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1.  Rotations with Coastal Bermudagrass and Fallow for Management of Meloidogyne incognita and Soilborne Fungi on Vegetable Crops 
Journal of Nematology  1995;27(4):457-464.
The efficacy of fallow and coastal bermudagrass (Cynodon dactylon) as a rotation crop for control of root-knot nematode (Meloidogyne incognita race 1) and soilborne fungi in okra (Hibiscus esculentus cv. Emerald), squash (Cucurbita pepo cv. Dixie Hybrid), and sweet corn (Zea mays cv. Merit) was evaluated in a 3-year field trial. Numbers of M. incognita in the soil and root-gall indices were greater on okra and squash than sweet corn and declined over the years on vegetable crops following fallow and coastal bermudagrass sod. Fusarium oxysporum and Pythium spp. were isolated most frequently from soil and dying okra plants. Numbers of colony-forming units of soilborne fungi generally declined as the number of years in sod increased, but were not affected by coastal bermudagrass sod. Yields of okra following 2-year and 3-year sod and squash following 2-year sod were greater than those following fallow. Yield of sweet corn was not different following fallow and coastal bermudagrass sod.
PMCID: PMC2619638  PMID: 19277312
coastal bermudagrass; Cucurbita pepo; Cynodon dactylon; fallow; Hibiscus esculentus; management; Meloidogyne incognita; nematode; okra; root-knot; rotation; squash; sweet corn; Zea mays
2.  Nematode Numbers and Crop Yield in a Fenamiphos-Treated Sweet Corn-Sweet Potato-Vetch Cropping System 
Journal of Nematology  1992;24(4):533-539.
Nematode population densities and yield of sweet corn and sweet potato as affected by the nematicide fenamiphos, in a sweet corn-sweet potato-vetch cropping system, were determined in a 5-year test (1981-85). Sweet potato was the best host of Meloidogyne incognita of these three crops. Fenamiphos 15G (6.7 kg a.i./ha) incorporated broadcast in the top 15 cm of the soil layer before planting of each crop increased (P ≤ 0.05) yields of sweet corn in 1981 and 1982 and sweet potato number 1 grade in 1982 and 1983. Yield of sweet corn and numbers of M. incognita second-stage juveniles (J2) in the soil each month were negatively correlated from planting (r = - 0.47) to harvest (r = -0.61) in 1982. Yield of number 1 sweet potato was inversely related to numbers of J2 in the soil in July-October 1982 and July-September 1983. Yield of cracked storage roots was positively related to the numbers of J2 in the soil on one or more sampling dates in all years except 1985. Some factor(s), such as microbial degradation, resistant M. incognita development, or environment, reduced the effect of fenamiphos.
PMCID: PMC2619302  PMID: 19283032
fenamiphos; Ipomoea batatas; Meloidogyne incognita; nematicide; nematode; root-knot nematode; sweet corn; sweet potato; vetch; Vicia sativa; Zea mays
3.  Chemigation for Control of Black Shank-Root-knot Complex and Weeds in Tobacco 
Journal of Nematology  1992;24(4S):648-655.
Tank mixes of a fungicide (metalaxyl) and a nematicide (fenamiphos) with herbicides (isopropalin or pendimethalin) and an insecticide (chlorpyrifos) were applied by soil incorporation or irrigation to control the black shank-root knot complex and weeds on four tobacco cultivars. The disease complex was more severe on cultivars McNair 944, NC-2326, and K-326 than on Speight G-70. The disease complex was reduced (P ≤ 0.05) on all cultivars with the pesticide combinations containing metalaxyl + fenamiphos. On most cultivars, percentage disease, disease index, root-gall index, yield, and weed control did not differ (P ≤ 0.05) between the tank mixes containing isopropalin or pendimethalin or among methods of application. Generally, the most effective method of treatment application for control of the disease complex and weeds was preplant incorporated followed by postplant irrigation and preplant irrigation.
PMCID: PMC2629858  PMID: 19283041
black shank; chemigation; Meloidogyne spp.; nematode; Nicotiana tabacum; Phytophthora parasitica; root-knot nematode
4.  Effects of Rapeseed and Vetch as Green Manure Crops and Fallow on Nematodes and Soil-borne Pathogens 
Journal of Nematology  1992;24(1):117-126.
