Number Of Plant-parasitic Nematodes Research Articles

SOME NEW RECORDS OF HELICOTYLENCHUS (STEINER, 1945) SPECIES FROM PAKISTAN (NEMATODA: HOPLOLAIMIDAE)

The detailed morphological and taxonomical studies revealed the presence of number of plant parasitic nematodes from grass (Cynodon dactylon L.) at different areas of University of Karachi. The genus Helicotylenchus was encountered with highest occurrence among other plant parasitic genera. In the present investigations, two known spiral nematode species viz. Helicotylenchus abuharazi Zeidan and Geraert, 1990 and Helicotylenchus wajihi Sultan, 1981 associated with grass were found as new records and were studied for their taxonomic descriptions. Brief redescription along with their measurements and illustrations are provided herein. These species were reported for the first time from Pakistan.

Evaluation The Effect of Intercropping Garlic with Grapevines on Productivity, Phytoremediation, Competitive Indices and Plant Parasitic Nematode Community تقييم تأثير تحميل الثوم مع العنب على الإنتاجية والمعالجة النباتية والعلاقات التنافسية ومجتمع النيماتودا المتطفلة على النبات

The present investigation was carried out during winter of the consecutive seasons (2018/2019 and 2019/2020) on 9 year old Flame Seedless grapevines grown in a private vineyard at Sharkia Governorate, Egypt. Garlic (Balady cv) was intercropped with grapevines (Flame Seedless cv) on dripper irrigation lines, as a try to reduce numbers of phytonematodes in grapevine soil. For grapevines, the obtained results referred that intercropping insignificantly (P≤0.05) increased number of berries/bunch, weight of 100 berries and berry firmness, separation force, total soluble solids percentage, anthocyanin content and yield/ vine as well as bunch weight and width, berry length, berry diameter and berry shape index compared to sole grapevines. For garlic (Balady cv), the achieved results pointed out that plant height, number of leaves/plant, leaf fresh weight/ plant, nick diameter as well as bulb diameter, height and weight/ plant insignificantly decreased when garlic intercropped with grapevines compared to control. Competition indices; i.e., land equivalent ratio (LER), area time equivalent ratio (ATER) and land utilization efficiency (LUE) showed that, intercropping garlic with grapevines was more efficient than sole cropping system. Aggressively estimation demonstrated that grapevines were dominant advantages while garlic was dominated. Moreover, intercropping garlic (Balady cv) with grapevines was obviously decreased population density of phytonematodes infesting grapevine orchard. Generally, garlic together with other biocontrol agents in grapevine orchards has the potential to be an efficient and environmentally agricultural management method to reduce numbers of plant parasitic nematodes.

Effect of Chemical Nematicides, Chicken Manure and Biocontrol Agents as a Control Method for Certain Plant Parasitic Nematodes Infecting Orchards under Field Conditions in Sharkia Governorate, Egypt

A field treatment was conducted to evaluate the nematicidal activity of chicken manure and biopesticides (bio- arc , bio-zeid and nemex) viz. chemical nematicides (fydal 24 % SL , tervigo (2% SC), laguna (40% EC) and nemathorin (10% G) against plant –parasitic nematodes infecting fruit orchard located in Sharkia Governorate during 2018. Treatments of chicken manure was at the rate of 30 Kg/ tree , while that of biopesticides were applied at rate of 160 g/tree with bio-arc and bio-zeid , whereas nemex was applied at rate of 24 mL/ tree. Chemical nematicides were applied at rates of 15 mL//tree , 50 g/ tree , 24 mL/tree and 12 mL with fydal 24 % SL, tervigo , laguna and nemathorin , respectively. Samples were taken monthly during three months after application. Results indicated that of the eight tested materials, fydal was the most effective in suppressing umbers of phytonematodes followed by chicken manure while among biopesticides , bio- arc was the least effective one. After one month of application, remarkable decreased in numbers of plant-parasitic nematodes was detected. For instance, in fydal and chicken manure treatments, percentages of reduction in numbers of Tylenchulus semipenetrans, Pratylenchus spp., Tylenchorhynchus spp., Hoplolaimus spp. and Helicotylenchus spp. were diminished by 49.75 %(40.92 %) ,56.97% (53.54%), 55.47% (55.83%), 50.53% (50.53%) and 52.52 % (50.42%), respectively. After two months of application, percentage of reduction was increased to reach 69.25 %(68.53%) ,81.26% (71.37%), 83.18% (80.08%), 86.92% (83.00%) and 81.77 % (61.93%), respectively for mentioned nematodes. On the other hand, after three months of application, no significant differences ) P ≤ 0.05) was noticed between fydal and chicken manure whereas, the biopesticides were the least effectiveness against plant –parasitic nematodes. Generally, results emphasized that chicken and biopesticides could be used to minimize the population density of plant- parasitic nematodes in citrus orchards.

