Nematode Management Research Articles

Characterization of finger millet extracts and evaluation of their nematicidal efficacy and plant growth promotion potential.

Plant-parasitic nematodes pose a significant threat to finger millet crops, potentially causing yield reduction of up to 70%. Extracts derived from finger millet varieties contain potent bioactive compounds that can mitigate nematode damage and promote plant growth. This study aimed at isolating and characterizing bioactive compounds from the finger millet varieties Ikhulule, Okhale-1, and U-15; evaluating the impact of Ikhulule and U-15 extracts on the mortality of the root lesion nematode Pratylenchus vandenbergae; assessing the growth promotion effects of Ikhulule and U-15 extracts on the finger millet variety Okhale-1; and determining the efficacy of these extracts in managing plant-parasitic nematodes under greenhouse conditions. Extracts were obtained from both leaves and roots and tested invitro for nematode mortality and invivo for growth promotion and nematode control. The results showed that finger millet extracts exhibited strong nematicidal properties invitro, achieving a mortality rate of up to 98% against P. vandenbergae nematodes. Applying these extracts to finger millet shoots significantly reduced nematode populations in both soil and roots and decreased the reproductive factor to below one (1), indicating an effective nematode control. The study attributes the enhanced nematicidal effects of finger millet extracts to their bioactive compounds, particularly dodecanoic acid, phytol, 1,1,4a-trimethyl-6-decahydro naphthalene, 2,3-dihydro-benzofuran, 2-methoxy-4-vinylphenol and ethyl ester, and hexadecanoic acid. These findings suggest that finger millet-derived extracts offer a natural solution for nematode management and broader agronomic benefits, ultimately contributing to overall plant health and productivity.

Seasonal Fluctuations in Plant-Parasitic Nematode Vertical Distributions and Their Interactions with Edaphic Factors in Vegetable Fields of South Georgia, U.S.A.

Plant-parasitic nematodes (PPNs) can be found deep in the soil profile, compounding nematode management decisions and detection. This study aimed to understand how seasonal fluctuations in edaphic factors are associated with the vertical distribution of PPNs in south Georgia's vegetable cropping systems. Five-core composite soil samples were taken monthly (March 2020 to February 2022) at three random locations in six vegetable fields. Fields represented three cropping systems (vegetable plasticulture, bare ground cucumber, and plastic bed watermelon rotation) and two regions (north and south) sampled from five 15-cm strata (0 to 15, 15 to 30, 30 to 45, 45 to 60, and 60 to 75 cm). Only soil temperatures and precipitation had seasonal fluctuations; the other edaphic factors were vertically stratified. Latitude and stratum had the strongest associations with nematode composition, showing a clear separation between the north and south regions. Variations in soil texture, porosity, moisture, and PPN vertical distribution suggested that the illuvial zone in the north region was the main factor in the differences observed between regions and strata. Seasonal fluctuations in vertical distribution were found among Meloidogyne incognita and Nanidorus spp. Higher abundances of deep-dwelling PPNs were limited to the south region in the winter for deep-dwelling M. incognita and summer and winter for Nanidorus spp., probably due to the illuvial zone barrier in the north region. Because most root-knot nematodes dwell at ≤30 cm during the summer, fumigant/nematicide applications are recommended during this season to minimize the risk of deep-dwelling escapees.

Plant-parasitic nematode research in the arid desert landscape: a systematic review of challenges and bridging interventions.

