136 Diseases of Greenhouse Crops 



tons of nitrate of soda, 6^ tons of high grade sul- 

 phate of potash, 2 tons of 16 per cent, phosphate, 

 and 1 ton of hydrated lime. To express it in terms 

 of a mixed fertilizer it would amount to 14^^ tons 

 of a formula testing 4 per cent, nitrogen, 23 per cent, 

 actual potash and 2.25 per cent, available phosphoric 

 acid. The injurious effect on cucumbers is not due to 

 the excess of any one element but rather to the toxi- 

 city of the combined excess of soluble salts. 



Physiological Wilt 



Symptoms. Cucumber growers often find that 

 their plants wilt badly when subjected to the in- 

 tense rays of the sunlight. This is especially true 

 when bright weather follows a continued cloudy 

 spell. This trouble is common in houses which are 

 poorly ventilated, and where the plants are weak. 

 Too high a temperature and poor lighting will great- 

 ly favor wilting. The removal of these causes will 

 effect a cure. 



Lack of Color in Fruit 



Cucumber fruit, especially of the White Spine va- 

 riety, often becomes very white, thus commanding a 

 lower market price. This discoloration is probably 

 due to a lack of available nitrogen in the soil. It 

 may be remedied by the application of one part 

 liquid nitrate of soda to one thousand parts of water. 



