Diversity and population densities of plant-parasitic nematodes in commercial and smallholder pineapple production in Kenya

Nematology ◽  
2021 ◽  
pp. 1-14
Author(s):  
Agnes W. Kiriga ◽  
Danny Coyne ◽  
Janet G. Atandi ◽  
Nikolai V. Beek ◽  
Solveig Haukeland
Keyword(s):  
Management Practices ◽  
Crop Yields ◽  
Production Systems ◽  
Ananas Comosus ◽  
Parasitic Nematodes ◽  
Yield Reduction ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
High Level ◽  
Plant Parasitic

Summary Plant-parasitic nematodes (PPN) cause significant yield reduction in commercial pineapple (Ananas comosus) worldwide. In Kenya, few nematode studies have been conducted, although the main commercial pineapple producer has sole dispensation to use Telone II (1,3-Dichloropropene) indicating the magnitude of the nematode problem. This study was conducted with the aim to investigate the population densities and diversity of nematodes in two commercial plantations with two contrasting management practices. We additionally assessed the influence of crop age and compared this with nearby smallholder pineapple production systems. Soil and root samples were collected from fields of different ages in each commercial plantation and from 29 smallholder fields. A total of 18 genera were associated with pineapple, with a relatively greater diversity found in smallholder than commercial farms. The most prevalent genus was Meloidogyne spp. (M. javanica) followed by Helicotylenchus spp., Tylenchus spp. and Aphelenchoides spp. PPN densities were higher in relatively older fields of 24 and 36 months than from fallow and 3-month-old fields. Regression analysis additionally demonstrated the rise of PPN densities with age of pineapple fields, especially Meloidogyne spp., while free-living nematode densities declined. This study provides an indication of the high level of PPN infection in pineapple in Kenya, which would constitute an important factor contributing to low yields. The study confirms an obvious need for pineapple producers to control PPN to improve crop yields.

The role of plant-parasitic nematodes in reducing yield of sugarcane in fine-textured soils in Queensland, Australia

2007 ◽  
Vol 47 (5) ◽  
pp. 620 ◽  
Author(s):  
B. L. Blair ◽  
G. R. Stirling
Keyword(s):  
Growth And Yield ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Root Knot Nematode ◽  
Population Densities ◽  
Lesion Nematode ◽  
Yield Responses ◽  
The Impact ◽  
Stalk Length ◽  
Plant Parasitic

Damage to sugarcane caused by root-knot nematode (Meloidogyne spp.) is well documented in infertile coarse-textured soils, but crop losses have never been assessed in the fine-textured soils on which more than 95% of Australia’s sugarcane is grown. The impact of nematodes in these more fertile soils was assessed by repeatedly applying nematicides (aldicarb and fenamiphos) to plant and ratoon crops in 16 fields, and measuring their effects on nematode populations, sugarcane growth and yield. In untreated plant crops, mid-season population densities of lesion nematode (Pratylenchus zeae), root-knot nematode (M. javanica), stunt nematode (Tylenchorhynchus annulatus), spiral nematode (Helicotylenchus dihystera) and stubby-root nematode (Paratrichodorus minor) averaged 1065, 214, 535, 217 and 103 nematodes/200 mL soil, respectively. Lower mean nematode population densities were recorded in the first ratoon, particularly for root-knot nematode. Nematicides reduced populations of lesion nematode by 66–99% in both plant and ratoon crops, but control of root-knot nematode was inconsistent, particularly in ratoons. Nematicide treatment had a greater impact on shoot and stalk length than on shoot and stalk number. The entire community of pest nematodes appeared to be contributing to lost productivity, but stalk length and final yield responses correlated most consistently with the number of lesion nematodes controlled. Fine roots in nematicide-treated plots were healthier and more numerous than in untreated plots, and this was indicative of the reduced impact of lesion nematode. Yield responses averaged 15.3% in plant crops and 11.6% in ratoons, indicating that nematodes are subtle but significant pests of sugarcane in fine-textured soils. On the basis of these results, plant-parasitic nematodes are conservatively estimated to cost the Australian sugar industry about AU$82 million/annum.

scholarly journals Optimizing Safe Approaches to Manage Plant-Parasitic Nematodes

Plants ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1911
Author(s):  
Mahfouz M. M. Abd-Elgawad
Keyword(s):  
Crop Yields ◽  
Abiotic Factors ◽  
Alternative Methods ◽  
Soil Microbiome ◽  
Parasitic Nematodes ◽  
Control Mechanisms ◽  
Plant Parasitic Nematodes ◽  
Safe Alternative ◽  
Microbial Groups ◽  
Plant Parasitic

