860 



Hint the riiimiis wdiild i;r(i\v ('(|ii;illy well (Ui alkaline and acid media in 

 any stren^xtli whieji could lie used on the snij. From this it seems prob- 

 ahle that changing the acidity of the snji wonhl he nf no benefit here, as 

 It is in the ease of some otlier Lcinseng diseases. T'ntil some other means 

 lor Its control is found, it would be ad\isal)le to keep a sharp h)okout for 

 black roots when digging In the fall, and to examine all spots where plants 

 fail to come up in the s])ring. If any diseased roots are found, search 

 the area carefully and remove and liurn all of them. The soil in the in- 

 fested area should tlien he sterilized with formalin, diluted 1-100. care 

 being taken not to injure the adjacent healthy roots, or if suitable appa- 

 ratus is at hand, steam sterilization may be used. If the .garden becomes 

 too badly infested, the only remedy is to move the seedlings to another 

 garden, carefully sterilizing all tools with formtilin or corrosive sublimate 

 before using them in the new garden. Y.an Hook ("04) cites a case where 

 a grower had set roots in a bed from which black roots had been taken 

 six or seven years before. The roots failetl to come up in the spring, and 

 on being examined were found to be infected with Black Rot, thus show- 

 ing that this fungus is aiiparentl.\' capable of remaining in the soil as a 

 saiirojihyte for several years. 



CROWN ROT. 



This disease has been Known to ginseng growers for several years, 

 but except in a few cases it has not been found vei'y abundant. The first 

 mention of it was by J. II. Koehler ("O.'!)^ in a letter to Special Crops. Since 

 then it has been reported from various counties in New York and from 

 States as far west as Wisconsin. 



'IMiere aie two different types of the disease^; one in which it attacks 

 the u])per p.aii of the stem, and the otluT in which it .attacks tlH> ro(»t at 

 or near the crown. In the latter type, the org;inisni causing the trouble 

 seems to gain entrance into the plant throu,gh the base of the st(Mn near 

 the surface of the ground, or in some cases through the upper p.ut of the 

 I'oot. It works slowly \\\) tlie stem and quite rapidly down, soon entering 

 and rotting the root. The stem loses its green color and the tissue be- 

 comes shrunken, so th.it tlie fil)ro-vascular-l»undles st.md out shai'iily as 

 long strialions or lidgcs. The stem soon lu-conies hollow and inside arft 

 found largi' l.l.ack sclcrolia. 'Chese an> also t"<unid .m Hi.' i-o:i|s. Tlift 

 lissin- of Ihc diseased rool ^cnc'i-ally iiec I's soft and ■douu'h.v ." TiiO 



'(•03) Koclilcr, .7. U. l.ctl.T li> Ivlilor. S|).fi:il rrops •_' : 1 IS. Sept. lOO:?, 



* 



