Search tips
Search criteria

Results 1-25 (120)

Clipboard (0)
Year of Publication
1.  Evaluation of Thuringiensin for Control of Heterodera glycines on Soybean 
Journal of Nematology  1990;22(4S):763-766.
The efficacy of ABG-6162A (1.5 L formulation of thuringiensin) for control of Heterodera glycines on soybean (Glycine max cv. Williams 82) was evaluated in the greenhouse at rates of 0, 10, 100, 500, and 1,000 ppm a.i. and in a field experiment at rates of 0, 3.4, 10.2, and 20.3 g a.i./100 m of row applied in an 18-cm-wide band. In the greenhouse, the 100-ppm rate was as effective as an equivalent rate of aldicarb and caused no phytotoxicity, but the higher rates of thuringiensin were highly phytotoxic. In the field experiment, numbers of females recovered from plots treated with thuringiensin at the 3.4-g and 10.2-g rates were greater (P ≤0.05) than from plots treated with aldicarb at 20.3 g a.i./100 m of row in an 18-cm-wide band or from the H. glycines-resistant soybean cv. Fayette. Yield of the untreated Williams 82 control differed significantly only from the 10.2-g rate of thuringiensin, but yield of untreated Fayette was greater than that from any of the treatments involving Williams 82.
PMCID: PMC2619120  PMID: 19287793
aldicarb; chemical control; Glycine max; Heterodera glycines; resistance; soybean; soybean cyst nematode; thuringiensin
2.  Effects of Soil Fumigants and Aldicarb on Bacterial Wilt and Root-knot Nematodes in Potato 
Journal of Nematology  1990;22(4S):681-688.
Preplant soil applications of oxamyl to shade grown tobacco in Globodera tabacum-infested field soil increased green leaf yields over untreated plots by 10.7 and 21.0% for 2.2 and 6.7 kg a.i. oxamyl/ha, respectively. Green leaf yield was negatively correlated (r = -0.60, P = 0.04) with initial G. tabacum density, which ranged from 33 to 154 second-stage juveniles (J2)/cm³ soil. Numbers of G. tabacum J2 and developing juveniles and adults (J3-adults) per gram root were fewer in plants from oxamyl-treated plots than in plants from untreated plots. Numbers of J2 in roots 4, 6, and 8 weeks after transplanting were reduced by 80, 89, and 4%, respectively, and numbers of J3-adults were reduced by 96, 89, and 21%, respectively, in high-rate oxamyl plots, compared with untreated plots. Globodera tabacum reproduction, as measured by the ratio of final to initial soil densities, was less in oxamyl-treated plots than in untreated plots.
PMCID: PMC2619119  PMID: 19287780
chemical control; Globodera tabacum; Nicotiana tabacum; oxamyl; tobacco; tobacco cyst nematode
3.  Distribution, Hosts, and Morphological Characteristics of Tylenchulus palustris in Florida and Bermuda 
Journal of Nematology  1990;22(4S):724-728.
Studies on the geographical distribution and hosts of Tylenchulus palustris were conducted over a 3-year period in Florida and Bermuda. Tylenchulus palustris was found on Aster elliottii and Liquidambar styraciflua roots in swamps of northern and central Florida. It was detected also on Borrichia arborescens and B. frutescens roots in tidal marshes of northern Florida and coastal rocklands of southern Florida and Bermuda. Posterior bodies of T. palustris swollen females from Bermuda did not differ from those of the paratypes; however, second-stage juvenile bodies and male tails from Bermuda were longer than those of the paratypes. Greenhouse host tests indicated that Mikania scandens is a host of T. palustris but not of T. semipenetrans.
PMCID: PMC2619118  PMID: 19287787
aster; Aster elliottii; Bermuda; Borrichia arborescens; Borrichia frutescens; citrus nematode; climbing hempweed; ecology; Florida; host range; Liquidambar styraciflua; Mikania scandens; sea oxeye; sweet gum; Tylenchulus palustris; Tylenchulus semipenetrans
4.  Inability of a Seed Treatment with Pseudomonas cepacia to Control Heterodera glycines on Soybean 
Journal of Nematology  1990;22(4S):792-794.