Plant-parasitic nematodes (PPNs) infect and cause substantial yield losses of many foods, feed, and fiber crops. Increasing concern over chemical nematicides has increased interest in safe alternative methods to minimize these losses. This review focuses on the use and potential of current methods such as biologicals, botanicals, non-host crops, and related rotations, as well as modern techniques against PPNs in sustainable agroecosystems. To evaluate their potential for control, this review offers overviews of their interactions with other biotic and abiotic factors from the standpoint of PPN management. The positive or negative roles of specific production practices are assessed in the context of integrated pest management. Examples are given to reinforce PPN control and increase crop yields via dual-purpose, sequential, and co-application of agricultural inputs. The involved PPN control mechanisms were reviewed with suggestions to optimize their gains. Using the biologicals would preferably be backed by agricultural conservation practices to face issues related to their reliability, inconsistency, and slow activity against PPNs. These practices may comprise offering supplementary resources, such as adequate organic matter, enhancing their habitat quality via specific soil amendments, and reducing or avoiding negative influences of pesticides. Soil microbiome and planted genotypes should be manipulated in specific nematode-suppressive soils to conserve native biologicals that serve to control PPNs. Culture-dependent techniques may be expanded to use promising microbial groups of the suppressive soils to recycle in their host populations. Other modern techniques for PPN control are discussed to maximize their efficient use.

Occurrence and importance of plant-parasitic nematodes in organic farming in Germany

Nematology ◽  
2007 ◽  
Vol 9 (6) ◽  
pp. 869-879 ◽  
Author(s):  
Andrea Frankenberg ◽  
Andreas Paffrath ◽  
Johannes Hallmann ◽  
Harald Schmidt
Keyword(s):  
Organic Farming ◽  
High Frequency ◽  
Production Systems ◽  
Parasitic Nematodes ◽  
Yield Losses ◽  
Plant Parasitic Nematodes ◽  
Severe Damage ◽  
Production Factors ◽  
Main Emphasis ◽  
Plant Parasitic

AbstractIn an attempt to evaluate the occurrence and economic importance of plant-parasitic nematodes in organic farming in Germany, a survey was conducted with the main emphasis on vegetable and cereal production systems. For vegetables, the survey included quantification and identification of plant-parasitic nematodes in soil samples and a questionnaire for growers querying production factors and damage levels. For cereals, the survey focused on quantification and identification of plant-parasitic nematodes in soil and plant samples. Overall, Pratylenchus and Tylenchorhynchus were the most prominent nematode genera under both production systems with an incidence of over 90% of the samples. Meloidogyne was detected in 51% of the samples in both systems. Other nematode genera showed differences between the two production systems. In production systems with a high frequency of vegetables, Paratylenchus was detected in 56% of the samples and Heterodera in 15%, whereas in rotations with a high cropping frequency of cereals, incidences of plant-parasitic nematodes were 56% for Heterodera, 47% for Trichodorus and 45% for Paratylenchus. Yield losses could exceed 50% on carrots, onions and cereals and were most pronounced on sandy soils. In many cases, nematode problems started 5 to 10 years after conversion to organic farming. The survey indicated that plant-parasitic nematodes are widely spread in organic farming in Germany and can cause severe damage which may result in complete loss of the crop.

scholarly journals Incidence, Population Density, and Spatial Heterogeneity of Plant-Parasitic Nematodes in Corn Fields in Ohio

Plant Disease ◽  
2018 ◽  
Vol 102 (12) ◽  
pp. 2453-2464 ◽  
Author(s):  
Abasola C. M. Simon ◽  
Horacio D. Lopez-Nicora ◽  
Laura E. Lindsey ◽  
Terry L. Niblack ◽  
Pierce A. Paul
Keyword(s):  
Population Density ◽  
Spatial Scales ◽  
Management Strategies ◽  
Parasitic Nematodes ◽  
Growth Stages ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Sampling Protocols ◽  
Corn Fields ◽  
Plant Parasitic

