Q2 AGRICULTURE. 



on the seed wheat are killed by dipping it into hot water shortly 

 before sowing, but the bluestone treatment is preferred. 



The potato tubers are sometimes found to be covered with a 

 rough scurf. On cutting the potato it will be found to be affect- 

 ed also under the skin. This roughness is the result of a 

 disease called the potato scab. If scabby potatoes are planted 

 the tubers produced from them will be scabby, and if clean 

 potatoes are planted in the ground where scabby potatoes were 

 lately grown, the new crop will likely be scabby. The best rule 

 to follow, then, is to plant only perfectly clean potatoes in ground 

 where no scabby potatoes were previously grown. Some success 

 has been had from rolling scabby potatoes in sulphur before 

 planting, but it is much more satisfactory to destroy the scabby 

 potatoes and plant only clean tubers in clean ground. 



The rot or blight of potatoes is quite a different disease, 

 produced by a different fungus. Different names for this 

 disease are rot, blight, and downy mildew. It is also called 

 " late blight," because there is a somewhat similar disease that 

 attacks the plants earlier in the season called " early blight." 

 The potato leaves show brown spots. These spread rapidly, 

 especially if the weather is warm and moist. The under sides 

 of the leaves soon become covered with a light colored growth ; 

 these are the spores or seeds growing on tiny threads. The 

 spores appear to fall to the ground and by rains are washed 

 through until they reach the tubers, to which they at once 

 attach themselves and then begin their growth. Then the rot 

 ing of the potato begins. 



It is thought by some that the disease in some way reaches 

 the tubers by way of the stem. It may be that the disease is 

 transmitted from the leaves to the tubers in both ways. To 

 prevent the spread of this disease the growing plants are sprayed 

 or sprinkled with a solution of bluestone (sulphate of copper). 

 The disease is sometimes called a. fungus (plural, fungi), hence 

 the preventive is called a. fungicide. 