Plant-parasitic nematode research in the Middle East and North Africa (MENA) region faces significant challenges rooted in a need for proper assembly, diversity, and a unified and purpose-driven framework. This led to exacerbating their detrimental effects on crop production. This systematic review addresses the current situation and challenges that require targeted interventions to sustainably manage plant-parasitic nematodes and reduce their detrimental impact on agriculture production in the MENA region. We analyzed the nematode-related research conducted within the region over the past three decades to assess available resources and promote diverse research approaches beyond basic morphology-focused surveys. We show that crops are attacked by a diverse spectrum of plant-parasitic nematodes that exceed the global economic threshold limits. In particular, Meloidogyne species exceed the threshold limit by 8 - 14-fold, with a 100% frequency of occurrence in the collected soil samples, posing a catastrophic threat to crop production and the economy. We highlight detrimental agriculture practices in the MENA region, such as transferring soil from established fields to barren land, which enhances the dissemination of plant-parasitic nematodes, disrupting soil ecology and causing significant agricultural challenges in newly cultivated areas. Looking into the behavior of farmers, raising awareness must be accompanied by available solutions, as more practical alternatives are needed to gain the confidence of the farmers. We propose integrating microbial-based products and soil development practices in hygienic farming as resilient and sustainable solutions for nematode management. Increased emphasis is required to diversify the nematode-related research areas to bridge the gaps and facilitate the transition from fundamental knowledge to practical solutions. A cohesive network of nematologists and collaboration with national and international entities is crucial for exchanging knowledge related to legislation against invasive species.

Plant-parasitic nematodes associated with maize, and their relationship with soil properties in southern and southwestern Ethiopia

Summary Maize is an important cereal crop in sub-Saharan Africa (SSA). Plant-parasitic nematodes significantly impact maize production. However, research on maize nematodes in SSA is limited. The current study aimed to assess the occurrences and densities of nematodes associated with maize and to assess the correlation of some soil physicochemical properties with nematodes in southern and southwestern Ethiopia. One hundred and eighty-six soil and root samples were collected from 62 maize fields (31 from Hawassa Zuria and 31 from Mana districts). Eleven plant-parasitic nematode genera were identified. The most important genera of plant-parasitic nematodes identified were Meloidogyne and Pratylenchus, followed by Helicotylenchus and Tylenchorhynchus. The nematodes Pratylenchus and Criconemoides were significantly and positively associated with pH, soil organic carbon (SOC) and soil organic matter (SOM). Additionally, Tylenchorhynchus, Pratylenchus and Rotylenchulus were significantly positively correlated with soil available phosphorus (SAP). However, Criconemoides and Meloidogyne had a strong negative correlation with soil bulk density (SBD). This study provides useful baseline information on maize-associated nematodes, and will be useful for agricultural policy makers, private farmers, non-governmental organisations and agricultural extension workers enabling them to establish sustainable maize nematode management strategies.

Nematocidal activity and biocontrol efficacy of endophytic Bacillus velezensis Pt-RP9 from Pinus tabuliformis against pine wilt disease caused by Bursaphelenchus xylophilus

Pine wilt disease (PWD) is a globally significant quarantine forest disease caused by Bursaphelenchus xylophilus (PWN), resulting in substantial ecological and economic losses. Traditional nematode management practices are neither cost-effective nor environmentally friendly, prompting the exploration of biocontrol as a promising alternative for managing this devastating forest disease. Obtaining novel and specific biocontrol agents is extremely crucial for the effective and precise control of PWD. In the present study, a total of 136 endophytic isolates were obtained from the roots, stems and needles of Pinus tabuliformis in the Qinling Mountains of China, which were then subjected to nematocidal activity assay against PWN in vitro. Nine endophytic bacterial isolates exhibited exceptionally strong nematocidal capacity, with a corrected mortality rate exceeding 90 %, which were then identified as the genus of Bacillus through morphological features, endospore staining, and 16S rDNA sequencing, with one strain as B. mycoides, two as B. cereus, and six as B. velezensis. Additionally, the inhibition effects of the three Bacillus species on the reproduction of PWN in vitro was assessed using an original detection model, with B. velezensis Pt-RP9 identified as the most promising strain. Subsequently, the biocontrol efficacy of B. velezensis Pt-RP9 against PWD was evaluated in greenhouse experiments. Pt-RP9 demonstrated significant biocontrol effectiveness against PWD, with control efficiencies ranging from 31.25 % to 68.89 % across all treatments, particularly showing improved efficacy when pine seedlings were pre-treated with Pt-RP9 before PWN inoculation. Furthermore, pine seedlings treated with Pt-RP9 exhibited significantly reduced PWN density and lipid peroxidation levels in cell membranes compared to the control groups, along with increased activities of peroxidase, catalase, and polyphenol oxidase. To our knowledge, this study is the first to showcase the nematocidal activity of endophytes from P. tabuliformis against PWN and their biocontrol efficacy against PWD, marking a significant advancement in the field. The findings highlight the potential of B. velezensis Pt-RP9 as a crucial biological control agent against PWD, presenting a novel and sustainable disease management approach for pine forests.