A commercial seed treatment containing Pseudomonas cepacia was applied to Glycine max cv. Williams 82 (susceptible to Heterodera glycines) and was compared to Fayette soybean (resistant to H. glycines) for control of H. glycines at two locations in Illinois. The soil at the first location was sandy in texture and the field was irrigated, whereas the soil at the second location was a silty clay loam and the field was not irrigated. At both locations there was no yield increase associated with the seed treatment , but yield of Fayette was significantly (P < 0.05) greater than Williams 82 regardless of treatment.
PMCID: PMC2619117  PMID: 19287798
biological control; Glycine max; Heterodera glycines; Pseudomonas cepacia; resistance; seed treatment ; soybean; soybean cyst nematode
5.  Effects of Soil Fumigants and Aldicarb on Nematodes, Tuber Quality, and Yield in Potato 
Journal of Nematology  1990;22(4S):767-774.
Efficacy of the fumigants ethylene dibromide (EDB), EDB + chloropicrin, and 1,3-dichloropropene (1,3-D) applied with one or three chisels per row, singly or in combination with aldicarb, was evaluated in 1982 and 1983 on potato (Solanum tuberosum) cultivars Atlantic and Sebago for control of several nematodes, including Belonolaimus longicaudatus, Meloidogyne incognita, and trichodorids. Generally, nematode populations were lowest following application of fumigants with three chisels per row, following EDB or EDB + chloropicrin, and when fumigants were applied in combination with aldicarb. These treatment combinations also resulted in highest yields in 1983. Cosmetic appearance of tubers was improved (P ≤ 0.05) by aldicarb in 1982. Both bacterial wilt and nematodes reduced yield; however, stepwise multiple regression analysis estimated that the greater loss in yield was associated with bacterial wilt, especially in Atlantic during 1983. Economic analysis showed that addition of aldicarb to all 1,3-D treatments increased profits. The increase was greater in Atlantic than in Sebago. Triple-chisel fumigation produced greater profits than single-chisel fumigation in Atlantic during both years and in Sebago in 1982.
PMCID: PMC2619116  PMID: 19287794
aldicarb; bacterial wilt; Belonolaimus longicaudatus; corky ringspot; Meloidogyne incognita; Paratrichodorus minor; potato; Pseudomonas solanacearum; soil fumigation; Solanum tuberosum; tobacco rattle virus; trichodorid; Trichodorus proximus; Trichodorus viruliferous
6.  An Assessment of Progress toward Microbial Control of Plant-Parasitic Nematodes 
Journal of Nematology  1990;22(4S):621-631.
PMCID: PMC2619115  PMID: 19287771
bacteria; biological control; cyst nematode; nematophagous fungus; root-knot nematode; suppressive soil
7.  Effects of Soil Fumigants and Aldicarb on Corky Ringspot Disease and Trichodorid Nematodes in Potato 
Journal of Nematology  1990;22(4S):665-671.
In 1982 and 1983 the soil fumigants ethylene dibromide (EDB), EDB + chloropicrin, and 1,3-dichloropropene (1,3-D) applied with one or three chisels per row were evaluated singly and in combination with aldicarb on potato, Solanum tuberosum cvs. Atlantic and Sebago, for control of trichodorid nematodes and potato corky ringspot disease (CRS). In 1982 dosages per chisel for EDB, EDB + chloropicrin, and 1,3-D were 16.8, 23.9, and 56.1 liters/ha, respectively. EDB was applied at 12.6 liters per chisel per ha in 1983. Aldicarb was applied at 3.4 kg a.i./ha in-the-row. Differences (P ≤ 0.05) in the percentages of tubers having CRS and in mean trichodorid population densities were recorded between methods of fumigant application and among fumigants. The reductions in CRS associated with triple-chisel applications compared with single-chisel applications of the fumigants were insufficient to justify their commercial use solely for CRS control. Addition of aldicarb to all fumigation treatments, regardless of the fumigant application method, resulted in highly effective control of CRS. The disease was less severe in Atlantic; however, CRS was sufficiently severe to justify use of aldicarb on either cultivar.
