ROOT KNOT NEMATODE INFESTATION 71 



Isbell 1934 (116): Extremely resistant, even more so than Victor (304 

 plants, 0.33 percent infested; 2 seasons). Alabama. 



Kendrick 1929 (121): "No evidence of disease" (wilt and root knot; 1 

 season). California. 



Watson 1937: 46 Some strains susceptible. Florida. 



— and Bratley 1936 (257): An extremely resistant strain discovered. 



Florida. 



Var. Early Black. 



Kendrick 1929 (121) : "No evidence of disease" (wilt and root knot; 1 season) . 

 California. 



Black cowpea, the group to which this variety belongs, was suggested by God- 

 frey (98) for use as a trap crop in Hawaii. Orton (186) found it "much affected" 

 in South Carolina. 



Var. Extra Early Blackeye. 



Isbell 1934 ((116): Infestation to light (110 plants, 22.4 percent infested; 

 2 seasons). Alabama. 



Orton (188) mentioned that early cowpeas might escape injury by maturing 

 before infestations became heavy. 



Var. Iron. 



Arizona Agricultural Experiment Station 1936 (3): Iron No. 762 was 

 less resistant than velvetbean. 



Arzberger, E. G. (unpublished manuscript in files of Division of Neonatol- 

 ogy, Bureau of Plant Industry. 1913): Suberized and other protective 

 tissues better developed than in susceptible varieties; roots deep, with 

 minimum exposure of later? Is. Virginia. 



Barrons 1938: 47 Samples from different seed sources showed variation in 

 habit of growth and date of maturity, indicating that there are definite 

 strains now in commerce; two samples were resistant, two lightly in- 

 fested, and one was moderately susceptible. Alabama. 



■ — ■ — — 1939 (13): Numerous larvae entered root tips of seedlings heavily 

 inoculated in greenhouse. Alabama. 



Bessey 1911 (16): Apparently free under most conditions; usually suffi- 

 ciently resistant for a starvation rotation. 



and Byars 1915 (17): Highly resistant, but subject to injury in 



certain parts of Florida. 



Carns 1937 (32): Valuable for its "immunity" to root knot and wilt; 



vigorous growth. South Carolina. 

 Collins 1938 (41)' Not attacked (1 season). Rhodesia. 

 Georgia Coastal Plain Experiment Station 1938 (85) : Of only slight 



value for control rotation with tobacco. 

 Godfrey 1928 (93): Comparatively free from infestation during early 



growth, galls prominent after 3 months; plants long outlived susceptible 



varieties. Hawaii. 

 Kendrick 1929 (121): "No evidence of disease" (wilt and root knot; 1 



season) . California. 

 Kime 1937: 48 Iron and Brabham have shown more tolerance than other 



varieties. Nematode resistance seems to be related to fusarium-wilt 



resistance. North Carolina. 



Owens, and Poole 1937 (124) '• A strain obtained several years ago 



in Wilson County, North Carolina, has remained highly resistant under 

 severe testing. 



McClintock 1922 (145): Resistant in tests. Georgia. 



Mackie 1934 (151): Resistance dominant; may probably be explained by 

 the occurrence of suberin in the root cortex. [Data in letter, 1938: 

 Highly resistant to root knot and to wilt; many highly susceptible types 

 have proved to be field hybrids; K890-3 is still the most resistant Iron 

 strain. (Strain K890-3 was selected by P. B. Kennedy and is now 

 widely sold in California.)] California. 



Malloch 1923 (154): Infested at Berkeley, and also in the Imperial Valley. 

 California. 



Morse 1920 (168): "Immune." 



46 See comment by Watson on p. 116 of reference given in footnote 3, p. 6 



17 See footnote 70, p 44. 



48 See remarks of Kime on p. 117 of reference given in lootnote 3, p. 6. 



