ROOT KNOT NEMATODE INFESTATION 31 



Digitaria spp. 



A distinctly heavy infestation has been reported on Chinese crabgrass, D. 

 chinensis. 43 D. ischaemum, smooth crabgrass, is also a host (N). 



Dill, see Anethum. 



Diospyros kaki, Japanese, kaki, or Oriental persimmon. (C) 



Bessey 1911 (16): Injury severe. 

 Hume 1937: 44 Many of the Oriental persimmon roots may probably be 



resistant. Florida. 

 Taubenhaus and Ezekiel 1933 (226) : Losses rarely serious. Texas. [No 



distinction was made between D. kaki and D. virginiana in the discussion 



of their several diseases.] 

 Watson and Goff 1937 (258) : Japanese persimmon rated as No. 38 in order 



of susceptibility [from okra, No. 1, to corn, No. 46]. Florida. 



Diospyros virginiana, common persimmon. 



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

 Hume 1937: 45 Native persimmon roots quite free from damage. Florida. 



Diospyros spp., persimmon. 



California Nematode Committee 1925: 46 Resistant on some types of root. 



Ernst 1924 (58) : Persimmon was thought "immune," but found susceptible 

 in a survey of Los Angeles County by the Horticultural Commissioner's 

 office. California. 



Ryerson 1927 (204) • Root knot has been reported on injured roots, but 

 apparently the persimmon is not very susceptible. R. H. McLean, 

 Agricultural Commissioner of San Diego County, has made a study of 

 persimmon roots and fig roots in a heavily infested soil area at Point 

 Loma. No infestation was found on the persimmon roots even when 

 intertwining with badly infested fig roots. California. 



Taubenhaus and Ezekiel 1933 (226): Losses rarely serious. Texas. [No 

 distinction was made between D. kaki and D. virginiana in the discus- 

 sion of their several diseases.] 



Whittle and Drain 1935 (263): Listed as slightly infested. Tennessee (?) # 



In California three different species of persimmon have been used as rootstocks 

 at different times. 



Diplolophium zambesianum. (C) 



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

 Dolicholus, see Rhynchosia. 

 Dolichos lablab, bonavist-bean, hyacinth-bean, lablab, Madagascar-bean. (S) 



Bessey 1911 (16): Injury severe. 



Harris 1938 (104): Madagascar-bean susceptible. Tanganyika. 



Krishna Ayyar 1933 (182): Infestation slight in pot experiment. India. 



Orton 1902 (186): Good early growth, bad injury later (P. I. No. 6319, 

 white, and No. 6320, purple). South Carolina. 



Piper and Morse 1915 (189): Many if not all varieties susceptible. 



Dolichos umbellatus. 



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

 Dolichos, see also Pueraria and Vigna. 



Drymaria cordata. (C) 



Linford 1939 (142): No grouping of root knot larvae around roots in vitro, 

 in limited tests; roots of all other plants tested proved highly attractive. 

 Hawaii. 



There are no field nor greenhouse reports for this genus. 

 Dusty-miller, see Senecio. 



Echeveria spp. (N, S) 



Grower: All species very susceptible, but grow new roots if sufficiently 

 moist. California. 



« See footnote 10, p. .11 

 "» See footnote 5, p. 8. 

 « See footnote 6, p. 8. 