A preliminary study on the interaction between Meloidogyne incognita and some strains of Pseudomonas spp. on growth performance of tomato under greenhouse conditions

The present study investigated the biological management of root-knot nematode (Meloidogyne incognita) in tomato plants using different strains of Pseudomonas spp. The experiment involved five treatments: a healthy control (T1), a nematode-inoculated control (T2), Pseudomonas fluorescens strain A (T3), P. fluorescens strain B (T4), and P. putida (T5). The results demonstrated significant differences in plant growth and root gall formation across treatments. The healthy control exhibited an average plant height of 12 cm and weight of 11 g. Nematode inoculation slightly reduced growth, with plants averaging 11 cm in height and 10 g in weight. Treatment with P. fluorescens strain A resulted in the highest growth, with plants reaching 13 cm in height and 12 g in weight. P. fluorescens strain B and P. putida treatments produced plants with average heights of 12 cm and 12.5 cm, and weights of 11 g and 10 g, respectively. Leaf and flower counts also varied, with T3, T4, and T5 treatments increasing leaf counts to 26, 40, and 33, respectively, compared to 15 in the nematode-inoculated control. The application of P. fluorescens strains A and B significantly reduced root galls to 8 and 15, respectively, compared to 29 in T2. P. putida treatment resulted in 21 root galls. These findings highlight the potential of Pseudomonas spp., especially P. fluorescens strains, in managing nematode infestation in tomato plants. Future studies should explore the mechanisms behind these microbial interactions and their long-term effects on plant health and yield.

Host-induced RNA interference targeting the neuromotor gene FMRFamide-like peptide-14 (Mi-flp14) perturbs Meloidogyne incognita parasitic success in eggplant.

The study demonstrates the successful management of Meloidogyne incognita in eggplant using Mi-flp14 RNA interference, showing reduced nematode penetration and reproduction without off-target effects across multiple generations. Root-knot nematode, Meloidogyne incognita, causes huge yield losses worldwide. Neuromotor function in M. incognita governed by 19 neuropeptides is vital for parasitism and parasite biology. The present study establishes the utility of Mi-flp14 for managing M. incognita in eggplant in continuation of our earlier proof of concept in tobacco (US patent US2015/0361445A1). Mi-flp14 hairpin RNA construct was used for generating 19 independent transgenic eggplant events. PCR and Southern hybridization analysis confirmed transgene integration and its orientation, while RT-qPCR and Northern hybridization established the generation of dsRNA and siRNA of Mi-flp14. In vitro and in vivo bio-efficacy analysis of single-copy events against M. incognita showed reduced nematode penetration and development at various intervals that negatively impacted reproduction. Interestingly, M. incognita preferred wild-type plants over the transgenics even when unbiased equal opportunity was provided for the infection. A significant reduction in disease parameters was observed in transgenic plants viz., galls (40-48%), females (40-50%), egg masses (35-40%), eggs/egg mass (50-55%), and derived multiplication factor (60-65%) compared to wild type. A unique demonstration of perturbed expression of Mi-flp14 in partially penetrated juveniles and female nematodes established successful host-mediated RNAi both at the time of penetration even before the nematodes started withdrawing plant nutrients and later stage, respectively. The absence of off-target effects in transgenic plants was supported by the normal growth phenotype of the plants and T-DNA integration loci. Stability in the bio-efficacy against M. incognita across T1- to T4-generation transgenic plants established the utility of silencing Mi-flp14 for nematode management. This study demonstrates the significance of targeting Mi-flp14 in eggplant for nematode management, particularly to address global agricultural challenges posed by M. incognita.

