6o THE CONNECTICUT POMOLOGICAL SOCIETY. 



where his worst enemies find their winter conceahnent and 

 must know their hfe histories or development, in order to 

 know just where to attack them. For example, for Oyster- 

 shell Scale there is no time for spraying like the early part 

 of May just after the eggs hatch, and with the Codling Moth, 

 there is no time when they are so vulnerable nor as easily 

 attacked and destroyed as just after the blossoms fall, re- 

 peating this arsenical spray again in about ten days. 



Now the horticulturist must learn this point, perhaps 

 new to him, that plant diseases likewise have their life cycles 

 and life histories, and there are certain places in which they 

 pass the winter, and different forms in which they appear 

 upon the plants. He must know that if he should destroy 

 them in one place, they may yet continue in another. It is 

 necessary in successful horticulture and agriculture to know 

 the different places and methods by which these disease germs 

 can exist. For example, the farmer can treat his potatoes 

 successfully for Scab by soaking them in a solution of For- 

 malin, composed of one-half pint or a pint of this liquid in 

 fifteen gallons of water, and he will kill the Scab germs on 

 the potatoes without hurting them for growing. If, now, he 

 should plant these treated seed potatoes in clean ground, they 

 would be free from Scab, but if he should plant them in the 

 ground where the Scab previously existed, they would again 

 become infected. Likewise, if he should plant untreated 

 scabby seed in clean (uninfested) ground, the potatoes taken 

 from that soil would be Scabby. Thus, it becomes necessary 

 in preventing the recurrence of this particular disease not only 

 to treat the seed crop to destroy the germs, but to provide 

 against planting them where these germs already exist in the 

 soil. The same is true of certain diseases of the fruit that 

 may take two or more forms, such as the Bitter Rot of the 

 apple, presenting canker spots in the l^ark, as well as rotting 

 the fruit, or Ripe Rot of peach in the form of brown spots 

 on the twigs, or of brown decay of ripening peaches, plums 

 and cherries. 



What to Spray. In considering what to spray, the rec- 

 ommendation can be established that the horticulturist should 



