Geocenamus angelescresti n. sp. (Nematoda: Belonolaimidae) was found in rhizosphere of Pinus ponderosa and Arctostaphylos patula growing along Angeles Crest Highway in the San Gabriel mountains of California. The nematode species is characterized by a round-to-hexagonal labial disc with six bulging sectors, lateral sectors of first labial annule smaller than the submedian sectors, six to eight ...

Sweet potato is infested by root-knot and reinform nematodes. Root-knot nematode infestation in sweet potato is studied in detail. A number of resistant varieties are released in sweet potato from USA, Japan and China. A number of germplasm accessions and cultivars/ varieties were found resistant to the nematodes in Peru. Studies carried out by the authors indicated that sweet potato germplasm ...

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 com...

Ditylenchus dipsaci is an anhydrobiotic nematode which can withstand direct exposure to extreme desiccation. Water loss has been determined gravimetrically and morphological changes quantified by light microscopy. Water loss occurs in two distinct phases, with a permeability slump 2 min after the onset of desiccation. The permeability slump remains after treatment with sodium azide or carbon di...

The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from a...

'Wando ' pea is susceptible to Ditylenchus dipsaci f rom Raleigh, N. C. (RNC) but resistant to the same species from Waynesville, N. C. (WNC) . Homogenates of RNC and WNC were analyzed for pectolytic and cellulolytic enzyme activity; both had high Cx activity with W N C two to three times more active than RNC. Polymethylglacturonase activity was three to five times higher in RNC, but polygalact...

The root-galling index of tomatoes inoculated with Meloidogyne javanica was decreased 70% when collagen was used as a soil amendment (0.1% w/w) and 90% when the amendment was supplemented with the collagenolytic fungus Cunninghamella elegans. The root-galling index was reduced 80% when the fungus was homogenized in collagen culture medium and added to soil without collagen supplement. Culture f...