RADISH 257 
nearly large enough to market may cause the roots to 
crack. 
The radish thrives best in a humid atmosphere. Over- 
head watering, which diffuses a mist over the beds, pro- 
vides the most favorable soil and atmospheric conditions 
so far as moisture is concerned. 
Temperature.—Too high temperatures produce spin- 
dling plants and excessive top growth, and the roots will 
be small. Too low temperatures, on the other hand, 
cause slow growth and the development of roots that are 
lacking in quality. A night temperature of 48 to 45 de- 
grees and a day temperature of 55 to 60 degrees will be 
found satisfactory. Sixty-five degrees or above on 
bright, sunny days will do no harm. 
Ventilation—The ventilators should be opened a little 
every day, unless the weather is unusually severe. In 
warm, bright weather, air should be admitted as freely 
as possible. 
Cultivation—Small weeders used between the rows 
are beneficial in conserving moisture and in keeping the 
soil in a loose, friable condition. In wide, ground beds, 
a five-prong wecder attached to a long handle, as illus- 
trated in Fig. 75, will be found a most excellent tillage 
tool. 
Enemies.—The radish, when grown under glass, has 
very few enemies. As previously. stated, damping-off 
fungi may attack the seedlings in beds that have not been 
sterilized. The green aphis is the most important insect 
pest of this crop. It may be controlled by fumigating 
with tobacco. The radish is more susceptible to injury 
from tobacco smoke than is lettuce. The safer policy is 
to make light fumigations rather frequently. 
Frame culture.—This is one of the most important 
crops for growing in hotbeds and frames. (See page 405.) 
Marketing.—The proper time to begin pulling the 
roots depends on a-number of factors. If prices are very 
good it may pay to begin selling them when they are 
