428 The Profitable Culture of Vegetables. 



and burnt. After such a clearance spray the ground thoroughly with 

 copper sulphide solution then dress it with lime. Where the disease is 

 very prevalent it would probably be beneficial as a preventive to spray the 

 bed early in the spring with Bordeaux mixture, following this at intervals 

 with cupram. 



Stocks may be kept comparatively clear of the disease by forming a fresh 

 plantation with healthy plants on new ground each year, and not allowing 

 the plants to occupy the same ground more than two years in succession. 



MUSHROOM DISEASE (Hypomyces perniciosus).This disease fre- 

 quently attacks cultivated mushrooms. When affected by it they fail to 

 develop properly into a cap and stem, but the latter becomes much swollen 



and distorted, whilst the cap is very 

 small and deformed. The cause of the 

 disease is a small parasitic fungus which 

 grows up with the mushroom. After a 

 time the mushroom becomes a soft 

 putrid mass. 



Treatment; If the greater part of 

 the mushrooms are diseased the entire 

 bed should be removed and put where 

 there is no possibility of contact with 

 other mushroom beds or manure. Then 

 clean and disinfect the interior of the 

 house, the ground, and all tools used in 

 taking away the bed. A solution of 

 copper sulphate (lib. to 10 gallons water) 

 sprayed over the walls, floor, and roof of 

 the house is very effective if repeated 

 two or three times at intervals of from 

 seven to ten days. 



If only a small proportion of the mushrooms are affected the beds should 

 be looked over every day or two and the diseased mushrooms, with the soil 

 adhering, taken out and burned. 



The spawn used may be the cause of infection, therefore care should be 

 taken to procure it only from a reliable source. 



PEA MILDEW (Erysiphe Martii).Peas arc very liable to attack in 

 late summer and early autumn from a fungus which appears on the leaves, 

 pods and stems in the form of a white downy mildew, which stops the 

 growth of the plants and ruins the crop. 



Treatment : Owing to the waxy covering on the leaves it is not easy to 

 make liquid fungicides adhere. Hence it is better to use powders lime 

 and sulphur or strawsonite. Apply whilst the leaves arc damp (not wet) 

 with rain or dew. Repeat at intervals and after heavy rain. 



In the case of a bad attack recovery is practically hopeless, and the 

 best proceeding is to pull up and burn the plants. 



Diseased Mushrooms. 

 (Reduced.) 