In a rapeseed-squash cropping system, Meloidogyne incognita race 1 and M. javanica did not enter, feed, or reproduce in roots of seven rapeseed cultivars. Both nematode species reproduced at low levels on roots of the third crop of rapeseed. Reproduction of M. incognita and M. javanica was high on squash following rapeseed, hairy vetch, and fallow. The application of fenamiphos suppressed (P = 0.05) root-gall indices on squash following rapeseed, hairy vetch, and fallow; and on Dwarf Essex and Cascade rapeseed, but not Bridger and Humus rapeseed in 1987. The incorporation of 30-61 mt/ha green biomass of rapeseed into the soil 6 months after planting did not affect the population densities of Criconemella ornata, M. incognita, M. javanica, Pythium spp., Rhizoctonia solani AG-4; nor did it consistently increase yield of squash. Hairy vetch supported larger numbers of M. incognita and M. javanica than rapeseed cultivars or fallow. Meloidogyne incognita and M. javanica survived in fallow plots in the absence of a host from October to May each year at a level sufficient to warrant the use of a nematicide to manage nematodes on the following susceptible crop.
PMCID: PMC2619259  PMID: 19283212
Brassica napus; Criconemella ornata; Cucurbita pepo; fungus; Meloidogyne incognita; M. javanica; nematode; Pythium spp.; rapeseed; Rhizoctonia solani; ring nematode; root-knot nematode; squash
5.  Nematodes Associated with Blackberry in Arkansas 
Journal of Nematology  1991;23(4S):620-623.
A survey of the nematodes in blackberry (Rubus sp.) rhizospheres was conducted in Arkansas from 1986 to 1989. The state was divided arbitrarily into four quadrants. A total of 134 soil samples was collected, and 150-cm 3 subsamples were assayed for nematodes. Twenty-one species of plant-parasitic nematodes in 11 genera were extracted from the samples. There were differences (P = 0.05) among quadrants of the state in percentage occurrence of the nematodes and in population densities in samples. Xiphinema americanum, Helicotylenchus spp. (H. paraplatyurus, H. platyurus, and H. pseudorobustus), and Pratylenchus spp. (P. vulnus and P. zeae) were found in all quadrants. Xiphinema americanum population density was near 1,000 per 150 cm³ soil in soil samples from two locations. Other nematodes found in one or more quadrants were Criconemella spp. (C. axeste, C. curvata, C. denoudeni, C. ornata, C. sphaerocephala, and C. xenoplax), Paratrichodorus minor, Tylenchorhynchus claytoni, Hirschmanniella oryzae, Hoplolaimus magnistylus, Scutellonema bradys, and undescribed species of Criconema, Tylenchulus, Xiphinema, and Meloidogyne. Criconemella sphaerocephala and Helicotylenchus platyurus are reported from Arkansas for the first time. Helicotylenchus paraplatyurus is reported from the United States for the first time.
PMCID: PMC2619228  PMID: 19283173
blackberry; Criconemella sphaerocephala; Helicotygenchus paraplatyurus; Helicotylenchus platyurus; nematode; Rubus spp.; survey; Xiphinema americanum
6.  Tylenchulus palustris Parasitizing Peach Trees in the of nited States 
Journal of Nematology  1990;22(1):45-55.
Most morphological characteristics of three populations of a Tylenchulus sp. from peach roots in Alabama, Arkansas, and Georgia did not differ from those of T. palustris paratypes. However, some mature females differed slightly from those of T. palustris paratypes from Florida. These mature females were more swollen in the posterior portion of their bodies, and they possessed digitate postvulval body sections with round rather than conoid termini. These morphological variants had a wide postvulval section core (PVSC), as do T. palustris paratypes; they did not differ from the paratypes in other characteristics. Second-stage juveniles and males were less morphologically variable and were not different from the paratypes. No males were found in populations from Alabama and Georgia. The Tylenchulus sp. from three peach sites was determined to be T. palustris. This is the first report of T. palustris on an economically important crop.
PMCID: PMC2619015  PMID: 19287688
Alabama; Arkansas; citrus nematode; Georgia; morphological variability; peach; Prunus persica; scanning electron microscopy (SEM); systematics; Tylenchulus palustris; Tylenchulus semipenetrans
7.  Plant Nematodes Occurring in Arkansas 
Journal of Nematology  1989;21(4S):677-681.
A total of 110 species of plant nematodes were found in various habitats in Arkansas. Thirty species from 19 genera are reported here for the first time. Included in the new reports are the known plant pathogens Criconemella onoense, Hirshmanniella oryzae, Longidorus elongatus, and Pratylenchus pratensis.
