Extracts of nematodes of the Raleigh, North Carolina (RNC), Waynesville, N. C. (WNC), and onion populations of Ditylenchus dipsaci were examined for pectolytic activity. RNC nematodes contained a NaCl-stimulated endo-polymethylgalacturonase with optimal pH for activity of 6.0, whereas nematodes of the WNC and onion populations possessed a NaCl-stimulated endo-polygalacturonase with pH optimum o...

With the need to obtain new methods protect seed material from Ditylenchus dipsaci (KĂźhn, 1857) nematodes, a study was conducted evaluate nematicidal effects of several plants' essential oils on mortality D. dipsaci. Tests were performed under in vitro conditions; concentration 2 000 ppm tested, nematodes added into diluted oils, and numbers living/dead scored after 4 24 h. The results show si...

DOUDA O. (2005): Host range and growth of Stem and Bulb Nematode (Ditylenchus dipsaci) populations isolated from garlic and chicory. Plant Protect. Sci., 41: 104–108. Host range and growth of two Ditylenchus dipsaci (Stem and Bulb Nematode) populations on onion, garlic, leek, spinach and chicory were compared. Inoculation was conducted by placing a droplet of 1.5% CMC suspension containing nema...

A number of studies have reported the presence of dopamine in free-living and animal-parasitic nematodes (6), but, to our knowledge, Aphelenchus avenae is the only plant-parasitic nematode in which this neurotransmitter has been shown by direct assay of tissue homogenates (7). This paper presents experimental evidence of the existence of biochemical pathways leading to the production of dopamin...

Pratylenchus penetrans and Ditylenchus dipsaci were reared at 15-16 C, and their behavior towards single and combined heat and CO stimuli was studied at ambient temperatures of 8.6 and 27.3 C. At the lower temperature, attractivity of the heat source was prevalent in both species, but CO was also attractive. At the higher ambient temperature (27.3 C), the reaction to CO was more positive and mo...

Treatment of daffodil (Narcissus pseudonarcissus) bulbs in a 0.37% formaldehyde water solution at 44 C for 240 minutes is a standard practice in California for management of the stem and bulb nematode, Ditylenchus dipsaci. Recent concern over the safety of formaldehyde and growers' requests for a shorter treatment time prompted a reevaluation of the procedure. The time (Y, in minutes) required ...

cots in the family Commeliaceae. The basic morphology of these plants appears to favor root-knot nematode development in aboveground plant parts. Leaves of both plants develop in the crown near the soil; they are large, 20-30 cm long, and densely arranged so that nematodes on younger leaves are protected from direct solar irradiation. The dense pubescent foliage, especially the convoluted young...