m2 in nursery bed + B. subtilis 2.5kg along with 2.5 tons of FYM/ha. The highest growth of the plant at 45 DAT (49.2cm) and at harvest (81.2cm) and maximum fresh (711.3g) and dry weight (265g) was found in B. subtilis @50g/m2 in nursery bed + B. subtilis 2.5kg along with 2.5 tons of FYM/ha. B. subtilis @50g/m2 in nursery bed + B. subtilis 2.5kg along with 2.5 tons of FYM/ha exhibited lowest gall index (1.2/plant) and highest reduction of nematode population and provided highest yield of tomato fruits (335.75q/ha).

scholarly journals Variation in Calcium Content of Ginger Germplasm Inoculated with Bio-Agent, Trichoderma viride against Root-Knot Nematode, Meloidogyne incognita

2021 ◽  
pp. 101-105
Author(s):  
Manaswini Mahapatra ◽  
Dhirendra Kumar Nayak ◽  
Pranaya Pradhan ◽  
Antaryami Mishra
Keyword(s):  
Plant Growth ◽  
Effective Treatment ◽  
Meloidogyne Incognita ◽  
Trichoderma Viride ◽  
Calcium Content ◽  
Dry Weight ◽  
Combined Treatments ◽  
Root Knot Nematode ◽  
Nutrient Deposition ◽  
Maximum Content

The study was aimed to control nematodes in ginger crop in a sustainable way through inoculation of bio-agent, Trichoderma viride. The outcome of our research revealed that Trichoderma viride alone (T2) was the most effective treatment among all. This bio-agent has lowered the root-knot nematode populations by suppressing the disease intensity and responsible for enhancement of plant growth, increases the availability of nutrients to host plant. Meloidogyne incognita alone (T1) infected rhizomes resulted in highest reduction of calcium content amounting 2.26 and 2.43 mg/100g dry weight whereas maximum content was recorded in Trichoderma viride alone (T2) inoculated rhizomes as 2.84 and 3.08 mg 100g-1 dry weight in suravi and suprabha over control (T7) respectively. Trichoderma viride inoculated 15 days prior to Meloidogyne incognita (TV→MI) was found to be most efficient one among all combined treatments. Susceptibility towards nematode induced more nutrient deposition in rhizomes of ginger crop due to poor translocation process through xylem.

scholarly journals Potential of non-fumigant nematicides at different formulations against southern root-knot nematode (Meloidogyne incognita) on tomato plants

2019 ◽  
Vol 8 (1) ◽  
pp. 23-28
Author(s):  
Mohamed S. Khalil ◽  
Abdulqawi A. A. Alqadasi
Keyword(s):  
Meloidogyne Incognita ◽  
Dry Weight ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Tomato Plants ◽  
Shoot Dry Weight ◽  
Soil Population ◽  
Meloidogyne Spp ◽  
Southern Root Knot Nematode

Currently, plant parasitic nematodes (PPN) especially root knot nematodes, Meloidogyne spp. have been found involved in the global losses of tomato crops. The most employed tactic for managing PPN in Africa is non-fumigant nematicides. Recently, in Egypt abamectin was recorded as a new tool to control PPN. Thus, two pot experiments were conducted to evaluate the potential of abamectin and certain non-fumigant nematicides namely; oxamyl and ethoprophos at two different formulations (granular and liquid) against southern root knot nematode (Meloidogyne incognita) on tomato plants under greenhouse conditions. Results revealed the granular formulations of ethoprophos and oxamyl, in addition to abamectin, showed the same significance (P≤0.05) in suppressing tomato soil population and root galls of M. incognita, during both experiments. However, liquid formulations of ethoprophos and oxamyl gave relatively less decreasing in soil population and root galls. On the other hand, all applied treatments improved plant growth criteria ranging from 36.92 to 126.44% in shoot dry weight and from 31.25 to 137.50% in root dry weight for both experiments.

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 Gibberellin A3 Treatment of Seeds, Container Volume, Substrate pH, and Nitrogen Source and Rate Influence Growth of Containerized Seabeach Amaranth (Amaranthus pumilus)

2012 ◽  
Vol 30 (2) ◽  
pp. 65-72
Author(s):  
Daniel S. Norden ◽  
Stuart L. Warren ◽  
Frank A. Blazich ◽  
David L. Nash
Keyword(s):  
Leaf Area ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Nutrient Content ◽  
Water Soluble ◽  
Gibberellin A3 ◽  
Application Rates ◽  
Top Dry Weight ◽  
Soluble Fertilizer ◽  
Substrate Ph

Seeds of seabeach amaranth (Amaranthus pumilus Raf.), a species federally listed as ‘threatened,’ were stratified (moist-chilled) for 90 days at 4C (39F) or treated with a solution of the potassium (K) salt (K-salt) of gibberellin A3 (K-GA3) at 1000 mg·liter−1 (ppm) for 24 hr. After treatment, both groups of seeds were sown in containers of two volumes, 139 or 635 cm3 (9 or 39 in3) with a substrate of peat:pine bark (1:1, v/v) amended with one of two rates of pulverized dolomitic lime [2.24 or 4.48 kg·m−3 (3.8 or 7.6 lb·yd−3)]. Containers were maintained in a greenhouse. After seedling emergence, seedlings were fertilized with a 20N-4.4P-16.6K (20N-10P205-20K20) acidic, water soluble fertilizer or a 15N-2.2P-12.5K (15N-5P205-15K20) basic, water soluble fertilizer applied thrice weekly at nitrogen (N) application rates (NARs) of 75, 150, 225, or 300 mg·liter−1. The study was terminated 8 weeks after seeds were sown and data recorded. Regardless of fertilizer, acidic or basic, top dry weight and leaf area of seabeach amaranth increased linearly with increasing NAR. Maximum top dry weight and leaf area occurred with N at 300 mg·liter−1, whereas root dry weight was unaffected by NAR. Both fertilizers increased electrical conductivity (EC) linearly with increasing NAR, and EC values of 1.15 to 1.18 dS·m−1 were adequate for maximum top growth or leaf area. Substrate pH decreased linearly with increasing NAR 21, 43, and 57 days after initiation. Top and root dry weights and leaf area were greatest for seedlings derived from seeds treated with K-GA3. Large containers yielded top and root dry weights and leaf area 61, 33, and 57% greater, respectively, than smaller containers. Top N concentration increased linearly with increasing NAR for acidic and basic fertilizers with N concentrations of 58.4 and 50.4 mg·g−1, respectively, at maximum top dry weight. Although top nutrient content of N increased linearly with NAR, top N content was unaffected by either rate of lime or type of fertilizer.

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