INSECTS, DISEASES, AND CONTROL 285 



wat«r. In this, place potatoes which are to be used as seed in the 

 garden. For larger amounts of seed potatoes use the solution of 

 the same strength. The liquid may be used over and over for a day 

 or so until it loses strength by evaporation. 



Potato scab is a serious disease in all potato growing sec- 

 tions (Fig. 150). Many seed potatoes which show none of the 

 disease may have the spores upon them, by having been kept 



Fig. 146. — A bucket sprayer, 

 well suited to work in home 

 gardens. (Fights of the Farmer.) 



Fig. 147. — Knapsack sprayer, suitable 

 for use in fighting garden pests, (Fights of 

 the Farmer.) 



with scabby potatoes. All seed potatoes before planting should 

 be treated to avoid getting the disease into the field or garden. 

 Time to Spray. — ^Students should take apple and pear 

 blossoms in different stages of development. Some may be 

 in full blossom, others with the petals just fallen, and others 

 with the green calyx leaves closing. These should be com- 

 pared to see which are in right condition for spraying to fight 

 codling-moth. After the petals close no spray can reach the 

 nest where the little insect begins eating to enter the apple. 

 If spraying is done before the petals fall many bees at work 

 in pollinizing the blossoms for the future crop will be poisoned 

 and killed. 



