Final Nematode Population Research Articles

Management of Root-Knot Nematode, Meloidogyne incognita Infecting Tuberose by Using Bioformulations under Field Condition

Aims: To evaluate the effectiveness of different bioformulations for management of root-knot nematode, Meloidogyne incognita infecting tuberose under field condition. Study Design: Randomized Block Design. Place and Duration of Study: Biswanath College of Agriculture, AAU, Biswanath Chariali, Assam during summer season 2024. Methodology: Bulbs of tuberose cultivar Prajwal were planted in root-knot nematode infested sick plot. In this experiment seven treatments were considered and the treatments were replicated thrice. Bioformulations viz., Neem cake, Neem leaf power, Biover, Biozium, Biomonas and AAU-Bioguard were applied treatment wise and mixed with soil before planting of bulbs. Observations on plant height and floral characteristics viz. spike length, rachis length, spike weight, number of floret per spike, floret length and nematode multiplication parameters like number of galls, egg masses per root system and final nematode population in soil were recorded. Results: Upon observation results showed that all the treatments were significantly effective in increasing the plant height, floral characteristic and reducing the number of galls, eggmasses and final nematode population in soil as compared to that of untreated control. Highest plant height(46.50cm), spike length (66.33cm), spike weight (37.33g), rachis length(32cm), number of florets per spike(25.26) and floret length(4.66cm) was recorded in the treatment with Biover@5kg enriched with FYM 5t/ha, which was followed by the treatment with Biozium @5kg enriched with FYM 5t/ha and neem cake @ 1t/ha. Maximum reduction of number of galls (35.18%), eggmasses (31.79%) and final nematode population in soil (39.65%) was recorded in the treatment with Biover@5kg enriched with FYM 5t/ha. Conclusion: From this experiment it can be concluded that all the bioformulations were found to be effective for increasing plant height, floral characteristic and reducing the nematode multiplication and these can be incorporated in root-knot nematode management programme. Among the bioformulations Biover was found to be most effective.

Reaction and quantification of damage in pineapple parasite by Meloidogyne spp.

Four pineapple cultivars (Vitória, Smooth Cayenne, Pérola and MD-2 (Gold)) were inoculated M. javanica and M. enterolobii in two experiments. In the first, sixty days after planting the seedlings, the plants were inoculated with 5,000 eggs + juveniles of the second stage (J2) of M. javanica or M. enterolobii, in a completely randomized design (CRD) with 10 replications. After 90 days of inoculation, we evaluated: a fresh matter of the root system, the final population and reproduction factor of nematodes (RF). Cultivars with RF≥1.00 were considered susceptible and with RF<1 resistant. Smooth Cayenne cultivar was susceptible to both nematodes. In the second experiment, pineapple cv. Smooth Cayenne was inoculated with increasing levels of M. enterolobii (0, 2,500, 7,500 and 15,000 eggs+J2) in DIC with 8 replications, aiming to quantify the damage caused to plants by the nematode. The weight of the fruit per fruit, weight of the peel, weight of the juice, weight of the fruit without the crown, median diameter of the fruit, a diameter of the central axis of the fruit, the height of the fruit and titratable acidity were evaluated. The higher the population level of M. enterolobii, the lower the recorded values ​​of the evaluated variables.

Efficacy of Noval Nematicide on Root-knot Nematode, Meloidogyne javanica and Establishment of Recommended Dose in Mung Bean (Vigna radiata L.)

The study was carried out to efficacy of newer nematicide (fluensulfone 2% GR) at different doses under field conditions on mung bean. Total seven treatments were used with different doses of fluensulfone 2% GR i.e., T1 - fluensulfone 2% GR 10 kg/ha., T2 - fluensulfone 2% GR 12 kg/ha., T3 - fluensulfone 2% GR 14 kg/ha., T4 - fluensulfone 2% GR 16 kg/ha., T5- fluensulfone 2% GR 18 kg/ha., T6- fluensulfone 2% GR 20 kg/ha., T7 - carbofuran 3G 50 kg/ha and T8 - untreated check (control) maintained for comparison. The observations were recorded on plant growth characters (shoot length (cm), shoot weight (gm), root length (cm), and root weight (gm)) and nematode reproduction (number of galls per plant, number of egg mass per plant, number of eggs per egg mass, nematode juveniles per 200 cc soil and final nematode population). Treated plant with fluensulfone 2% GR with the dose of 20kg/ha found to be the best to given the maximum plant growth characters and minimized nematode reproduction.

