CUCUMBER 321 
rule fresh horse manure is employed, and a layer about 
3 inches thick is placed on the beds after the plants have 
attained a height of several feet. The conservation of 
soil moisture and special nourishment of the plants are 
especially important when fruit formation and develop- 
ment are most active. As pointed out in the previous 
paragraph, many of the cucumber roots feed near the 
surface of the ground where they are easily injured by 
cultivation, and this is an additional reason for reducing 
the escape of soil moisture by means of mulches rather 
than by tillage. Very fine crops, however, are often 
grown without mulching, so that this operation cannot 
be regarded as absolutely essential to success. , 
Temperature.—The cucumber requires even more heat 
than the tomato, as explained on page 285, and it is ex- 
tremely sensitive to sudden and repeated changes in 
temperature. Abnormally low temperatures, after the 
plants are set in the beds, will stunt or check the growth 
and render the plants more susceptible to the ravages of 
diseases. 
There is a considerable difference of opinion concern- 
ing the proper night temperature, but most growers agree 
that it should not be lower than 65 degrees or higher than 
70 degrees. Some growers who plant cucumbers for the 
spring crop in beds of lettuce, compromise in the heat re- 
quirements of the two crops by maintaining a night 
temperature of about 60 degrees, which is not ideal for 
either vegetable. 
On dull, cloudy days the temperature should be only a 
few degrees higher than at night, otherwise the plant 
tissues will become succulent and tender and subject to 
disease, and the plants will be almost certain to wilt 
when bright sunshine-causes a sudden and pronounced 
rise in the temperature, which cannot be fully controlled 
by means of ventilation. Ordinarily, the day tempera- 