Rootstocks for stone fruits in South Africa

Soil conditions in the stone fruit producing areas of South Africa are extremely varied. Many soils are poor, sandy and contain plant-parasitic nematodes. In the Little Karoo region, the soils are generally of medium potential, calcareous and contain moderate to high numbers of plant-parasitic nematodes. There are also low-lying areas in which high winter water tables may persist into spring. In combination with fluctuating temperatures, these conditions may cause tree die-back. Production under such conditions necessitates the use of rootstocks that can lower risks, promote adaptability, whilst complementing the scion cultivar. Knowledge concerning the characteristics of candidate rootstocks is obtained by continuously monitoring experimental plantings in representative areas. Results obtained from existing peach and plum trials are discussed. Early nectarines (Prunus persica) growing on poor sandy soils containing moderate numbers of plant-parasitic nematodes in low chill regions performed better on Flordaguard than on other potential rootstocks. In low-lying, ridged and adequately drained sandy soils, plum trees (Prunus salicina) performed well on Maridon. On high pH soils containing high numbers of Criconemoides xenoplax (ring nematode), plum trees performed best, in terms of yield and fruit weight, on GF 677, Atlas and Cadaman.

Evaluation of Selected Methods in the Control of Plant Parasitic Nematodes Infecting Carnation

Plant parasitic nematodes, whose control options are restricted, continue to cause enormous losses in crop production systems including carnations. This study was carried out with the aim of developing environmentally sound approaches for adoption in the management of phytonematodes affecting carnations. Various organic amendments were evaluated namely sugarcane bagasse, tea and assorted flower composts and molasses, in addition nematophagous fungus Paecilomyces lilacinus (PL plus®) and neem (Achook®). Meanwhile, a standard chemical nematicide, fenamiphos (Nemacur®), was used next to untreated plots were as control. The experiments were carried out under greenhouse conditions. Soil samples were collected before application of the amendments and at 90 and 180 days after treatment. Parasitic nematodes belonging to 16 genera were detected in plots where carnation had been produced under monoculture over several years. The most predominant of the nematodes detected were in the genera Scutellonema, Helicotylenchus and Meloidogyne, with 100, 82 and 100% frequencies of occurrence, respectively. Treatments effects caused a reduction in numbers of plant parasitic nematodes, with the exception of nematodes in the genera Helicotylenchus, Criconema and Longidorus. Galling due to root-knot nematode was reduced by between 53%, in plots treated with sugarcane bagasse, and 69% in those treated with neem. This study has established that application of organic substrates, neem and P. lilacinus reduced plant parasitic nematodes. The materials can be recommended for use in sustainable carnation production systems.