Pomegranate (Punica granatum L.) growth and biochemical alterations in response to meloidogyne incognita infection, minerals, and nano-fertilizers

The effects of four inoculum levels (500, 1,000, 2,000, or 4,000 second-stage juveniles (J2) per plant) of the root-knot nematode, Meloidogyne incognita, on two pomegranate cultivars (‘Manfalouty’ and ‘Wonderful’) were investigated under greenhouse conditions in response to plant inorganic and organic chemical concentrations. Furthermore, the effects of six commercial chemical fertilizers (inorganic fertilizers and nano-fertilizers) on plant growth and nematode reproduction were also studied. Both cultivars recorded the highest gall formation, embedded stages, and final nematode population at the inoculum dosage of 2,000 J2/plant. The highest reproductive rate was achieved with 500 J2/plant, while the lowest rate was observed with 4,000 J2/plant on both cultivars. ‘Wonderful’, at all M. incognita inoculum levels, was more sensitive to nematode infestation than ‘Manfalouty’. ‘Wonderful’ showed a greater reduction in fresh and dry plant weights than ‘Manfalouty’ at 2,000 and 4,000 J2/plant. In both cultivars, the concentrations of N, P, and K decreased with increasing nematode inoculum levels. This decline was more pronounced in ‘Manfalouty’ than in ‘Wonderful’. The nano-fertilizers, Hyper Feed®, and Hyper Feed Solo® reduced all nematode parameters but only in ‘Wonderful’. Treatment with Hyper Feed® resulted in the highest percentage increases in all plant growth parameters in ‘Wonderful’. Total carbohydrate concentration was increased in ‘Manfalouty’ treated with the nano-fertilizers, especially with Hyper Feed®. Also, concentrations of total phenols and tannins increased in ‘Wonderful’ when treated with either nano-fertilizer. Generally, both nano-fertilizers showed an increase in plant N levels. We recommend using nano-fertilizers in integrated pest management (IPM) programs on pomegranate where they improved plant growth parameters and reduced nematode multiplication parameters more markedly than inorganic fertilizers.

Potential Role of the Yeast Papiliotrema terrestris Strain PT22AV in the Management of the Root-Knot Nematode Meloidogyne incognita

The nematicidal potential of the yeast Papiliotrema terrestris strain PT22AV (YSY) was investigated against the root nematode (RKN) Meloidogyne incognita in in vitro bioassays on infective juveniles (J2) and experiments on tomatoes in pot and greenhouse conditions. The J2 nematodes were exposed to YSY solutions for 19 days, using abamectin (ABA), fosthiazate (FOS) and distilled water as controls. In the experiments on potted and greenhouse tomatoes, 0.5 and 1 kg ha−1 doses of YSY were tested in comparison to ABA, biocontrol agents Purpureocillium lilacinus strain 251 (PUL) and Bacillus firmus strain 1-1582 (BAF), a plant biostimulant/fertilizer (ERG) and the nematicide Fluopyram (FLU). J2’s viability was affected by YSL after 7 days, decreasing to zero on the 15th exposure day, while ABA and FOS resulted in 83 and 100% J2 mortality within 24 h. Only the 1.0 kg ha−1 dose of YSY was able to significantly reduce the final nematode population in soil and gall formation on tomato roots, without significant differences from PUL and BAF. All treatments in comparison also resulted in a significant increase in tomato growth and crop yield, except for 0.5 kg ha−1 of YSY. Data indicated that YSY could represent an additional tool for organic and integrated RKN management.

