PLATE 5 
INFLUENCE OF SOIL MOISTURE UPON CLUBROOT OF CABBAGE 
Note absence of disease at the lower moisture, 45 per cent, and the extreme 
development at the highest moistures, 90 and 105 per cent. 
Plants grown at like soil and air temperatures, which ranged from 12° to 18° C. 
Soil a sandy loam (soil B of the text, p. 552) uniformly infested with the clubroot 
organism and of a nature favorable for the development of clubroot. The 
amount of water constantly kept in the cans was equivalent to the per cent of 
water-holding capacity as indicated. The clubbed roots in the 75 per cent 
cans and above were partially decayed as a result of secondary decay organisms, 
bo could not be removed without loss of parts of the roots that were diseased* 
