Vertical and horizontal distribution of and soil sampling for root lesion nematodes (Pratylenchus neglectus and P. thornei) in South Australia

1998 ◽  
Vol 27 (2) ◽  
pp. 90 ◽  
Author(s):  
S.P. Taylor ◽  
M.L. Evans
Keyword(s):  
South Australia ◽  
Horizontal Distribution ◽  
Soil Sampling ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Vertical And Horizontal Distribution ◽  
Root Lesion Nematodes

Relationship between root lesion nematodes (Pratylenchus neglectus and P. thornei) and performance of wheat varieties

1998 ◽  
Vol 38 (2) ◽  
pp. 181 ◽  
Author(s):  
V. A. Vanstone ◽  
A. J. Rathjen ◽  
A. H. Ware ◽  
R. D. Wheeler
Keyword(s):  
Wheat Yield ◽  
South Australia ◽  
Nematode Species ◽  
Significant Negative Correlation ◽  
Limiting Factors ◽  
Wheat Varieties ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes ◽  
The Relationship

Summary. The root lesion nematodes Pratylenchus neglectus andP. thornei occur throughout the cereal cropping areas of South Australia. In 1996, field trials on the Eyre Peninsula of South Australia were assessed to determine the relationship between density of nematodes within field plots in early October and harvested grain yield of 9 wheat varieties. The Pratylenchus species present was either P. neglectus (at Streaky Bay, Minnipa and Kalanbi) or P. thornei (at Nunjikompita). Absence of other major yield limiting factors at these sites in 1996 enabled determination of the relationship between nematode population and wheat yield. There was a significant, negative correlation between mean yield and nematode populations for the 9 varieties at 3 of the sites (P<0.01 for Streaky Bay and Nunjikompita; P<0.05 for Minnipa). Root lesion nematodes were responsible for 56–74% of the observed varietal differences in yield at these sites. The tolerant variety Excalibur yielded 19% (Streaky Bay), 23% (Minnipa) or 33% (Nunjikompita) more than the intolerant variety Spear, and Excalibur resulted in 69, 63 or 66% fewer nematodes, respectively, than in plots of Spear. Although nematode populations could not be assessed at the Kalanbi site, varietal yield relations were similar to the other sites, with Excalibur yielding 18% more than Spear. The 9 varieties were ranked for both resistance and tolerance to the 2 nematode species.

Pratylenchus penetrans and P. neglectus in tubers of potato (Solanum tuberosum) in Ontario

1991 ◽  
Vol 71 (4) ◽  
pp. 1251-1256 ◽  
Author(s):  
Th. H. A. Olthof ◽  
M. S. Wolynetz
Keyword(s):  
Solanum Tuberosum ◽  
Inner Core ◽  
Pratylenchus Penetrans ◽  
Potato Tubers ◽  
Population Densities ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Cold Room ◽  
Mist Chamber ◽  
Root Lesion Nematodes

Root-lesion nematodes (Pratylenchus penetrans) were extracted from peels of potato tubers (Solanum tuberosum 'Russet Burbank'). The average number of P. penetrans recovered over a 2-wk period in a mist chamber from four batches of tubers, stored for 3–18 wk at 7 °C in a cold room, ranged from 11 to 1925 nematodes tuber−1. An average of 374 Pratylenchus neglectus tuber−1 were recovered from the peels of potato Norchip, grown in soil containing on average 4370 nematodes kg−1 of soil at harvest, and stored for 19 wk at 7 °C. P. penetrans and P. neglectus were recovered only from the outer layer of potato tubers; none was found in the inner core. Planting halves of tubers containing an average of 1925 P. penetrans tuber−1 into nematode-free soil resulted in soil population densities of 2225 P. penetrans kg−1 of soil and root population densities of 884 nematodes root system−1 after 8 wk in the greenhouse. Although many, if not most, potato fields in southern Ontario are already infested by P. penetrans, these studies have shown that stored, infested tubers can initiate a new infestation. Key words: Peel, potato tuber, Pratylenchus neglectus, Pratylenchus penetrans, root-lesion nematode, Solanum tuberosum

POPULATION DENSITIES OF FOUR SPECIES OF ROOT-LESION NEMATODES (Pratylenchus) IN THE OAT CULTIVARS, SAIA AND OAC WOODSTOCK

1989 ◽  
Vol 69 (3) ◽  
pp. 903-905 ◽  
Author(s):  
J. L. TOWNSHEND
Keyword(s):  
Population Density ◽  
Avena Sativa ◽  
Pratylenchus Penetrans ◽  
Population Densities ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Oat Cultivars ◽  
Root Lesion Nematodes