Effect of Bio Control Agents in the Management of Citrus Nematode (T. semipenetrans) on Khasi Mandarin Seedling

Studies on the effect of Purpureocillium lilacinum, Glomus fasciculatum, Trichoderma harzianum, vermicompost and carbofuran 3G in the management of Tylenchulus semipenetrans on Khasi mandarin under pot condition showed that all thetreatments were effective in increasing plant growth parameters of Khasi mandarin. All the treatments significantly decreased the final nematode population in soil and root over control. The treatment with vermicompost @ 15g/plant+ T. harzianum 10g/plant was found to be most effective in plant growth parameters of Khasi mandarin. The treatment with carbofuran 3G@ 4g/plant was found to be best in suppressing the final nematode population in soil and root followed by the treatment with G. fasciculatum@ 150spores/plant + P. lilacinus@10g/plant.

Management of Root Knot Nematode Meloidogyne incognita on Carrot

A pot experiment was conducted in the net house, Department of Nematology, during the rabi season to know the efficacy of certain botanicals, Azadiracta indica, Azeratum conizoides, Tagetes erecta, Ricinus Communis, Lantana camara and Parthenium hysterophorus each @ 1.0 and 1.5%(w/w) against Meloidogyne incognita on carrot. The result revealed that all the treatments were effective in increasing plant growth parameters with corresponding decreased in number of galls, eggmasses per root system and final nematode population in soil over control. The treatment with Azadiracta indica @1.5%(w/w) was most effective in increasing plant growth characters, reducing number of galls, eggmasses per root system and final nematode population in soil. A microplot experiment was conducted during rabi season to study the efficacy of Glomus fasciculatum, consortia (T. harzianum, T. viride and Pseudomonas fluorescenes) and vermicompost for the management of M.incognita on carrot. All the treatments were effective in increasing plant growth parameters and yield with corresponding decreased in number of galls, eggmasses per root system and final nematode population in soil over control. The treatment with G. fasciculatum @ 300 spores/m2 + consortia @ 5ml/lt + vermicompost @ 1.25t/ha was found most effective in increasing plant growth parameters, yield of carrot and reducing number of galls and egg masses and final nematode population in soil.

In vivo Evaluation of Silver Nanoparticles on the Management of Meloidogyne incognita in Green Gram

In the investigations, on the effect of Ag NPs on the management of M. incognita in green gram, the results showed that all the treatments were found to be effective in increasing all growth parameters. Maximum growth parameter viz., plant height, fresh and dry weight of shoot and root were recorded in the treatment with 0.15 ppm Ag NPs + M. incognita. Maximum reduction in galls, egg masses and final nematode population in soil were recorded in the treatment with 0.15 ppm Ag NPs. All the treatments significantly differed from control except the treatment with 0.0015 ppm Ag NPs + M. incognita.

Host Status of Ornamental Shade Trees and Shrubs to Plant Parasitic Nematodes.

Oregon leads the United States in nursery production of shade trees and is third in deciduous and broadleaf evergreen shrub production. Plant-parasitic nematodes have been implicated in problems with the growth of plants in nurseries and are also of phytosanitary risk. A greenhouse experiment was conducted to evaluate the host status of four trees (Quercus alba, Quercus garryana, Acer campestre, Thuja occidentalis) and two shrubs (Buxus sempervirens, Rhododendron catawbiense) to Meloidogyne incognita, Meloidogyne hapla, and Pratylenchus neglectus. Each plant/nematode treatment was replicated five times, and the experiment was conducted twice. Plants were inoculated with 3,000 eggs of M. incognita or M. hapla and 2,500 individuals of P. neglectus two weeks after planting. After three months, the plants were harvested, and the total density of nematodes in soil and roots for P. neglectus and the total density of second-stage juveniles (J2) in soil and eggs on roots for M. hapla and M. incognita were determined. The final nematode population (Pf) and reproductive factor (RF = Pf/initial population density) were calculated. For M. incognita and M. hapla, all of the ornamental trees and shrubs would be considered as fair to good hosts with RF values > 1. Meloidogyne incognita had the highest Pf (5,234 total J2 and eggs/pot) and RF value (28.4) on A. campestre. For P. neglectus, all of the ornamental trees and shrubs were fair to good hosts, except for B. sempervirens. Buxus sermpervirens was not a host for P. neglectus, with an RF value of almost 0. This is the first report of Q. alba, Q. garryana, and A. campestre as hosts for M. incognita, M. hapla, and P. penetrans. This is also the first report of T. occidentalis and R. catawbiense as hosts for P. penetrans and the non-host status of B. sermpervirens for P. penetrans.