INNOVATIVE INTERCROPPING SYSTEM TO IMPROVE SOIL HEALTH IN ORGANIC GREENHOUSE CULTIVATION

INNOVATIVE INTERCROPPING SYSTEM TO IMPROVE SOIL HEALTH IN ORGANIC GREENHOUSE CULTIVATION

KEANEKARAGAMAN NEMATODA DALAM TANAH PADA BERBAGAI TIPE TATAGUNA LAHAN DI ASB-BENCHMARK AREA WAY KANAN

The soil nematode diversity in several land-use types in Way Kanan ASB-Benchmark Area. The conversion of forest to intensive agroecosystem such as monoculture system reduces biodiversity of the plant, herbivore, and decomposer subsystems. Those changes affected the litter and plant root quality. Consequently, few soil nematode species could be dominant and cause of disturbance of the stability of the below ground community. The increasing populations of plant parasitic nematodes usually occur on monoculture system . The research was conducted to study the effect of forest changes in several land use types on soil nematode diversity in Way Kanan Benchmark Area. Soil sampling on five land use types (secondary forest, agroforest or tree based agriculture, plantation, cassava field, and Imperata grass land) was conducted in November1996 and December 1997. Nematodes were extracted by decantation-centrifugation with sugar method. The soil nematodes were grouped into order and generic level including plant parasitic and non- parasitic. The results show that the order of Rhabditida, Dorylaimida, and Tylenchida were found from those five land-use types. The total genera of plant parasitic nematodes in Imperata grass land were the highest among the other four land use types. The total number of non-plant parasitic nematodes in secondary forest (28.0 individual per 300 cc of soil) was higher than total number in the plantation ( 2.6 individual per 300 cc of soil), cassava field (4.0 individual per 300 cc of soil) or Imperata grass land (6.6 individual per 300 cc of soil). The total number of plant parasitic nematodes in Imperata grass land (59.8 individual per 300 cc of soil), agroforest (59.0 individual per 300 cc of soil), secondary forest (48.2 individual per 300 cc of soil), and plantation (17.6 individual per 300 cc of soil) were not significantly different, but total number in Imperata grass land and agroforest were significantly higher than that in cassava field (11,6 individual per 300 cc of soil).

The effect of cover crops on plant parasitic-nematodes of sugarcane

Plant-parasitic nematodes cause significant yield losses to sugarcane crops in South Africa. The currently available chemicals for nematode control are both expensive and potentially detrimental to the environment. Various alternative crops have been reported to reduce the numbers of plant-parasitic nematodes. Mindful of this, we evaluated 27 cover crops in pot trials to assess their host status to important plant-parasitic nematodes of sugarcane. All of the crops tested in pots hosted significantly lower numbers of Pratylenchus than did sugarcane. Crops such as cowpeas, tomato and grazing vetch were good hosts for Meloidogyne and would not be good choices as part of a sugarcane rotation system in heavily-infested soils. Conversely, crops such as oats, wheat, forage peanuts and marigolds reduced numbers of Meloidogyne. Velvet beans increased the abundance of Helicotylenchus, a beneficial nematode genus. A field trial was also conducted to study the effect of different cover cropping sequences. Our results show that changes in nematode communities occurred within three months of growing these crops and often remained low for the duration (the remaining 15 months) of the crops' growth. Nematodes such as Pratylenchus and Tylenchorhynchus were significantly lowered and remained so for the duration of the trial.

Sampling for Plant-parasitic Nematodes in Corn Strip Trials Comparing Nematode Management Products

Protectant seed treatments are a new management option for plant-parasitic nematodes that feed on corn. Many growers and agribusiness personnel are conducting strip-trial comparisons of nematode seed treatments in growers' fields. Yield monitors in combines and weigh wagons can be used to collect yield data from multiple-row strips that stretch across an entire field. But some growers and agribusiness personnel also want to assess plant-parasitic nematode populations in these strip trials to gauge whether the seed treatments are affecting nematode population densities (numbers). Drawing conclusions about the effects of treatments on numbers of plant-parasitic nematodes in strip trials is problematic because of the natural variability of nematode populations and their densities in the field. This guide discusses various points to consider about collecting samples to assess possible effects of treatments on population densities of plant-parasitic nematodes in strip trials. Accepted for publication 15 July 2011. Published 1 September 2011.

The effect of two compost soil amendments, based on municipal green and penicillin production wastes, on plant parasitic nematodes

Abstract Suppressive effect of two composts, applied at five doses (0 %, 1 %, 2.5 %, 5 % and 10 % w/w), was studied on spring barley to control different genera of plant parasitic nematodes in potting mixtures. Amendment of soil with these materials resulted in a significant decreasing effect of plant parasitic nematode populations. The best reduction of number of plant parasitic nematodes was found for the nematode genera Bitylenchus, Helicotylenchus, Heterodera, Paratylenchus and Rotylenchulus by a municipal green compost (C1) and nematode genera Bitylenchus, Geocenamus, Helicotylenchus, and Rotylenchulus by a compost derived from penicillin production residues (C2). The compost C1 with a lower C:N ratio was more effective in the nematode control than the compost C2. The analysis of variance showed a significant interaction among all factors involved in the experiment: type of compost, different doses and nematode genera. Relationship between applied doses and number of nematodes showed a significantly high negative correlation.