PMCID: PMC2619114  PMID: 19287777
aldicarb; corky ringspot; crop loss; ethylene dibromide (EDB); 1,3-dichloropropene (1,3-D); Paratrichodorus minor; potato; soil fumigation; Solanum tuberosum; stubby-root nematode; Trichodorus spp.
8.  Soil Fumigation: Principles and Application Technology 
Journal of Nematology  1990;22(4S):632-644.
The principal soil fumigants and their order of discovery are carbon disulfide, chloropicrin, methyl bromide, 1,3-dichloropropene, ethylene dibromide, 1,2-dibromo-3-chloropropane, and methyl isothiocyanate. Biological activity of soil fumigants ranges from limited to broad spectrum. Fumigants diffuse through the continuous soil air space as gases. Physical and chemical characteristics determine diffusion rates, distribution between the soil air and moisture, and sorption onto and into the soil particles. The principal soil factors affecting the efficacy of each treatment are the size and continuity of air space, moisture, temperature, organic matter, and depth of placement. Application can be made overall with tractor injection or plow-sole, or as a row or bed treatment. Treatment for trees is best made in conjunction with tree site backhoeing.
PMCID: PMC2619113  PMID: 19287772
application technology; backhoeing; chemical control; chloropicrin (Pic); fumigation depth; 1,3-dichloropropene (1,3-D); fumigant; methyl bromide (MBr); methyl isothiocyanate (MIT); nematicide; soil fumigation; ethylene dibromide (EDB); 1,2-dibromo-3-chloropropane (DBCP)
9.  Distribution, Frequency, and Population Density of Nematodes in West Virginia Peach Orchards 
Journal of Nematology  1990;22(4S):712-717.
Nematode population densities were determined in soil and root samples collected from 205 peach (Prunus persica L.) orchard blocks between 25 March and 5 May 1986. Representative specimens from 75 blocks were identified to species; 28 species of plant-parasitic nematodes were identified. Predaceous nematodes (Mononchidae) were observed in 71% of the samples. The most common plant-parasitic genera were Paratylenchus, Helicotylenchus, Pratylenchus, and Xiphinema, occurring in 85, 84, 77, and 74% of the samples, respectively. Population densities of Xiphinema, Pratylenchus, Meloidogyne, Hoplolaimus, and Criconemella were at potentially damaging levels in 74, 19, 13, 10, and 2% of the samples, respectively. Potentially damaging nematode densities were observed in 78% of orchard blocks surveyed, with 35% having two or more nematodes with densities high enough to warrant concern. Nematode densities differed among soil types and tree rootstocks and were correlated with tree mortality rates.
PMCID: PMC2619112  PMID: 19287785
Criconemella; Helicotylenchus; Hoplolaimus; Meloidogyne; distribution; peach; Pratylenchus; predaceous nematode; Prunus persica; soil texture; survey; Xiphinema
10.  Spring or Fall Fumigation for Control of Meloidogyne spp. on Tobacco 
Journal of Nematology  1990;22(4S):645-650.
Tests were conducted in 1987-88 to compare the efficacy of spring or fall fumigant nematicide applications for control ofMeloidogyne arenaria and M. incognita on tobacco. Chloropicrin, 1,3-D, methyl isothiocyanate, and a methyl isothiocyanate-l,3-D mixture were applied as row treatments. Fenamiphos, fenamiphos + fensulfothion, or ethoprop were applied in the spring as nonfumigant nematicide standards. Fumigant nematicides increased yields and reduced galling (P = 0.01) in all four tests. Spring or fall applications of fumigant nematicides were effective in controlling M. arenaria and M. incognita and were superior to the nonfumigant nematicides tested.
PMCID: PMC2619111  PMID: 19287773
chemical control; fumigation; management; Meloidogyne arenaria; Meloidogyne incognita; nematicide; Nicotiana tabacum; root-knot nematode; tobacco
11.  Plant-Parasitic Nematodes in Maine Agricultural Soils 
Journal of Nematology  1990;22(4S):745-749.
