

ROOT KNOT NEMATODE INFESTATION 27 



Cosmos sulphureus, golden cosmos, yellow cosmos. (N) 



Barrons 1939 (IS): Numerous larvae entered root tips of seedlings (Var. 



Orange Flare) heavily inoculated in greenhouse. Alabama. 

 Watkins 1929 (248): Rated as "resistant." Florida. 





Cotton, see Gossypium. 

 Couchgrass, see Agropyron. 

 Cowpea, see Vigna. 

 Crabgrass, see Digitaria. 

 Cracca, see Tephrosia. 

 Cress, see Lepidium. 



Crotalaria juncea, sunn-hemp. (C) 



Beeley 1939 (14): Found attacked, but somewhat "resistant." Malaya (?). 

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

 Collins 1938 (41): Sunn-hemp not attacked (1 season). Rhodesia. 

 Godfrey 1928 (93): "Appears to be absolutely immune to root knot." 



Hawaii. 

 Krishna Ayyar 1933 (182): No infestation found in pot experiment. India 



(Madras). 

 Le Roux and Stofberg 1935 (187): Resistant; used in rotation. Transvaal. 

 Linford 1939 (142): Green stem tissue was highly attractive to larvae in 



vitro. Hawaii. 

 Smee 1928 (214): "Sunn-hemp has so far appeared to be entirely immune" 

 (grown several years) . N 3 asaland. 



Crotalaria retusa. 



See reports of Georgia Coastal Plain Experiment Station under C. spectabilis. 

 Crotalaria saltiana, rattlepod. 



Godfrey 1935: 35 Infestation commonly observed to be light. Hawaii. 

 Crotalaria spectabilis. 



Barrons 1939 (18): Numerous larvae entered root tips of seedlings heavily 



inoculated in greenhouse. 

 Georgia Coastal Plain Experiment Station 1936 (88) : Crotalaria grown 

 every other vear with tobacco gives fair commercial control. 



1938 (85): Crotalaria is highly resistant. [The 1935 report (81) 



states that the two species being tested are C. spectabilis and C. retusa.] 



Hume 1937: 36 Has been used in summer rotations, making possible the 

 continuation of tobacco black-shank experiments that were being 

 ruined by the increasing abundance of root knot. Florida. 



Shaw 1940 (213a): Tobacco in enclosure units showed less than 10 percent 

 severe infestation following C. spectabilis or other highly resistant crops, 

 and 100 percent following tobacco or other susceptible crops. [North 

 Carolina.] 



Watson 1929-32 (256): No infestation observed, even in heavily infested 

 soil. Grown in rows with constant cultivation after a heavy loss on 

 cucumbers in 1931; root knot apparently eliminated; no infestation 

 observed on 1932 cucumbers. Florida. 



Crotalaria striata. 



Watson 1932 (256): A considerable infestation was found on one planting 

 in an orange grove. Florida. 



and Goff 1937 (258): Has generally been "absolutely immune"; 



some infestations have been seen. Florida. 



Crotalaria usaramoensis. 



Collins 1930 (42): Infestation rather heavy after 10 months' growth, 

 though not seen at 6 months. Hawaii. 



« See footnote 10, p. 11. 



38 See remarks of Hume on p. 113 of reference given in footnote 3, p. 6. 