Response of a soil nematode community to liquid hog manure and its acidification

A study was conducted to determine why the number of opportunistic bacterial-feeding nematodes increase following addition of liquid hog manure and acidified mixtures of the manure to soil. A sandy loam soil harboring a wide range of nematode taxa, representing various trophic and colonizer–persister groups (c–p 1 through 5) and augmented with the plant-parasitic nematode, Pratylenchus spp., was used in microcosm experiments. Treatments were additions of liquid hog manure (0.15 v v −1 soil water), mixtures of manure (0.05, 0.10, and 0.15 v v −1 soil water) and sulfuric acid, as well as a sulfuric acid alone and a non-treated control. Three days post-treatment and during the presence of non-ionized volatile fatty acids from manure in soil, numbers of plant-parasitic nematodes, including Pratylenchus spp., decreased by at least 50% for all manure treatments compared to non-manure treatments. Thereafter, c–p 1 and c–p 2 nematode numbers increased in all manure but not in non-manure treatments. At week 4, c–p 1 and c–p 2 nematode numbers were greater by at least 6000 and 5000 individuals kg −1 soil, respectively, compared to non-manure treatments. In contrast, numbers of c–p 3–5 nematodes were not affected by the treatments. At week 4, the enrichment index, an assessment of the abundance of opportunistic c–p 1 and some c–p 2 nematodes compared to all c–p 2 nematodes, was around 70% for all manure treatments and lower, 32 and 29, respectively, for acid alone and non-treated control treatments. The increase in opportunistic nematodes following manure treatment was likely due to the increase in their food resources associated with the enrichment of the soil environment with readily degradable compounds. Volatile fatty acids present in the manure persisted in the soil for only four days before biological degradation. We conclude liquid hog manure is effective in killing plant-parasitic nematodes while increasing bottom-up food web interactions but not, as with soil fumigants, decimating top-down trophic interactions.

Plant Parasitic Nematodes Associated with Olea europea L. Fauna of Turkey

Abstract The olive (Olea europea L.) is characteristic of the culture in the Mediterranean region. Its origins are Anatolian in Turkey and neighboring Syria. Olive trees serve as host to a fairly high number of plant parasitic nematodes in the Mediterranean countries. Several of these nematodes are sedentary endoparasitic forms, which are recognized as pathogens to olives. In this study, records of plant parasitic nematodes associated with olive in Turkey were examined faunistically and taxominically. The records were compiled to create a current record of these fauna of plant parasitic nematodes of olive in Turkey. Their biology, distribution and associated host plants were described. This fauna consists of 19 Tylenchida plant parasitic nematode species. Since Turkish records are scant and poorly documented, this study documents the most current list of these important species.

Differential effects of raw and composted manure on nematode community, and its indicative value for soil microbial, physical and chemical properties

The impacts of two organic soil amendments on nematode abundance, community structure and soil characteristics were studied in field grown tomatoes. We hypothesized that as the raw (labile form) and composted (non-labile form) manures differ in their chemical composition and effect on microbial activity. Also they will have different effects on soil properties and directly and indirectly affect nematode community structure. Experiments were conducted during 2001–2002 in Wooster, Ohio on a silt loam soil. Treatments [raw or composted dairy cow manure in 2001 and beef calf manure in 2002, and an untreated control] were arranged in a randomized complete block design. Amendments were applied in the spring at a rate estimated to deliver 95–100 kg N ha −1, and incorporated prior to planting. Soil samples were collected in the spring (before adding amendments) and autumn (after crop harvest) to determine nematode abundance, community structure and soil characteristics: Shannon–Weiner ( H′), Simpson ( λ), Pielou ( J′) and combined maturity indices were used to compare nematode community structure in amended and non-amended plots. Spring incorporation of both organic amendments increased the abundance of bacterial feeding, fungal feeding, omnivorous and predatory nematodes, but decreased plant parasitic nematode populations. Plots treated with raw manure had the lowest number of plant parasitic nematodes while increases in non-plant parasitic nematodes were similar in both treatments. Shannon diversity ( H′) and combined maturity (∑MI) indices of soil nematodes were reduced in plots receiving raw but not composted manure. Application of raw manure increased total organic matter, microbial biomass-N, potentially mineralizable-N and C over composted manure in 2001, while both raw and composted manure increased particulate organic matter in both years. The effect of raw and composted manure on community indices was different in 2001 and 2002. We found a strong negative relationship ( r = −82, p < 0.0001) between the abundance of non-plant parasitic and plant parasitic nematodes across all treatments and sampling times, thus supporting the utility of the ratio between non-plant parasitic and plant parasitic nematodes as a useful soil quality indicator.