Nitrated fly ash inhibits root-knot nematode and alleviates biotic stress in beetroot: A novel approach towards soil friendly nematode management

Due to the toxic effects of chemical pesticides on the beneficial soil microbiome, alternative ecofriendly tactics are required for sustainable disease management in crops. To find a cost-effective and comparatively safe management practice, we investigated a novel approach by evaluating the waste fly ash modified as nitrated fly ash to control a notorious pest, Meloidogyne enterolobii, which causes considerable losses to beetroot through root-knot disease. Molecular characterization through SSU rRNA confirmed the identification of the pathogen M. enterolobii, which significantly hampers plant growth, pigment content, and yield of beetroot plants. However, applying optimum nitrated fly ash (15 % fly ash + 150 kg/ha N) significantly reduced disease severity significantly and substantially improved the plant biomass, biochemical attributes, and yield of beetroot plants. Furthermore, scanning electron microscopy revealed a significant improvement in nematode stress-induced stomatal closure with the application of nitrated fly ash at 15 % fly ash +150 kg/ha nitrogen amendment to the soil. The nematicidal activities of fly ash were also confirmed through in vitro experiments combined with cell viability methods. Our results suggest that exploiting nitrated fly ash at optimum concentrations can be a promising approach to manage this waste product and control root-knot nematodes (RKNs) in an eco-friendly manner.

Residue and dissipation kinetics of novel nematicide fluopyram in rice assessed by QuEChERS-liquid chromatography-tandem mass spectrometry.

Supervised field trial was conducted to study the dissipation pattern of fluopyram in rice plant after application of fluopyram 400g/L SC(Velum Prime) as soil drenching at the time of sowing in nursery bed at X (500g a.i. ha-1) and 1.25X (625.2g a.i. ha-1) doses. Samples of rice plant were collected on 0, 1, 3, 7, 10, 15, and 20days after transplanting. QuEChERS-based extraction method was validated and adopted to determine the residues of fluopyram in rice seedlings, whole rice grains (with husk), polished rice grain, husk, straw, and soil using LC-MS/MS (liquid chromatography-tandem mass spectrometry).The initial deposit of fluopyram in rice plant recorded were 0.27 and 0.41mgkg-1in X and 1.25X doses, respectively. Fluopyram residues dissipated following first-order kinetics with half-life of 2.53 and 2.57days at X and 1.25X doses, respectively. Residues were detected in seedlings up to 15days after transplanting and were at below LOQ in whole rice grains (with husk), polished rice grain, husk, straw, and soil collected at harvest. Monitoring study revealed that application of novel nematicide fluopyram for the management of nematodes in rice does not pose any risks to consumers.

Seasonal population dynamics and impact of abiotic factors on plant parasitic nematodes under temperate conditions of Kashmir, India

Plant parasitic nematodes (PPNs) pose a significant threat to the successful cultivation of grapevines globally. Abiotic parameters such as temperature, moisture and pH critically influence nematode population growth. Ecological investigation was conducted on three grapevine cultivars (Sahibi, Hussaini and Thompson) in Kashmir, India, from January 2021 to December 2022. The population dynamics of the identified PPNs around the grapevine rhizosphere were studied in relation to various factors. Nematode abundance peaked during the warm months of the summer season and dipped during winter. Soil and air temperatures positively correlated with the abundance of nematodes; however, soil moisture and rainfall showed a negative correlation. This study underscores the critical role of environmental factors on the population dynamics of plant parasitic nematodes, with temperature being an important influential factor. Effective nematode management in grapevine cultivation requires a thorough understanding of these dynamics to mitigate the impact of these parasites.

Enhancing Reniform Nematode Management in Sweetpotato by Complementing Host-Plant Resistance with Nonfumigant Nematicides.