In a survey of plant-parasitic nematodes associated with agricultural crops in nine Maine counties, 744 soil samples from 26 potential host plants were analyzed between November 1987 and January 1989. The most commonly encountered nematode genus was Pratylenchus, occurring in 85% of the samples from most crops, except blueberries and onions. Pratylenchus penetrans and P. crenatus were found commonly as species mixtures, with P. penetrans composing 40-80% of the mixture. Meloidogyne hapla was encountered in 16% of the samples in four counties, generally in potato rotations. Other nematodes encountered were Aphelenchoides spp., Criconemella curvature, Ditylenchus spp., Helicotylenchus pseudorobustus, H. digonicus, Heterodera trifolii, Paratylenchus projectus, Trichodorus spp., Tylenchorhynchus maximus, and Xiphinema americanum. Potato fields were the most heavily sampled and thus weighted the statewide results.
PMCID: PMC2619110  PMID: 19287791
Aphelenchoides sp.; Criconemella curvatum; Helicotylenchus digonicus; Helicotylenchus pseudorobustus; Heterodera trifolii; Meloidogyne hapla; survey; Pratylenchus crenatus; Pratylenchus penetrans; Paratylenchus projectus; Trichodorus sp.; Tylenchorhynchus maximus; Xiphinema americanum
12.  Effects of Soil Solarization on Nematodes Parasitic to Chickpea and Pigeonpea 
Journal of Nematology  1990;22(4S):658-664.
Solarization by covering the soil with transparent polyethylene sheets during the summer months (April, May, June) in 1984 and 1985 significantly (P = 0.01) reduced the population densities of nematodes (Heterodera cajani, Rotylenchulus reniformis, Helicotylenchus retusus, Pratylenchus sp., and Tylenchorhynchus sp.) parasitic to chickpea and pigeonpea. Population density reductions of 93% of Heterodera cajani eggs and juveniles, 99% ofHelicotylenchus retusus, 98% of Pratylenchus sp., and 100% of R. reniformis were achieved by solarization in 1984. Irrigation before covering soil with polyethylene improved (P = 0.01) the effects of solarization in reducing the population densities of Heterodera cajani. Similar trends in population density reductions were observed in 1985, but the solarization effects were not the same. Nematode population reductions in the 1984-85 season were evident until near crop harvest, but in the 1985-86 season the effects on nematode populations were not as great and did not last until harvest. Factors such as rains during the solarization, duration of solarization, and sunshine hours may have influenced the efficacy of solarization. Solarization for two seasons reduced the population densities each year about the same as single season solarization, and residual effects of solarization on nematode populations did not last for more than a crop season.
PMCID: PMC2619109  PMID: 19287776
Cajanus cajan; Cicer arietinum; Helicotylenchus retusus; Heterodera cajani; India; irrigation; Pratylenchus sp.; residual effect; Rotylenchulus reniformis; solar heating; solarization; Tylenchorhynchus sp.
13.  Effect of Oxamyl on Globodera tabacum Population Dynamics and Shade Tobacco Growth and Yield 
Journal of Nematology  1990;22(4S):654-657.
Preplant soil applications of oxamyl to shade grown tobacco in Globodera tabacum-infested field soil increased green leaf yields over untreated plots by 10.7 and 21.0% for 2.2 and 6.7 kg a.i. oxamyl/ha, respectively. Green leaf yield was negatively correlated (r = -0.60, P = 0.04) with initial G. tabacum density, which ranged from 33 to 154 second-stage juveniles (J2)/cm³ soil. Numbers of G. tabacum J2 and developing juveniles and adults (J3-adults) per gram root were fewer in plants from oxamyl-treated plots than in plants from untreated plots. Numbers of J2 in roots 4, 6, and 8 weeks after transplanting were reduced by 80, 89, and 4%, respectively, and numbers of J3-adults were reduced by 96, 89, and 21%, respectively, in high-rate oxamyl plots, compared with untreated plots. Globodera tabacum reproduction, as measured by the ratio of final to initial soil densities, was less in oxamyl-treated plots than in untreated plots.