Soil samples were collected from 425 corn fields in 28 Ohio counties between growth stages V3 and V6 during the 2013 and 2014 growing seasons. Ten morphological groups of plant-parasitic nematodes, namely spiral, lesion, lance, dagger, stunt, pin, ring, stubby-root, cyst, and “tylenchids” (several genera morphologically similar to members of the subfamily Tylenchinae [NCBI Taxonomy] including Cephelenchus, Filenchus, Malenchus, and Tylenchus) were identified. Eight species belonging to six of these groups were characterized. Spiral, tylenchids, lesion, pin, lance, stunt, and dagger nematodes were detected in 94, 96, 80, 57, 48, 48, and 37% of the fields, respectively, whereas the stubby-root, cyst, and ring nematodes were present in fewer than 14% of the samples. Averaged across fields, the spiral, tylenchids, and pin nematodes had the highest mean population densities. For all groups, incidence and population density varied among counties, and in some cases, among soil regions and cropping practices. Both population parameters were heterogeneous at multiple spatial scales, with the lowest heterogeneity among soil regions and the highest among fields within county and soil region. Estimated variances at the soil region level were not significantly different from zero for most of the nematodes evaluated. Stunt and lance were two of the most variable groups at all tested spatial scales. In general, the population densities were significantly more heterogeneous at the field level than at the county level. Findings from this study will be useful for developing sampling protocols and establishing on-farm trials to estimate losses and evaluate nematode management strategies.

scholarly journals Survey of Plant-Parasitic Nematodes in Kansas and Eastern Colorado Wheat Fields

2014 ◽  
Vol 15 (3) ◽  
pp. 112-117 ◽  
Author(s):  
T. C. Todd ◽  
J. A. Appel ◽  
J. Vogel ◽  
N. A. Tisserat
Keyword(s):  
Great Plains ◽  
Yield Loss ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Economic Thresholds ◽  
Lesion Nematodes ◽  
Maximum Root ◽  
Root Lesion Nematodes ◽  
Plant Parasitic

Observations on the prevalence and abundance of plant-parasitic nematodes were made from soil and root samples collected from 2,640 wheat fields in Kansas and Colorado during 2007-2010. Stunt nematodes (predominately Merlinius brevidens and Quinisulcius acutus), root-lesion nematodes (predominately Pratylenchus neglectus), and pin nematodes (Paratylenchus projectus) were the most commonly encountered taxa. Maximum soil population densities of 6,520 and 1,880 nematodes/100 cm3 soil were observed for pin and stunt nematodes, respectively, while a maximum root population density of 90,309 nematodes/g dry root was observed for root-lesion nematodes. Lower nematode densities were associated with wheat following corn, grain sorghum, or soybean for pin and stunt nematodes, and with wheat following fallow for root-lesion nematodes. Based on the results of this survey, 6% and 8% of wheat acreage in the central Great Plains are estimated to be at risk for significant (>5%) yield loss due to stunt nematodes and root-lesion nematodes, respectively. The number of fields with high population densities of both stunt and root-lesion nematodes was negligible (1%); therefore, the total wheat acreage with nematode populations above provisional economic thresholds is estimated to be ∼13%. Damage relationships with greater accuracy, precision, and relevance are necessary to establish reliable yield loss estimates for this region. 3 June 2014. 11 August 2014.

Prevalence of plant parasitic nematodes associated with rice in Ghana with a discussion of their importance

Nematology ◽  
1999 ◽  
Vol 1 (4) ◽  
pp. 399-405
Author(s):  
Daniel L. Coyne ◽  
Richard A. Plowright ◽  
Joe Twumasi ◽  
David J. Hunt
Keyword(s):  
Nematode Species ◽  
Lowland Rice ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Forest Zone ◽  
Agroecological Zones ◽  
Rice Ecosystems ◽  
Savannah Zone ◽  
Plant Parasitic

Abstract A survey of plant parasitic nematodes of rice was made in Ghana between 1994-1997. Fifty-one species in 29 genera were found in 145 fields from upland, hydromorphic, rainfed lowland and irrigated lowland ecosystems in the savannah and forest agroecological zones. Eighteen species were endoparasites of roots. In upland/hydromorphic rice fields in the savannah zone Pratylenchus spp. (80% of fields) and an undescribed species of Ditylenchus (78%) were most prevalent, whilst Coslenchus franklinae (84%) and Helicotylenchus spp. (76%) were most prevalent in the forest zone fields. Maximum population densities encountered were 960 C. franklinae per 100 ml soil and 700 Ditylenchus n. sp. per g root. In the savannah zone Hirschmanniella spp. (100%) were more prevalent than other nematodes in lowland rice, but in the forest zone Xiphinema bergeri (71%) was the most prevalent nematode in lowland rice. Occurrence of nematode species was different in different agroecological zones and rice ecosystems. There was no relationship between rice plant height and nematode population densities in crops close to harvest time in upland/hydromorphic fields in the savannah zone. Predominance des nematodes phytoparasites sur le riz au Ghana et discussion sur leur importance - Une prospection concernant les nematodes associes au riz a ete effectuee au Ghana de 1994 a 1997. Cinquante-et-une especes appartenant a 29 genres ont ete trouvees dans 145 rizieres de plateau, de bas-fonds, pluviales ou irriguees, tant en savane que dans des zones agroecologiques forestieres. Dix-huit especes sont des endoparasites racinaires. Dans les rizieres de plateau ou de bas-fonds en zone de savane Pratylenchus spp. (80% des rizieres) et une espece non encore decrite de Ditylenchus (78%) sont les plus abondants, tandis que Coslenchus franklinae (84%) et Helicotylenchus spp. (78%) le sont dans les rizieres de zone forestiere. Les densites maximales de population observees concernent C. franklinae (960 per 100 cm3 de sol) et Ditylenchus n. sp. (700 per 1 g de racines). Hirschmanniella spp. etaient plus abondants (100 %) que les autres nematodes dans les rizieres de bas-fonds de savane, tandis c'etait Xiphinema bergeri (71%) dans ce meme type de rizieres en zones forestieres. La presence des differentes especes de nematodes varie suivant la zone agroecologique et l'ecosysteme de la riziere. Il n'y a pas de relation entre la hauteur des plants de riz et la densite des populations de nematodes pour des cultures proches de la recolte dans les rizieres de plateau ou de bas-fonds situees en savane.