The reniform nematode (Rotylenchulus reniformis Linford and Oliveira) adversely impacts the quality and quantity of sweetpotato storage roots. Management of R. reniformis in sweetpotato remains a challenge because host plant resistance is not available, fumigants are detrimental to the environment and health, and crop rotation is not effective. We screened a core set of 24 sweetpotato plant introductions (PIs) against R. reniformis. Four PIs were resistant, and 10 were moderately resistant to R. reniformis, suggesting these PIs can serve as sources of resistance for sweetpotato resistance breeding programs. PI 595869, PI 153907, and PI 599386 suppressed 83 to 89% egg production relative to the susceptible control 'Beauregard', and these PIs were employed in subsequent experiments to determine if their efficacy against R. reniformis can be further increased by applying nonfumigant nematicides oxamyl, fluopyram, and fluensulfone. A 34 to 93% suppression of nematode reproduction was achieved by the application of nonfumigant nematicides, with oxamyl providing the best suppression followed by fluopyram and fluensulfone. Although sweetpotato cultivars resistant to R. reniformis are currently not available and there is a need for the development of safer yet highly effective nonfumigant nematicides, results from the current study suggest that complementing host plant resistance with nonfumigant nematicides can serve as an important tool for effective and sustainable nematode management.

CRISPR/Cas9-induced knockout of an amino acid permease gene (AAP6) reduced Arabidopsis thaliana susceptibility to Meloidogyne incognita

BackgroundPlant-parasitic root-knot nematode (Meloidogyne incognita) causes global yield loss in agri- and horticultural crops. Nematode management options rely on chemical method. However, only a handful of nematicides are commercially available. Resistance breeding efforts are not sustainable because R gene sources are limited and nematodes have developed resistance-breaking populations against the commercially available Mi-1.2 gene-expressing tomatoes. RNAi crops that manage nematode infection are yet to be commercialized because of the regulatory hurdles associated with transgenic crops. The deployment of the CRISPR/Cas9 system to improve nematode tolerance (by knocking out the susceptibility factors) in plants has emerged as a feasible alternative lately.ResultsIn the present study, a M. incognita-responsive susceptibility (S) gene, amino acid permease (AAP6), was characterized from the model plant Arabidodpsis thaliana by generating the AtAAP6 overexpression line, followed by performing the GUS reporter assay by fusing the promoter of AtAAP6 with the β-glucuronidase (GUS) gene. Upon challenge inoculation with M. incognita, overexpression lines supported greater nematode multiplication, and AtAAP6 expression was inducible to the early stage of nematode infection. Next, using CRISPR/Cas9, AtAAP6 was selectively knocked out without incurring any growth penalty in the host plant. The ‘Cas9-free’ homozygous T3 line was challenge inoculated with M. incognita, and CRISPR-edited A. thaliana plants exhibited considerably reduced susceptibility to nematode infection compared to the non-edited plants. Additionally, host defense response genes were unaltered between edited and non-edited plants, implicating the direct role of AtAAP6 towards nematode susceptibility.ConclusionThe present findings enrich the existing literature on CRISPR/Cas9 research in plant-nematode interactions, which is quite limited currently while compared with the other plant-pathogen interaction systems.

Influence of Integrated Nematode Management Modules against Meloidogyne incognita Infecting Cucumber in Poly-house

Nematodes management in poly-house through a single practice is a very typical task in present agricultural scenario so, an integrated nematode management trial was conducted for the management of Meloidogyne incognita on cucumber in poly-house. In the investigation different combinations of physical, cultural and chemical treatments were applied for effective management of hidden enemy of cucumber, M. incognita. The combinations of hot water at 1 litre per poly bag, organic amendment (tea waste, tobacco churi, poultry manure, water hyacinth powder and lantana leaf powder at 20 g/plant) and carbofuran (0.25 g a.i./plant and 0.50 g a.i./plant) were applied. Standard (Hot water at 1 litre + Neem cake 50 g/plant + phorate at 0.5 g a.i./plant) and untreated checks were also maintained to compare experimental findings. The results of investigation shows that all the applied treatments significantly reduced nematode infection and increase plant growth over untreated check. Among all treatment combinations, Highest yield of cucumber (4.171 kg/plant) was obtained with integration of Hot water at 1 litre + Neem cake 50 g/plant + phorate at 0.5 g a.i./plant followed by Hot water + Tobacco churi + carbofuran at 0.5 g a.i./plant (3.924 kg/plant) and Hot water + Tea waste + carbofuran at 0.5 g a.i./plant (3.781 kg/plant) as compared to untreated check (1.092 kg/plant).

