54 



United States Bureau of Plant Industry (unpublished data in files of 

 Division of Nematology; material collected by H. N. Hansen, California 

 station. 1939) : Seedlings of P. lambertiana, sugar pine, heavily infested; 

 grown on a garbage dump at 6,000 feet elevation in Tuolumne County, 

 California. 



Piper nigrum, black pepper. (S) 



Rutgers 1916 (202) : Infestation "practically harmless," found in the best 

 pepper plantations of Java and Sumatra; heavy infestation may destroy 

 some of the roots, but injuries occur only when cultural conditions are 

 unfavorable for new root growth; Van Breda de Haan, Soltwedel, and 

 Zimmermann convinced people that nematodes were responsible for the 

 sudden death of plantations. 



Pistacia vera, pistache. (C) 



Milbrath 1928 (164): Infestation found for the first time; "of uncommon 

 occurrence in California." 



Pisum sativum (P. arvense), pea. (N, S) 



Bessey 1911 (16): Nematodes not abundant and no injury observed ("field 



pea, P. arvense") ; nematodes abundant, injury apparently not great 



("garden pea, P. sativum"). 

 Frank 1885 (68) : No infestation found; other hosts preferred (one planting). 



Germany. 

 Pittman 1929 (192) : Peas not usually attacked to such an extent as other 



market-garden crops. [Illustration shows numerous small galls on 



garden pea.] Western Australia. 



All other references agree that infestation is serious on field pea (including 

 Austrian Winter pea) and on garden pea. 



Plantago major, common or greater plantain. (M) 



Frank 1885 (68) : Original host record. Germany. 



Hostermann 1922 (111) : No infestation found in pot experiment. Germany. 

 Tischler 1902 (229) : Infestation abundant; somewhat less than on coleus. 

 Germany (experimental). 



Plantago media. 



Hostermann 1922 (111) : No infestation found in pot experiment. Germany. 

 Plum, see Prunus. 



Poa annua, annual bluegrass. (C, N) 



Hauser 1937 (106): No infestation found in greenhouse. Netherlands. 

 Hostermann 1922 (111): Infestation very light. Germany (experimental). 

 Steiner, G. (Division of Nematology, Bureau of Plant Industry. 1939): 



Infested plants show practically no gall development. 

 Whittle and Drain 1935 (263): Bluegrass listed as seldom infested or 

 highly resistant. Tennessee. 



Poa pratensis, Kentucky bluegrass. (N) 



Steiner, G. (Division of Nematology, Bureau of Plant Industry. 1939): 

 Infested plants show practically no gall development. 



Poinsettia, see Euphorbia. 



Polycarpaea corymbosa. (C) 



Collins 1937 (4-1): No signs of nematode attack. Rhodesia. 

 Polygonum convolvulus, cornbind. (M) 



Hostermann 1922 (111): Infestation very light; roots very resistant, early 

 lignified. Germany (experimental). 



Linford and Vaughan 1927: 4 Found infested in Wisconsin. 



Polygonum persicaria, knotweed, ladysthumb. (N) 



Muszynski and Strazewicz 1932 (174): No infestation found. Poland. 



This weed has been found infested in greenhouses in the District of Columbia, 

 England, and the Netherlands. 



Polygonum tomentosum. 



Collins 1937 (41) : No signs of nematode attack. Rhodesia, 

 4 See report of Linford and Vaughan on p. 306 of reference given in footnote 60, p. 39. 