PMCID: PMC2619108  PMID: 19287775
chemical control; Globodera tabacum; Nicotiana tabacum; oxamyl; tobacco; tobacco cyst nematode
14.  Interaction Among a Nematode (Heterodera glycines), an Insect, and Three Weeds in Soybean 
Journal of Nematology  1990;22(4S):729-734.
A 2 x 3 x 4 factorial field experiment was established to determine the interaction among a nematode, an insect, and three weed species on soybean in 1983-86. Low (nematicide treated) or high (untreated) population densities of the soybean cyst nematode (SCN), Heterodera glycines, and 0, 30, or 70% main stem girdling by the threecornered alfalfa hopper (TCAH), Spissistilus festinus, were combined with no weeds, one common cocklebur (CC), Xanthium strumarium, one sicklepod (SP), Cassia obtusifolia, or one pitted morningglory (PMG), Ipomoea lacunosa, per meter of row in all possible combinations. Most of the losses from the pests were significant (P ≤ 0.05) and additive. The high population density of SCN suppressed soybean seed yield by 14%. Girdling of 30 and 70% by TCAH suppressed yields by 10 and 25%, respectively. One CC, SP, or PMG per meter of row suppressed yield by 22, 14, and 12%, respectively. The addition of loss predictions for each pest was approximately the actual treatment losses recorded. The pests did not have an evident interactive effect on yield losses; however, the losses attributed to each pest were additive.
PMCID: PMC2619107  PMID: 19287788
Cassia obtusifolia; common cocklebur; Glycine max; Heterodera glycines; Ipomoea lacunosa; pest complex; pitted morningglory; sicklepod; soybean; soybean cyst nematode; Spissistilus festinus; threecornered alfalfa hopper; Xanthium strumarium; yield loss
15.  Survey of Current Distribution of Rotylenchulus reniformis in the United States 
Journal of Nematology  1990;22(4S):695-699.
The reniform nematode, Rotylenchulus reniformis, has been reported from all Gulf Coast states, Arkansas, Hawaii, North Carolina, and South Carolina. Experts in 11 states identified the counties or parishes where the nematode is found and provided information regarding associated soil parameters, climate, crops, and crop management. Rotylenchulus reniformis has been detected in 187 counties and parishes of the southeastern United States and is most widespread in Louisiana, Mississippi, Alabama, Florida, and Georgia. In every state except Florida and Hawaii, economically damaging soil populations were associated with continuous cotton production. Other crops considered to be damaged by R. reniformis were soybean, tobacco, several vegetables, and pineapple (Hawaii). There was no consistent relationship between the nematode's presence and soil texture, soil pH, rainfall, or irrigation regime. However, certain respondents associated damage from the nematode primarily with silty or clay soils (Texas, Hawaii, Florida, and Georgia) or with silty soils with exceptionally tow pH (Hawaii and Louisiana).
PMCID: PMC2619106  PMID: 19287782
geographical distribution; reniform nematode; Rotylenchulus reniformis; soil type; survey
16.  Evaluation of Soybean Cultivars for Production in Meloidogyne arenaria Race 2-Infested Soil 
Journal of Nematology  1990;22(4S):740-744.
Field trials with 56 soybean cultivars and breeding lines from public and private sources were conducted from 1986 through 1988 at a site infested with Meloidogyne arenaria race 2. Differences (P < 0.05) among yields were found each year and yields were negatively correlated (P < 0.01) with root-knot nematode galling. All entries were galled and the highest-yielding entries, 'Kirby' and 'Coker 6738', were determined to have average yield reductions of 56% and 62%, respectively, when compared with uninfested sites over the 3-year period.
PMCID: PMC2619105  PMID: 19287790
Glycine max; Meloidogyne arenaria; root-knot nematode; soybean; resistance
17.  Effects of Fenamiphos on Pratylenchus penetrans and Growth of Apple 
Journal of Nematology  1990;22(4S):779-782.