PMCID: PMC2618999  PMID: 19287671
Arkansas; geographic distribution; host record; survey
9.  First Report of a Tylenchulus sp. on Peach in Alabama, Arkansas, Georgia, and South Carolina 
Journal of Nematology  1987;19(Annals 1):127-128.
A Tylenchulus sp. found in a Georgia peach orchard parasitized peach roots in the greenhouse. Citrus roots were not parasitized, indicating that the nematode was not the citrus nematode. Morphologically similar populations were found in one peach orchard in Alabama, two orchards in Arkansas, and one in South Carolina. Males were present in the Alabama populations and one of the Arkansas populations. A population was also found in an area of mixed hardwood and pine in Arkansas. The populations are morphologically different from the citrus nematode Tylenchulus semipenetrans.
PMCID: PMC2618689  PMID: 19290292
Alabama; Arkansas; citrus nematode; Georgia; peach; South Carolina; Tylenchulus
10.  Criconemella spp. in Pennsylvania Peach Orchards with Morphological Observations of C. curvata and C. ornata 
Journal of Nematology  1987;19(4):420-423.
Criconemella xenoplax and C. curvata, previously associated with decline of peach trees in other parts of the United States, were found in 20 of 25 Pennsylvania peach orchards. Population densities were high in some samples. Morphometrics of juveniles and adult females of Criconemella curvata and C. ornata, are provided. Cuticular crenations were observed on J2 and J3 stages of C. curvata and J2-J4 stages of C. ornata.
PMCID: PMC2618673  PMID: 19290165
Criconemella curvata; C. ornata; C. xenoplax; Hirsutella rhossiliensis; morphometrics; peach decline; ring nematode
11.  Description of Thecavermiculatus andinus n.sp. (Meloidoderidae), a Round Cystoid Nematode from the Andes Mountains of Peru 
Journal of Nematology  1983;15(3):357-363.
Thecavermiculatus andinus n.sp. is described and illustrated from Oxalis tuberosa originally collected in the vicinity of Lake Titicaca high in the Andes mountains of southern Peru. This new species differs markedly front the other two species in the genus, especially in having a much greater female vulval-anal distance and annules with lined punctation on most of the female body with a lacelike pattern restricted to the posterior portion, particularly at the vulva and anus which do not protrude. Females are essentially spherical with protruding neck, white to yellowish in color, and can easily be mistaken for potato cyst nematodes. Among the dozen or more known weed and crop host plants are potato and eggplant. In order to accommodate this new species, the genus Thecavermieulatus is emended. A key to the species of this genus is presented.
PMCID: PMC2618287  PMID: 19295818
taxonomy; morphology; Thecavermiculatus; new species; cystoid nematode; Oxalis tuberosa; potato; hosts
12.  On the Taxonomy and Morphology of the Pine Wood Nematode, Bursaphelenchus xylophilus (Steiner &Buhrer 1934) Nickle 1970 
Journal of Nematology  1981;13(3):385-392.
During the past 3 yr, nematologists in the United States have found specimens of Bursaphelenchus sp. in the wood of dead and dying pine trees. This nematode-host association resembles a similar interaction reported from Japan where pine trees are being killed by the pine wood nematode. This taxonomic research was conducted to determine if the Japanese pine wood nematode and similar populations in the United States are of the same species. Based upon typical morphological characters of original specimens of Bursaphelenchus xylophilus (Steiner and Buhrer 1934) Nickle 1970 that were rediscovered in the USDA Nematode Collection and genetic crosses among the Japanese and American nematode populations, it was concluded that they are all the same species, B. xylophilus.
PMCID: PMC2618084  PMID: 19300780
13.  Nacobbodera chitwoodi, n. gen., n. sp., (Nacobbidae:Nematoda) on Douglas Fir in Oregon 
Journal of Nematology  1974;6(1):30-37.
Nacobbodera chitwoodi, n. gen., n. sp., representing Nacobboderinae n. subfam, in the Nacobbidae, is described and illustrated from roots of Douglas fir, Pseudotsuga menziesii near Florence Oregon. This new species, having characters common to Nacobbidae, Heteroderidae, and Meloidogynidae, appears to represent a connecting link between these three families of the Heteroderoidea. Especially, a distinct tail on swollen adult females, vermiform shape of juvenile females, and the shape and sclerotization of the head of the various stages, indicate a Nacobbidae relationship. Certain other characteristics present in this new species are of the Heteroderidae and Meloidogynidae type as follows: Gross shape of adult female in posterior half of body, two ovaries, anterior position of excretory pore as in Meloidogyne females, absence of a bursa, and development of male within a sausage-shaped cuticle as in root-knot and cyst nematodes.