Nematicidal Activity of Newbouldia laevis (P. Beauv.) Seem. Leaf Extract Against Root-Knot Nematode (Meloidogyne javanica (Treub.) Chitwood on Eggplant (Solanum spp.) in Jalingo, Nigeria

Solutions to problems of pests ravaging man’s crops abound in nature and are known to be quite soft on the environment. Extracts of leaves of Newbouldia laevis were assayed for activity against the rootknot nematode, Meloidogyne javanica. The treatments which included the crude extract, 5 ml and 10 ml dilutions and Control as distilled water were used both in the laboratory and field experiments. Twelve petridishes containing 1000 nematode eggs and another 12 petridishes containing 1000 juveniles were each treated with the extracts and arranged in complete randomized design. Results showed the crude extract was the most effective in reducing the hatching of M. javanica eggs (90.33%) and caused greater mortality of juveniles (93.10%) than all other treatments. In the field experiment, twelve 2 m x 2 m-sized prepared plots were transplanted with nine three week old seedlings of ‘Eggplant cv Yar Bello’ into holes drenched with 10 ml of appropriate treatment. Ten ml of these treatments were drenched into soil around the plants weekly for eight weeks. Result showed that the crude extract performed better than other treatments in all parameters some of which included plant height (112.77 cm in 2017; 113.33 cm in 2018), number of leaves (120.00 in 2017; 120.77 in 2018), number of fruits (35.44 in 2017; 35.88 in 2018), fruit weight (73.81g in 2017; 74.44 g in 2018), yield (58.70 tons/ha in 2017;59.94 tons/ha in 2018), final nematode population (159.66 in 2017; 149.26 in 2018) and reproduction factor (0.42 in 2017; 0.39 in 2018). In conclusion, extract of N. laevis particularly the crude extract shows potential for managing M. javanica and allowing for profitable cultivation of ‘Eggplant cv Yar Bello’.

Response of soybean and tomato plants under dual inoculation with Glomus sp. and root-knot nematode Meloidogyne incognita

The arbuscular mycorrhiza fungus Glomus can increase plant’s water and nutrient uptake and provide protection against plant parasitic nematodes. This study aimed to determine the response of soybean and tomato plants under inoculation with Glomus sp. and root-knot nematode Meloidogyne incognita at different application times in pot experiments. On soybean, Glomus sp. alone or in combination with M. incognita significantly increased plant height, while simultaneous inoculation of both microorganisms significantly increased the root dry weight. The total leaf P content of soybean however, significantly decreased in response to all inoculation methods. On tomato plants, Glomus alone significantly increased tomato shoot dry weight, total plant dry weight, and the total leaf P content. The final nematode population, the number of nematodes penetrating the root, and the root gall scores were not significantly impacted by either Glomus or M. incognita inoculation The inconsistent effect of Glomus inoculation on plant growth and total leaf P content as well as the inability of Glomus to reduce M. incognita infestation may be contributed by the extent of root colonization by Glomus and variability in the species of Glomus.

Evaluation of Wheat Cultivars and Germplasm Lines for Resistance to Pratylenchus neglectus Populations Collected in North Dakota.