Note: Effect of neem and organic amendments on nematode populations in a coastal savanna tropical soil

Nematode numbers were assessed at 2-week intervals in a coastal savanna soil amended with neem leaves and animal manure for 12 weeks under fallow conditions. The number of plant-parasitic nematodes decreased significantly with the application of the neem-based amendments, whereas the number of non-parasitic nematodes increased.

Crop Damage by Nematodes in Improved-fallow Fields in Western Kenya

The rotation of leguminous shrubs and crops is being tested on farms and recommended as a means of improving soil fertility and increasing crop yield in eastern and southern Africa, including western Kenya. However, this improved fallow practice may also increase the nematode population in the soil. An experiment was conducted to monitor the effects of plant-parasitic nematodes on crops after improved fallow. Soil was collected from a maize (Zea mays L.)/bean (Phaseolus vulgaris L.) field, a natural fallow, a Crotalaria (Crotalaria grahamiana Wight & Arn.) fallow, a Tephrosia (Tephrosia vogelii Hook. f.) fallow and a Crotalaria — Tephrosia mixed fallow and used to fill plastic pots placed in a shade. Three successive crop cycles of 2 months were tested in these pots using maize and beans, the most important staple foods in western Kenya. In the first cycle, beans grew poorly on the Tephrosia and Crotalaria — Tephrosia soil due to the high incidence of root knot nematodes, Meloidogyne spp., while maize did not suffer any loss. Although the populations of root knot nematodes reduced drastically in the second and third cycles, both maize and beans experienced heavy losses on the soil under improved fallow probably due to the spiral nematodes, Scutellonema spp., which became dominant in the nematode communities. Despite the use of fertilisers (N, P, K), both crops became highly sensitive to spiral nematodes in the third cycle because of the degradation of the soil physical properties. The study showed that the benefits of improved fallows in terms of crop production may be limited by the high number of plant-parasitic nematodes they help develop in the process.

PARASITIC NEMATODES ASSOCIATED WITH OLIVE IN COUNTRIES BORDERING THE MEDITERRANEAN SEA

PARASITIC NEMATODES ASSOCIATED WITH OLIVE IN COUNTRIES BORDERING THE MEDITERRANEAN SEA

Do plant parasitic nematodes have differential effects on the productivity of a fast- and a slow-growing grass species?

We have examined the interaction between plant parasitic nematodes and plant species from different stages of grassland succession. In these grasslands, fertiliser application was stopped in order to restore the former nutrient-poor ecosystems. This management resulted in a reversed succession of high- to low-productivity. Nematodes isolated from a high-productive early-successional field and a low-productive late-successional field were inoculated to sterilised soil planted with seedlings of either Lolium perenne (a fast-growing early-successional species) or Festuca rubra (a slow-growing late-successional species). The experiment was performed at low and high supply rates of nutrients. We hypothesised that at a low nutrient supply rate the growth of L. perenne will be more reduced by nematode herbivory than the growth of F. rubra. Furthermore, we hypothesised that higher numbers of plant parasitic nematodes will develop under L. perenne. We found no support for our first hypothesis, because nematodes did not affect plant growth. Our results suggest that changes in the nutrient availability rather than plant parasitic nematodes affect plant succession in impoverished grasslands. On the other hand, plant species and nutrient supply rate significantly affected the density and composition of the plant parasitic nematode community. In line with our second hypothesis, plant parasitic nematodes reproduced better on the fast-growing L. perenne than on the slow-growing F. rubra. Our results, therefore, suggest that the succession of the plant parasitic nematode community is probably more affected by changes in the plant community than the other way round.