scholarly journals Plant-Parasitic Nematodes Are Potential Pathogens of Miscanthus × giganteus and Panicum virgatum Used for Biofuels

Plant Disease ◽  
2011 ◽  
Vol 95 (4) ◽  
pp. 413-418 ◽  
Author(s):  
Tesfamariam Mekete ◽  
Kimberly Reynolds ◽  
Horacio D. Lopez-Nicora ◽  
Michael E. Gray ◽  
Terry L. Niblack
Keyword(s):  
Panicum Virgatum ◽  
Damage Threshold ◽  
Threshold Value ◽  
Nematode Species ◽  
Soil Samples ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Miscanthus Giganteus ◽  
Plant Parasitic

A survey of Miscanthus × giganteus and switchgrass plots throughout the midwestern and southeastern United States was conducted to determine the occurrence and distribution of plant-parasitic nematodes associated with these biofuel crops. During 2008, rhizosphere soil samples were collected from 24 Miscanthus × giganteus and 38 switchgrass plots in South Dakota, Iowa, and Illinois. Additional samples were collected from 11 Miscanthus × giganteus and 10 switchgrass plots in Illinois, Kentucky, Georgia, and Tennessee the following year. The 11 dominant genera recovered from the samples were Pratylenchus, Helicotylenchus, Xiphinema, Longidorus, Heterodera, Hoplolaimus, Tylenchorhynchus, Criconemella, Paratrichodorus, Hemicriconemoides, and Paratylenchus. Populations of Helicotylenchus, Xiphinema, and Pratylenchus were common and recorded in 90.5, 83.8, and 91.9% of the soil samples from Miscanthus × giganteus, respectively, and in 91.6, 75, and 83.3% of the soil samples from switchgrass, respectively. Prominence value (PV) (PV = population density × √frequency of occurrence/10) was calculated for the nematodes identified. Helicotylenchus had the highest PV (PV = 384) and was followed by Xiphinema (PV = 152) and Pratylenchus (PV = 72). Several of the nematode species associated with the two biofuels crops were plant parasites. Of these, Pratylenchus penetrans, P. scribneri, P. crenatus, Helicotylenchus pseudorobustus, Hoplolaimus galeatus, X. americanum, and X. rivesi are potentially the most damaging pests to Miscanthus × giganteus and switchgrass. Due to a lack of information, the damaging population thresholds of plant-parasitic nematodes to Miscanthus × giganteus and switchgrass are currently unknown. However, damage threshold value ranges have been reported for other monocotyledon hosts. If these damage threshold value ranges are any indication of the population densities required to impact Miscanthus × giganteus and switchgrass, then every state surveyed has potential for yield losses due to plant-parasitic nematodes. Specifically, Helicotylenchus, Xiphinema, Pratylenchus, Hoplolaimus, Tylenchorhynchus, Criconemella, and Longidorus spp. were all found to have population densities within or above the threshold value ranges reported for other monocotyledon hosts.

scholarly journals Frequencies and population densities of plant-parasitic nematodes on banana (Musa AAA) plantations in Ecuador from 2008 to 2014

2016 ◽  
Vol 34 (1) ◽  
pp. 61-73 ◽  
Author(s):  
Orlando Aguirre ◽  
César Chávez ◽  
Alejandro Giraud ◽  
Mario Araya
Keyword(s):  
Parasitic Nematodes ◽  
Radopholus Similis ◽  
Plant Parasitic Nematodes ◽  
Absolute Frequency ◽  
Santo Domingo ◽  
Economic Threshold ◽  
Population Densities ◽  
Meloidogyne Spp ◽  
Mesh Sieve ◽  
Plant Parasitic