Root-lesion nematode (RLN; Pratylenchus neglectus) is a migratory endoparasite and a major soilborne pathogen that affects wheat (Triticum spp.) production worldwide. Genetic resistance is one of the most economical and effective ways to manage P. neglectus in wheat. This study evaluated 37 local cultivars and germplasm lines in seven greenhouse experiments, including 26 hexaploid wheat, six durum wheat, two synthetic hexaploid wheat, one emmer wheat, and two triticale for P. neglectus resistance from 2016 to 2020. North Dakota field soils infested with two RLN populations (350 to 1,125 nematodes per kilogram of soil) were used for resistance screening under controlled greenhouse conditions. The final nematode population density for each cultivar and line was counted under the microscope to categorize the resistance ranking of these entries as resistant, moderately resistant, moderately susceptible, and susceptible. Out of the 37 cultivars and lines, one was classified as resistant (Brennan); 18 were moderately resistant (Divide, Carpio, Prosper, Advance, Alkabo, SY Soren, Barlow, Bolles, Select, Faller, Briggs, WB Mayville, SY Ingmar, W7984, PI 626573, Ben, Grandin, and Villax St. Jose); 11 were moderately susceptible; and seven were susceptible to P. neglectus. The resistant to moderately resistant lines identified in this study could be used in breeding programs after the resistance genes or loci are further elucidated. This research provides valuable information about P. neglectus resistance among wheat and triticale cultivars used in the Upper Midwest region of the United States.

Nematicidal activity of <i>Ageratum conyzoides</i> leaf extract against root-knot nematode (<i>Meloidogyne javanica</i>) on eggplant in Jalingo, Nigeria

Devastation of crops by pests is exacerbated by human activities but nature provides remedies that are environmentally friendly. This study was carried out to evaluate the activity of A. conyzoides leaf extract against Meloidogyne javanica on eggplant in Jalingo, Nigeria. Three concentrations (crude extract, 5 ml and 10 ml dilutions) of extract of Ageratum conyzoides as well as control (no application) were applied on juveniles and eggs of M. javanica in petri dishes in the laboratory in 2018 and 10 ml of the same extract was applied into holes at the base of eggplants transplanted into a nematode-infested field in 2018 and 2019. Result of the juvenile mortality test showed that the extract treatments caused the mortality of M. javanica juveniles with crudes extract being highest at 90.3%. Results of the egg hatch inhibition test also showed the extract treatments significantly reduced egg hatch compared to control with crude extract having the highest inhibition of 85.5%. Field experiment in both years indicated that the extract treatments recorded significantly (P˂0.05) better result than control in all parameters in both years. There was reduced root galling and nematode reproduction and by extension final nematode population with attendant high yield in extract-treated plants. It is therefore concluded that A. conyzoides has the potential for use as a bio-pesticide against M. javanica.

Population dynamics and damage threshold of Pratylenchus n. sp. and Meloidogyne javanica on finger millet

Summary Finger millet (Eleusine coracana) is a staple crop for subsistence farmers and is primarily cultivated in arid and semi-arid regions. Nevertheless, there are limited data available on the occurrence of plant-parasitic nematodes that specifically target finger millet, and the damage arising from such infections. In this study, we investigated the population dynamics, damage threshold and tolerance of the lesion nematode, Pratylenchus n. sp., and the root-knot nematode, Meloidogyne javanica, on finger millet ‘P-224’. We used 11 initial population densities (Pi) of second-stage juveniles (J2): 0, 0.125, 0.25, 0.5, 1, 2, 4, 8, 16, 32 and 64 J2 (g soil)−1 for M. javanica and the same densities of mixed life-stages for Pratylenchus n. sp. The logistic growth model, Seinhorst yield loss and population dynamic models were fitted to the shoot height, plant biomass and final nematode population density. Based on the population dynamics model parameters, maximum multiplication rates and maximum population densities for each nematode species were estimated. The maximum multiplication rates (a) were 32.39 and 17.46, whilst the maximum population densities (M) were 18.83 nematodes (g soil)−1 and 19.78 J2 (g soil)−1 for Pratylenchus n. sp. and M. javanica respectively. The maximum height reached (C) was negatively affected by increasing Pi for both nematode genera, while the rate of growth (B) and the time to reach was not affected based on the logistic model. A tolerance limit (T) of 1.70 nematodes (g soil)−1 and 0.65 J2 (g soil)−1; relative minimum grain yield (m) of 0.23 and 0.40 for Pratylenchus n. sp. and M. javanica was found, respectively. The results indicate that ‘P-224’ is a good host for both Pratylenchus n. sp. and M. javanica, which significantly reduce yield. These findings can be used as a base to develop effective nematode management strategies for finger millet.

