I Mil HOOT OK < nil IFEHS 



109 



Till- nsults sliiiwii in t.ilili- 2 ari' t-oiitr;uliitor_v in 

 seviT.'il cases. 'I'liis is iloulitlcss due in many in- 

 stances to outside factors sucli as those wliicli iiiHu- 

 ence tlie cfTectivencss of lime and other basic fer- 

 tilizers. DitTerenees in time .-iiid methods of ai)l)lic;i- 

 tion. de};ree of soil infestation, soil moisture, etc.. ob- 

 viously operate here also. As is shown in table 2 

 uspulun has been extensively used, especially in Eu- 

 rope, and wiieii applied at rates of 0.5 to 1 gm. per 

 ksr. of soil or 120 to 300 gms. per sq. ni. in the field 

 two weeks or more before }>lanting it is the most 

 etl'ectivc and practical of all fiiiijiicides for the con- 

 trol of club root, according to the data in the litera- 

 ture. On the otiicr iiand. numerous workers have re- 

 ported it to be unsatisfactory. It may be used as a 

 solution and jjoured over the soil or as dust mixed 

 with fertilizers, but Honig ('31 ) stated that its eft'eet 

 is less certain and complete when used in solution. 

 \\licther or not uspulun will jirove practical in large- 

 scale operations is uncertain, according to Blunck 

 ("29). but Honig claimed that its practicability in 

 this respect has already been demonstrated. In com- 

 bination with solibar. lime and other basic fertilizers 

 its use may be greatly extended, but even when mixed 

 with soil alone it is too expensive for practical pur- 

 poses, according to Riehm ('2.5). 



The effect of uspulun on the parasite and host is 

 not definitely known. Whether it kills the spores or 

 prevents germination is uncertain. Bremer ('23) 

 found that 1 gm. per kg. of soil destroys about one 

 half of the spores, and held that it acts primarily in 

 killing the amoebae. Honig ('31 ) believed that uspu- 

 lun may possibly stimulate spore germination and 

 kills the amoebae as they emerge, or that it increases 

 the resistance of the host, along with a weakening of 

 the amoebae. 



Mercuric chloride is generally reported to be 

 eflTective. but whether or not it is economically prac- 

 tical in large-scale operations is still uncertain. For- 

 malin has been extensively employed, but the results 

 obtained are very conflicting, as is shown in table 2. 

 Its efficacy in the field is doubtful, and Hammarlund 

 ("I.t). Burkhardt ('15), and Lindfors ('21) .stated 

 that it is too expensive for commercial use. 



Sulphur has proven ineffective, and in only a few- 

 instances has corrosive sublimate reduced infection, 

 Bordeauj mixture is also of little or no value in com- 

 bating club root. C arbolineum alone and mixed with 

 various types of humus, however, has been reported 

 to be fairly satisfactory. 



In addition to fungicides listed in table 2 various 

 other chemicals, substances, and remedies have been 

 used in combating club root. These have been used 

 singly or in combination, and with or without alka- 

 line fertilizers, but here again the results obtained 

 are contradictory and generally unsatisfactory. 



Segetan, a mercury compound, is ineffective ac- 

 cording to Osterwalder ('29). 



Cresol (2 kg. per 1. of water) applied at the rate 

 of 2.5 1. per c. m. of soil is effective, according to 



I.ocw (12), but .JO gms. per eu. m. of soil lias no 

 <llVcl. 



Liquid ammonia. 1 i)er cent solution, has no in- 

 hibitory properties (Osterwalder, 29). 



Sultjine is worthless, according to Lindfors ('2 I). 



Soot or lampblack has been used in England to 

 control club root, .Kcording to \\'oronin ('78), but 

 Eggemeyer ('20) found it to be useless. 



Petroleum was re])ortcd to be effective by Pfeiffer 

 and Stacs ('02). Miillers (Honig. '31) got 80.41 per 

 cent healthy plants by its use in Cjcrmany. 



Chloropicrin in the jjlant holes or added to the soil 

 reduces infection in cabbage to \ i)er cent or less 

 (Aiiony., R. I., '39). 



Pure carbolic acid added to the soil completely 

 eliminates club root from experimental plots, ac- 

 cording to Jorgensen ('33). 



Mustard oil (3 cc. per 1. of soil) gives complete 

 control (Anony., Ger., '39). 



Parachlorbenzine gives only partial control and 

 injures the host plants ( Vladimirskaya, '30). 



Germisan, 20 gms. in 10 liters of water per plant 

 is not effective, or only partially so (Hertel, '26; 

 Vilkaitis, '33). 



Sulcan is less satisfactory than Beka-Wurzel- 

 schutz (Esmarch, '25) but sufficiently effective for 

 practical purposes. 



Potassium and calcium permanganate applied di- 

 rectly to the soil are ineffective. (Miiller and Oster- 

 walder, '23, '24; Osterwalder, '29). 



Mercurous chloride is less satisfactory than mer- 

 curic chloride, according to Bailie and Muskett 

 ('33). but Preston's ('31) earlier report contradicts 

 their results. Palmer ('H), however, secured strik- 

 ing control in cabbages with mercurous chloride sus- 

 pended in water with the aid of gum arable at the 

 rates of 5 and 7.5 lbs. per acre. 



Folosan (pentachlornitrobenzine) and brassisan 

 (trichlornitrobenzine). 18 oz. per c. yd. of soil, are 

 superior to an equal concentration of mercuric chlo- 

 ride in seed boxes, but in tlie field they are less effec- 

 tive (Smieton, '39). All three compounds check 

 growth to some extent, but nonetheless give good con- 

 trol. Eolosan and brassisan are more effective when 

 used with lime. Brown ('35) likewise found brassi- 

 san to be effective against club root. 



Semesan is equally as effective as mercuric chlo- 

 ride (Clayton, '26). 



Liquid ceresan, 0.1-0.15 per cent, applied to seed 

 bed at time of jjlanting, to seedlings a day or two 

 before transplanting, and 6 to 8 days after setting 

 out gives excellent control, according to Kiipke 

 (•35). 