Phytochemical Volatiles as Potential Bionematicides with Safer Ecotoxicological Properties.

The management of plant-parasitic nematodes (PPNs) still relies on traditional nematicides that threaten the environment and human health. Novel solutions are urgently needed for PPN pest management that are effective while safeguarding non-target organisms. Volatile phytochemicals belong to a structurally diverse group of bioactive metabolites that are believed to hold safer environmental characteristics than synthetic pesticides. Nonetheless, not many studies have analysed the potential environmental benefits of shifting to these novel bionematicides. In the present study, 20 phytochemical volatiles with reported nematicidal activity were compared to traditional pesticides using specific parameters of environmental and human health safety available on applied online databases and predicted in silico through specialised software. Overall, the reviewed nematicidal phytochemicals were reportedly less toxic than synthetic nematicides. They were predicted to disperse to the air and soil environmental compartments and were reported to have a lower toxicity on aquatic organisms. On the contrary, the synthetic nematicides were reportedly toxic to aquatic organisms while showing a predicted high affinity to the water environmental compartment. As alternatives, β-keto or fatty acid derivatives, e.g., aliphatic alcohols or ketones, showed more adequate properties. This study highlights the importance of complementing studies on nematicidal activity with a risk assessment-based analysis to allow for a faster selection of nematicidal phytochemical volatiles and to leverage the development and implementation of bionematicides.

Efficacy of chemical and biological nematicides for the management of stem and bulb nematode, Ditylenchus dipsaci, in garlic

Efficacy of chemical and biological nematicides for the management of stem and bulb nematode, <i>Ditylenchus dipsaci</i>, in garlic

Plant-Parasitic Nematode Genera Associated with Turfgrass in Maryland Golf Courses and Athletic Fields.

Field surveys were conducted to assess the occurrence and diversity of plant-parasitic nematodes (PPNs) in golf courses and athletic fields across Maryland, USA, during 2022 and 2023. A total of 28 golf courses and ten athletic fields were surveyed, revealing the prevalence and abundance of 13 PPNs taxa in the region. Criconemoides was identified as the most prevalent (94.9%) and Tylenchorhynchus as the most abundant (2.3) across all samples. Central golf courses (west side of the Chesapeake Bay) exhibited a high prevalence of Criconemoides and Tylenchorhynchus, while Eastern Shore golf courses and athletic fields displayed a higher prevalence of Helicotylenchus and Criconemoides. Further, Belonolaimus longicaudatus was reported for the first time from turfgrass in Maryland, raising concerns due to its potential to cause severe damage on both cool- and warm-season turfgrass. Biodiversity analysis indicated that richness (R2) was higher in athletic fields, while diversity (H') and evenness (J') were significantly greater in golf courses. This study provides baseline information for monitoring PPNs distribution in Maryland and also for the development of effective nematode management approaches in turfgrass ecosystems.

Silencing of the T-type voltage-gated calcium channel α1 subunit by fungus-mediated RNAi altered the structure of F-actin and caused defective behaviors in Ditylenchus destructor.

T-type calcium channels, characterized as low-voltage activated (LVA) calcium channels, play crucial physiological roles across a wide range of tissues, including both the neuronal and nonneuronal systems. Using in situ hybridization and RNA interference (RNAi) techniques in vitro, we previously identified the tissue distribution and physiological function of the T-type calcium channel α1 subunit (DdCα1G) in the plant-parasitic nematode Ditylenchus destructor. To further characterize the functional role of DdCα1G, we employed a combination of immunohistochemistry and fungus-mediated RNAi and found that DdCα1G was clearly distributed in stylet-related tissue, oesophageal gland-related tissue, secretory-excretory duct-related tissue and male spicule-related tissue. Silencing DdCα1G led to impairments in the locomotion, feeding, reproductive ability and protein secretion of nematodes. To confirm the defects in behavior, we used phalloidin staining to examine muscle changes in DdCα1G-RNAi nematodes. Our observations demonstrated that defective behaviors are associated with related muscular atrophy. Our findings provide a deeper understanding of the physiological functions of T-type calcium channels in plant-parasitic nematodes. The T-type calcium channel can be considered a promising target for sustainable nematode management practices.