The population densities of four species of root-lesion nematodes (Pratylenchus) were examined in two cultivars of oat (Avena sativa L.) grown in greenhouse pots. The cultivar Saia harbored fewer P. neglectus and P. penetrans than the cultivar OAC Woodstock, while both cultivars were similar hosts for P. sensillatus. Pratylenchus crenatus did not develop in either cultivar.Key words: Oat, population density, Pratylenchus crenatus, Pratylenchus neglectus, Pratylenchus penetrans, Pratylenchus sensillatus

scholarly journals PLANT-PARASITIC NEMATODES ASSOCIATED WITH WALNUT IN THE SANANDEJ REGION OF WEST IRAN

2013 ◽  
Vol 53 (4) ◽  
pp. 404-408 ◽  
Author(s):  
Jebraeil Bahmani ◽  
Farhad Khozeini ◽  
Shapour Barooti ◽  
Saeed Rezaee ◽  
Reza Ghaderi
Keyword(s):  
Meloidogyne Incognita ◽  
Parasitic Nematodes ◽  
Routine Laboratory ◽  
Plant Parasitic Nematodes ◽  
Pratylenchus Neglectus ◽  
Pratylenchus Vulnus ◽  
Time Period ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes ◽  
Plant Parasitic

Abstract A survey of plant-parasitic nematodes associated with walnut was carried out in the Sanandej region, of the province of Kurdistan, in western Iran, during the 2011-2012 time period. After taking samples from fifty-four localities and then doing the routine laboratory work for processing, fixing, and mounting of the nematodes, twenty-one species of plant-parasitic nematodes were finally identified. Among the identified species: Cacopaurus pestis, Mesocriconema xenoplax, Pratylenchus vulnus and Meloidogyne incognita are likely to cause damage. Spiral (Helicotylenchus crassatus, H. digonicus, H. pseudorobustus and H. vulgaris), ring (Mesocriconema antipolitanum and M. xenoplax) and root-lesion nematodes (Pratylenchus neglectus, P. thornei, P. vulnus and P. delattrei) were the most predominant nematodes in the sampled area (frequencies in soil were 87.0, 77.8, and 72.2% and 46.3, 20.4 and 14.8% in root samples, respectively). In the present study, Pratylenchus delattrei, Trophurus lomus, Paratylenchus similis, Geocenamus stegus, Helicotylenchus crassatus, Scutellonema brachyurus and Meloidogyne incognita were reported as new species associated with walnut in Iran.

Measuring yield loss in cereals caused by root lesion nematodes (Pratylenchus neglectus and P. thornei) with and without nematicide

1999 ◽  
Vol 50 (4) ◽  
pp. 617 ◽  
Author(s):  
S. P. Taylor ◽  
V. A. Vanstone ◽  
A. H. Ware ◽  
A. C. McKay ◽  
D. Szot ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Yield Loss ◽  
Wheat Variety ◽  
Significant Negative Correlation ◽  
Multiplication Rate ◽  
Nematode Density ◽  
Wheat Varieties ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes

Yield loss caused by root lesion nematodes (Pratylenchus neglectus and P. thornei) was measured using the nematicide aldicarb (Temik 150GTM) or by correlating yield with initial or final nematode densities. In 1996, rotation trials (1 P. neglectus and 1 P. thornei) were established with susceptible and moderately resistant wheat varieties and resistant barley and triticale varieties. An intolerant oat variety (cv. Echidna) was planted over all plots in 1997. Nematode densities were 90% (P. neglectus) or 95% (P. thornei) lower in oat plots following the resistant triticale (cv. Tahara) relative to the susceptible wheat (cv. Machete). In 1997, a significant, negative correlation between both initial and final nematode density and yield was obtained. In wheat variety trials (3 sites) in 1997, a significant, negative correlation was also obtained between mean variety yield and mean final P. neglectus density or mean P. neglectus multiplication rate. Yield loss of up to 20% was calculated from the regression. In all trials, cereal varieties that were more resistant were also more tolerant. In 1996, aldicarb rate trials (1 P. neglectus and 1 P. thornei) were established to assess the affect of rate and timing of aldicarb application on yield of 2 susceptible/intolerant wheat varieties (cvv. Machete and Janz). Lower rates of aldicarb (≤1.5 kg a.i./ha) gave inconsistent nematode control and did not significantly increase yield. Rates ≥2.5 kg a.i./ha reduced nematode densities by 70–90%, resulting in up to 23% greater yield for Machete. The magnitude of yield loss caused by P. neglectus or P. thornei determined with or without nematicide was similar between trials.

