ROOT KNOT NEMATODE INFESTATION 9 



Goffart 1934 (97): Various plants were grown 6 years in the same plots, 

 infested with the sugar-beet nematode, Heterodera schachtii; potato and 

 the legumes became infested by the root knot nematode, not previously 

 known to be present in this land; barley, mustard, oats, rye, sugar beet, 

 and wheat remained free from root knot. Goffart concludes that cereals 

 are never attacked, or are at least unlikely to increase the soil population, 

 but he exempts sugar beet and mustard from this generalization because 

 they were infested by H. schachtii. The same four cereals remained 

 free in another plot where root knot developed rather gradually on the 

 legumes. When inoculated with root knot, sugar beets became infested 

 but wheat and oats remained free. [Mustard was not tested in the 

 latter series.] Germany (Berlin-Dahlem). 



Jack 1920 (119): Small cereals not attacked. Rhodesia (?). 



King and Hope 1934 (127): Small grains beneficial in rotation for control. 

 Arizona. 



McClintock 1922 (145): In tests thus far cereals and grasses are not seri- 

 ously infested. Georgia. 



Orton 1903 (187): Corn, oats, or other grains and grasses ("immune") 

 are recommended for a starvation rotation. 



Reh 1906 (198): Especially injurious in Germany to cereals. [This state- 

 ment is not documented. It is followed by an extended citation (see 

 Avena) from papers on the sugar-beet nematode, Heterodera schachtii, 

 in Sweden. Wilke's (264) 1925 revision of this material in Sorauer's 

 Handbuch repeats, under root knot, the statement that cereals are 

 sometimes heavily infested in Sweden.] 



Rolfs 1907 (201): "The grasses generally" are "almost quite immune." 



Scott, Lindsay, and Harrison 1939 (209): Root knot present on all grasses 

 in certain districts. [Ms. data: No apparent injury; carries over soil 

 populations.] California (San Joaquin Valley). 



Shaw 1940 (218a): Tobacco in enclosure units showed less than 10 percent 

 severe infestation following bare fallow or certain highly resistant crops, 

 75.8 percent following weeds with crabgrass, and 100 percent following 

 tobacco or other susceptible crops. [North Carolina. See Weeds, 

 below, for results of other weed rotations, presumably also "with 

 crabgrass."] 



Stone and Smith 1898 (224): According to Kiihn (134), the grass family, 

 with 46 species "subject to nematodes," is one of the most susceptible. 

 [This misquotation of a paper on the sugar-beet nematode, Heterodera 

 schachtii, is found in a bulletin on root knot. Kuhn's statement, 

 moreover, was that only 4 of the 46 species tested became infested.] 



Watson 1929 (255): Millet is usually "immune" or only slightly infested. 

 Florida (?). 



and Goff 1937 (258): Most grasses harbor some root knot, which 



does not materially interfere with their growth. Florida. 



Whittle and Drain 1935 (263): Practically all weeds and wild grasses are 

 susceptible. Tennessee (?). 



Galls are formed on grass roots by the nematode Ditylenchus radicicola 

 (Greeff) Filipjev. Until recently (99) the species described by Greeff (101) was 

 thought to be the root knot nematode. Grasses are infested by a number of other 

 nematodes, more specific in their host relationships, which form galls on the 

 various above-ground parts. See also the final paragraph under Avena. 



Umbelliferae (Apiaceae), parsley family. 



Frank 1896 (69) : Especially favored as host plants; e. g., angelica, caraway, 



carrot, and parsnip. Germany. 

 Neal 1889 (176): Umbelliferae not susceptible. Florida. 



The following genera are known as hosts : Anethum, Angelica, Apium, Astrantia, 

 Carum, Coriandrum, Cuminum, Daucus, Foeniculum, Hydrocotyle, Oenanthe, 

 Pastinaca, Petroselinum, Sanicula, Trachymene, Tr achy sper mum. Apium, Daucus, 

 Pastinaca, and Petroselinum are frequently reported infested. 



Weeds. 



Anonymous 1939 (2) : One of the rotations in the Texas rose industry uses 

 Bermuda grass and weeds for 3 or more years; "root knot is no longer 

 a serious problem." 