Management of Soybean Cyst Nematode and Sudden Death Syndrome with Nematode-Protectant Seed Treatments Across Multiple Environments in Soybean.

As soybean (Glycine max) production continues to expand in the United States and Canada, so do pathogens and pests that directly threaten soybean yield potential and economic returns for farmers. One such pathogen is the soybean cyst nematode (SCN; Heterodera glycines). SCN has traditionally been managed using SCN-resistant cultivars and rotation with nonhost crops, but the interaction of SCN with sudden death syndrome (SDS; caused by Fusarium virguliforme) in the field makes management more difficult. Nematode-protectant seed treatments have become options for SCN and SDS management. The objectives of this study were to evaluate nematode-protectant seed treatments for their effects on (i) early and full season SCN reproduction, (ii) foliar symptoms and root-rot caused by SDS, and (iii) soybean yield across environments accounting for the above factors. Using a standard protocol, field trials were implemented in 13 states and one Canadian province from 2019 to 2021 constituting 51 site-years. Six nematode-protectant seed treatment products were compared with a fungicide + insecticide base treatment and a nontreated check. Initial (at soybean planting) and final (at soybean harvest) SCN egg populations were enumerated, and SCN females were extracted from roots and counted at 30 to 35 days postplanting. Foliar disease index (FDX) and root rot caused by the SDS pathogen were evaluated, and yield data were collected for each plot. No seed treatment offered significant nematode control versus the nontreated check for in-season and full-season nematode response, no matter the initial SCN population or FDX level. Of all treatments, ILEVO (fluopyram) and Saltro (pydiflumetofen) provided more consistent increases in yield over the nontreated check in a broader range of SCN environments, even when FDX level was high.

Evaluation of Some New Nematicides for the Management of Reniform Nematode (Rotylenchulus reniformis) on tomato (Solanum lycopersicum L.)

Investigations were carried out to evaluate the efficacy of two nematicides viz., Nimitz®(Fluensulfone) and Velum Prime (Fluopyrum) for the management of Reniform nematode (R. reniformis) on tomato (var. Pusa Ruby) under net house condition. The plant growth parameters in tomato were found to be increased in the treatment with Nimitz® @2.5kg/ha followed by Carbofuran CG @3.0 kg a.i./ha, Velum Prime @1000 ml/ha, Nimitz® @2.00 kg/ha , and Velum Prime @750 ml/ha. The chemicals suppressed nematode reproduction as indicated by the lower nematode population and lower numbers of eggs on the roots as compared to control. The minimum populations of R. reniformis were recorded with the treatment Nimitz® @2.5kg/ha followed by Carbofuran CG @3.0 kg a.i./ha, Velum Prime @1000 ml/ha, Nimitz® @2.00 kg/ha , and Velum Prime @750 ml/ha.

Phytoparasitic Nematodes of Musa spp. with Emphasis on Sources of Genetic Resistance: A Systematic Review.

Bananas are a staple food that considerably contributes to both food security and income generation, especially in countries of Africa, Asia, and Central and South America. The banana plant (Musa spp.) is affected by various pathogens, of main concern being the plant-parasitic nematodes associated with the rhizosphere, the most important of which are Radopholus similis (burrowing nematode), Helicotylenchus sp. (spiral nematode), Pratylenchus sp. (root lesion nematode), and Meloidogyne sp. (gall nematode). Infected plants reduce their ability to absorb water and nutrients, which can lead to delayed flowering, fewer bunches, and lower fruit mass. Obtaining nematode-resistant banana cultivars through genetic improvement is an effective and sustainable option compared with chemical control with nematicides. Here, we provide the first systematic review of existing banana sources of resistance to nematodes to aid the management and control of nematodes in banana and plantain crops. Articles selected from different databases were evaluated, and searches were conducted using pre-established inclusion and exclusion criteria. We found 69 studies dealing with genetic improvement for nematode resistance in banana cultivation. Our findings revealed that sources of resistance are currently under investigation to combat the diseases caused by different nematode species in banana plants.