PMCID: PMC2620033  PMID: 19319361
taxonomy; morphology; new taxa
14.  Heterodera achilleae n. sp. (Nematoda: Heteroderidae) from Yarrow in Yugoslavia 
Journal of Nematology  1973;5(3):196-201.
Heterodera achilleae n. sp., a member of the H. rostochiensis group, is described and illustrated from roots of yarrow, Achillea millefolium L. in Sarajevo, Yugoslavia. This new, round-cyst species differs from closely related species especially as follows: (1) from H. leptonepia, by having stouter larvae (a = 21), with longer styler (25 μ), and with outlet of dorsal esophageal gland averaging 5.7 μ from base o f styler; (2) from H. millefolii, in having excretory pore at base of neck and small, straight vulval slit of 5 μ; (3) from H. rostochiensis, in having a B/A ratio (Granek's ratio) of 1.6 ; (4) from H. tabacum, by longer female stylet, two annules on female head, and males with outlet of dorsal esophageal gland further back (5.7 μ). In addition, H. achilleae n. sp. differs from the latter three species in having prominent longitudinal striae on the anterior half, or more, of cysts and females.
PMCID: PMC2620010  PMID: 19319331
taxonomy; morphology; new Heterodera species; Achillea millefolium
15.  Heterodera longicolla, n. sp. (Nematoda: Heteroderidae) from Buffalo-grass (Buchloë dactyloides) in Kansas 
Journal of Nematology  1973;5(2):150-154.
Heterodera longicolla n. sp., a member of the H. goettingiana group, is described and illustrated from roots of buffalo-grass, Buchloë dactyloides (Nutt.) Engelm., in Manhattan, Kansas. This new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to H. cyperi Golden, Rau & Cobb, 1962, but differs particularly in having a shorter stylet in larvae, males and females; in possessing only three annules on the head of larvae and males; in having a shorter tail in larvae; and by the presence on cysts of a small anus without a circum-anal pattern.
PMCID: PMC2619992  PMID: 19319322
taxonomy; morphology
16.  Heterodera graminophila n. sp. (Nematoda Heteroderae) from Grass with a Key to Closely Related Species 
Journal of Nematology  1972;4(2):147-154.
Heterodera graminophila n. sp., a member of the H. goettingiana group, is described and illustrated from roots of barnyard grass, Echinochloa colonum (L.) Link, in Baton Rouge, La. This new abullate species, having second-stage larvae with only three lines in the lateral field, is most closely related to H. cyperi Golden, Rau &Cobb, 1962, and H. graminis Stynes, 1971, but differs particularly in having a small, inconspicuous anus without a circum-anal pattern and located about 20% of the cyst length from the vulval cone terminus, and a longer vulval slit averaging 45 μ in length. A key, based on cyst and larval characters, is presented for identification of the 10 Heterodera species in the H. goettingiana group.
PMCID: PMC2619924  PMID: 19319258
taxonomy; morphology; new Heterodera species; Echinochloa colonum; barnyard grass
18.  Description and Larval Heteromorphism of Hoplolaimus concaudajuvencus, n. sp. (Nematoda: Hoplolain-lidae) 
Journal of Nematology  1970;2(2):161-166.
Hoplolaimus concaudajuvencus n. sp., of the genus Hoplolaimus Daday, 1905, characterized by larval heteromorphism, is described and illustrated as recovered from ryegrass/bermudagrass golf green turf in Florida. Females and males are closely related to H. galeatus (Cobb, 1913) Thorne, 1935, but have longer stylets with more definitely tulip-shaped stylet knobs which anteriorly tend to close upon the stylet shaft more than in H. galeatus. First and second-stage larvae have a conically-pointed tail unlike any known species of the genus. Subsequent stages, including females, have rounded tails essentially similar to other species of the genus and males possess the typical hopolaimid tail and bursa. The first molt was found to occur within the egg.
PMCID: PMC2618730  PMID: 19322290
Taxonomy; Hoplolaimus concaudajuvencus n. sp.; Morphology; Larval heteromorphism

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