A 3-year study was conducted to evaluate fenamiphos at 20.2 kg a.i./ha applied in both fall and spring or in spring only for the control of Pratylenchus penetrans on apple, Malus domestica cv. Granny Smith on M7a rootstock. The initial population densities of P. penetrans within the plot area were 89/250 cm³ soil and 268/g root dry weight. Fenamiphos increased (P < 0.05) trunk diameter in years 2 and 3 and shoot length in years 1 and 2. Yield data obtained in year 3 showed that the spring only and the fall plus spring fenamiphos treatments increased (P < 0.05) yields by 36 and 80% with a net gain of $2,352 and $5,456/ha, respectively. Results suggest that P. penetrans may be of economic importance in Washington state.
PMCID: PMC2619104  PMID: 19287796
apple; chemical control; fenamiphos; lesion nematode; Malus domestica; nematode control; Pratylenchus penetrans
18.  Response of Rotylenchulus reniformis to Nematicide Applications on Cotton 
Journal of Nematology  1990;22(4S):707-711.
Field experiments were conducted to evaluate the efficacy of five nematicides for the management of Rotylenchulus reniformis and for their effects on growth, development, and yield of cotton. Treatments included 1,3-dichloropropene (1,3-D), fenamiphos, phorate, terbufos, aldicarb, and 1,3-D + aldicarb. Average R. reniformis population densities across all treatments increased from 5,284 at 10 days after planting to a final density at harvest of 15,622 nematodes/500 cm³ soil. The 1,3-D + aldicarb combination was the only treatment with an average R. reniformis population density significantly (P ≤ 0.05) lower than that of the untreated control. Seedling stand at 28 days after planting was significantly less in aldicarb-treated plots than in control plots. Plant height was significantly greater in plots treated with nematicides than in the controls. Seed cotton yield was significantly greater from treated plots. Cotton plots treated with the 1,3-D + aldicarb combination produced the highest average yield of 4,139 kg/ha.
PMCID: PMC2619103  PMID: 19287784
1,3-dichloropropene (1,3-D); aldicarb; chemical control; cotton; fenamiphos; Gossypium hirsutum; nematicide; phorate; reniform nematode; Rotylenchulus reniformis; terbufos
19.  Survey of Soybean Cyst Nematode Races in Tennessee 
Journal of Nematology  1990;22(4S):672-675.
Cordell soybean is a newly released cultivar resistant to Heterodera glycines (SCN) races 3 and 5. The hectarage infested with these races and with other races that can parasitize Cordell in Tennessee is not known. A survey of races in Tennessee soybean fields with sampling weighted by soybean hectarage on a county basis was conducted in 1988. The SCN race plus female development on Bedford and Cordell soybeans were determined in a greenhouse for 21 field populations. Races 2, 3, 4, 5, 6, and 9 were 14%, 5%, 10%, 38%, 19%, and 14% of these populations, respectively. The SCN female indices on the differentials that were sources of SCN resistance in Bedford and Cordell were not accurate indicators of female development on these cultivars. The female index was < 10 on PI 90763 for 19 populations, but four of these populations had an index > 30 on Cordell, which derives SCN resistance from PI 90763. The index was < 10 on PI 88788 for seven populations, but two populations had an index > 40 on Bedford, which derives resistance from PI 88788. When recommending cultivars to be planted by soybean producers, SCN reproduction should be determined on the cultivars, instead of on race differentials.
PMCID: PMC2619102  PMID: 19287778
Glycine max; Heterodera glycines; host race; soybean; soybean cyst nematode
20.  Interaction of Three Plant-Parasitic Nematodes on Corn and Soybean 
Journal of Nematology  1990;22(4S):783-791.