Host-parasite Interactions between Solanum aethiopicum, Meloidogyne incognita, and Fusarium oxysporum f.sp. melongenae as Portrayed by Disease Traits and Crop Yield

Solanum aethiopicum L. cultivation is highly constrained by wilt disease induced by Fusarium oxysporum f.sp melongenae and Meloidogyne incognita. The effects of initial population densities of these pathogens on the crop were investigated to enhance knowledge of the host-parasite interactions. The 4 x 4 factorial set of treatments were laid out in the field using the randomized complete block design with three replications. Data were collected on plant vigour, vascular discoloration, fruit weight, shoot weight, root-gall index, final nematode population, disease incidence, and disease severity. The different initial population densities of Fusarium and/or Meloidogyne spp. had detrimental effects on the crop compared to the Control. The main effects of the pathogens on the crop/wilt showed the existence of cross-over interactions for all the disease parameters. The effects of the pathogens on yield (fruit weight and shoot weight) were partially directly proportional to population densities even though the effects were significantly different (P≤0.05) compared to the Control. All the disease parameters were positively correlated. Each of the pathogens was capable of causing severe damage to the crop in either single or concomitant infection.

Transgenic East African Highland Banana Plants Are Protected against Radopholus similis through Host-Delivered RNAi.

The burrowing nematode Radopholus similis is considered a major problem of intensive banana cultivation. It can cause extensive root damage resulting in the toppling disease of banana, which means that plants fall to the ground. Soaking R. similis in double-stranded (ds) RNA of the nematode genes Rps13, chitin synthase (Chs-2), Unc-87, Pat-10 or beta-1,4-endoglucanase (Eng1a) suppressed reproduction on carrot discs, from 2.8-fold (Chs-2) to 7-fold (Rps13). The East African Highland Banana cultivar Nakitembe was then transformed with constructs for expression of dsRNA against the same genes, and for each construct, 30 independent transformants were tested with nematode infection. Four months after transfer from in vitro culture to the greenhouse, the banana plants were transferred to a screenhouse and inoculated with 2000 nematodes per plant, and thirteen weeks later, they were analyzed for several parameters including plant growth, root necrosis and final nematode population. Plants with dsRNA constructs against the nematode genes were on average showing lower nematode multiplication and root damage than the nontransformed controls or the banana plants expressing dsRNA against the nonendogenous gene. In conclusion, RNAi seems to efficiently protect banana against damage caused by R. similis, opening perspectives to control this pest.

Combined effect of neem leaf powder and vermicompost in the management of root-knot nematode disease in Celosia argentea

Due to the rising demand for alternative options for root-knot nematode management, Neem (Azadirachta indica) leaf powder and Vermicompost were tested for their efficacy in controlling this disease in Celosia argentea. An experiment, laid out in Completely Randomized Design, was carried out in the screenhouse. It involved the testing of eight treatments which were replicated four times thus making a total of 32 experimental pots. The trial was repeated once to validate results obtained. Plants were inoculated with 5000 Meloidogyne incognita (Mi) eggs. The experimental pots without Mi egg served as the control. Data were collected on plant height, stem girth, number of leaves, branches and flowers, leaf area index, shoot weight, root weight, dry weight, number of galls, final nematode and egg population and subjected to Analysis of Variance. The New Duncan Multiple Range Test was used to separate statistically significant treatment means. Results showed that the amendments used, reduced the infestation of the treated plants whose final Mi nematode population (2360, 2020, 2050, 1720, 1540, 1230) and egg population (2250, 2030, 2120, 1690, 1540, 1230) which were lower (P d” 0.05) than their initial population (5000 eggs) and when compared to the untreated Mi-inoculated (control) plants which had the highest final population (5858 and 5620) that outnumbered the original inoculum. Neem leaf powder and Vermicompost combined at 1% was statistically at par with other treatments in the reduction of the root-knot disease of C. argentea

Reproduction of Meloidogyne morocciensis (Tylenchida: Meloidogynidae) in weeds found in Brazil.

