ROOT KNOT NEMATODE INFESTATION 15 



Yunnan selections, P. I. Nos. 55885, 55886, 55888. 



Tufts and Day 1934 (234) '• No visible infestation on seedlings (3 years in 

 nursery; 1 season in heavily infested orchard); seedlings vigorous. 

 [Data in letter, 1939: 461 seedlings 1 to 5 years old in several orchard 

 plots, 16.0 percent "affected."] California. 



Amygdalus persica nectarina, nectarine. (S) 



Tufts and Day 1934 {234): Moderate and heavy infestations found on 40 

 varieties of nectarine. California. 



Var. Lippiatt Late Orange. 



Tufts and Day 1934 (234) - Infestation light. California. 



Var. Quetta. 



Tufts and Day 1934 (234): No visible infestation; seedlings rather vigorous 

 (preliminary test; six seedlings, 1 season). [Data in letter, 1939: Ten 

 seedlings in nursery in 1936, 1 "affected"; viability of seeds is extremely 

 low.] California. 



Var. Togatch Moneck. 



Tufts and Day 1934 (234): Infestation light (tentative rating); seedlings 

 rather vigorous. California. 



Var. Traveler. 



Tufts and Day 1934 (234): No visible infestation (preliminary test). [Data 

 in letter, 1939: No infestation found in 1937 (15 seedlings in test nursery).] 

 California. 



Anagallis arvensis, poisonous pimpernel, red pimpernel. (C) 



Godfrey 1935: 14 Infestation commonly observed to be light. Hawaii. 

 Ananas comosus (^4. sativus). pineapple. (N, S) 



Collins and Hagan 1932 (43): A wild form from Kailua showed some 



variation in size of infested plants, lateral and fibrous roots somewhat 



reduced, relatively low percentage of terminal galls and of infestations 



on short roots. Hawaii. 

 Vosbury and Winston 1921 (244): Var. Spanish is "less susceptible" than 



Var. Cayenne. Florida. [Question: Does this statement refer to root 



knot or to red wilt?] 

 Watson arid Goff 1937 (258): Rated as No. 24 in order of susceptibility 



[from okra, No. 1, to corn, No. 46]; there is no definite knot formation 



when the fleshy roots are infested. Florida. 



Var. "Natal." 



Collins and Hagan 1932 (43): Fibrous roots somewhat reduced; fewer 

 terminal galls than on some other varieties. Hawaii. 



Var. Pernambuco. 



Collins and Hagan 1932 (43): Size of infested plants irregular; root tips 

 not blinded by infestation; relatively high percentage of roots free from 

 galls; considerable reduction, however, in root development. Hawaii. 



Hagan and Collins 1935 (102) : Reduction in root length and in plant 

 weight, though less severe than in Var. Cayenne. Hawaii. 



Ananas sp., and hybrid. 



Hagan and Collins 1935 (102): A wild pineapple from Brazil was highly 

 tolerant of nematode attack ; no reduction in plant weight nor in average 

 length of roots. Hawaii. 



Lot 520 (F x hybrid, vegetatively reproduced, between Var. Cayenne and a wild 

 pineapple from Brazil). 



Collins and Hagan 1932 (43): Highly tolerant; root tips not blinded by 

 infestation; root length not significantly reduced during test (8 months); 

 a greater proportion of gall-free roots than other varieties tested. 

 Hawaii. 

 Hagan and Collins 1935 (102) : Losses in stump weight and in fibrous roots, 

 though less severe than in Var. Pernambuco; considerable genetic vari- 

 ability found. Hawaii. 



14 See footnote 10, p. 11. 



