Diseases of Plants 289 
R. F. Poole, N. J. Expt. Sta. 
Fic. 164. Cabbage plants badly infected with the clubroot disease. 
such crops and of the various means that are employed 
in combating them. 
CLUBROOT OF CABBAGE 
All the members of the cabbage group, as well as 
turnips, radishes, rutabagas, and mustards, serve as the 
hosts of a parasite which causes a disease known as club- 
root. This disease is especially common in cabbage over 
most of the United States east of the Mississippi River. 
Young plants are often attacked in the seed bed. They 
become stunted and sickly and seldom grow to maturity. 
They wilt during the heat of the day. The roots soon 
become greatly swollen and misshapen. This condition 
leads the gardener to speak of the disease as the club- 