Weeds can be hosts of root-knot nematodes of the genus Meloidogyne. The importance of the species Meloidogyne morocciensis parasitizing many crops is recognized, but their reproductive capacity in weeds is not known. The present study hypothesizes the ability of M. morocciensis to parasitize and reproduce in different weed species found in Brazil. The objective was to evaluate the reproduction of M. morocciensis in 36 weed species. The plants were individually inoculated with 5,000 eggs and second stage juveniles and kept in greenhouse for 60 days. The experimental design was completely randomized with twelve replications. The root system of each plant was evaluated for gall index (GI), final nematode population (PF), number of nematode/g of root (NNGR) and reproduction factor (RF). It was verified that M. morocciensis has the capacity to parasite 36 weed species belonging to 16 different botanical families, confirming the hypothesis proposed. From the 36 species evaluated, 77.8% (28) were susceptible (FR ≥ 1.0) to M. morocciensis. The present study is the first to identify different weeds as hosts of M. morocciensis, evidencing its polyphagous habit, indicating species of plants with high capacity to multiply this nematode and that need more attention during the integrated management of these pathogen.

Integrated Management of Meloidogyne Incognita and Soilborne Fungi Infecting Cucumber Under Protected Cultivation.

Relative efficacy of various approaches for management of Meloidogyne incognita and the soilborne fungus Fusarium oxysporum f. sp. cucumerinum has been tested in cucumber under protected cultivation conditions for two seasons. Management practices, namely, chemicals (fumigant, nonfumigant, and fungicide), organic amendments (neem cake, leaves, and oil opted as soil and seed treatment), and biocontrol agents (egg-parasitic fungus and Purpureocillium lilacinum), were combined for the management of the disease complex in a randomized block design. Two significant parameters were measured: plant growth parameters (shoot length, dry shoot weight, dry root weight, and yield) and disease parameters (galls per plant, final nematode population, egg masses per plant, and fungal incidence). All treatments significantly improved plant growth parameters and reduced nematode reproduction as compared to untreated check. The integration of formalin and neem oil seed treatment favors the low root galling index compared to all other treatments in both the seasons. Formalin and neem oil seed treatment reduced the nematode population and fungal incidence, and increased the yield of cucumber during both the seasons.

Is the Arbuscular Mycorrhizal Fungus Funneliformis mosseae a Suitable Agent to Control Criconematid Populations?

Several studies have shown the potential of using mycorrhizal fungi in increasing the plant yield by simultaneously reducing damages caused by pathogens. Plant parasitic nematodes (PPNs) are among the most feared pathogens for crops. This study aimed to evaluate the effects of Funneliformis mosseae as a mycorrhizal fungus on the population abundance of three world widespread species of nematodes from the family Criconematidae: Mesocriconema xenoplax, Mesocriconema antipolitanum, and Criconemides informis. Pure and highly abundant populations of each species were collected from Urmia city in Northwestern Iran, after the identification morphological and morphometric characteristics. The experiments were carried out in greenhouse conditions on three different rhizospheres of alfalfa, sugar beet, and wheat. After five months, the final population of nematodes and fungus, and the root surface on host plants inoculated and non-inoculated with the fungus F. mosseae, were evaluated. The results showed that the population of nematodes was increased in the presence of the fungus. It could be assumed that the extension of the host surface level of roots by the fungus resulted in more feeding sites for nematode activity and, consequently, higher population densities. In this study, the fungus did not seem to play a suitable role in controlling ectoparasitic nematode growth. However, since there are still many open questions about mycorrhizal fungi’s role in agriculture, more research should be conducted.