Interaction of Belonolaimus longicaudatus, Meloidogyne incognita, and Pratylenchus brachyurus on corn and B. longicaudatus, M. incognita, and Heterodera glycines on soybean was investigated in micropiots during two seasons for corn and one season for soybean. Changes in population densities and effects on plant growth of each nematode on corn or soybean alone and in mixed culture were compared. No interactions occurred on corn in 1987. In 1988, midseason population densities of B. longicaudatus were greater in corn plots infested with M. incognita (P ≤ 0.05), but at harvest, population densities or B. longicaudatus were less in corn plots infested with P. brachyurus (P ≤ 0.05). Except for stalk weight at harvest, plant growth was not affected by any treatment. In soybean, midseason densities of M. incognita were increased in combination with H. glycines (P ≤ 0.05), but this trend reversed at harvest. Soybean yield was reduced in plots infested with H. glycines (P ≤ 0.001), whereas B. longicaudatus or M. incognita had no effect on plant growth either singly or in mixed culture.
PMCID: PMC2619101  PMID: 19287797
Belonolaimus longicaudatus; corn; Glycine max; Heterodera glycines; interaction; Meloidogyne incognita; Pratylenchus brachyurus; soybean; Zea mays
21.  Reproduction of Meloidogyne incognita on Open-pollinated Maize Varieties 
Journal of Nematology  1990;22(4S):651-653.
Forty-three open-pollinated maize varieties were tested for resistance to the southern root-knot nematode, Meloidogyne incognita race 4, in greenhouse tests. An experiment repeated on five different planting dates assessed nematode reproduction 60 days after inoculation with 3,000 eggs per plant. Tebeau and Old Raccoon showed consistently high levels of resistance in all plantings, with the lowest reproduction factor (RF) values (0.2 and 0.4) and low numbers of eggs per gram of fresh root (222 and 955). Bill Dailey Variety and Sheppard Corn had the same level of resistance to M. incognita as the resistant hybrid, Mp307 x Mp707, but they were less consistent in different plantings. Levi Mallard, African Bushman, and Field's White Variety were the most susceptible varieties with RF values of 3.1-3.3 and 2,479-3,678 eggs per gram of fresh root.
PMCID: PMC2619100  PMID: 19287774
corn; maize; Meloidogyne incognita; resistance; southern root-knot nematode; Zea mays
22.  Correlations of Rotylenchulus reniformis Population Densities with 1,3-Dichloropropene Dosage Rate and Pineapple Yields 
Journal of Nematology  1990;22(4S):735-739.
The relationships between Rotylenchulus reniformis population densities and pineapple growth and yield were studied in a small-plot field experiment. Increasing rates of handgun-injected 1,3-dichloropropene (1,3-D) preplant fumigant from 0 to 337 liters/ha resulted in greater nematode control, faster plant growth, and larger pineapple fruits. Rotylenchulus reniformis population densities at 2, 4, 6, and 8 months postplant were correlated with plant size and yield. The shorter the time period following planting in which R. reniformis densities remained low, the greater was the average loss in yield. A measurement of nematode-days as the area under the R. reniformis population growth curve indicated that this parameter was also correlated with plant growth and yield. Both population density and length of the control period affected the amount of crop damage.
PMCID: PMC2619099  PMID: 19287789
1,3-dichloropropene (1,3-D); Ananas comosus; crop loss; pineapple; population fluctuation; Rotylenchulus reniformis; soil fumigation
23.  Isolates of the Pasteuria penetrans Group from Phytoparasitic Nematodes in Bermudagrass Turf 
Journal of Nematology  1990;22(4S):750-762.
A survey was conducted between 1985 and 1989 of isolates of the Pasteuria penetrans group on phytoparasitic nematodes in bermudagrass (Cynodon spp.) turf in southern Florida. Six different isolates of the P. penetrans group were observed from five different species of phytoparasitic nematode hosts. Five of the bacterial isolates were different (P ≤ 0.01) in sporangium diameter, endospore width, and ratio of sporangium diameter to endospore width. All locations surveyed had one or more isolates present, suggesting that the Pasteuria penetrans group is widespread in its distribution in southern Florida. Three survey sites had high densities of Belonolaimus longicaudatus, with more than 60% of the host population encumbered with a large-spored isolate of Pasteuria (mean sporangium diameter = 6.10 μm). One of these sites was monitored for 16 months during which the proportion of nematodes encumbered with this Pasteuria isolate remained constant. Soil infested with this isolate was not suppressive to Pasteuria-free populations of B. longicaudatus grown on bermudagrass for 6 months after controlled soil inoculation. However, the proportion of spore-encumbered and parasitized B. longicaudatus after 6 months was 73%, which was similar to the 74% level observed at the field site. The uhrastructure of mature sporangia of the large-spored isolates of Pasteuria from B. longicaudatus and Hoplolaimus galeatus is described and compared with ultrastructural descriptions of P. penetrans sensu strictu and P. thornei from the literature. These B. longicaudatus and H. galeatus isolates of Pasteuria appear to be distinct from the known species and may warrant new species status.
