Populations of Pratylenchus penetrans Relative to Decomposing Nitrogenous Soil Amendments
Walker, J.T.
Journal of Nematology 3(1): 43-49
1971
ISSN/ISBN: 0022-300X PMID: 19322339 Document Number: 33231
The survival of populations of Pratylenchus penetrans exposed to soil containing organic and inorganic nitrogen-containing substances at the rate of 70 and 700 p.p.m. N (dry wt.) was studied. The organic materials used were peptone, soyabean meal (SBM), skimmed milk and urea; the inorganic substances included ammonium carbonate, sulfate and hydroxide, potassium and sodium nitrites. One thousand nematodes at various stages of development were added to each 250 ml. soil sample and nematode counts were made on 5 c.c. soil samples after one, 2 and 6 weeks. Amended and untreated soils were analysed for carbon dioxide and ammoniacal N by mass spectroscopy and gas chromatography was used to determine minor components. Nitrite, ammonium and organic nitrogen sources caused greater reduction in populations of P. penetrans than nitrate compounds. Nitrites were lethal to the nematode at 700 p.p.m. after one week.