An analysis of the plant-parasitic nematodes found on the banana (Musa AAA) plantations in the provinces of Cañar, El Oro, Guayas, Los Rios and Santo Domingo of Ecuador from 2008 to 2014 was carried out. The nematode extraction was done from 25 g of fresh roots that were macerated in a blender and from which nematodes were recovered in a 0.025 mm (No 500) mesh sieve. The data were subjected to frequency analysis in PC-SAS and the absolute frequency was calculated for each individual genus. Four plant parasitic nematodes were detected and, based on their frequencies and population densities, the nematode genera in decreasing order was: Radopholus similis > Helicotylenchus spp. > Meloidogyne spp. > Pratylenchus spp. Radopholus similis was the most abundant nematode, accounting for 49 to 66% of the overall root population, followed by Helicotylenchus spp. with 29 to 45% of the population through- out the different analyzed years. From a total of 13,773 root samples, 96% contained R. similis, 91% Helicotylenchus spp., 35% Meloidogyne spp., and 25% Pratylenchus spp. and, when all of the nematodes that were present were pooled (total nematodes), 99.9% of the samples had nematodes. A large number of samples with a nematode population above the economic threshold suggested by Agrocalidad, INIAP and Anemagro (2,500-3,000 nematodes/100 g of roots) was observed in all of the years, the months and the five sampled provinces. The statistical differences (P<0.0001) detected for the nematode frequencies among the years, months and provinces, more than likely, were associated with the high number of samples included in each year, month and province because the variations in the frequencies for each nematode genus were small.

scholarly journals Plant-Parasitic Nematodes Infecting Grapevine in Southern Spain and Susceptible Reaction to Root-Knot Nematodes of Rootstocks Reported as Moderately Resistant

Plant Disease ◽  
2007 ◽  
Vol 91 (9) ◽  
pp. 1147-1154 ◽  
Author(s):  
Daniel Téliz ◽  
Blanca B. Landa ◽  
Hava F. Rapoport ◽  
Fernando Pérez Camacho ◽  
Rafael M. Jiménez-Díaz ◽  
...  
Keyword(s):  
Vascular System ◽  
Southern Spain ◽  
Parasitic Nematodes ◽  
Histopathological Study ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Root Knot Nematodes ◽  
Meloidogyne Spp ◽  
Plant Parasitic ◽  
Susceptible Response

Incidence and nematode population densities of plant-parasitic nematodes were determined in 64 samples of soil and grapevine roots collected from commercial vineyards in southern Spain between October 2003 and May 2005. In addition, a histopathological study was done of root-stock roots naturally infected by root-knot nematodes (Meloidogyne spp.). Nematodes infecting the rootstocks were identified according to conventional procedures, and the Meloidogyne spp. were furthermore identified by sequence characterized amplified region-polymerase chain reaction (SCAR-PCR) and isozyme esterase analyses. The most important plant-parasitic nematodes detected, in order of decreasing frequency of total soil infestation and root infection (percentage of samples), were Mesocriconema xenoplax (34.4%), Meloidogyne incognita (26.6%), Meloidogyne javanica (14.1%), Xiphinema index (12.5%), Xiphinema italiae (10.9%), Pratylenchus vulnus (6.3%), and Meloidogyne arenaria (1.6%). No disease symptoms were observed on aboveground plant parts of the infected grapevines, except for plants in some fields where soil was infested with the virus-vector nematodes X. index and X. italiae. Those grapevines showed a yellow mosaic pattern in leaves early in the growing season and the internode shortening characteristic of infections by Grapevine fanleaf virus. Rootstocks infected by root-knot nematodes (Meloidogyne spp.) showed distorted feeder roots and large- to moderate-sized root galls, present either singly or in clusters. Histopathology of galled roots showed a typical susceptible response to infection by root-knot nematodes: cellular alterations were induced in the cortex, endodermis, pericycle, and vascular system, including giant-cell formation and severe distortion of vascular tissues. Most Meloidogyne egg masses ocurred on the surface of the galled root tissues, a position that could facilitate dispersion of the nematode eggs and juveniles and the occurrence of secondary infections. Some of the grapevine rootstocks surveyed in this study (Paulsen 1103, Richter 110, Rupestris du Lot, and SO4) had previously been reported to be resistant to Meloidogyne spp.; however, the population densities of these nematodes found in soil and roots sampled in the present study, as well as the compatible host-parasite relationship revealed by histopathology, indicate a susceptible response to Meloidogyne spp. from southern Spain.

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