scholarly journals First Report of Pratylenchus neglectus and P. thornei Infecting Canola and Weeds in Iran

Plant Disease ◽  
2006 ◽  
Vol 90 (12) ◽  
pp. 1555-1555 ◽  
Author(s):  
S. Fatemy ◽  
E. Abootorabi ◽  
N. Ebrahimi ◽  
F. Aghabeigi
Keyword(s):  
Nematode Species ◽  
Heterodera Schachtii ◽  
Potential Threat ◽  
Brassica Napus L ◽  
Pratylenchus Neglectus ◽  
First Report ◽  
Winter Canola ◽  
Plastic Bags ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes

Cultivation of canola (Brassica napus L.) is relatively new in Iran. Because nearly 90% of Iran's edible oil is imported, farmers are subsidized and encouraged to grow this crop. Except for the sugar beet cyst nematode, Heterodera schachtii, to which susceptibility of some canola cultivars has been established (1), information on other nematode pests of canola is lacking. During a survey from April—May 2002 and repeated in 2003, soil and root samples of winter canola and weeds were collected at harvest of canola from research stations and farmers' fields in the south, west, and northwest of Tehran Province. Each sample was a composite of 25 roots and 2 kg of soil per hectare, collected from the rhizosphere of canola with a 2.5-cm-diameter soil corer. Samples were put in plastic bags and kept at 5°C until they were processed, within 2 weeks from sampling. Samples were sieved through a 0.840-cm aperture sieveand mixed thoroughly. Nematodes were extracted from subsamples of 5 g of roots and 250 g of soil with a modification of the sugar centrifugal flotation method (2), counted, and identified. Two species of root lesion nematodes, Pratylenchus neglectus and P. thornei, were found. When they were present in the same field, they occurred in the roots of both Regents × Cobra and Orient cultivars. Averages of 28 and 321 P. thornei per gram were found in the roots of cvs. Regents × Cobra and Orient, respectively. Averages of 30, 1,026, 626, and 450 P. neglectus per gram of roots of cvs. Regents × Cobra, Orient, Ocapi, and GLSIO were detected, respectively, in different fields. Heavily infected plants were stunted and had roots with dark lesions, a symptom typical of the attacks by these nematodes. Generally, greater nematode densities were in the roots than in the soil and both nematode species were more abundant in cooler than in warmer areas of the province. Since these nematodes are also severe pests of wheat, which is also grown in the province, they could pose a potential threat to both crops. Weeds that were present in the sampled fields belonged to the botanical families Scrophulariaceae, Gramineae, Euphorbiaceae, Crucifereae, and Compositeae. Between 22 and 1,500 P. thornei and 17 P. neglectus per gram of roots of Crucifereae and 280 P. thornei per gram of roots of Gramineae were found. To our knowledge, this is the first report of lesion nematodes infecting canola plants in Iran. References: (1) S. Fatemy and E. Abootorabi. Nematol. Mediterr. 30:163, 2002. (2) W. R. Jenkins. Plant Dis. Rep. 48:692, 1964.

Growth of `Bartlett' Pear Seedlings in Response to Number of Root-lesion Nematodes and Temperature

HortScience ◽  
1990 ◽  
Vol 25 (3) ◽  
pp. 318-320
Author(s):  
J.L. Townshend
Keyword(s):  
Root Growth ◽  
Pyrus Communis ◽  
Leaf Number ◽  
Pratylenchus Penetrans ◽  
Leaf Production ◽  
Lesion Nematodes ◽  
Effects Of Temperature ◽  
Root Lesion Nematodes

The effects of temperature and root-lesion nematodes [Pratylenchus penetrans (Cobb)] on the growth of newly germinated `Bartlett' pear seedlings (Pyrus communis L.) were examined. At five temperatures from 10 to 30C, P. penetrans (five per gram of soil) did not purple the leaves. After 8 weeks, leaf number, trunk height, and top and root weights were reduced only at 25C. The number of P. penetrans in the roots were greatest at 15 and 20C. At 20C, P. penetrans (16 per gram of soil) caused the leaves of seedlings to turn purple, and, by 6 weeks after treatment, the nematodes had reduced leaf production, trunk elongation, and top and root growth.

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