

ROOT KNOT NEMATODE INFESTATION 37 



Helianthus annuus, common sunflower. (N, S) 



Atkinson 1889 (4) : "Badly affected" in Alabama. 

 Collins 1938 (41)'. Sunflower readily attacked, suggested for a trap crop. 



Rhodesia. 

 Goff 1936 (96) : Infestation light to very heavy (131 plants, 3 tests). Florida. 

 Hostermann 1922 (111): Infestation moderate. Germany (experimental). 

 Sandground 1922 (207) : Parasitized more or less severely in South Africa. 

 Taubenhaus and Ezekiel 1933 (226) : Losses rarely serious. Texas. 

 Watson 1921 (251) : Sunflowers seem more or less tolerant; good yield, 



although roots are badly knotted. Florida. 

 1923 (253): Infestation heavy; used for indicator. Florida. 



Helianthus debilis, cucumber-leaved sunflower. 



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

 Helichrysum argyrosphaerum. (C) 



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

 Helichrysum pachyrhizum. 



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

 Helichrysum spp., everlasting, strawflower. 



Bessey 1911 (16): On "H. bracteatum, Immortelle," nematodes abundant, 



injury apparently not great. 

 Collins 1937 (41): "No signs of nematode attack" in two additional un- 

 identified species. Rhodesia. 

 Goff 1936 (96): Infestation very heavy, some plants stunted (two tests). 



Florida. 

 Watkins 1929 (248): Annual helichrysum rated as "resistant." Florida. 



Hemerocallis hybrid, daylily. (C, N) 



Grower: Some hybrid varieties have been grown without galls in heavily 



infested soil, but infestation has been found on Var. Aureole. Florida. 

 Hume 1938: 67 In handling many hundreds of plants, of many varieties, only 



one sample has been found infested. Florida. 



The California State Department of Agriculture has a record of infestation 

 in this genus. 



Hemp, sunn-, see Crotalaria. 



Herdsgrass, see Agrostis. 



Hevea brasiliensis, Para rubbertree. (C) 



Bally and Reydon 1931 (8): Host plant. Java. 



Beeley 1939 (14): Apparently resistant to attack; considerable injury to 

 other plants grown for cover in rubber plantations. Malaya. 



Ghesquiere 1921 (86) : Infestation found. Belgian Congo. 



Hicoria spp. (C) 



United States Division of Pomology 1896 (240): "Pecan and other 

 hickories . . . are known to be free from injury or but slightly affected." 

 [See also Carya.] 



Hippeastrum spp. (C) 



Grower: Apparently "immune" or nearly so. Florida. 

 Holcus, see Sorghum. 

 Honeysuckle, see Lonicera. 

 Hordeum vulgare (H. sativum), barley. 



Balachowsky and Mesnil 1935 (6) : Vars. Chevalier, Primus, Svanhals 

 ("Cou de Cygne"), "etc.," appear resistant. [These varieties are not 

 found in the literature on root knot; they were named by Nilsson-Ehle 

 (180) as resistant to the sugar-beet nematode, Heterodera schachtii. See 

 Gramineae.] 

 Bessey 1911 (16): No infestation found ("some varieties"). 

 Godfrey 1928 (92) : Infestation abundant (one test). Hawaii. 

 Goffart 1934 (97): Negative results. [See Gramineae.] 



47 See remarks of Hume on p. 142 of reference given in footnote 4, p. 6. 