PMCID: PMC2619098  PMID: 19287792
bacterial parasite; Belonolaimus longicaudatus; bermudagrass; biological control; Helicotylenchus microlobus; Hoplolaimus galeatus; Meloidogyne spp.; Pasteuria penetrans group; Tylenchorhynchus annulatus; ultrastructure
24.  Plant-Parasitic Nematodes and Fungi Associated with Root Rot of Peas on Prince Edward Island 
Journal of Nematology  1990;22(4S):676-680.
Eight commercial pea fields on Prince Edward Island were sampled in June and July over a 2-year period (1986-87) to determine soil population densities and the incidence of nematodes and fungi associated with root rot of peas. Root lesion nematodes (Pratylenchus spp.) were the dominant endoparasitic nematodes recovered from roots and soil. Low populations of the northern root-knot nematode (Meloidogyne hapla) were also present. Tylenchorhynchus spp. and Paratylenchus spp. were recovered frequently from soil in the root zone, and Helicotylenchus spp. were also frequent, but in low numbers. Fusarium solani was the most common fungal species isolated from the epicotyl and hypocotyl tissues of pea. Fusarium oxysporum was also isolated frequently, and both Fusarium species were found in soil from all fields. Rhizoctonia solani and Verticillium albo-atrum were common in hypocotyl tissue, but V. dahliae was isolated infrequently. Root rot was rated as severe in all fields and was positively and significantly correlated (P ≤ 0.05) with densities of Tylenchorhynchus spp. in soil and with incidence of F. solani in pea tissue. The incidence of F. solani root infections was positively and significantly correlated with densities in soil of Tylenchorhynchus spp. (P ≤ 0.01), Helicotylenchus spp. (P ≤ 0.01), and Paratylenchus spp. (P ≤ 0.05).
PMCID: PMC2619097  PMID: 19287779
Fusarium solani; Helicotylenchus spp.; Meloidogyne hapla; Paratylenchus spp.; pea; Pisum sativum; Pratylenchus spp.; root rot; Tylenchorhynchus spp
25.  Efficacy of Fumigant Nematicides to Control Hoplolaimus columbus on Cotton 
Journal of Nematology  1990;22(4S):718-723.
Four rates of methyl bromide (Mbr) (16.8, 33.6, 67,2, and 134.4 kg a.i./ha) and one rate of 1,3-dichloropropene (1,3-D) (28.1 liters a.i./ha) were evaluated over 2 years for control of Hoplolaimus columbus on cotton. All nematicide treatments were applied through a tarpless subsoiler-bedder prior to planting cotton, Gossypium hirsutum cv. Dehapine 90. Nematode population densities were monitored before and after treatment, at midseason, and at harvest, and yields were measured at maturity. Soil fertility variables (pH, P, K, Ca, Mg) were measured for each plot. Cotton yields were significantly increased by treatment with 1,3-D in 1988 and by all nematicidal treatments in 1989. Levels of nematode control varied from year to year among treatments. The responses of H. columbus numbers to rate of Mbr were best described by quadratic regression models. Levels of soil calcium and magnesium were significant factors in a multiple regression model relating a measure of control efficacy to rates of Mbr.
PMCID: PMC2619096  PMID: 19287786
1,3-dichloropropene (1,3-D); Columbia lance nematode; cotton; Gossypium hirsutum; Hoplolaimus columbus; methyl bromide; nematicide; soil fertility

Results 1-25 (120)