CULTURE OF POD-BEARING CROPS. 71 



Pea Mildew (Peronospora vicice). This is a de- 

 structive disease when the attack is severe, covering 

 the leaves with a fine white mould, which changes 

 to a pinkish-gray colour, causing them to wilt and 

 turn yellow. 



Powdery Mildew (Erysiphe potygoni). This dis- 

 ease appears on the leaves of pea plants in the form 

 of yellowish blotches on the upper surface, while the 

 under surface is covered with a whitish mildew which 

 soon spreads all over the plants, including the pods. 

 This disease, if unchecked, will kill the plants out- 

 right. 



Either of these diseases injures the crop in pro- 

 portion to the amount of mildew present on the 

 foliage, and prompt measures should be taken to 

 suppress them whenever they are detected. 



Remedies. Spray thoroughly with liver of sul- 

 phur (sulphide of potassium), at the rate of 1 oz. in 

 4 gallons of water, adding a little soft soap. Spray 

 again ten days later. 



For pea mildew, half-strength Bordeaux Mixture 

 also gives good results. See BORDEAUX MIXTURE, 

 page 54. 



Those two diseases can only be carried over the 

 winter in the form of resting spores, which are pro- 

 duced on the plants in late summer and early autumn. 

 It is therefore very important that, as soon as the 

 crop is gathered from infected rows, all leaves, haulm, 

 and refuse should at once be collected and burned. 

 Empty pods should also be burned as the crop is 

 being used. A rotation of crops is also important. 