A survey of the plant parasitic nematodes associated withPinus patulain selected plantations in the Eastern Cape Province

SYNOPSIS During November 1997 a plant parasitic nematode survey was conducted in the plantations of the North East Cape Forests (NECF), situated between Maclear and Ugie in the Eastern Cape Province, South Africa. No plant parasitic nematodes were found in the wood samples from Pinus patula trees. The genera Helicotylenchus, Rotylenchus, Meloidogyne, Paratrichodorus, Pratylenchus and Xiphinema, found among the roots of declining Pinus patula trees in the present survey, have also been associated with declining pine trees in other parts of the world. In the present survey the mean number of plant parasitic nematodes in the root zones of declining trees were about 271 per 250 cm3. High numbers of plant parasitic nematodes were found in natural veld and old maize fields, suggesting that they might have an adverse effect on pine seedlings when they are planted in these soils. Although further surveys and pathogenicity tests are needed, the results of the present survey strongly suggest that plant parasitic nematodes, whether in disease complexes or not, are a problem in Pinus patula plantations in the area studied.

Effects of three microbial broth cultures and an organic amendment on growth and populations of free living and plant-parasitic nematodes on banana

The effect of 24 treatment combinations of cultures of Streptomyces costaricanus sp. nov. (ATCC55274), Bacillus thuringiensis (ATCC55273) and a strain of Paecilomyces marquandii, nematicide (cadusaphos), and/or wheat mash on growth and response of potted banana plants (Musa AAA) and populations of Radopholus similis, Helicotylenchus multicinctus and free living nematodes were studied in Rio Frio, Costa Rica. The best plant responses (height, leaf numbers, healthy root weight), lowest numbers of plant parasitic nematodes and highest numbers of free living nematodes were observed for treatments containing wheat as a component. Two treatments, viz. wheat + Streptomyces costaricanus (200-ml culture) and wheat + P. marquandii (200-ml culture), gave the overall best results. Numbers of free living nematodes increased up to 1500-fold only for treatments containing wheat. Significant positive correlations existed between numbers of free living nematodes and shoot weight, healthy root biomass, plant height, and leaf numbers. Non-wheat treatments, including nematicide only, gave the poorest responses in general. Observations of nematodes sampled 50 days following planting in wheat-containing treatments showed most of the free-living nematodes (≈ 90%) to be infected by nematophagous fungi (species not recorded). The results show that an organic amendment to soil, with or without a microbial component, can be an effective inducer of processes that regulate plant-parasitic nematode populations in soil.

Harmful soil organisms in coastal foredunes involved in degeneration of Ammophila arenaria and Calammophila baltica

The presence of harmful soil organisms in the root zone of Ammophila arenaria (marram grass) was examined by biotesting. For this investigation three locations along the sandy shoreline of The Netherlands were chosen: Voorne, Texel, and Schouwen. At all three locations harmful organisms were detected in sand from stable dunes, as well as in sand from mobile dunes (degenerated and vigorous A. arenaria, respectively). In beach sand, however, no harmful organisms occurred. Since A. arenaria shows vigorous growth only when it is buried regularly by windblown sand from the beach, it is concluded that this sand deposition enables the plants to escape from harmful soil organisms. Ammophila arenaria and Calammophila baltica (purple or hybrid marram grass) from the Voorne location were grown outdoors in containers filled with sand from the beach, the mobile dunes, and the stable dunes, and sterilized sand from the stable dunes. Biomass production of both species was highest in sterilized sand from the stable dune, followed by (in descending order) beach sand, sand from the mobile dune, and unsterilized sand from the stable dune. As compared with A. arenaria, however, growth of C. baltica was reduced less and without mortality of cuttings. Degree of growth reduction by harmful soil organisms could not be related to numbers of plant parasitic nematodes. Key words: Ammophila arenaria, Calammophila baltica, coastal sand dunes, succession, harmful soil organisms.